Categories
Network Technologies

When is a switch not a switch: when it’s a Cisco Nexus

Intro

I don’t think we ask a lot of our switches. A packet comes in on this port and goes out on this other port. That sort of thing. But, apparently, when the switch is a Cisco Nexus, that is asking too much. Maybe it will go to that other port. Let’s see, it depends who sent it. So then again, maybe not. So maybe device A can ping device B. Device B cannot ping device A. But it can ping device C and device C can ping A. Or maybe Jack can ping device 1 but not device 2 on the same subnet. Yet Jill can ping device 2 but not device 1!

Yes. Those are not theoretical examples, but, sadly, actual examples lifted from recent massive debugging sessions I’ve participated in, which, eventually, focused on the Nexus switch not treating all traffic as it should. Another example: larger packets were not getting through on the same vlan.

Sometimes the Cisco support engineer is too clever by half. We had one find a few errors on supervisor board 5 so we switched to board 6. That did nothing. We finally noticed that all problems were related to FEXes connected to slot 8. As a test we plugged a FEX into a different slot and, voila, things began to work better. But the Cisco guy did not see any errors on slot 8.

Well, you only get the same Cisco engineer for a limited time. Then their shift turns over and you get to explain the whole problem all over again to the next one. Yeah, supposedly they’re briefed, but ni reality not so much. So finally the second engineer was a little more pragmatic than the first too-clever guy. This is a quote from her: “I do not see errors on that module, but logically, it has to be the problem.” This of course is after we presented all the evidence to her. So we ordered an RMA, replaced that board and yes everything began to work.

I’ve been involved in two such massive debugging session over the last four months. No one from the Cisco side is saying it, but I will. These Nexus switches define flows behind the scenes. They can probably do some very clever things with these flows. But it is no longer a simple switch. And, sadly, when the flows don’t all work, no one at Cisco is prepared to look for that issue or even consider it as a possibility. They look for obscure errors. And, heaven forbid, they are, I guess, incapable of proving to themselves their switch as at fault – eating packets – by doing what any first semester network class would have, namely, mirroring some of the ports and examining the traffic for themselves. It is instead up to the customer to prove the switch is at fault.

So in my first debugging session, which lasted about 16 hours, Cisco did not really find the errors that would lead them to believe slot 8 was a problem. Yet its replacement fixed everything. In fairness, in the second debugging session, which only lasted five hours or so, they did see errors which justified a replacement. But at no time did they ever use the word flow or offer in detail how the errors they saw could have produced the weird results we were seeing (that was the Jack and Jill example from above).

Conclusion

We guys who run servers would like to think a switch is a switch is a switch. But Cisco is requiring us to up our game, even if they don’t up theirs. Their Nexus switches absolutely can eat some of your network traffic while passing other over the same ports. I’d like to call that flows, even if they refuse to use that term.

Categories
Admin Network Technologies

What is the one DHCP problem managed network providers never recognize?

Answer: the one where their switch eats the DHCPDISCOVER packets. And the zmzaing thing is they never learn. And the second amazing thing is that they actually don’t apply the most basic networing debugging techniques when such a problem occurs. I’m talking your basic, DHCPDISCOVER packet goes to yuor switch, same DHCPDISCOVER packet never arrives to the DHCP server on same switch. We know it to be the case, but, to help convince yourself that your switch is eating the pakcets, do networky things like create a span port of the DHCP server’s port to prove to yourself that no DHCP requests are coming in. And yet, they are never prepared to do that, to propose that. So instead indirect proxies are used to draw the conclusion.

I’ve been involved in three of four such debugging sessions. They take hours. I took notes when it happened again this weekend. I guess that setup is pretty typical of how it plays out. A data center was moved, including a DHCP server. The new data center has a MAN network to the old one. All IPs were preserved. When they turned on the moved DHCP server DHCP lease were no longer getting handed out. In fact it was worse than that. With the moved DHCP sever turned off, most DHCP leases were working. But with it on, that’s when things really began to go south!

Here’s the switch port they noted for the iDRAC:

sh run int gi1/0/24
Building configuration…
Current configuration : 233 bytes
!
interface GigabitEthernet1/0/24
description --- To-cnshis01-iDRAC - iDRAC
switchport access vlan 202
switchport mode access
logging event link-status
speed 100
duplex full
spanning-tree portfast
ip dhcp snooping trust
end

The first line of course if the IOS command. OK, so they had that on the iDRAC, right. But on the actual server port they had this:

sh run int gi1/0/23
Building configuration…
Current configuration : 258 bytes
!
interface GigabitEthernet1/0/23
description --- To-cnshis01-Gb1 - Gb1
switchport access vlan 202
switchport mode access
logging event link-status
spanning-tree portfast
service-policy input PMAP_COS_REMARK_IN
service-policy output PMAP_COS_OUT
end

I basically told them cheekily up front that this is usually a network switch problem and that they have to play with the DHCP snooping enable setting.

And I have to say that the usual hours of debugging were short-circuited this time as they seemed to believe me, and simply experimented by adding

ip dhcp snooping trust

to the DHCP server’s main port. We immediately began seeing DHCPDISCOVER pakcets come in to the DHCP server, and the team testified that people were getting leases.

Final mystery explained

Now why were things behaving really badly – no leases – when the DHCP server was up but no DHCPDISCOVER requests were getting to it? I have the explanation for that as well. You see theer is a standby DHCP server which is designed for failure of the primary DHCP server. But not for this type of failure! That’s right. There is an out-of-band (by that I mean not carried over DHCP ports like UDP port 67) communication between standby and primary which tells the standby Hey, although you got this DHCPDISCOVER request, ignore it becasue the primary is active and will serve it! And meanwhile, as we have said, the primary wasn’t getting the requests at all. Upshot: no one gets leases.

Just to mention it

My second-to-last debugging session of this sort was a little different. There they mentioned that there was a “global setting” which governed this DHCP snooping on the switch. So they had to do something with that (enable or disable or something). So there was no issue with the individual switch ports. For me that’s just a variation on the same theme.

What’s the idea behind this feature?

Having done a total of zero minutes of research on the topic, I will anyway weigh in with my opinion! Suppose someone comes along and plugs in a consumer grade home router into your network. It’s probably going to act as a rogue DHCP server. Imagine the fun trying to debug that situation? We’ve all been there… These rogue devices are probably fairly common. So if your corporate switch doesn’t suppress certain DHCP packets from ports where they are not expected, then this rogue device will begin to take down your subnet and totally bewilder everyone. I imagine this setting that is the topic of this blog post stems from trying to suppress all unknown DHCP packets in advance. Its just that sometimes the setting is taken too far and, e.g., a firewall which relays DHCP requests is also getting its DHCP packets suppressed.

Conclusion

I normally would have presented this as part of my IT Detective series. But I feel this is more like a lament about the sad state of affairs with our network providers. And though I’ve seen this issue about four times in the past 12 months, they always act like they have no idea what we’re talking about. They’ve never encountered this problem. They have no idea how to fix it. And they have no idea how to further debug it.. What steps does the customer wish?

References and related

Juat because I mentioned it, here’s on of those IT Detective Agency blog posts: The IT Detecive Agency: web site not accessible

Categories
Admin Web Site Technologies

TCL iRule program with comments for F5 BigIP

Intro

A publicity-adverse colleague of mine wrote this amazing program. I wanted to publish it not so much for what it specifically does, but as well for the programming techniques it uses. I personally find i relatively hard to look up concepts when using TCL for an F5 iRule.

Program Introduction

Test

                    
# RULE_INIT is executed once every time the iRule is saved or on reboot. So it is ideal for persistent data that is shared accross all sessions.
# In our case it is used to define a template with some variables that are later substituted

when RULE_INIT {
# "static" variables in iRules are global and read only. Unlike regular TCL global variables they are CMP-friendly, that means they don't break the F5 clustered multi-processing mechanism. They exist in memory once per CMP instance. Unlike regular variables that exist once per session / iRule execution. Read more about it here: https://devcentral.f5.com/s/articles/getting-started-with-irules-variables-20403
#
# One thing to be careful about is not to define the same static variable twice in multiple iRules. As they are global, the last iRule saved overwrites any previous values.
# Originally the idea was to load an iFile here. That's also the main reason to even use RULE_INIT and static variables. The reasoning was (and I don't even know if this is true), that loading the iFile into memory once would have to be more efficient than to do it every time the iRule is executed. However, it is entirely possible that F5 already optimized iFiles in a way that loads them into memory automatically at opportune times, so this might be completely unnecessary.
# Either way, as you can tell, in the end I didn't even use iFiles. The reason for that is simply visibility. iFiles can't be easily viewed from the web UI, so it would be quite inconvenient to work with.
# The template idea and the RULE_INIT event stayed, even though it doesn't really serve a purpose, except maybe visually separating the templates from the rest of the code.
#
# As for the actual content of the variable: First thing to note is the use of  {} to escape the entire string. Works perfectly, even though the string itself contains braces. TCL magic.
# The rest is just the actual PAC file, with strategically placed TCL variables in the form of $name (this becomes important later)

            set static::pacfiletemplate {function FindProxyForURL(url, host)
{
            var globalbypass = "$globalbypass";
            var localbypass = "$localbypass";
            var ceglobalbypass = "$ceglobalbypass";
            var zpaglobalbypass = "$zpaglobalbypass";
            var zscalerbypassexception = "$zscalerbypassexception";

            var bypass = globalbypass.split(";").concat(localbypass.split(";"));
            var cebypass = ceglobalbypass.split(";");
            var zscalerbypass = zpaglobalbypass.split(";");
            var zpaexception = zscalerbypassexception.split(";");

            if(isPlainHostName(host)) {
                        return "DIRECT";
            }

            for (var i = 0; i < zpaexception.length; ++i){
                        if (shExpMatch(host, zpaexception[i])) {
                                   return "PROXY $clientproxy";
                        }
            }

            for (var i = 0; i < zscalerbypass.length; ++i){
                        if (shExpMatch(host, zscalerbypass[i])) {
                                   return "DIRECT";
                        }
            }

            for (var i = 0; i < bypass.length; ++i){
                        if (shExpMatch(host, bypass[i])) {
                                   return "DIRECT";
                        }
            }

            for (var i = 0; i < cebypass.length; ++i) {
                        if (shExpMatch(host, cebypass[i])) {
                                   return "PROXY $ceproxy";
                        }
            }

            return "PROXY $clientproxy";
}
}

            set static::forwardingpactemplate {function FindProxyForURL(url, host)
{
            var forwardinglist = "$forwardinglist";
            var forwarding = forwardinglist.split(";");

            for (var i = 0; i < forwarding.length; ++i){
                        if (shExpMatch(host, forwarding[i])) {
                                   return "PROXY $clientproxy";
                        }
            }

            return "DIRECT";
}
}
}

# Now for the actual code (executed every time a user accesses the vserver)
when HTTP_REQUEST {
    # The request URI can of course be used to differentiate between multiple PAC files or to restrict access.
    # So can basically any other request attribute. Client IP, host, etc.
            if {[HTTP::uri] eq "/proxy.pac"} {

                        # Here we set variables with the exact same name as used in the template above.
                        # In our case the values come from a data group, but of course they could also be defined
                        # directly in this iRule. Using data groups makes the code a bit more compact and it
                        # limits the amount of times anyone needs to edit the iRule (potentially making a mistake)
                        # for simple changes like adding a host to the bypass list
                        # These variables are all set unconditionally. Of course it is possible to set them based
                        # on for example client IP (to give different bypass lists or proxy entries to different groups of users)
                        set globalbypass [ class lookup globalbypass ProxyBypassLists ]
                        set localbypass [ class lookup localbypassEU ProxyBypassLists ]
                        set ceglobalbypass [ class lookup ceglobalbypass ProxyBypassLists ]
                        set zpaglobalbypass [ class lookup zpaglobalbypass ProxyBypassLists ]
                        set zscalerbypassexception [ class lookup zscalerbypassexception ProxyBypassLists ]
                        set ceproxy [ class lookup ceproxyEU ProxyHosts ]

                        # Here's a bit of conditionals, setting the proxy variable based on which virtual server the
                        # iRule is currently executed from (makes sense only if the same iRule is attached to multiple
                        # vservers of course)
                        if {[virtual name] eq "/Common/proxy_pac_http_90_vserver"} {
                            set clientproxy [ class lookup formauthproxyEU ProxyHosts ]
                        } elseif {[virtual name] eq "/Common/testproxy_pac_http_81_vserver"} {
                            set clientproxy [ class lookup testproxyEU ProxyHosts]
                        } elseif {[virtual name] eq "/Common/proxy_pac_http_O365_vserver"} {
                            set clientproxy [ class lookup ceproxyEU ProxyHosts]
                        } else {
                            set clientproxy [ class lookup clientproxyEU ProxyHosts ]
                }

                        # Now this is the actual magic. As noted above we have now set TCL variables named for example
                        # $globalbypass and our template includes the string "$globalbypass"

                        # What we want to do next is substitute the variable name in the template with the variable values
                        # from the code.
                        # "subst" does exactly that. It performs one level of TCL execution. Think of "eval" in basically
                        # any language. It takes a string and executes it as code.
                        # Except for "subst" there are two in this context very useful parameters: -nocommands and -nobackslashes.
                        # Those prevent it from executing commands (like if there was a ping or rm or ssh or find or anything
                        # in the string being subst'd it wouldn't actually try to execute those commands) and from normalizing
                        # backslashes (we don't have any in our PAC file, but if we did, it would still work).
                        # So what is left that it DOES do? Substituting variables! Exactly what we want and nothing else.
                        # Now since the static variable is read only, we can't do this substitution on the template itself.
                        # And if we could it wouldn't be a good idea, because it is shared accross all sessions. So assuming
                        # there are multiple versions of the PAC file with different proxies or bypass lists, we would
                        # constantly overwrite them with each other.
                        # The solution is simply to save the output of the subst in a new local variable that exists in
                        # session context only.
                        # So from a memory point of view the static/global template doesn't really gain us anything.
                        # In the end we have the template in memory once per CMP and then a substituted copy of the template
                        # once per session. So as noted earlier, could've probably just removed the entire RULE_INIT block,
                        # set the template in session context (HTTP_REQUEST event) and get the same result,
                        # maybe even slightly more efficient.
                        set pacfile [subst -nocommands -nobackslashes $static::pacfiletemplate]

                        # All that's left to do is actually respond to the client. Simple stuff.
                        HTTP::respond 200 content $pacfile "Content-Type" "application/x-ns-proxy-autoconfig" "Cache-Control" "private,no-cache,no-store,max-age=0"
            # In this example we have two different PAC files with different templates on different URLs
            # Other iRules we use have more differentiation based on client IP. In theory we could have one big iRule
            # with all the PAC files in the world and it would still scale very well (just a few more if/else or switch cases)
            } elseif { [HTTP::uri] eq "/forwarding.pac" } {
                set clientproxy [ class lookup clientproxyEU ProxyHosts]
                set forwardinglist [ class lookup forwardinglist ProxyBypassLists ]
            set forwardingpac [subst -nocommands -nobackslashes $static::forwardingpactemplate]
            HTTP::respond 200 content $forwardingpac "Content-Type" "application/x-ns-proxy-autoconfig" "Cache-Control" "private,no-cache,no-store,max-age=0"
            } else {
                # If someone tries to access a different path, give them a 404 and the right URL
                HTTP::respond 404 content "Please try http://webproxy.drjohns.com/proxy.pac" "Content-Type" "text/plain" "Cache-Control" "private,no-cache,no-store,max-age=0"
            }
}

To be continued...

