This is a short module to grab various informations from a video (or audio) file. I did two versions : one using mpgtx (http://mpgtx.sourceforge.net/) one using ffmpeg (http://ffmpeg.sourceforge.net/).
The mpgtx version works only with MPEG files, obviously, but it reports the duration right. FFMPEG reads most formats (avi, divx, etc) BUT reports the duration very approximately.
mpgtx version 
#!/usr/bin/perl -w
#
######################################################################
+#####
#
# videoinfo.pm
#
# V 0.3.1 08/04/05
# returns duration in frames (25f/s default)
#
# V 0.3.0 08/01/05
# use mpginfo instead of ffmpeg
#
# V 0.2.0 du 13/12/2004
# support of ffmpeg CVS
#
# V 0.1.0 of 20/11/2004
#
######################################################################
+#####
# 
#    Copyright (c) Intellique 2004
#    All rights reserved.
#
#
#    This program is free software; you can redistribute it and/or mod
+ify
#    it under the terms of the GNU General Public License as published
+ by
#    the Free Software Foundation; either version 2 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.

use strict;
require Exporter;

our @ISA=qw(Exporter);
our @EXPORT=qw(videoinfo);

# débug (set to true top get debugging messages)
my $debug;

# mpginfo command
my $mpginfo='/usr/bin/mpgtx -i';

##########################################################
# videoinfo
# returns media information in a hash
#
##########################################################

sub videoinfo {

# variables
my %finfo =    ('duration'    => "0",    # duration in frames
        'bitrate'    => "0",        # Mux bitrate video + audio
        'vcodec'    => "",
        'vformat'    => "",
        'framerate'    => "0.00",
        'acodec'    => "",
        'samplerate'    => "0",
        'stereo'    => "0",        # 0 false (mono), 1 true (stereo)
        'audiorate'    => "0"
        );
        
# file to test
my $file=shift;
# escaping characters
$file=~s/(\W)/\\$1/g;
my @res;

#scan only MPEG
if ( $file =~ m/(MP.)$/i) {
    @res= `$mpginfo $file` or warn "can't run $mpginfo\n";
}

# parse mpgtx output
foreach (@res) {
    # bitrate total        
    if ( m!Muxrate : (\d+\.?\d*) Mbps! ) {
        $finfo{'bitrate'}=$1;
        next;
    }

    # Duration 
    if ( m!Duration: (.*[0-9][0-9]\.[0-9][0-9])s! ) {
        $finfo{'duration'}=$1;
        # convert to frame count
        my @tu=split(/:|\./, $finfo{'duration'});
        
        # parse duration from end
        my ($c, $s, $m, $h)=reverse(@tu);
        # duration in seconds, converted to frames later
        no warnings qw(uninitialized);
        $finfo{'duration'}=($h*360000+$m*6000+$s*100+$c)/100;
        
        use warnings;
        next;
    }


    # vformat and framerate
    if ( /Size \[(\d+ x \d+)\]\s+(\d+\.\d+) fps/) {
        $finfo{'vformat'}=$1; $finfo{'framerate'}=$2;
        next;
    }

    # acodec    
    if ( m!Audio : (.*)! ) {
        $finfo{'acodec'}=$1;
        next;
    }

    # audiorate and samplerate    
    if ( m!\s+(\d+) kbps  (\d+) Hz! ) {
        $finfo{'audiorate'}=$1; $finfo{'samplerate'}=$2;
        next;
    }
    
    # Stereo or mono
    if ( /Stereo/ ) {
        $finfo{'stereo'}=1;
    }

}

# compute the duration in frames
if ($finfo{'framerate'}>1) {
    $finfo{'duration'}=sprintf( "%.0f", $finfo{'duration'}*$finfo{'fra
+merate'});
} else {
    #if no framerate (audio) set to default 25/s
    $finfo{'duration'}=sprintf( "%.0f", $finfo{'duration'}*25);
}



return %finfo;
}


##########################################
#   end
##########################################

1;

[download]
ffmpeg version 
#!/usr/bin/perl -w
#
######################################################################
+#####
#
#
# V 0.2.0 du 13/12/2004
# support of ffmpeg CVS
#
# videoinfo.pm
# V 0.1.0 du 20/11/2004
#
######################################################################
+#####
# 
#    Copyright (c) Intellique 2004
#    All rights reserved.
#
#
#    This program is free software; you can redistribute it and/or mod
+ify
#    it under the terms of the GNU General Public License as published
+ by
#    the Free Software Foundation; either version 2 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.

use strict;
require Exporter;
use IPC::Open3;

our @ISA=qw(Exporter);
our @EXPORT=qw(videoinfo);

