#!/usr/bin/perl

# "linux" video encoder for the D-Link DCS-900 series ip cameras.
# (c) Copyright 2004 Seth Alan Woolley, released under GPL v2 or above.
# reverse-engineered with packet analysis from the windows drivers.

# example fcrontab file:
# &exesev(true) 0 * * * * perl /home/camera/captureimage.pl 01 3600 10.10.1.121
# &exesev(true) 0 * * * * perl /home/camera/captureimage.pl 02 3600 10.10.1.122
# &exesev(true) 0 0 * * * bash /home/camera/purgeold.sh '01 02' 14
# purges videos after 14 days.

# example purgeold.sh:
# #!/bin/bash
# 
# LIST="$1"
# DAYS="$2"
# 
# cd /home/camera/video/
# for i in $LIST; do
#   for j in $(
#                ls video-$i-*.avi |
#                  sed -e 's/-[0-9.]\+\.avi$//' -e 's/^video-//' |
#                  sort |
#                  head -n -$((24*$DAYS))
#            ); do
#     rm video-$j-*.avi video-$j-*.sub ../logs/capture-$j.log
#   done
# done


use Socket;
use Time::HiRes qw ' time sleep ';

$cameraid    = $ARGV[0]  eq ''?"01"                 :$ARGV[0] ;
$runseconds  = $ARGV[1]  eq ''?3600                 :$ARGV[1] ;
$cameraaddr  = $ARGV[2]  eq ''?"10.10.1.121"        :$ARGV[2] ;
$cameraport  = $ARGV[3]  eq ''?80                   :$ARGV[3] ;
$height      = $ARGV[4]  eq ''?640                  :$ARGV[4] ;
$width       = $ARGV[5]  eq ''?480                  :$ARGV[5] ;
$minkbits    = $ARGV[6]  eq ''?000                  :$ARGV[6] ;
$maxkbits    = $ARGV[7]  eq ''?300                  :$ARGV[7] ;
$minquant    = $ARGV[8]  eq ''?3                    :$ARGV[8] ;
$maxquant    = $ARGV[9]  eq ''?16                   :$ARGV[9] ;
$softdropfps = $ARGV[10] eq ''?4                    :$ARGV[10];  # delay network reads to be at most this fps
$harddropfps = $ARGV[11] eq ''?30                   :$ARGV[11];  # drop already read frames to be at most this fps
$softdropnow = $ARGV[12] eq ''?30                   :$ARGV[12];  # point-based drops, the aboves are averages
$harddropnow = $ARGV[13] eq ''?30                   :$ARGV[13];  # ditto
$imagestore  = $ARGV[14] eq ''?"/home/camera/image/":$ARGV[14];
$moviestore  = $ARGV[15] eq ''?"/home/camera/video/":$ARGV[15];
$logstore    = $ARGV[16] eq ''?"/home/camera/logs/" :$ARGV[16];
$password    = $ARGV[17] eq ''?""                   :$ARGV[17];  # in basic auth format

$timeout = 15; # seconds to wait before we assume catastrophe, flush connections, and retry
$f       = 1 ; # start frame number
$sub     = ''; # mpsub file contents;

$time = time();                   # when we begin this capture (now)
$timestop = $time + $runseconds;  # when we end this capture (later)

($sec,$min,$hour,$mday,$mon,$year,$wday,$yday) = gmtime($time); $_=$wday.$yday; #these not used
$date = sprintf("%04d-%02d-%02d-%02d-%02d-%02d-%06d", 1900+$year, $mon+1, $mday, $hour, $min, $sec, $runseconds);

$avgkbits = ($maxkbits + $minkbits) / 2; $errkbits = ($maxkbits - $minkbits) / 2;

open(LOG, ">>${logstore}capture-$cameraid-$date.log");

begin:

$SIG{INT} = sub { die "int\n" }; 

socket(SH, PF_INET, SOCK_STREAM, getprotobyname("tcp"))
  or die "socket: $!"; 

connect(SH,sockaddr_in($cameraport,inet_aton($cameraaddr)))
  or warn "connect: $!"; # may be a network error, keep retrying until we re-establish

$| = 1; binmode(SH);

# username 'read' and password 'data' in Authorization header below

syswrite SH, "GET /VIDEO.CGI HTTP/1.0\r\nhost: $cameraaddr\r\nAuthorization: Basic $password\r\n\r\n"
  or die "syswrite: $!";

eval {

  local $SIG{ALRM} = sub { die "alarm\n" }; 
  alarm $timeout; # set the alarm for reading the header

  while(<SH>) {

    if (/^Content-length: ([0-9]+)/) { 

      alarm 0;
      $SIG{ALRM} = undef; 

      local $dropframe = undef ;
            $oldst     = $st   ;
            $st        = time();
            $stactual  = $st   ;

      $ah = (1  / $softdropnow) - ($st - $oldst); if ($ah > 0 ) { sleep($ah); $st = time(); }
      $ah = ($f / $softdropfps) - ($st - $time ); if ($ah > 0 ) { sleep($ah); $st = time(); }
      $ah = (1  / $harddropnow) - ($st - $oldst); if ($ah > 0 ) { $dropframe      = 1     ; }
      $ah = ($f / $harddropfps) - ($st - $time ); if ($ah > 0 ) { $dropframe      = 1     ; }