Categories
Consumer Tech

Consumer Tech: Netflix video and audio out of sync using Firestick

Intro

While watching Mad Men last night on IMDB we saw a terribly annoying audio delay – probably about three seconds after the video. Then it cuts to the commercials and they were perfectly in sync. Then back to the show – still a 2 – 3 -second delay. Is it the brand of TV? We use a Firestick plus a Samsung LCD TV.

The solution

Well, my first inclination was to look for audio settings on either the TV or the Amazon Firestick which might be set to delay audio. I had such a setting on an old sound system, though I think it was only for a sub-second delay. But, there are no such settings on either Firestick or Samsung TV, so that’s not it.

An Internet search proved not too useful.

What I eventually realized – the in-sync commercials was a hint – is that I could rewind the show a tiny bit, and that might pop it back into sync. And…it did!

How it happens

I think it happens when I pause a show one night, to return to it a later time. It remembers where I was, which is great. But it sometimes gets out of sync this way. I have seen this with Netflix and IMDB. The common element seems to be the Firestick.

Categories
Raspberry Pi

Raspberry Pi photo frame using the pictures on your Google Drive II

Intro

This is basically the same post as my previous post, Raspberry Pi photo frame using your pictures on your Google Drive. The are several ideas I am introducing in this treatment.

  • better time separation of the photos for a more meaningful viewing
  • smart resizing of photos to effectively enlarge narrow photos
  • analysis of photos for date and time
  • analysis of photos for GPS info, converting to city and even address!
  • build up of alternate slideshow which includes date, file, folder and location information embedded at the bottom of every picture
  • quality control check to make sure file is an actual JPEG
  • tiny thumbnail pictures are skipped
  • pictures of documents are excluded (future enhancement)
  • a nice picture is displayed when the slideshow is refreshed

Mostly for my own sake, I’ve re-named most of the relevant files and re-worked some as well in order to avoid name conflicts.

I find this treatment is pretty robust and can withstand a lot of errors and mistakes.

So let’s get started.

The easier way to get the files

Because there are now so many files – 18 at last count! – I’ve bundled them all into a tar file. So to get them all in one fell swoop do this.

$ wget https://drjohnstechtalk.com/blog/downloads/photoFrameII.tar

$ tar xvf photoFrameII.tar

Then skip down to the section of this post called crontab entries, which you will still need to do.

But because I think the scripts could be useful for other projects as well, I’m including them here in their entirety in the following section.

The files

The brains of the thing is master3.sh.

master3.sh

                    

#!/bin/sh
# DrJ 1/2021
# call this from cron once a day to refesh random slideshow once a day
NUMFOLDERS=20
DEBUG=1
HOME=/home/pi
RANFILE=$HOME/random.list
REANFILE=$HOME/rean.list
DISPLAYFOLDER=$HOME/Pictures
DISPLAYFOLDERTMP=$HOME/Picturestmp
EXIFTMP=$HOME/EXIFtmp
EXIF=$HOME/EXIF
TXTDIR=$HOME/picstxt
MSHOW=$HOME/mediashow
MSHOW2=$HOME/mediashowtmp2
MSHOW3=$HOME/mediashowtmp3
SLEEPINTERVAL=1
STARTFOLDER="MaryDocs/Pictures and videos"

echo "Starting master process at "`date`


cd $HOME

rm -rf $DISPLAYFOLDERTMP
mkdir $DISPLAYFOLDERTMP

#listing of all Google drive files starting from the picture root
# this takes a few minutes so we may want to skip for debugging
if [ "$1" = "skip" ]; then
  if [ $DEBUG -eq 1 ]; then echo SKIP Listing all files from Google drive; fi
else
  if [ $DEBUG -eq 1 ]; then echo Listing all files from Google drive; fi
  rclone ls remote:"$STARTFOLDER" > files
# filter down to only jpegs, lose the docs folders and the tiny JPEGs
  if [ $DEBUG -eq 1 ]; then echo Picking out the JPEGs and losing the small images; fi
  egrep '\.[jJ][pP][eE]?[gG]$' files |awk '$1 > 11000 {$1=""; print substr($0,2)}'|grep -i -v /docs/ > jpegs.list
fi

# check if we got anything. If our Internt dropped there may have been a problem, for instance
flines=`cat files|wc -l`
if [ $flines -lt 60 ]; then
  echo "rclone did not produce enough files. Check your Internet setup and rclone configuration."
  echo Only $flines files in the file listing - not enough - so pausing 60 seconds and starting over... at `date`
# start a new job and kill ourselves!
  nohup $HOME/master3.sh > master.log 2>&1 &
  exit
fi

# throw NUMFOLDERS or so random numbers for picture selection, select triplets of photos by putting
# names into a file
if [ $DEBUG -eq 1 ]; then echo "\nGenerate random filename triplets"; fi
./random-files3.pl -f $NUMFOLDERS -j jpegs.list -r $RANFILE

# copy over these 60 jpegs
if [ $DEBUG -eq 1 ]; then echo "\nCopy over these random files"; fi
cat $RANFILE|while read line; do
  if [ $DEBUG -eq 1 ]; then echo filepath is $line; fi
  rclone copy remote:"${STARTFOLDER}/$line" $DISPLAYFOLDERTMP
  sleep $SLEEPINTERVAL
done

# do a re-analysis to push pictures further apart in time
if [ $DEBUG -eq 1 ]; then echo "\nRe-analyzing pictures for their timestamps"; fi
cd $DISPLAYFOLDERTMP; $HOME/reanalyze.pl

# copy over just the new pictures that we determined were needed
if [ $DEBUG -eq 1 ]; then echo "\nCopy over the needed replacement files"; fi
cat $REANFILE|while read line; do
  if [ $DEBUG -eq 1 ]; then echo filepath is $line; fi
  rclone copy remote:"${STARTFOLDER}/$line" $DISPLAYFOLDERTMP
  sleep $SLEEPINTERVAL
done

# QC: toss out the pics which are not actually JPEGs
if [ $DEBUG -eq 1 ]; then echo "\nQC: Toss out the pics which are not actually JPEGs"; fi
cd $DISPLAYFOLDERTMP; ../QC.pl

# save EXIF metadata for later
if [ $DEBUG -eq 1 ]; then echo "\nSave EXIF metadata for later"; fi
cd $DISPLAYFOLDERTMP; $HOME/get-all-EXIF.sh
rm -rf $EXIF;mv $EXIFTMP $EXIF

# analyze EXIF info to extract most interesting things
if [ $DEBUG -eq 1 ]; then echo "\nAnalyze EXIF data"; fi
rm -rf $TXTDIR; $HOME/analyze.sh

# rotate pics as needed
if [ $DEBUG -eq 1 ]; then echo "\nRotate the pics which need it"; fi
cd $DISPLAYFOLDERTMP; $HOME/rotate-as-needed.sh

# resize pics
if [ $DEBUG -eq 1 ]; then echo "\nSize all pics to the display size"; fi
$HOME/resize.sh

# create text info + images
if [ $DEBUG -eq 1 ]; then echo "\nEmbed pic info"; fi
$HOME/embedpicinfo.sh

cd ~

# kill any old slideshow
if [ $DEBUG -eq 1 ]; then echo Killing old fbi slideshow; fi
sudo pkill -9 -f fbi
pkill -9 -f m3.pl

# remove old pics
if [ $DEBUG -eq 1 ]; then echo Removing old pictures; fi
rm -rf $DISPLAYFOLDER

mv $DISPLAYFOLDERTMP $DISPLAYFOLDER
cp $MSHOW3 $MSHOW

touch refresh

#run looping fbi slideshow on these pictures
if [ $DEBUG -eq 1 ]; then echo Start "\nfbi slideshow in background"; fi
cd $DISPLAYFOLDER ; nohup ~/m3.pl  >> ~/m3.log 2>&1 &

if [ $DEBUG -eq 1 ]; then echo "And now it is "`date`; fi

random-files3.pl

                    
#!/usr/bin/perl
use Getopt::Std;
my %opt=();
getopts("c:df:j:r:",\%opt);
$nofolders = $opt{f} ? $opt{f} : 20;
$DEBUG = $opt{d} ? 1 : 0;
$cutoff = $opt{c} ? $opt{c} : 5;
$cutoffS = 60*$cutoff;
$jpegs = $opt{j} ? $opt{j} : "jpegs.list";
$ranpicfile = $opt{r} ? $opt{r} : "jpegs-random.list";
print "d,f,j,r: $opt{d}, $opt{f}, $opt{j}, $opt{r}\n" if $DEBUG;
$mshowt = "mediashowtmp";
open(JPEGS,$jpegs) || die "Cannot open jpegs listing file $jpegs!!\n";
@jpegs = <JPEGS>;
# remove newline character
$nopics = chomp @jpegs;
open(RAN,"> $ranpicfile") || die "Cannot open random picture file $ranpicfile!!\n";
for($i=0;$i<$nofolders;$i++) {
  $t = int(rand($nopics-2));
  print "random number is: $t\n" if $DEBUG;
# a lot of our pics follow this naming convention
# 20160831_090658.jpg
  ($date,$time) = $jpegs[$t] =~ /(\d{8})_(\d{6})/;
  if ($date) {
    print "date, time: $date $time\n" if $DEBUG;
# ensure neighboring picture is at least five minutes different in time
    $iPO = $iP = $diff = 1;
    ($hr,$min,$sec) = $time =~ /(\d\d)(\d\d)(\d\d)/;
    $secs = 3600*$hr + 60*$min + $sec;
    print "Pre-pic logic\n";
    while ($diff < $cutoffS) {
      $iP++;
      $priorPic = $jpegs[$t-$iP];
      $Pdate = $Ptime = 0;
      ($Pdate,$Ptime) = $priorPic =~ /(\d{8})_(\d{6})/;
      ($Phr,$Pmin,$Psec) = $Ptime =~ /(\d\d)(\d\d)(\d\d)/;
      $Psecs = 3600*$Phr + 60*$Pmin + $Psec;
      print "hr,min,sec,Phr,Pmin,Psec: $hr,$min,$sec,$Phr,$Pmin,$Psec\n" if $DEBUG;
      $diff = abs($secs - $Psecs);
      print "diff: $diff\n" if $DEBUG;
# end our search if we happened upon different dates
      $diff = 99999 if $Pdate ne $date;
    }
# post-picture logic - same as pre-picture
    print "Post-pic logic\n";
    $diff = 0;
    while ($diff < $cutoffS) {
      $iPO++;
      $postPic = $jpegs[$t+$iPO];
      $Pdate = $Ptime = 0;
      ($Pdate,$Ptime) = $postPic =~ /(\d{8})_(\d{6})/;
      ($Phr,$Pmin,$Psec) = $Ptime =~ /(\d\d)(\d\d)(\d\d)/;
      $Psecs = 3600*$Phr + 60*$Pmin + $Psec;
      print "hr,min,sec,Phr,Pmin,Psec: $hr,$min,$sec,$Phr,$Pmin,$Psec\n" if $DEBUG;
      $diff = abs($Psecs - $secs);
      print "diff: $diff\n" if $DEBUG;
# end our search if we happened upon different dates
      $diff = 99999 if $Pdate ne $date;
    }
  } else {
    $iP = $iPO = 2;
  }
  $priorPic = $jpegs[$t-$iP];
  $Pic = $jpegs[$t];
  $postPic = $jpegs[$t+$iPO];
  print RAN qq($priorPic
$Pic
$postPic
);
# this is how we'll preserve the order of the pictures. ls -1 often gives a different order!!
($p1) = $priorPic =~ /([^\/]+)$/;
($p2) = $Pic =~ /([^\/]+)$/;
($p3) = $postPic =~ /([^\/]+)$/;
print "p1 p2 p3: $p1 $p2 $p3" if $DEBUG;
$picsinorder .= $p1 . "\0" . $p2 . "\0" . $p3 . "\0";
}
close(RAN);
open(MS,">$mshowt") || die "Cannot open mediashow file $mshowt!!\n";
print MS $picsinorder;
close(MS);
print "pics in order: $picsinorder\n" if $DEBUG;

reanalyze.pl

                    