##########################################################
# videoinfo
# returns media information in a hash
#
##########################################################

sub videoinfo {
# ffmpeg command
my $ffmpeg='/usr/bin/ffmpeg';

# variables
my %finfo =    ('duration'    => "00:00:00.0",
        'bitrate'    => "0",
        'vcodec'    => "",
        'vformat'    => "",
        'framerate'    => "0.00",
        'acodec'    => "",
        'samplerate'    => "0",
        'stereo'    => "0",        # 0 false (mono), 1 true (stereo)
        'audiorate'    => "0"
        );
        
# fichier à traiter
my $file=shift;
# escaping characters
$file=~s/(\W)/\\$1/g;

open3("</dev/null",">/dev/null",\*ERPH, "$ffmpeg -i $file") or die "ca
+n't run $ffmpeg\n";
my @res=<ERPH>;

# parse ffmpeg output
foreach (@res) {
    # duration and bitrate
    if ( m!Duration: ([0-9][0-9]:[0-9][0-9]:[0-9][0-9].[0-9]), bitrate
+: (\d*) kb/s! ) {
        $finfo{'duration'}=$1; $finfo{'bitrate'}=$2;
        }
    # vcodec, vformat and framerate
    if ( /Video: (\w*), (\d*x\d*), (\d*.\d*) fps/) {
        $finfo{'vcodec'}=$1; $finfo{'vformat'}=$2; 
        $finfo{'framerate'}=$3;
        }
    # acodec, samplerate, stereo and audiorate    
    if ( m!Audio: (\w*), (\d*) Hz, (mono|stereo), (\d*) kb/s!) {
        $finfo{'acodec'}=$1; $finfo{'samplerate'}=$2; 
        $finfo{'stereo'}=(($3 eq 'stereo')|| 0 ); $finfo{'audiorate'}=
+$4;
        }
    }

return %finfo;
}


##########################################
#   end
##########################################

1;

[download]

Replies are listed 'Best First'.
Re: Video information
by ihb (Deacon) on May 09, 2005 at 20:06 UTC

    Have you checked out Video::Info on CPAN?

    ihb

    See perltoc if you don't know which perldoc to read!

[reply]
      Yes, and it didn't do what I needed at the time I checked a few months ago. There was an older one (MPEG::Info?) that did, but has been removed, so I made this quick hack to scratch my itch :)
[reply]
Re: Video information
by jeffa (Bishop) on May 09, 2005 at 16:48 UTC

    That's not really a module ... first, even if you do consider that a module, it really is two modules. Second, modules are not meant to be executed, so no need for the 'she-bang' line. Third, if you are going to make a module, i really recommend you stick with the Object Oriented paradigm, but that's just me. Here is a shell that uses OO as well as allows the client to chose whether to use mpgtx or ffmpeg. (This is untested.) 

    package Info::Video;

use strict;
use warnings;

my %value_types = (
    mpginfo => '/usr/bin/mpgtx -i',
    ffmpeg  => '/usr/bin/ffmpeg',
);


sub new {
    my $class = shift;
    my $type  = shift || 'mpginfo';

    die "invalid type:$type\n" unless $valid_type{$type};

    my $self = {
        type       => $type,
        duration   => '00:00:00.0',
        bitrate    => 0,
        vcodec     => '',
        vformat    => '',
        framerate  => '0.00',
        acodec     => '',
        samplerate => 0,
        stereo     => 0,
        audiorate  => 0,
    };

    return bless $self, $class;
}


sub video_info {
    my $self = shift;
    my $file = shift;

    # note: use $valid_types{ $self->{type} } for executable

    if ($self->{type} eq 'mpginfo') {

        # handle mpginfo
    }
    elsif ($self->{type} eq 'ffmpg') {

        # handle ffmpg
    }

    return $self;
}

1;

    [download]
    And a simple client: 
    #!/usr/bin/perl

use strict;
use warnings;
use Info::Video;

my $info = Info::Video->new('ffmpeg');
$info->video_info();

# now $info contains the video information

    [download]

    That's a decent "first stab" at the problem. It is far from optimal, but it should illustrate a better way of getting things done. I don't like having to use an if-elsif inside the video_info() sub ... i would consider using a Factory Pattern instead (or Class::Factory). I would also consider using Class::MethodMaker so that you can automatically add accessor methods to your object, instead of mucking directly with the attributes. Finally ... use POD! Don't use simple # comments for documentation, save those for simple comments.

    And finally finally, don't stick use warnings; in the middle of a for loop. Cheers! :)

    jeffa

    L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)
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