      $SIG{ALRM} = sub { die "alarm 1\n" }; 
      alarm $timeout; # reset the alarm for reading more of the header

      $l = $1;
      print LOG "$l bytes\t";

      do true until <SH> eq "\r\n";      # queue to the end of the header
      $/ = \$l; $data = <SH>; $/ = "\n"; # read $l bytes of data

      alarm 0;
      $SIG{ALRM} = sub { die "alarm 2\n" }; 
      alarm $timeout; # reset the alarm for reading the payload

      $file = "${imagestore}image-${cameraid}-${date}-" . sprintf("%08d", $f) . ".jpg";

      $timestamp = scalar(localtime($stactual)) . " " . sprintf("%06d", ($stactual - int($stactual))*1000000) . " us";

      if (!$dropframe) { 

        open(FILE, ">$file")
          or die "open: $!";

        print(FILE "$data") && $f++;

        close(FILE)
          or die "close: $!"; 

        print LOG "$file\t$timestamp\n";
        # $sub .= "\n0 1\n" . scalar(localtime($stactual)) . "\n";
        $sub .= "\n0 1\n$timestamp\n";

      } else {

        print LOG "$file\t$timestamp DROPPED\n";

      }


    }

    if (time() > $timestop) { die "done\n"; }

    alarm 0;
    local $SIG{ALRM} = sub { die "alarm\n" };
    alarm $timeout; # reset the alarm for reading the header

  }


}; if ($@) { # eval completed

  die unless $@ eq "alarm\n" or $@ eq "alarm 2\n" or $@ eq "alarm 1\n" or $@ eq "done\n" or $@ eq "int\n";
    # propagate unexpected errors

  if ($@ eq "alarm\n") {

    print LOG "SIGALRM received: restarting due to $timeout second timeout in reading data header\n";

    close(SH)
      or die "close: $!"; # close the socket

    goto begin;

  } elsif ($@ eq "alarm 1\n") {

    print LOG "SIGALRM received: restarting due to $timeout second timeout in reading more data header\n";

    close(SH)
      or die "close: $!"; # close the socket

    goto begin;

  } elsif ($@ eq "alarm 2\n") {

    print LOG "SIGALRM received: restarting due to $timeout second timeout in reading data payload\n";

    close(SH)
      or die "close: $!"; # close the socket

    goto begin;

  } elsif ($@ eq "int\n") {

    alarm 0; # we are interrupted, turn off any alarm

    close(SH)
      or die "close: $!"; # close the socket

    opendir(DIR, $imagestore);
    @imagefiles = grep { /^image-${cameraid}-${date}-.*\.jpg$/ && -f "${imagestore}$_" } readdir(DIR);
    close(DIR);

    print LOG "unlinking all jpeg frames\n";

    for (@imagefiles) {
      unlink "${imagestore}$_" or die "unlink: $!";
    }

    print LOG "no video generated\n";

  } else {

    alarm 0; # we are done, turn off any alarm

    close(SH)
      or die "close: $!"; # close the socket

    opendir(DIR, $imagestore);
    @imagefiles = grep { /^image-${cameraid}-${date}-.*\.jpg$/ && -f "${imagestore}$_" } readdir(DIR);
    close(DIR);

    $frames = ($#imagefiles + 1);
    $fps = sprintf("%.3f", $frames / $runseconds );

    print LOG "Images captured, now encoding $frames frames at $fps fps...\n";

    $captime = time();
    print LOG "starting generation at " . scalar(localtime($captime)) . " " . 
      sprintf("%06d", ($captime - int($captime))*1000000) . " us\n";

    $SIG{INT} = sub { 
      print LOG "unlinking all jpeg frames\n";

      for (@imagefiles) {
        unlink "${imagestore}$_" or warn "unlink: $!";
      }

    die "SIGINT received during encoding, no video generaged.\n";

    };

    print LOG "creating mpsub file for feeding into mencoder\n";

    open(SUB, ">${moviestore}video-${cameraid}-${date}-${fps}.sub");
    print SUB "FORMAT=$fps\n$sub" or warn "print SUB: $!";
    close(SUB);

    print LOG "executing mencoder now...\n";

    system("mencoder -quiet -vc ijpg -mf type=jpg:h=${height}:w=${width}:fps=${fps} " . 
           "        mf://${imagestore}image-${cameraid}-${date}-*.jpg      " .
           "          -o ${moviestore}video-${cameraid}-${date}-${fps}.avi " .
           "        -sub ${moviestore}video-${cameraid}-${date}-${fps}.sub " . 
           "-ovc lavc -lavcopts " . 
           "vcodec=msmpeg4v2:mv0:trell:cbp:vqmin=${minquant}:vqmax=${maxquant}:vbitrate=${avgkbits}:vratetol=${errkbits}000 " .
           "-vf hqdn3d=1:1:16" .
           ":decimate=3:512:32:1 " .
           " > /dev/null 2> /dev/null" . 
           "");
    print LOG "...unlinking all jpeg frames\n";

    for (@imagefiles) {
      unlink "${imagestore}$_" or die "unlink: $!";
    }

    $donetime = time();
    print LOG "video-${cameraid}-${date}-${fps}.avi generated at " . scalar(localtime($donetime)) . " " . 
      sprintf("%06d", ($donetime - int($donetime))*1000000) . " us, taking " . ($donetime - $captime) . " seconds\n";

  }

}
 
close(SH);
close(LOG);

1;