#!/usr/bin/perl
use Getopt::Std;
my %opt=();
#
# assumption is that we are runnin this from a directory containing pictures
$tier1 = 100; $tier2 = 200; $tier3 = 300; # secs
$DEBUG = 1;
$HOME = "/home/pi";
# pics are here
$pNames = "$HOME/reanpicnames";
$ranfile = "$HOME/random.list";
$reanfile = "$HOME/rean.list";
$origfile = "$HOME/jpegs.list";
$mshowt = "$HOME/mediashowtmp";
$mshow2 = "$HOME/mediashowtmp2";

open(REAN,">$reanfile") || die "Cannot open reanalyze file $reanfile!!\n";
$ms = `cat $mshowt`;
print "Original media show: $ms\n" if $DEBUG;
@lines = split('\0',$ms);
$Pdate = $Phr = $Pmin = $Psec = 0;
$diff = 9999;
for($i=0;$i<@lines;$i++){
  $date = 0;
  $secs = $ymd = 0;
  $_ = $lines[$i];
  $file = $_;
# ignore pictures with names like 20130820_180050.jpg
  next if /\d{8}_\d{4}/;
  open(ANAL,"$HOME/getinfo.py \"$file\"|") || die "Cannot open file: $file!!\n";
  print "filename: $file\n" if $DEBUG;
  while(<ANAL>){
#extract date and time from remaining pictures, if possible
# # DateTimeOriginal = 2018:08:18 20:16:47
#    print STDERR "DATE: $_" if $DEBUG;
if (/date/i && $date++ < 1) {
   print "date match in getinfo.pyoutput: $_" if $DEBUG;
   ($ymd,$hr,$min,$sec) = /(\d{4}:\d\d:\d\d) (\d\d):(\d\d):(\d\d)/;
   $secs = 3600*$hr + 60*$min + $sec;
   print "file,secs,ymd,i: $file,$secs,$ymd,$i\n" if $DEBUG;
   $YMD[$i] = $ymd;
   $SECS[$i] = $secs;
}
} # end loop over analysis of this pic
} # end loop over all files
# now go over that
$oldfolder = 0;
for($i=1;$i<@lines;$i++){
 $folder = int($i/3) + 1;
 next unless $folder != $oldfolder;
   print "analyzing results. folder no. $folder\n" if $DEBUG;
# analyze pics in triplets
# center pic
   $j = ($folder - 1)*3 + 1;
   for ($o=-1;$o<2;$o+=2){
     $k=$j+$o;
     print "j,k,o: $j,$k,$o\n" if $DEBUG;
     next unless $SECS[$j] > 0 && $YMD[$j] == $YMD[$k] && $YMD[$j] > 0;
     print "We have non-0 dates we're dealing with\n" if $DEBUG;
     $file = $lines[$k];
     chomp($file);
     $diff = abs($SECS[$j] - $SECS[$k]);
     print "diff: $diff\n" if $DEBUG;
     next unless $diff < $tier3;
# the closer the files are together the more we push away
     $bump = 1 if $diff < $tier3;
     $bump = 2 if $diff < $tier2;
     $bump = 3 if $diff < $tier1;
# get full filepath
     $filepath = `grep \"$file\" $ranfile`;
     chomp($filepath);
# now use that to search within the jpegs file listing
     $prog = $o < 0 ? "head" : "tail";
     $newfilepath = `grep -C$bump "$filepath" $origfile|$prog -1`;
     ($newfile) = $newfilepath =~ /([^\/]+)$/;
     chomp($newfile);
     print "file,filepath,newfile,newfilepath,bump: $file,$filepath,$newfile,$newfilepath,$bump\n" if $DEBUG;
     print REAN $newfilepath;
# we'll get the new pictures over in a separate step to keep this more atomic
     $ms =~ s/$file/$newfile/;
    }
    $oldfolder = $folder;
} # end loop over pics
# print out new mediashow pics in order
print "Printing new mediashow: $ms\n" if $DEBUG;
open(MS,">$mshow2") || die "Cannot open mediashow $mshow2!!\n";
print MS $ms;
close(MS)

QC.pl

                    

#!/usr/bin/perl
# kick out the non-JPEG files - sometimes they creep in
$DEBUG = 1;
$HOME = "/home/pi";
$mshow2 = "$HOME/mediashowtmp2";
$mshow3 = "$HOME/mediashowtmp3";
$ms = `cat $mshow2`;
@pics = split('\0',$ms);
foreach $file (@pics) {
  print "file is $file\n" if $DEBUG;
#DSC00185.JPG: JPEG image data, JFIF standard 1.01...
  $res = `file "$file"|cut -d: -f2`;
  if ($res =~ /JPEG/i){
    print "This file is indeed a JPEG image\n" if $DEBUG;
  } else {
    print "Not a JPEG image! We have to remove this file form the mediashow\n" if $DEBUG;
    $ms =~ s/$file\0//;
  }
}
# print out new mediashow pics in order
print "Printing new mediashow: $ms\n" if $DEBUG;
open(MS,">$mshow3") || die "Cannot open mediashow $mshow3!!\n";
print MS $ms;
close(MS);

get-all-EXIF.sh

                    

#!/bin/sh
# DrJ 1/2021
# preserve EXIF info of all the images because our rotate step removes it
# and we will use it in subsequent steps
# assumption is that our current directory is the one where we want to read files
EXIFTMP=~/EXIFtmp
mkdir $EXIFTMP
ls -1|while read line; do
  echo file is "$line"
  ~/getinfo.py "$line" > $EXIFTMP/"$line"
done

analyze.sh

                    

#!/bin/sh
# DrJ 1/2021
# try to extract date, file and folder name and even GPS info, create jpegs with info
# for each image
# assumption is that are current directory is the one where we want to alter files
HOME=/home/pi
TXTDIR=$HOME/picstxt
# it's assumed EXIF info for each pic has already been extracted and put into EXIF diretory
EXIF=$HOME/EXIF
mkdir $TXTDIR
cd $EXIF
ls -1|while read line; do
  echo file is "$line"
  echo -n "$line"|../analyzeDate.pl > "$TXTDIR/${line}"
  echo -n "$line"|../analyzeGPS.pl >> "$TXTDIR/${line}"
done

rotate-as-needed.sh

                    

#!/bin/sh
# DrJ 12/2020
# some of our downloaded files will be sideways, and fbi doesn't auto-rotate them as far as I know
# assumption is that our current directory is the one where we want to alter files
ls -1|while read line; do
  echo file is "$line"
  o=`~/getinfo.py "$line"|grep -ai orientation|awk '{print $NF}'`
  echo orientation is $o
  if [ "$o" -eq "6" ]; then
    echo "90 clockwise is needed, o is $o"
# rotate and move it
    ~/rotate.py -90 "$line"
    mv rot_"$line" "$line"
  elif [ "$o" -eq "8" ]; then
    echo "90 counterclock is needed, o is $o"
# rotate and move it
    ~/rotate.py 90 "$line"
    mv rot_"$line" "$line"
  elif [ "$o" -eq "3" ]; then
    echo "180 rot is needed, o is $o"
# rotate and move it
    ~/rotate.py 180 "$line"
    mv rot_"$line" "$line"
  fi
done

resize.sh

                    

#!/bin/sh
# DrJ 2/2021
# To combat the RPi's inherent sluggish performance we'll downsize the pictures in advance to save fbi the effort
#
# on the pidisplay fbset gives:
#mode "800x480"
#    geometry 800 480 800 480 32
#    timings 0 0 0 0 0 0 0
#    rgba 8/16,8/8,8/0,8/24
#endmode
displaywidth=`fbset|grep geometry|awk '{print $2}'`
displayheight=`fbset|grep geometry|awk '{print $3}'`

ls -1|while read line; do
  echo file is "$line"
  ~/fancyresize.py $displaywidth $displayheight "$line"
  mv resize_"$line" "$line"
done

embedpicinfo.sh

                    

#!/bin/sh
# DrJ 2/2021
# To combat the RPi's inherent sluggish performance we'll downsize the pictures in advance to save fbi the effort
#
# on the pidisplay fbset gives:
#mode "800x480"
#    geometry 800 480 800 480 32
#    timings 0 0 0 0 0 0 0
#    rgba 8/16,8/8,8/0,8/24
#endmode
displaywidth=`fbset|grep geometry|awk '{print $2}'`
displayheight=`fbset|grep geometry|awk '{print $3}'`

ls -1|while read line; do
  echo file is "$line"
# this will create a new image with same name prepended with txt_
  ~/embedpicinfo.py $displaywidth $displayheight "$line"
done

Auxiliary files

rotate.py

                    

#!/usr/bin/python3
# call with two arguments: degrees-to-rotate and filename
import PIL, os
import sys
from PIL import Image
# first do: pip3 install piexif
import piexif

degrees = int(sys.argv[1])
pic = sys.argv[2]

picture= Image.open(pic)
# see https://github.com/hMatoba/Piexif for piexif writeup
# this method of preserving EXIF info does not always work, and
# causes script to crash when it fails!
##exif_dict = piexif.load(picture.info["exif"])
##exif_bytes = piexif.dump(exif_dict)
## both rotate and preserve EXIF data
##picture.rotate(degrees,expand=True).save("rot_" + pic,"jpeg", exif=exif_bytes)
# rotate (which will blow away EXIF info, sorry...)
picture.rotate(degrees,expand=True).save("rot_" + pic,"jpeg")

getinfo.py

                    

#!/usr/bin/python3
import os,sys
from PIL import Image
from PIL.ExifTags import TAGS

for (tag,value) in Image.open(sys.argv[1])._getexif().items():
        print ('%s = %s' % (TAGS.get(tag), value))

print ('%s = %s' % (TAGS.get(tag), value))

embedpicinfo.py

                    

#!/usr/bin/python3
# from https://auth0.com/blog/image-processing-in-python-with-pillow/
# fonts are described here:
# https://pillow.readthedocs.io/en/stable/reference/ImageDraw.html
from PIL import Image, ImageDraw, ImageFont
import sys, os

width = int(sys.argv[1])
height = int(sys.argv[2])
# for Pidisplay:
#width = 800
#height = 480
imageFile = sys.argv[3]
imageandtext = 'txt_' + imageFile

tfile = '../picstxt/' + imageFile
f = open(tfile)
txtlines = f.readlines()
f.close()

# our fonts
fnt = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", 14)
#fnt = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 40)
fnt36 = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", 36)
fnt2 = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 18)
fntBold = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", 40)
# PiDisplay resolution is 800x480
margin = 35
# semi-parameterized variables
x0 = margin - 30
x1 = margin -15
cwidth = 6
yline = 27
ychevron=(yline-28)/2
ycoff = 5
yoffset = 12
yrec= -10
rpad = 15
#
textimagey = 130
textimagex = width

# menu items
textimage = Image.new('RGB', (textimagex, textimagey), 'white')
for t in txtlines:
    img_draw = ImageDraw.Draw(textimage)
    img_draw.text((margin, yoffset), t, font=fnt, fill='MidnightBlue')
    yoffset += yline

# merge three images together...
# black background covering whole display:
masterimage = Image.new('RGB',(width,height),'black')
# original image:
oimage = Image.open(imageFile)
# original image width
owidth = oimage.size[0]
# get offset so narrow pictures are centered
xoffset = int((width - owidth)/2)
masterimage.paste(oimage,(xoffset,0))
masterimage.paste(textimage,(0,height - textimagey))

masterimage.save(imageandtext)

fancyresize.py

                    

#!/usr/bin/python3
# DrJ 2/2021
import PIL, os
import sys
from PIL import Image
# somewhat inspired by http://www.riisen.dk/dop/pil.html
# arguments:
# <width> <height> file
# with and height should be provided as values in pixels
# image file should be provided as argument.
# A pidisplay is 800x480

displaywidth = int(sys.argv[1])
displayheight = int(sys.argv[2])
smallscreen = 801
imageFile = sys.argv[3]
im1 = Image.open(imageFile)
narrowmax = .76
blowupfactor = 1.1
# take less from the top than the bottom
topshare = .3
bottomshare = 1.0 - topshare
# for DrJ debugging
DEBUG = True
if DEBUG:
  print("display width and height: ",displaywidth,displayheight)

def imgResize(im):
    width = im.size[0]
    height = im.size[1]
    if DEBUG:
      print("image width and height: ",width,height)

# If the aspect ratio is wider than the display screen's aspect ratio,
# constrain the width to the display's full width
    if width/float(height) > float(displaywidth)/float(displayheight):
      if DEBUG:
        print("In section width contrained to full width code section")

      widthn = displaywidth
      heightn = int(height*float(displaywidth)/width)
      im5 = im.resize((widthn, heightn), Image.ANTIALIAS) # best down-sizing filter
    else:
      heightn = displayheight
      widthn  = int(width*float(displayheight)/height)

      if width/float(height) < narrowmax and displaywidth < smallscreen:
# if width is narrow we're losing too much by using the whole picture.
# Blow it up by blowupfactor% if display is small, and crop most of it from the bottom
        heightn = int(displayheight*blowupfactor)
        widthn  = int(width*float(heightn)/height)
        im4 = im.resize((widthn, heightn), Image.ANTIALIAS) # best down-sizing filter
        top = int(displayheight*(blowupfactor - 1)*topshare)
        bottom = int(heightn - displayheight*(blowupfactor - 1)*bottomshare)
        if DEBUG:
          print("heightn,top,widthn,bottom: ",heightn,top,widthn,bottom)

        im5 = im4.crop((0,top,widthn,bottom))
      else:
        im5 = im.resize((widthn, heightn), Image.ANTIALIAS) # best down-sizing filter

    im5.save("resize_" + imageFile)

imgResize(im1)

analyzeDate.pl

                    

