#!/usr/bin/perl

#

# fixer.pl - this tool for fix broken video files with h264 and AVCC coding

# Copyright (c) 2017, BukkoJot

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program. If not, see <https://www.gnu.org/licenses/>.

#

use Data::Dumper;

my($ffmpeg,$ffprobe);

if($^O=~/win32/i){

$ffmpeg="ffmpeg.exe";

$ffprobe="ffprobe.exe";

} else {

$ffmpeg="ffmpeg";

$ffprobe="ffprobe";

}

if(@ARGV<3){

print "Usage:\n$0 <good_file.mp4> <bad_file.mp4> <output_prefix>\n";

exit(0);

}

my ($goodfile,$badfile,$outfile_prefix)=@ARGV;

my $sample_h264=$outfile_prefix."-headers.h264";

my $sample_stat_h264=$outfile_prefix."-stat.mp4";

my $sample_aac=$outfile_prefix."-headers.aac";

my $sample_nals=$outfile_prefix."-nals.txt";

my $sample_nals_stat=$outfile_prefix."-nals-stat.txt";

my $out_video=$outfile_prefix."-out-video.h264";

my $out_audio=$outfile_prefix."-out-audio.raw";

print "Build intemidiates...\n";

if(!-e($sample_h264)){`$ffmpeg -i "$goodfile" -c copy -frames 1 -bsf h264_mp4toannexb "$sample_h264"`;}

if(!-e($sample_stat_h264)){`$ffmpeg -i "$goodfile" -c copy -t 20 -an "$sample_stat_h264"`;}

if(!-e($sample_nals)){`$ffprobe -select_streams 0 -show_packets -show_data "$sample_stat_h264" > "$sample_nals"`;}

if(!-e($sample_aac)){`$ffmpeg -i "$goodfile" -c copy -t 1 -f adts "$sample_aac"`;}

print "Opening files...\n";

open(bfile,$badfile) or die "$badfile: $!";

open(vhead,$sample_h264);

open(nals,$sample_nals);

open(vout,">".$out_video) or die "$out_video: $!";

open(aout,">".$out_audio) or die "$out_audio: $!";

read(vhead,$header,0x100);

$header=~s/\x00\x00 \x01[\x65\x45\x25]. $//s;

binmode(vout);

binmode(aout);

binmode(bfile);

binmode(vhead);

# get nals

my $buf;

my $size;

my @nals=map{

{

min=>0xFFFFFF,

max=>0x0,

id=>$_

}

}(0..0b11111);

while(<nals>){

if(/^0.......: (.{40})/){

$buf.=$1;

next;

}

if(/^\[\/PACKET\]/ && $buf){

$buf=~s/[^0-9A-F]//igs;

while(1){

$size=hex(substr($buf,0,8));

print "NAL $size bytes, type: $type\n";

if(length($buf)>=$size*2 8){

$type=hex(substr($buf,8,2))&0b11111;

$bytes=pack("H*",substr($buf,8,$type==5?6:4));

$n=$nals[$type];

if($n->{min}>$size){ $n->{min}=$size;}

if($n->{max}<$size){ $n->{max}=$size;}

$n->{bytes}{$bytes}=1;

$n->{printbytes}{substr($buf,8,8)}=1;

$buf=substr($buf,8 $size*2);

} else {

last;

}

}

print "Remain ".length($buf).": ".substr($buf,0,32)."\n";

$buf="";

#$nals{$1.$2}=undef;

}

}

#print join("\n",keys %nals);

print Dumper(\@nals);

open(st,">".$sample_nals_stat);

print st Dumper(\@nals);

close(st);

##################################

#die;@nals{map{s/(..)/pack("C",hex($1))/eg;$_}split(/\n/,$nals)}=undef;

print vout $header;

$was_key=0;

# main loop

$shit="";

$fsize=-s(bfile);

$blocksize=10000000;

$file="";

while(1){

$fsize=read(bfile,$buf,$blocksize);

if($fsize==0){

last;

}

$file=$file.$buf;

$buf="";

$fsize=length($file)-10;

$stime=time();

for($q=0;$q<$fsize;){

my $size=unpack("N",substr($file,$q,4));

my $header=unpack("C",substr($file,$q 4,1));

my $zerobit=$header&0x80;

my $type=$header&0b11111;

if(time()!=$stime){

printf("testing at %.5x (of %.5x) gives us $size\n",tell(bfile)-$q,$fsize);

$stime=time();

}

if($size>0 && $zerobit==0 && $nals[$type]->{max}){

$nextbytes=substr($file,$q 4,$type==5?3:2);

$iskey=$type==5?1:0;

if(exists $nals[$type]->{bytes}{$nextbytes} && $size>=$nals[$type]->{min}/2 && $size <= $nals[$type]->{max}*2){

print "Got! $size bytes and ".length($shit)." shit\n";

if($ok){

print aout $shit;

}

#writing frame

$tail=length($file)-$q-4;

if($tail>$size){$tail=$size;}

$left=$size-$tail;

if($iskey || $was_key){

print vout "\x00\x00\x00\x01"; # signature

print vout substr($file,$q 4,$tail);

if($left){

read(bfile,$buf,$left);

print vout $buf;

$buf="";

}

$was_key=1;

} else {

# if very beginning and no key frames was yet - just skip this frames

if($left){

read(bfile,$buf,$left);

$buf="";

}

}

$shit="";

$ok ;

$q =$size 4;

next;

}

}

$shit.=substr($file,$q,1);

$q ;

}

$file=substr($file,$q);

}

print `stat $out_video`;