#!/usr/bin/perl
# 20180818_201647.jpg
use POSIX;
$DEBUG = 1;
$HOME = "/home/pi";
$random = "$HOME/random.list";
$rean   = "$HOME/rean.list";
#$file = "Picturestmp/20180422_134220.jpg";
while(<>){
$GPS = $date = 0;
$gpsinfo = "";
$file = $_;
#open(ANAL,"$HOME/getinfo.py \"$file\"|") || die "Cannot open file: $file!!\n";
open(ANAL,"cat \"$file\"|") || die "Cannot open file: $file!!\n";
print STDERR "filename: $file\n" if $DEBUG;
while(<ANAL>){
  $town = "";
  if (/DateTimeOriginal/i && $date++ < 1) {
# DateTimeOriginal = 2018:08:18 20:16:47
#or...  DateTimeDigitized = 2016/03/07 00:57:49
    print STDERR "DATE: $_" if $DEBUG;
    ($yr,$mon,$date,$hr,$min) = /(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d)/;
    print STDERR "$yr,$mon,$date,$hr,$min\n" if $DEBUG;
# my custom format: Saturday, August 18, 2018  8:16 pm
    $dateinfo =  strftime("%A, %B %d, %Y %l:%M %p", 0, $min, $hr, $date , $mon - 1, $yr - 1900, -1, -1, -1);
  }
}
# folder info from random.list
$match = `cat $random $rean|grep "$file"`;
($folder) = $match =~ /(.+)\/[^\/]+/;
print STDERR "matched line, folder: $match, $folder\n" if $DEBUG;

# if no date, use filesystem date
if ( ! $dateinfo ) {
  $jpegfile = "../Picturestmp/$file";
  $mtime = (stat($jpegfile))[9];
  $handtst = `ls -l "$jpegfile"`;
  @ltime = localtime $mtime;
  $dateinfo =  strftime("(guess) %A, %B %d, %Y %l:%M %p",@ltime);
  print STDERR "No date info. Use filesystem date. mtime is $mtime. dateinfo: $dateinfo\n";
  print STDERR "Hand test of file age: $handtst\n";
}

$dateinfo = $dateinfo || "No date found";
$gpsinfo = $gpsinfo || "No info found";

print qq(File: $file
Folder: $folder
Date: $dateinfo
);
}

analyzeGPS.pl

                    

#!/usr/bin/perl
# use in combination with this post https://drjohnstechtalk.com/blog/2020/12/convert-gps-coordinates-into-town-name/
use POSIX;
$DEBUG = 1;
$HOME = "/home/pi";
#$file = "Pictures/20180422_134220.jpg";
while(<>){
$GPS = $date = 0;
$gpsinfo = "";
$file = $_;
#open(ANAL,"$HOME/getinfo.py \"$file\"|") || die "Cannot open file: $file!!\n";
open(ANAL,"cat \"$file\"|") || die "Cannot open file: $file!!\n";
print STDERR "filename: $file\n" if $DEBUG;
while(<ANAL>){
  $postalcode = $town = $name = "";
  if (/GPS/i) {
    print STDERR "GPS: $_" if $DEBUG;
# GPSInfo = {1: 'N', 2: (39.0, 21.0, 22.5226), 3: 'W', 4: (74.0, 25.0, 40.0267), 5: 1.7, 6: 0.0, 7: (23.0, 4.0, 14.0), 29: '2016:07:22'}
   ($pole,$deg,$min,$sec,$hemi,$lngdeg,$lngmin,$lngsec) = /1: '([NS])', 2: \(([\d\.]+), ([\d\.]+), ([\d\.]+)...3: '([EW])', 4: \(([\d\.]+), ([\d\.]+), ([\d\.]+)\)/i;
   print STDERR "$pole,$deg,$min,$sec,$hemi,$lngdeg,$lngmin,$lngsec\n" if $DEBUG;
   $lat = $deg + $min/60.0 + $sec/3600.0;
   $lat = -$lat if $pole eq "S";
   $lng = $lngdeg + $lngmin/60.0 + $lngsec/3600.0;
   $lng = -$lng if $hemi = "W" || $hemi eq "w";
   print STDERR "lat,lng: $lat, $lng\n" if $DEBUG;
   #$placename = `curl -s "$url"|grep -i toponym`;
   next if $lat == 0 && $lng == 0;
# the address API is the most precise
   $url = "http://api.geonames.org/address?lat=$lat\&lng=$lng\&username=drjohns";
   print STDERR "Url: $url\n" if $DEBUG;
   $results = `curl -s "$url"|egrep -i 'street|house|locality|postal|adminName'`;
   print STDERR "results: $results\n" if $DEBUG;
   ($street) = $results =~ /street>(.+)</;
   ($houseNumber) = $results =~ /houseNumber>(.+)</;
   ($postalcode) = $results =~ /postalcode>(.+)</;
   ($state) = $results =~ /adminName1>(.+)</;
   ($town) = $results =~ /locality>(.+)</;
   print STDERR "street, houseNumber, postalcode, state, town: $street, $houseNumber, $postalcode, $state, $town\n" if $DEBUG;
# I think locality is pretty good name. If it exists, don't go  further
   $postalcode = "" if $town;
   if (!$postalcode && !$town){
# we are here if we didn't get interesting results from address reverse loookup, which often happens.
     $url = "http://api.geonames.org/extendedFindNearby?lat=$lat\&lng=$lng\&username=drjohns";
     print STDERR "Address didn't work out. Trying extendedFindNearby instead. Url: $url\n" if $DEBUG;
     $results = `curl -s "$url"`;
# parse results - there may be several objects returned
     $topelemnt = $results =~ /<geoname>/i ? "geoname" : "geonames";
     @elmnts = ("street","streetnumber","lat","lng","locality","postalcode","countrycode","countryname","name","adminName2","adminName1");
     $cnt = xml1levelparse($results,$topelemnt,@elmnts);

     @lati = @{ $xmlhash{lat}};
     @long = @{ $xmlhash{lng}};
# find the closest entry
     $distmax = 1E7;
     for($i=0;$i<$cnt;$i++){
       $dist = ($lat - $lati[$i])**2 + ($lng - $long[$i])**2;
       print STDERR "dist,lati,long: $dist, $lati[$i], $long[$i]\n" if $DEBUG;
       if ($dist < $distmax) {
         print STDERR "dist < distmax condition. i is: $i\n";
         $isave = $i;
       }
     }
     $street = @{ $xmlhash{street}}[$isave];
     $houseNumber = @{ $xmlhash{streetnumber}}[$isave];
     $admn2 = @{ $xmlhash{adminName2}}[$isave];
     $postalcode = @{ $xmlhash{postalcode}}[$isave];
     $name = @{ $xmlhash{name}}[$isave];
     $countrycode = @{ $xmlhash{countrycode}}[$isave];
     $countryname = @{ $xmlhash{countryname}}[$isave];
     $state = @{ $xmlhash{adminName1}}[$isave];
     print STDERR "street, houseNumber, postalcode, state, admn2, name: $street, $houseNumber, $postalcode, $state, $admn2, $name\n" if $DEBUG;
     if ($countrycode ne "US"){
       $state .= " $countryname";
     }
     $state .= " (approximate)";
   }
# turn zipcode into town name with this call
   if ($postalcode) {
     print STDERR "postalcode $postalcode exists, let's convert to a town name\n";
     print STDERR "url: $url\n";
     $url = "http://api.geonames.org/postalCodeSearch?country=US\&postalcode=$postalcode\&username=drjohns";
     $results = `curl -s "$url"|egrep -i 'name|locality|adminName'`;
     ($town) = $results =~ /<name>(.+)</i;
     print STDERR "results,town: $results,$town\n";
   }
   if (!$town) {
# no town name, use adminname2 which is who knows what in general
     print STDERR "Stil no town name. Use adminName2 as next best thing\n";
     $town = $admn2;
   }
   if (!$town) {
# we could be in the ocean! I saw that once, and name was North Atlantic Ocean
     print STDERR "Still no town. Try to use name: $name as last resort\n";
     $town = $name;
   }
   $gpsinfo = "$houseNumber $street $town, $state" if $locality || $town;
   } # end of GPS info exists condition
  } # end loop over ANAL file
  $gpsinfo = $gpsinfo || "No info found";
  print qq(Location: $gpsinfo
);
} # end loop over STDIN

#####################
# function to parse some xml and fill a hash of arrays
sub xml1levelparse{
# build an array of hashes
$string = shift;
# strip out newline chars
$string =~ s/\n//g;
$parentelement = shift;
@elements = @_;
$i=0;
while($string =~ /<$parentelement>/i){
 $i++;
 ($childelements) = $string =~ /<$parentelement>(.+?)<\/$parentelement>/i;
 print STDERR "childelements: $childelements" if $DEBUG;
 $string =~ s/<$parentelement>(.+?)<\/$parentelement>//i;
 print STDERR "string: $string\n" if $DEBUG;
 foreach $element (@elements){
  print STDERR "element: $element\n" if $DEBUG;
  ($value) = $childelements =~ /<$element>([^<]+)<\/$element>/i;
  print STDERR "value: $value\n" if $DEBUG;
  push @{ $xmlhash{$element} }, $value;
 }
} # end of loop over parent elements
return $i;
} # end sub xml1levelparse

m3.pl

                    

#!/usr/bin/perl
# show the pics ; rotate the screen as needed
# for now, assume the display is in a neutral
# orientation at the start
use Time::HiRes qw(usleep);
$DEBUG = 1;
$delay = 6; # seconds between pics
###$delay = 4; # for testing
$mdelay = 200; # milliseconds
$mshow = "$ENV{HOME}/mediashow";
$pNames = "$ENV{HOME}/pNames";
# pics are here
$picsDir = "$ENV{HOME}/Pictures";
$refreshFile = "$ENV{HOME}/refresh";

chdir($picsDir);
$cn = `ls -1|wc -l`;
chomp($cn);
print "$cn files\n" if $DEBUG;
# throw up a first picture - all black. Trick to make black bckgrd permanent
system("sudo fbi -a --noverbose -T 1 $ENV{HOME}/black.jpg");
# see if this is a new batch of pictures
$refresh = (stat($refreshFile))[9];
$now = time();
$diff = $now - $refresh;
print "refresh,now,diff: $refresh, $now, $diff\n" if $DEBUG;
if ($diff < 100){
  system("sudo fbi -a --noverbose -T 1 $ENV{HOME}/newslideshowintro.jpg");
  sleep(25);
}
system("sudo fbi -a --noverbose -T 1 $ENV{HOME}/black.jpg");
system("sleep 1; sudo killall fbi");
# start infinitely looping fbi slideshow
for (;;) {
# then start slide show
# shell echo cannot work with null character so we need to use a file to store it
    system("sudo xargs -a $mshow -0 fbi --noverbose -1 -T 1  -t $delay ");
    ###system("sudo xargs -a $mshow -0 fbi -a -1 -T 1  -t $delay "); # for testing
# fbi runs in background, then exits, so we need to monitor if it's still alive
    for(;;) {
      open(MON,"ps -ef|grep fbi|grep -v grep|") || die "Cannot launch ps -ef!!\n";
      $match = <MON>;
      if ($match) {
        print "got fbi match\n" if $DEBUG > 1;
        } else {
        print "no fbi match\n" if $DEBUG;
# fbi not found
          last;
      }
      close(MON);
      print "usleeping, noexist is $noexit\n" if $DEBUG > 1;
      usleep($mdelay);
    } # end loop testing if fbi has exited
} # close of infinite loop

Optional script

mshowtmp.pl (revision not yet reflected in the tar file)

                    

#!/usr/bin/perl
# add txt_ to beginning of filename
$DEBUG = 1;
$HOME = "/home/pi";
$mshow = "$HOME/mediashow.orig";
$mshow2 = "$HOME/mediashowtmp2";
$ms = `cat $mshow`;
@pics = split('\0',$ms);
$ms = "";
foreach $file (@pics) {
  print "file is $file\n" if $DEBUG;
  $ms .= "txt_" . $file . "\0";
}
# print out new mediashow pics in order
print "Printing new mediashow: $ms\n" if $DEBUG;
open(MS,">$mshow2") || die "Cannot open mediashow $mshow2!!\n";
print MS $ms;
close(MS);

crontab entries

                    
@reboot sleep 20; ./m3.pl >> m3.log 2>&1
26 5 * * * ./master3.sh >> master.log 2>&1

And… that’s it!

Reminder

Don’t forget to make all these files executable. Something like:

$ chmod +x *.pl *.py *.sh

should do it.

My equipment

RPi 3 running Raspbian Lite

Pi Display (probably would also work with an HDMI display)/ The Pi Display resolution is 800×480, so pretty small.

Pre-install

There are a few things you’ll need such as fbi, python3, pip, python Pillow and rclone. That’s basically described in my previous post so I won’t repeat it here.

Getting started

To see how badly things are going for you (hey, I like to be cautiously pessimistic) after you’ve created all these files and have installed rclone, do a

$ ./master3.sh

If you have your rclone file listing (which takes a long time) and want to focusing on debugging the rest of it, do a

$ ./master3.sh skip

Discussion

In this version of Raspberry Pi photo frame I’ve made more effort to force time separation between the randomly selected photos. But, that’s not all. I blow up pictures taken in a narrow (portrait) mode (see next paragraph). And I do some fancy analysis to determine filename, folder, date, time and even location of the pictures. And there’s more. I create an alternate version of each photo which embeds this info at the bottom – in anticipation of my even more fancy remote-controlled slideshow! I am afraid to overwrite what I have previously posted because that by itself is a complete solution and works quite well on its own. So this can be considered worthy of folks looking for a little more challenge to get better results.

The fancyresize.py script is designed around my small PiDisplay which has a horizontal resolution of only 800 pixels. It blows up a narrow, portrait-format picture only if the detected display has a horizontal resolution of no more than 800 pixels. It blows the picture up by 10%, chops off 3% from the top, 7% from the bottom, because that yields optimal results in my experience. If you like that approach but are using a larger HDMI display, you could edit the “801” in that file to make it a larger number (bigger than your display, like 5000).

Show pictures with embedded info

This process is not streamlined. But it can be cool to do it by hand. You could follow these steps.

$ ./mshowtmp.pl; mv mediashowtmp2 mediashow

If you wait the whole cycle the next time around it should display the pictures with the embedded info at the bottom. If you’re impatient, do this:

$ sudo pkill -9 fbi; sudo pkill -9 m3.pl

$ nohup ./m3.pl > m3.log 2>&1 &

Fun Fact

You know how those old digital cameras created files prefixed with DSC, like DSC00102.JPG? If you read the JPEG spec, which is a pretty dense document, you learn that DSC stands for Digital Still Camera.

Concept for tossing out pictures of documents

We sometimes take pictures of documents, or computer screens, or a slide at a presentation, or a historical marker. They don’t make for compelling slideshow material. Well, the historical markers are debatable since they have character. Anyway, I am looking at using an old open source program called tesseract to do OCR (optical character recognition) on all the photos to help identify those containing a lot of words so they can be excluded. I’ll include that if I determine it to be a good approach.

Installing a searchable dictionary on Raspberry Pi

To install a word dictionary that you can do simple searches against on an RPi, try:

$ sudo apt-get install wamerican

or maybe

$ sudo apt-get install wamerican-huge

Those will produce simple wordlists, not actual dictionaries with definitions as you might have expected. They go into /usr/share/dict, e.g., usr/share/dict/american-english-huge.

The dict program is quite nice. apt-get install dict. Then you run it like this

$ dict neume

and it shoots back definitions and cites sources for those definitions. The drawback for my purposes is that it uses your Internet connection and I’m trying to build a photo frame that doesn’t rely too much on the Internet after the photos themselves are fetched.

$ sudo apt-cache search wordlist

lists all available dictionaries, I believe.

Setting up tesseract

This page has these instructions

git clone https://github.com/thortex/rpi3-tesseract.git 
cd rpi3-tesseract 
cd release 
./install_requires_related2leptonica.sh ./install_requires_related2tesseract.sh 
./install_tesseract.sh

But you’re gonna need git first:

$ sudo apt-get install git

RPi lost Wifi

This could be a whole separate post. In the course of my hard work my RPi just would not acquire an IP address on wlan0.

Here’s a great command to see all the SSIDs it knows about:

$ sudo iwlist wlan0 scan > scan.log

Then you can inspect scan.log in an editor. Turns out the one SSID it needed wasn’t in the list. Turns out I had reserved a DHCP entry for it in my router. My router was simply not cooperating, it seems – the RPi wasn’t doing anything wrong. I was almost ready to re-install the whole thing and waste hours… My router is an older model Linksys WRT1200AC. I removed the DHCP reservation on the router, then did a

$ sudo service networking stop; sudo service networking start

on the RPi, and…all was good! Its assigned IP won’t change that often, I can always check the router to see what it is. The management software with the Linksys is quite good.

Conclusion

A more advanced treatment of photos is shown in this post than I have done previously. It is fairly robust and will withstand quite a few user errors in my experience. The end result will be an interesting display of your photos, randomly selected but in small groupings.

References and related

The tar file which contains everything: https://drjohnstechtalk.com/blog/downloads/photoFrameII.tar

Please see this popular post Raspberry Pi photo frame using your pictures on your Google Drive for more details.

m3.pl refers to a black.jpg and a newslideshowintro.jpg file. It’s not a disaster to not have those, but the overall experience will be slightly better. Here’s black.jpg:

And the beautiful newslideshowintro.jpg I created is at the top of this blog post.

Tesseract, an surprisingly old and surprisingly good OCR open-source OCR program, is basically impossible to compile for RPi. Fortunately, someone has done it for us. This page has the instructions: https://github.com/thortex/rpi3-tesseract

Categories
Raspberry Pi

Raspberry Pi advanced photo frame

Intro

I am assembling a lot of different ideas I have to do some more cool things than was possible with my original Raspberry Pi photo frame effort although that contained a lot of original ideas as well.

Skillset

Intermediate or better linux skills required. Beginners/newbies: please do not attempt as you will encounter insurmountable problems and be left in a trail of tears. I don’t have time to help.

I will be using this remote control which I can attest is indeed compatioble with the RPi:

The inexpensive Rii remote controller with keyboard works with your Raspberry Pi

But it has no CTRL key! I can’t survive without that. It seems aimed at media consumers. I guess those types never need that key. At this point in time my idea is to use the arrow keys + Enter button as a familiar way to navigate around a simple menu I plan to create, plus perhaps the menu key. the pre-defined keys fbi has created for navigation are simply not intuitive, nor are they adequate for the tasks I have in mind.

Rii keyValue
up arrow103
down arrow108
right arrow106
left arrow105
Menu127
OK28
Some interesting keys and their values when monitored

In my basic photo frame approach I had a simpler rotate image python script. This python program below rotates pictures by the specified amount and preserves the EXIF tags. It doesn’t update the orientation tag after rotating because for the fbi display program I use that doesn’t matter. I call it rotate.py.

                    
#!/usr/bin/python3
# call with two arguments: degrees-to-rotate and filename
import PIL, os
import sys
from PIL import Image
# first do: pip3 install piexif
import piexif

degrees = int(sys.argv[1])
pic = sys.argv[2]

picture= Image.open(pic)
# see https://github.com/hMatoba/Piexif for piexif writeup
exif_dict = piexif.load(picture.info[“exif”])
exif_bytes = piexif.dump(exif_dict)
# both rotate and preserve EXIF data
picture.rotate(degrees,expand=True).save(“rot_” + pic,”jpeg”, exif=exif_bytes)

As it says in the code you need to install piexif in addition to Pillow:

$ sudo pip3 install Pillow && sudo pip3 install piexif

Example call

$ ./rotate.py 90 20160514_131528.jpg

Difficult problem

I set for myself a problem that is much more difficult than anything I’ve tackled. I wanted to post a preliminary solution, but I don’t want to do constant re-writes which are time-consuming. I have a lot of code re-writes to do. I do have a menu system working, and a couple functions implemented to date. But there is so much more to do to even get to an alpha version.

To be continued…

Pie-in-the-sky To-Do list

  • Use of deep learning AI to toss out images which are poor quality
  • Use Facebook API to identify people in the images
  • Commercialization of idea
  • Smarthome enablement, e.g., hey Alexa, pause that picture and tell me about it, etc

Breaking those pie-in-the-sky ideas down, I believe the RPi is way vastly underpowered to do any serious image analysis; Facebook facial recognition is creepy and an invasion of privacy; commercialization sounds great on paper but in reality is a time sink doing unpleasant things for little or no profit in the end; and lastly Smarthome enablement is actually the most achievable and was my original thinking before I landed on the remote control. I may or may not get back to it one day.

References and related

A more basic approach to creating a Raspberry Pi – based photo frame is described here.

The Rii remote control I am using only cost $12! https://www.amazon.com/gp/product/B01CL3ZXGO/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

A great tutorial on the Pillow python package which I use for image processing: https://auth0.com/blog/image-processing-in-python-with-pillow/

The full documentation fills it out even more: https://pillow.readthedocs.io/en/stable/

The official Exif documentation is here: http://www.cipa.jp/std/documents/e/DC-008-2012_E.pdf . For instance, page 42 says UserComments get the Tag ID 37510.

Categories
Linux Raspberry Pi

How to create a software keyboard

Intro

This example will probably get used in my advanced Raspberry Pi photo frame treatment. I use image display software, fbi, which is designed to take key presses in order to take certain actions, such as, advance to the next picture, display information about the current picture, etc. qiv works similarly. But I am running an automated picture display, so no one is around to type into the keyboard. hence the need for software emulation of the physical keyboard. I’ve always believed it must be possible, but never knew how until this week.

I am not a python programmer, but sometimes you gotta use whatever language makes the job easier, and I only know how to do this in python, python3 specifically.

This will probably only make sense for Raspberry Pi owners.

Setup

I believe this will work best if your Raspberry Pi has only a keyboard and not a mouse hooked up because in that case your keyboard ought to be mapped to /dev/input/event0. But it’s easy enough to change that. To see whether your keyboard is /dev/input/event0 or /dev/input/event1 or some other, just cat one of those files and start typing. You should see some junk when you’ve selected the right /dev/input file.

The program

I call it keyinject.py.

                    
#!/usr/bin/python3
# inject a single key, acting like a software keyboard
# DrJ 12/20
import sys
from evdev import UInput, InputDevice, ecodes as e
from time import sleep
# set DEBUG = True to print out more information
DEBUG = False
sleepTime = 0.001 # units are secs
# dict of name mappings. key is how we like to enter it, value is what is after KEY_ in evdev ecodes
d = {
‘1’ : ‘1’,
‘2’ : ‘2’,
‘3’ : ‘3’,
‘4’ : ‘4’,
‘5’ : ‘5’,
‘6’ : ‘6’,
‘7’ : ‘7’,
‘8’ : ‘8’,
‘8’ : ‘8’,
‘9’ : ‘9’,
‘0’ : ‘0’,
‘a’ : ‘A’,
‘b’ : ‘B’,
‘c’ : ‘C’,
‘d’ : ‘D’,
‘e’ : ‘E’,
‘f’ : ‘F’,
‘g’ : ‘G’,
‘h’ : ‘H’,
‘i’ : ‘I’,
‘j’ : ‘J’,
‘k’ : ‘K’,
‘l’ : ‘L’,
‘m’ : ‘M’,
‘n’ : ‘N’,
‘o’ : ‘O’,
‘p’ : ‘P’,
‘q’ : ‘Q’,
‘r’ : ‘R’,
‘s’ : ‘S’,
‘t’ : ‘T’,
‘u’ : ‘U’,
‘v’ : ‘V’,
‘w’ : ‘W’,
‘x’ : ‘X’,
‘y’ : ‘Y’,
‘z’ : ‘Z’,
‘.’ : ‘DOT’,
‘,’ : ‘COMMA’,
‘/’ : ‘SLASH’,
‘E’: ‘ENTER’,
‘S’: ‘RIGHTSHIFT’,
‘C’: ‘LEFTCTRL’
}

# https://python-evdev.readthedocs.io/en/latest/tutorial.html
inputchars = sys.argv
ltrs = inputchars[1]
# get rid of program name

keybd = InputDevice(“/dev/input/event0”)

for ltr in ltrs:
ui = UInput.from_device(keybd, name=”keyboard-device”)
if DEBUG: print(ltr)
mappedkey = d[ltr]
key = “KEY_” + mappedkey
if DEBUG: print(key)
if DEBUG: print(e.ecodes[key])

ui.write(e.EV_KEY, e.ecodes[key], 1) # KEY_ down
ui.write(e.EV_KEY, e.ecodes[key], 0) # KEY_ up
ui.syn()
sleep(sleepTime)
ui.close()

And it gets called like this:

$ sudo ./keyinject.py my.injected.letters

or

$ sudo ./keyinject.py ./m2.plE

to run the m2.pl script in the current directory and have it behave as though it were launched from a console terminal. The “E” is the ENTER key.

Interesting observations

There really is no such thing as a separate “k” key and “K” key (lower-case versus upper-case). There is only a single key labelled “K” on a keyboard. It’s a physical layer versus logical layer type of thing. The k and K are characters.

In the above program I did some of the keys – the ones I will be needing, plus a few bonus ones. I do need the ENTER key, and I can’t think of a way to convey that to this program, so to send ENTER you would do

$ sudo ./keyinject.py ENTER

But I was able to have these characters represent themselves: . , / so that’s not bad.

Prerequisites

You will need pyhon3 version > 3.5, I think. And the evdev package. I believe you get that with

$ sudo pip3 install evdev

And if you don’t have pip3 you can install that with

$ sudo apt-get update python3-pip

Reading keyboard input

Of course the opposite of simulating key presses is reading what’s been typed from an actual keyboard. That’s possible too with this handy evdev package. The following program is not as polished as the writing program, but it gives you the feel for what to do. I call it evread.py.

                    
#!/usr/bin/python3
# https://python-evdev.readthedocs.io/en/latest/tutorial.html
import asyncio
from evdev import InputDevice, categorize, ecodes

dev = InputDevice(‘/dev/input/event0’)
# following line is optional – it takes away the keybd from fbi!
# there is also a dev.ungrab()
dev.grab()

async def helper(dev):
async for ev in dev.async_read_loop():
print(repr(ev))

loop = asyncio.get_event_loop()
loop.run_until_complete(helper(dev))

Note the presence of the dev.grab(). That permits your program to be the exclusive reader of keyboard input, shutting out fbi. It can be commented out if you want to share.

Conclusion

We have created an example program, mostly for Raspberry Pi, though easily adapted to other linux environments, that injects keyboard presses, via a python3 program, as though those keys had been typed by someone using the physical keyboard such that, graphics programs which rely on this, such as fbi or qiv (and probably others – vlc?), can be controlled through software.

We have also provided a basic python program for reading key presses from the actual keyboard. I plan to use these things for my advanced RPi photo frame project.

References and related

The python evdev tutorial is really helpful: https://python-evdev.readthedocs.iogeoh/en/latest/tutorial.html

Raspberry Pi advanced photo frame article does not exist yet. The basic RPi photo frame article is here.

Another piece to the puzzle is turning GPS coordinates into a town name. That brief write-up is here.

Categories
Linux Perl Raspberry Pi Web Site Technologies

Convert GPS Coordinates into town name or address

Intro

This is a small piece of a larger project – displaying your photos on Google Drive using a Raspberry Pi. That project will require completion of many small investigations, this being just one of them.

I thought, wouldn’t it be cool to ask your photo frame when and where a certain picture was taken? I thought that information was typically embedded into the picture by modern smartphones. Turns out this is disappointingly not the case – at least not on our smartphones, except in a small minority of pictures. But since I got somewhere with my investigation, I wanted to share the results, regardless.

Also, I naively assumed that there surely is a web service that permits one to easily convert GPS coordinates into the name – in text – of the closest town. After all, you can enter GPS coordinates into Google Maps and get back a map showing the exact location. Why shouldn’t it be just as easy to extract the nearest town name as text? Again, this assumption turns out to be faulty. But, I found a way to do it that is not toooo difficult.

Example for Cape May, New Jersey

$ curl -s http://api.geonames.org/address?lat=38.9302957777778&lng=-74.9183310833333&username=drjohns

<geonames>
<address>
<street>Beach Dr</street>
<houseNumber>690</houseNumber>
<locality>Cape May</locality>
<postalcode>08204</postalcode>
<lng>-74.91835</lng>
<lat>38.93054</lat>
<adminCode1>NJ</adminCode1>
<adminName1>New Jersey</adminName1>
<adminCode2>009</adminCode2>
<adminName2>Cape May</adminName2>
<adminCode3/>
<adminCode4/>
<countryCode>US</countryCode>
<distance>0.03</distance>
</address>
</geonames>

The above example used the address service. The results in this case are unusually complete. Sometime the lookups simply fail for no obvious reason, or provide incomplete information, such as a missing locality. In those cases the town name is usually still reported in the adminName2 element. I haven’t checked the address accuracy much, but it seems pretty accurate, like, representing an actual address within 100 yards, usually better, of where the picture was taken.

They have another service, findNearbyPlaceName, which sometimes works even when address fails. However its results are also unpredictable. I was in Merrillville, Indiana and it gave the toponym as Chapel Manor, which is the name of the subdivision! In Virginia it gave the name The Hamlet – still not sure where that came from, but I trust it is some hyper-local name for a section of the town (James City). Just as often it does spit back the town or city name, for instance, Atlantic City. So, it’s better than nothing.

The example for Nantucket

From a browser – here I use curl in the linux command line – you enter:

$ curl -s http://api.geonames.org/findNearbyPlaceName?lat=41.282778&lng=-70.099444&username=drjohns

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<geonames>
<geoname>
<toponymName>Nantucket</toponymName>
<name>Nantucket</name>
<lat>41.28346</lat>
<lng>-70.09946</lng>
<geonameId>4944903</geonameId>
<countryCode>US</countryCode>
<countryName>United States</countryName>
<fcl>P</fcl>
<fcode>PPLA2</fcode>
<distance>0.07534</distance>
</geoname>
</geonames>

So what did we do? For this example I looked up Nantucket in Wikipedia to find its GPS coordinates. Then I used the geonames api to convert those coordinates into the town name, Nantucket.

Note that drjohns is an actual registered username with geonames. I am counting on the unpopularity of my posts to prevent an onslaught of usage as the usage credits are limited for free accounts. If I understood the terms, a few lookups per hour would not be an issue.

I’m finding the PlaceName lookup pretty useless, the address lookup fails about 30% of the time, so I’m thinking as a backstop to use this sort of lookup:

$ curl ‘http://api.geonames.org/extendedFindNearby?lat=41.00050&lng=-74.65329&username=drjohn’

<?xml version=”1.0″ encoding=”UTF-8″ standalone=”no”?>
<geonames>
<address>
<street>Stanhope Rd</street>
<mtfcc>S1400</mtfcc>
<streetNumber>439</streetNumber>
<lat>41.00072</lat>
<lng>-74.6554</lng>
<distance>0.18</distance>
<postalcode>07871</postalcode>
<placename>Lake Mohawk</placename>
<adminCode2>037</adminCode2>
<adminName2>Sussex</adminName2>
<adminCode1>NJ</adminCode1>
<adminName1>New Jersey</adminName1>
<countryCode>US</countryCode>
</address>
</geonames>

Note that gets a reasonably close address, and more importantly, a zipcode. The placename is too local and I will probably discard it. But another lookup can turn a zipcode into a town or city name which is what I am after.

$ curl ‘http://api.geonames.org/postalCodeSearch?country=US&postalcode=07871&username=drjohns’

<?xml version=”1.0″ encoding=”UTF-8″ standalone=”no”?>
<geonames>
<totalResultsCount>1</totalResultsCount>
<code>
<postalcode>07871</postalcode>
<name>Sparta</name>
<countryCode>US</countryCode>
<lat>41.0277</lat>
<lng>-74.6407</lng>
<adminCode1 ISO3166-2=”NJ”>NJ</adminCode1>
<adminName1>New Jersey</adminName1>
<adminCode2>037</adminCode2>
<adminName2>Sussex</adminName2>
<adminCode3/>
<adminName3/>
</code>
</geonames>

See? It was a lot of work, but we finally got the township name, Sparta, returned to us.

Ocean GPS?

I was whale-watching and took some pictures with GPS info. Trying to apply the methods above worked, but just barely. Basically all I could get out of the extended find nearby search was a name field with value North Atlantic Ocean! Well, that makes it sounds like I was on some Titanic-style ocean crossing. In fact I was in the Gulf of Maine a few miles from Provincetown. So they really could have done a better job there… Of course it’s understandable to not have a postalcode and street address and such. But still, bodies of waters have names and geographical boundaries as well. Casinos seem to be the main sponsors of geonames.org, and I guess they don’t care. Yesterday my script came up with a location Earth! But now I see geonames proposed several locations and I only look at the first one. I am creating a refinement which will perform better in such cases. Stay tuned… And…yes…the refinement is done. I had to do a wee bit of xml parsing, which I now do.

To get your own account at geonames.org

The process of getting your own account isn’t too difficult, just a bit squirrelly. For the record, here is what you do.

Go to http://www.geonames.org/login to create your account. It sends an email confirmation. Oh. Be sure to use a unique browser-generated password for this one. The security level is off-the-charts awful – just assume that any and all hackers who want that password are going to get it. It sends you a confirmation email. so far so good. But when you then try to use it in an api call it will tell you that that username isn’t known. This is the tricky part.

So go to https://www.geonames.org/manageaccount . It will say:

Free Web Services
the account is not yet enabled to use the free web services. Click here to enable. 

And that link, in turn is https://www.geonames.org/enablefreewebservice . And having enabled your account for the api web service, the URL, where you’ve put your username in place of drjohns, ought to work!

For a complete overview of all the different things you can find out from the GPS coordinates from geonames, look at this link: https://www.geonames.org/export/ws-overview.html

Working with pictures

Please look at this post for the python code to extract the metadata from an image, including, if available GPS info. I called the python program getinfo.py.

Here’s an actual example of running it to learn the GPS info:

$ ../getinfo.py 20170520_102248.jpg|grep -ai gps

GPSInfo = {0: b'\x02\x02\x00\x00', 1: 'N', 2: (42.0, 2.0, 18.6838), 3: 'W', 4: (70.0, 4.0, 27.5448), 5: b'\x00', 6: 0.0, 7: (14.0, 22.0, 25.0), 29: '2017:05:20'}

I don’t know if it’s good or bad, but the GPS coordinates seem to be encoded in the degrees, minutes, seconds format.

A nice little program to put things together

I call it analyzeGPS.pl and a, using it on a Raspberry Pi, but could easily be adapted to any linux system.

                    
#!/usr/bin/perl
# use in combination with this post https://drjohnstechtalk.com/blog/2020/12/convert-gps-coordinates-into-town-name/
use POSIX;
$DEBUG = 1;
$HOME = "/home/pi";
#$file = "Pictures/20180422_134220.jpg";
while(<>){
$GPS = $date = 0;
$gpsinfo = "";
$file = $_;
open(ANAL,"$HOME/getinfo.py \"$file\"|") || die "Cannot open file: $file!!\n";
#open(ANAL,"cat \"$file\"|") || die "Cannot open file: $file!!\n";
print STDERR "filename: $file\n" if $DEBUG;
while(<ANAL>){
  $postalcode = $town = $name = "";
  if (/GPS/i) {
    print STDERR "GPS: $_" if $DEBUG;
# GPSInfo = {1: 'N', 2: (39.0, 21.0, 22.5226), 3: 'W', 4: (74.0, 25.0, 40.0267), 5: 1.7, 6: 0.0, 7: (23.0, 4.0, 14.0), 29: '2016:07:22'}
   ($pole,$deg,$min,$sec,$hemi,$lngdeg,$lngmin,$lngsec) = /1: '([NS])', 2: \(([\d\.]+), ([\d\.]+), ([\d\.]+)...3: '([EW])', 4: \(([\d\.]+), ([\d\.]+), ([\d\.]+)\)/i;
   print STDERR "$pole,$deg,$min,$sec,$hemi,$lngdeg,$lngmin,$lngsec\n" if $DEBUG;
   $lat = $deg + $min/60.0 + $sec/3600.0;
   $lat = -$lat if $pole eq "S";
   $lng = $lngdeg + $lngmin/60.0 + $lngsec/3600.0;
   $lng = -$lng if $hemi = "W" || $hemi eq "w";
   print STDERR "lat,lng: $lat, $lng\n" if $DEBUG;
   #$placename = `curl -s "$url"|grep -i toponym`;
   next if $lat == 0 && $lng == 0;
# the address API is the most precise
   $url = "http://api.geonames.org/address?lat=$lat\&lng=$lng\&username=drjohns";
   print STDERR "Url: $url\n" if $DEBUG;
   $results = `curl -s "$url"|egrep -i 'street|house|locality|postal|adminName'`;
   print STDERR "results: $results\n" if $DEBUG;
   ($street) = $results =~ /street>(.+)</;
   ($houseNumber) = $results =~ /houseNumber>(.+)</;
   ($postalcode) = $results =~ /postalcode>(.+)</;
   ($state) = $results =~ /adminName1>(.+)</;
   ($town) = $results =~ /locality>(.+)</;
   print STDERR "street, houseNumber, postalcode, state, town: $street, $houseNumber, $postalcode, $state, $town\n" if $DEBUG;
# I think locality is pretty good name. If it exists, don't go  further
   $postalcode = "" if $town;
   if (!$postalcode && !$town){
# we are here if we didn't get interesting results from address reverse loookup, which often happens.
     $url = "http://api.geonames.org/extendedFindNearby?lat=$lat\&lng=$lng\&username=drjohns";
     print STDERR "Address didn't work out. Trying extendedFindNearby instead. Url: $url\n" if $DEBUG;
     $results = `curl -s "$url"`;
# parse results - there may be several objects returned
     $topelemnt = $results =~ /<geoname>/i ? "geoname" : "geonames";
     @elmnts = ("street","streetnumber","lat","lng","locality","postalcode","countrycode","countryname","name","adminName2","adminName1");
     $cnt = xml1levelparse($results,$topelemnt,@elmnts);

     @lati = @{ $xmlhash{lat}};
     @long = @{ $xmlhash{lng}};
# find the closest entry
     $distmax = 1E7;
     for($i=0;$i<$cnt;$i++){
       $dist = ($lat - $lati[$i])**2 + ($lng - $long[$i])**2;
       print STDERR "dist,lati,long: $dist, $lati[$i], $long[$i]\n" if $DEBUG;
       if ($dist < $distmax) {
         print STDERR "dist < distmax condition. i is: $i\n";
         $isave = $i;
       }
     }
     $street = @{ $xmlhash{street}}[$isave];
     $houseNumber = @{ $xmlhash{streetnumber}}[$isave];
     $admn2 = @{ $xmlhash{adminName2}}[$isave];
     $postalcode = @{ $xmlhash{postalcode}}[$isave];
     $name = @{ $xmlhash{name}}[$isave];
     $countrycode = @{ $xmlhash{countrycode}}[$isave];
     $countryname = @{ $xmlhash{countryname}}[$isave];
     $state = @{ $xmlhash{adminName1}}[$isave];
     print STDERR "street, houseNumber, postalcode, state, admn2, name: $street, $houseNumber, $postalcode, $state, $admn2, $name\n" if $DEBUG;
     if ($countrycode ne "US"){
       $state .= " $countryname";
     }
     $state .= " (approximate)";
   }
# turn zipcode into town name with this call
   if ($postalcode) {
     print STDERR "postalcode $postalcode exists, let's convert to a town name\n";
     print STDERR "url: $url\n";
     $url = "http://api.geonames.org/postalCodeSearch?country=US\&postalcode=$postalcode\&username=drjohns";
     $results = `curl -s "$url"|egrep -i 'name|locality|adminName'`;
     ($town) = $results =~ /<name>(.+)</i;
     print STDERR "results,town: $results,$town\n";
   }
   if (!$town) {
# no town name, use adminname2 which is who knows what in general
     print STDERR "Stil no town name. Use adminName2 as next best thing\n";
     $town = $admn2;
   }
   if (!$town) {
# we could be in the ocean! I saw that once, and name was North Atlantic Ocean
     print STDERR "Still no town. Try to use name: $name as last resort\n";
     $town = $name;
   }
   $gpsinfo = "$houseNumber $street $town, $state" if $locality || $town;
   } # end of GPS info exists condition
  } # end loop over ANAL file
  $gpsinfo = $gpsinfo || "No info found";
  print qq(Location: $gpsinfo
);
} # end loop over STDIN

#####################
# function to parse some xml and fill a hash of arrays
sub xml1levelparse{
# build an array of hashes
$string = shift;
# strip out newline chars
$string =~ s/\n//g;
$parentelement = shift;
@elements = @_;
$i=0;
while($string =~ /<$parentelement>/i){
 $i++;
 ($childelements) = $string =~ /<$parentelement>(.+?)<\/$parentelement>/i;
 print STDERR "childelements: $childelements" if $DEBUG;
 $string =~ s/<$parentelement>(.+?)<\/$parentelement>//i;
 print STDERR "string: $string\n" if $DEBUG;
 foreach $element (@elements){
  print STDERR "element: $element\n" if $DEBUG;
  ($value) = $childelements =~ /<$element>([^<]+)<\/$element>/i;
  print STDERR "value: $value\n" if $DEBUG;
  push @{ $xmlhash{$element} }, $value;
 }
} # end of loop over parent elements
return $i;
} # end sub xml1levelparse

Here’s a real example of calling it, one of the more difficult cases:

$ echo -n 20180127_212203.jpg|./analyzeGPS.pl

GPS: GPSInfo = {0: b'\x02\x02\x00\x00', 1: 'N', 2: (41.0, 0.0, 2.75), 3: 'W', 4: (74.0, 39.0, 12.0934), 5: b'\x00', 6: 0.0, 7: (2.0, 21.0, 58.0), 29: '2018:01:28'}
N,41.0,0.0,2.75,W,74.0,39.0,12.0934
lat,lng: 41.0007638888889, -74.6533592777778
Url: http://api.geonames.org/address?lat=41.0007638888889&lng=-74.6533592777778&username=drjohns
results:
street, houseNumber, postalcode, state, town: , , , ,
Address didn't work out. Trying extendedFindNearby instead. Url: http://api.geonames.org/extendedFindNearby?lat=41.0007638888889&lng=-74.6533592777778&username=drjohns
childelements: <address> <street>Stanhope Rd</street> <mtfcc>S1400</mtfcc> <streetNumber>433</streetNumber> <lat>41.00121</lat> <lng>-74.65528</lng> <distance>0.17</distance> <postalcode>07871</postalcode> <placename>Lake Mohawk</placename> <adminCode2>037</adminCode2> <adminName2>Sussex</adminName2> <adminCode1>NJ</adminCode1> <adminName1>New Jersey</adminName1> <countryCode>US</countryCode> </address>string: <?xml version="1.0" encoding="UTF-8" standalone="no"?>
element: street
value: Stanhope Rd
element: streetnumber
value: 433
element: lat
value: 41.00121
element: lng
value: -74.65528
element: locality
value:
element: postalcode
value: 07871
element: countrycode
value: US
element: countryname
value:
element: name
value:
element: adminName2
value: Sussex
element: adminName1
value: New Jersey
dist,lati,long: 3.88818897839883e-06, 41.00121, -74.65528
dist < distmax condition. i is: 0
street, houseNumber, postalcode, state, admn2, name: Stanhope Rd, 433, 07871, New Jersey, Sussex,
postalcode 07871 exists, let's convert to a town name
url: http://api.geonames.org/extendedFindNearby?lat=41.0007638888889&lng=-74.6533592777778&username=drjohns
results,town: <geonames>
<name>Sparta</name>
<adminName1>New Jersey</adminName1>
<adminName2>Sussex</adminName2>
<adminName3/>
</geonames>
,Sparta
Location: 433 Stanhope Rd Sparta, New Jersey (approximate)

Or, if you just want the interesting stuff,

$ echo -n 20180127_212203.jpg|./analyzeGPS.pl 2>/dev/null

Location: 433 Stanhope Rd Sparta, New Jersey (approximate)

Conclusion

An api for reverse lookup of GPS coordinates which returns the nearest address, including town name, is available. I have provided examples of how to use it. It is unreliable, however, and Geonames.org does provide alternatives which have their own drawbacks. In my image gallery, only a minority of my pictures have encoded GPS data, but it is fun to work with them to pluck out the town where they were shot.

I have incorporated this functionality into a Raspberry Pi-based photo frame I am working on.

I have created an example Perl program that analyzes a JPEG image to extract the GPS information and turn it into an address that is remarkably accurate. It is amazing and uncanny to see it at work. It deals with the screwy and inconsistent results returned by the free service, Geonames.org.

References and related

There are lots of different things you can derive given the GPS coordinates using the Geonames api. Here is a list: https://www.geonames.org/export/ws-overview.html

In this photo frame version of mine, I extract all the EXIF metadata which includes the GPS info.

One day my advanced photo frame will hopefully include an option to learn where a photo was taken by interacting with a remote control. Here is the start of that write-up.

You can pay $5 and get a zip codes to cities database in any format. I’m sure they’ve just re-packaged data from elsewhere, but it might be worth it: https://www.uszipcodeslist.com/

For a more professional api, https://smartystreets.com/ looks quite nice. Free level is 250 queries per month, so not too many. But their documentation and usability looks good to me. For this post I was looking for free services and have tried to avoid commercial services.

Categories
Perl Python Raspberry Pi Web Site Technologies

Raspberry Pi photo frame using your pictures on your Google Drive

Editor’s Note

Please note I am putting all my currently active development and latest updates into this newer post: Raspberry Pi photo frame using your pictures on your Google Drive II

Intro

All my spouse’s digital photo frames are either broken or nearly broken – probably she got them from garage sales. Regardless, they spend 99% of the the time black. Now, since I had bought that Raspberry Pi PiDisplay awhile back, and it is underutilized, and I know a thing or two about linux, I felt I could create a custom photo frame with things I already have lying around – a Raspberry Pi 3, a PiDisplay, and my personal Google Drive. We make a point to copy all our cameras’ pictures onto the Google Drive, which we do the old-fashioned, by-hand way. After 17 years of digital photos we have about 40,000 of them, over 200 GB.

So I also felt obliged to create features you will never have in a commercial product, to make the effort worthwhile. I thought, what about randomly picking a few for display from amongst all the pictures, displaying that subset for a few days, and then moving on to a new randomly selected sample of images, etc? That should produce a nice review of all of them over time, eventually. You need an approach like that because you will never get to the end if you just try to display 40000 images in order!

Equipment

This work was done on a Raspberry Pi 3 running Raspbian Lite (more on that later). I used a display custom-built for the RPi, Amazon.com: Raspberry Pi 7″ Touch Screen Display: Electronics), though I believe any HDMI display would do.

The scripts
Here is the master file which I call master.sh.

                    
#!/bin/sh
# DrJ 8/2019
# call this from cron once a day to refesh random slideshow once a day
RANFILE=”random.list”
NUMFOLDERS=20
DISPLAYFOLDER=”/home/pi/Pictures”
DISPLAYFOLDERTMP=”/home/pi/Picturestmp”
SLEEPINTERVAL=3
DEBUG=1
STARTFOLDER=”MaryDocs/Pictures and videos”

echo “Starting master process at “`date`

rm -rf $DISPLAYFOLDERTMP
mkdir $DISPLAYFOLDERTMP

#listing of all Google drive files starting from the picture root
if [ $DEBUG -eq 1 ]; then echo Listing all files from Google drive; fi
rclone ls remote:”$STARTFOLDER” > files

# filter down to only jpegs, lose the docs folders
if [ $DEBUG -eq 1 ]; then echo Picking out the JPEGs; fi
egrep ‘\.[jJ][pP][eE]?[gG]$’ files |awk ‘$1 > 11000 {$1=””; print substr($0,2)}’|grep -i -v /docs/ > jpegs.list

# throw NUMFOLDERS or so random numbers for picture selection, select triplets of photos by putting
# names into a file
if [ $DEBUG -eq 1 ]; then echo Generate random filename triplets; fi
./random-files.pl -f $NUMFOLDERS -j jpegs.list -r $RANFILE

# copy over these 60 jpegs
if [ $DEBUG -eq 1 ]; then echo Copy over these random files; fi
cat $RANFILE|while read line; do
rclone copy remote:”${STARTFOLDER}/$line” $DISPLAYFOLDERTMP
sleep $SLEEPINTERVAL
done

# rotate pics as needed
if [ $DEBUG -eq 1 ]; then echo Rotate the pics which need it; fi
cd $DISPLAYFOLDERTMP; ~/rotate-as-needed.sh
cd ~

# kill any qiv slideshow
if [ $DEBUG -eq 1 ]; then echo Killing old qiv and fbi slideshow; fi
pkill -9 -f qiv
sudo pkill -9 -f fbi
pkill -9 -f m2.pl

# remove old pics
if [ $DEBUG -eq 1 ]; then echo Removing old pictures; fi
rm -rf $DISPLAYFOLDER

mv $DISPLAYFOLDERTMP $DISPLAYFOLDER

#run looping fbi slideshow on these pictures
if [ $DEBUG -eq 1 ]; then echo Start fbi slideshow in background; fi
cd $DISPLAYFOLDER ; nohup ~/m2.pl >> ~/m2.log 2>&1 &

if [ $DEBUG -eq 1 ]; then echo “And now it is “`date`; fi

I call the following script random-files.pl:

                    

#!/usr/bin/perl
use Getopt::Std;
my %opt=();
getopts("c:df:j:r:",\%opt);
$nofolders = $opt{f} ? $opt{f} : 20;
$DEBUG = $opt{d} ? 1 : 0;
$cutoff = $opt{c} ? $opt{c} : 5;
$cutoffS = 60*$cutoff;
$jpegs = $opt{j} ? $opt{j} : "jpegs.list";
$ranpicfile = $opt{r} ? $opt{r} : "jpegs-random.list";
print "d,f,j,r: $opt{d}, $opt{f}, $opt{j}, $opt{r}\n" if $DEBUG;
open(JPEGS,$jpegs) || die "Cannot open jpegs listing file $jpegs!!\n";
@jpegs = ;
# remove newline character
$nopics = chomp @jpegs;
open(RAN,"> $ranpicfile") || die "Cannot open random picture file $ranpicfile!!\n";
for($i=0;$i<$nofolders;$i++) {
  $t = int(rand($nopics-2));
  print "random number is: $t\n" if $DEBUG;
# a lot of our pics follow this naming convention
# 20160831_090658.jpg
  ($date,$time) = $jpegs[$t] =~ /(\d{8})_(\d{6})/;
  if ($date) {
    print "date, time: $date $time\n" if $DEBUG;
# ensure neighboring picture is at least five minutes different in time
    $iPO = $iP = $diff = 0;
    ($hr,$min,$sec) = $time =~ /(\d\d)(\d\d)(\d\d)/;
    $secs = 3600*$hr + 60*$min + $sec;
    print "Pre-pic logic\n";
    while ($diff < $cutoffS) {
      $iP++;
      $priorPic = $jpegs[$t-$iP];
      $Pdate = $Ptime = 0;
      ($Pdate,$Ptime) = $priorPic =~ /(\d{8})_(\d{6})/;
      ($Phr,$Pmin,$Psec) = $Ptime =~ /(\d\d)(\d\d)(\d\d)/;
      $Psecs = 3600*$Phr + 60*$Pmin + $Psec;
      print "hr,min,sec,Phr,Pmin,Psec: $hr,$min,$sec,$Phr,$Pmin,$Psec\n" if $DEBUG;
      $diff = abs($secs - $Psecs);
      print "diff: $diff\n" if $DEBUG;
# end our search if we happened upon different dates
      $diff = 99999 if $Pdate ne $date;
    }
# post-picture logic - same as pre-picture
    print "Post-pic logic\n";
    $diff = 0;
    while ($diff < $cutoffS) {
      $iPO++;
      $postPic = $jpegs[$t+$iPO];
      $Pdate = $Ptime = 0;
      ($Pdate,$Ptime) = $postPic =~ /(\d{8})_(\d{6})/;
      ($Phr,$Pmin,$Psec) = $Ptime =~ /(\d\d)(\d\d)(\d\d)/;
      $Psecs = 3600*$Phr + 60*$Pmin + $Psec;
      print "hr,min,sec,Phr,Pmin,Psec: $hr,$min,$sec,$Phr,$Pmin,$Psec\n" if $DEBUG;
      $diff = abs($Psecs - $secs);
      print "diff: $diff\n" if $DEBUG;
# end our search if we happened upon different dates
      $diff = 99999 if $Pdate ne $date;
    }
  } else {
    $iP = $iPO = 2;
  }
  $priorPic = $jpegs[$t-$iP];
  $Pic = $jpegs[$t];
  $postPic = $jpegs[$t+$iPO];
  print RAN qq($priorPic
$Pic
$postPic
);
}
close(RAN);

Bunch of simple python scripts

I call this one getinfo.py:

                    
#!/usr/bin/python3
import os,sys
from PIL import Image
from PIL.ExifTags import TAGS

for (tag,value) in Image.open(sys.argv[1])._getexif().items():
print (‘%s = %s’ % (TAGS.get(tag), value))

print (‘%s = %s’ % (TAGS.get(tag), value))

And here’s rotate.py:

                    
#!/usr/bin/python3
import PIL, os
import sys
from PIL import Image

picture= Image.open(sys.argv[1])

# if orientation is 6, rotate clockwise 90 degrees
picture.rotate(-90,expand=True).save(“rot_” + sys.argv[1])

While here is rotatecc.py:

                    
#!/usr/bin/python3
import PIL, os
import sys
from PIL import Image

picture= Image.open(sys.argv[1])

# if orientation is 8, rotate counterclockwise 90 degrees
picture.rotate(90,expand=True).save(“rot_” + sys.argv[1])

And rotate-as-needed.sh:

                    
#!/bin/sh
# DrJ 12/2020
# some of our downloaded files will be sideways, and fbi doesn’t auto-rotate them as far as I know
# assumption is that are current directory is the one where we want to alter files
ls -1|while read line; do
echo fileis “$line”
o=`~/getinfo.py “$line”|grep -ai orientation|awk ‘{print $NF}’`
echo orientation is $o
if [ “$o” -eq “6” ]; then
echo “90 clockwise is needed, o is $o”
# rotate and move it
~/rotate.py “$line”
mv rot_”$line” “$line”
elif [ “$o” -eq “8” ]; then
echo “90 counterclock is needed, o is $o”
# rotate and move it
~/rotatecc.py “$line”
mv rot_”$line” “$line”
fi
don

And finally, m2.pl:

                    

#!/usr/bin/perl
# show the pics ; rotate the screen as needed
# for now, assume the display is in a neutral
# orientation at the start
use Time::HiRes qw(usleep);
$DEBUG = 1;
$delay = 6; # seconds between pics
$mdelay = 200; # milliseconds
$mshow = "$ENV{HOME}/mediashow";
$pNames = "$ENV{HOME}/pNames";
# pics are here
$picsDir = "$ENV{HOME}/Pictures";

chdir($picsDir);
system("ls -1 > $pNames");
# forther massage names
open(TMP,"$pNames");
@lines = ;
foreach (@lines) {
  chomp;
  $filesNullSeparated .= $_ . "\0";
}
open(MS,">$mshow") || die "Cannot open mediashow file $mshow!!\n";
print MS $filesNullSeparated;
close(MS);
print "filesNullSeparated: $filesNullSeparated\n" if $DEBUG;
$cn = @lines;
print "$cn files\n" if $DEBUG;
# throw up a first picture - all black. Trick to make black bckgrd permanent
system("sudo fbi -a --noverbose -T 1 $ENV{HOME}/black.jpg");
system("sudo fbi -a --noverbose -T 1 $ENV{HOME}/black.jpg");
sleep(1);
system("sleep 2; sudo killall fbi");
# start infinitely looping fbi slideshow
for (;;) {
# then start slide show
# shell echo cannot work with null character so we need to use a file to store it
    #system("cat $picNames|xargs -0 qiv -DfRsmi -d $delay \&");
    system("sudo xargs -a $mshow -0 fbi -a --noverbose -1 -T 1  -t $delay ");
# fbi runs in background, then exits, so we need to monitor if it's still alive
# wait appropriate estimated amount of time, then look aggressively for fbi
    sleep($delay*($cn - 2));
    for(;;) {
      open(MON,"ps -ef|grep fbi|grep -v grep|") || die "Cannot launch ps -ef!!\n";
      $match = ;
      if ($match) {
        print "got fbi match\n" if $DEBUG > 1;
        } else {
        print "no fbi match\n" if $DEBUG;
# fbi not found
          last;
      }
      close(MON);
      print "usleeping, noexist is $noexit\n" if $DEBUG > 1;
      usleep($mdelay);
    } # end loop testing if fbi has exited
} # close of infinite loop

You’ll need to make these files executable. Something like this should work:

$ chmod +x *.py *.pl *.sh

My crontab file looks like this (you edit crontab using the crontab -e command):

@reboot sleep 25; cd ~ ; ./m2.pl >> ./m2.log 2>&1
24 16 * * * ./master.sh >> ./master.log 2>&1

This invokes master.sh once a day at 4:24 PM to refresh the 60 photos. My refresh took about 13 minutes the other day, but the old slideshow keeps playing until almost the last second, so it’s OK.

The nice thing about this approach is that fbi works with a lightweight OS – Raspbian Lite is fine, you’ll just need to install a few packages. My SD card is unstable or something, so I have to re-install the OS periodically. An install of Raspberry Pi Lite on my RPi 4 took 11 minutes. Anyway, fbi is installed via:

$ sudo apt-get install fbi

But if your RPi is freshly installed, you may first need to do a

$ sudo apt-get update && sudo apt-get upgrade

python image manipulation

The drawback of this approach, i.e., not using qiv, is that we gotta do some image manipulation, for which python is the best candidate. I’m going by memory. I believe I installed python3, perhaps as sudo apt-get install python3. Then I needed pip3: sudo apt-get install python3-pip. Then I needed to install Pillow using pip3: sudo pip3 install Pillow.

m2.pl refers to a black.jpg file. It’s not a disaster to not have that, but under some circumstances it may help. There it is!

Many of my photos do not have EXIF information, yet they can still be displayed. So for those photos running getinfo.py will produce an error (but the processing of the other photos will continue.)

I was originally rotating the display 90 degrees as needed to display the photos with the using the maximum amount of display real estate. But that all broke when I tried to revive it. And the cheap servo motor was noisy. But folks were pretty impressed when I demoed it, because I did it get it the point where it was indeed working correctly.

Picture selection methodology

There are 20 “folders” (random numbers) of three triplets each. The idea is to give you additional context to help jog your memory. The triplets, with some luck, will often be from the same time period.

I observed how many similar pictures are adjacent to each other amongst our total collection. To avoid identical pictures, I require the pictures to be five minutes apart in time. Well, I cheated. I don’t pull out the timestamp from the EXIF data as I should (at least not yet – future enhancement, perhaps). But I rely on a file-naming convention I notice is common – 20201227_134508.jpg, which basically is a timestamp-encoded name. The last six digits are HHMMSS in case it isn’t clear.

Rclone

You must install the rclone package, sudo apt-get install rclone.

Can you configure rclone on a headless Raspberry Pi?

Indeed you can. I know because I just did it. You enable your Pi for ssh access. do the rclone-config (or whatever it’s called) using putty from a Windows 10 system. You’ll get a long Google URL in the course of configuring that you can paste into your browser. You verify it’s you, log into your Google account. Then you get back a url like http://127.0.0.1:5462/another-long-url-string. Well, put that url into your clipboard and in another login window, enter curl clipboard_contents

That’s what I did, not certain it would work, but I saw it go through in my rclone-config window, and that was that!

Don’t want to deal with rclone?

So you want to use a traditional flash drive you plug in to a USB port, just like you have for the commerical photo frames, but you otherwise like my approach of randomizing the picture selection each day? I’m sure that is possible. A mid-level linux person could rip out the rclone stuff I have embedded and replace as needed with filesystem commands. I’m imagining a colossal flash drive with all your tens of thousands of pictures on it where my random selection still adds value. If this post becomes popular enough perhapsI will post exactly how to do it.

Getting started with this

After you’ve done all that, and want to try it out. you can run

$ ./master.sh

First you should see a file called files growing in size – that’s rclone doing its listing. That takes a few minutes. Then it generates random numbers for photo selection – that’s very fast, maybe a second. Then it slowly copies over the selected images to a temporary folder called Picturestmp. That’s the slowest part. If you do a directory listing you should see the number of images in that directory growing slowly, adding maybe three per minute until it reaches 60 of them. Finally the rotation are applied. But even if you didn’t set up your python environment correctly, it doesn’t crash. It effectively skips the rotations. A rotation takes a couple seconds per image. Finally all the images are copied over to the production area, the directory called Pictures; the old slideshow program is “killed,” and the new slideshow starts up. Whole process takes around 15 minutes.

I highly recommend running master.sh by hand as just described to make sure it all works. Probably some of it won’t. I don’t specialize in making recipes, more just guidance. But if you’re feeling really bold you can just power it up and wait a day (because initially you won’t have any pictures in your slideshow) and pray that it all works.

Still missing

I’d like to display a transition image when switching from the current set of photos to the new ones.

Suppressing boot up messages might be nice for some. Personally I think they’re kind of cool – makes it look like you’ve done a lot more techie work than you actually have!

You’re going to get some junk images. I’ve seen where an image is a thumbnail (I guess) and gets blown up full screen so that you see these giant blocks of pixels. I could perhaps magnify those kind of images less.

Movies are going to be tricky so let’s not even go there…

I was thinking about making it a navigation-enabled photo frame, such as integration with a Gameboy controller. You could do some really awesome stuff: Pause this picture; display the location (town or city) where this photo was taken; refresh the slideshow. It sounds fantastical, but I don’t think it’s beyond the capability of even modestly capable hobbyist programmers such as myself.

I may still spin the frame 90 degrees this way an that. I have the servo mounted and ready. Just got to revive the control commands for it.

References and related

This 7″ display is a little small, but it’s great to get you started. It’s $64 at Amazon: Amazon.com: Raspberry Pi 7″ Touch Screen Display: Electronics

I have an older approach using qiv which I lost the files for, and my blog post got corrupted. Hence this new approach.

In this slightly more sophisticated approach, I make a greater effort to separate the photos in time. But I also make a whole bunch of other improvements as well. But it’s a lot more files so it may only be appropriate for a more seasoned RPi command-line user.

My advanced slideshow treatment is beginning to take shape. I just add to it while I develop it, so check it periodically if that is of interest. Raspberry Pi advanced photo frame.

Categories
Consumer Interest Consumer Tech Network Technologies Raspberry Pi

Consumer Tech: Home Internet stopped working

Intro

We woke up yesterday to no Internet. The usual remedies consumers go through did nothing to resolve the issue. What to do?

The details – November 25, 2020

The usual restarts or my router and the cable modem did not work. I plugged in my work laptop directly to the cable modem for some quick tests but that did not work.

I plugged my work-issued VPN router directly to the cable modem and it did not pick up an IP and re-establish the tunnel.

When I logged into my router I saw that its WAN IP was listed as 0.0.0.0, which means none at all.

I called the ISP twice. Both time they said they could “see” my modem, and they tried to restart it on their end, but that did not seem to do anything at all, based on the constant status LEDs (see picture below). I got my service visit moved up from Dec 11th to Dec 2nd, but still that would mean a week without Internet – not so great when three people are relying on it for their work.

I rebooted the cable modem a couple times at least. Nothing changed.

Then I started some research on quickie alternatives. Ask a friend from work for a spare Cradlepoint air card? They’re already out on vacation. Get a Chinese-made unlocked hotspot with pre-purchased data? Seems fishy, and ultimately expensive. Verizon brand hotspot? We had a borrowed one. Very finicky. And no ethernet ports.

Raspberry Pi + DIY approach?

At one point in the evening, convinced I would have to wait days for for a visit from the cable guy, I rigged up a spare Raspberry Pi to act as a router between a mobile hotspot (a companion tablet to a Verizon phone) and my Linksys router. Why bother? Why not just use the hotspot directly? Mostly because it’s a pain in the rear to reprogram all those Internet of Things devices one has in ones home these days, notably the several Echo Dots, but as well, a wireless printer, a few laptops, Firesticks, tablets, etc. With this approach I keep the WiFi SSID as it was for all those devices. And, it sort of worked! At least I got one Echo Dot to work. I didn’t push my luck. This stuff consumes a lot of data, even when “idle.”

To be continued…

Linksys WRT1200AC status lights – when healthy!
Cable Modem tatus lights – when operating normally

But I am pretty good at troubleshooting. What I know that less experienced people may not is that all the testing I’ve done to that point was not ironclad proof of failure of the cable modem. I know the traditional advice of old is to hook up a laptop directly to the ethernet port and work with it that way. Furthermore the cable company support said that my status lights were reading normally. So, when I tested my work laptop? Are you kidding? That thing has so many problems when I switch between SSIDs due to some new security software – it loves to display the Globe in the system tray, and the only recourse is to reboot. That’s what I was seeing, but notice I said a quickie test? I did not have time to do that reboot and all that. And that work-issued VPN router? I don’t know how that thing really works either. Never having set it up that way I did not trust reading too much into its results (which was essentially an orange status light instead of the usual white).

So when I had more time in the evening, I hooked up a home laptop which I know should work. After a cable modem reboot in fact I did get an IP and could surf the Internet. That was a glimmer of hope. So I put my router back in place. Still it did not pick up an WAN IP address. Still reading 0.0.0.0 for its IP.

Then I put the laptop back, writing down the IP, subnet mask and default gateway. Then I put my router back, switched its WAN mode from DHCP to fixed IP, putting on the exact IP address the laptop had picked up, with correct subnet mask and default gateway. Still it was not working. When the router is not working the WAN status light is sort of orange-ish. It’s white (pictured above) when the WAN link is communicating.

I decided the fault should lie more with my router than anywhere else, and since it wasn’t working and no number of power cycles was changing that situation, I decided that a factory reset is the thing to try. The last thing I could try. I noted the exact name and passwords of my SSIDs, held the reset button for 15 seconds until the status lights flicked out, and let it start up. It went through a start-up process, which i saw after connecting to its default IP of 192.168.1.1. It was clear it was not seeing the cable modem at the point where it should, but it had some very specific advice to try: power off cable modem, wait two minutes, power it back on, and then it would try again. And that did work! Yeah!

What may have precipitated this

My local cable company was recently bought by a much bigger company. I know for a fact what my WAN IP used to be, and I see it has changed. They now draw from a giant pool of IPs – a /14 in CIDR notation – that’s 262,000 addresses – that belongs to the new owner. So I believe the problem occurred due to a poor implementation of the dhcp protocol within my router, or a poor interplay between my router’s DHCP client and the ISP’s DHCP server. But I can’t research that line of troubleshooting because the ISP’s DHCP policies would require a lot of time-consuming experimentation on my part to reverse engineer based on observed behaviour under different conditions. And I would need an open source DHCP client – but I have the Raspberry Pi running dnsmasq for that, so that end could gather all the needed client information.

Prior to this acquisition I would tend to keep the same WAN IP for years – that’s how stable it was.

Another approach

Very germane to this topic is the fact that my neighbor down the street experienced his own Internet outage the day after I did! His solution was to buy a better cable modem. I did not know you could do that – I thought they were proprietary. He also saw his router with the 0.0.0.0 WAN address. And his approach also worked. This makes me less sure my router was really at fault – maybe Altice screwed up their DHCP service for half a day.

Conclusion

Unusual for me, I’m going to write the conclusion before writing the tedious part which is the full explanation in the middle.

By the end of the day I got the Internet working. After isolating the problem to my home router, the Linksys WRT1200AC, and determining that any amount of power cycling was not clearing things up, a factory reset did the trick! The cable modem and my cable Internet service was fine all along.

References and related

How to turn your Raspberry Pi into a router which shares your hotspot with your home router.

The Linksys WRT1200AC is no longer sold. It looks like the newer version is the WRT1900AC – it even looks identical. It’s a good router. I know there are fancier solutions out there, but there are also worse ones as well, so I can only give my qualified endorsement: https://www.amazon.com/Linksys-AC1900-Source-Wireless-WRT1900AC/dp/B014MIBLSA/ref=sr_1_1?dchild=1&keywords=linksys+wrt1200ac&qid=1606519765&sr=8-1

DHCP and CIDR notation are both described in great detail in their respective Wikipedia articles.