Con el lector electrónico, resolví el problema que tenía para leer todos los libros y artículos que me interesaban en Internet sin tener que estar delante del ordenador.
Sin embargo, los vídeos se me resistían: al descargar vídeos de YouTube (con el Flash Video Downloader), Miro (los vídeos descargados se guardan en ~/.miro/Movies) o cualquier otro sistema parecido, acababa con archivos Flash (FLV) o MP4 usando el códec H264 que ni la PDA ni el reproductor multimedia del salón eran capaces de reproducir.
Después de pelearme con el Mobile Media Converter, el Arista Transcoder y otros parecidos, el que menos problemas me ha dado ha sido el Avidemux, que además incorpora la opción de usar scripts. Para instalar este último en Ubuntu:
sudo apt-get install avidemux
Con Avidemux y con este simple script en Perl (guardar como mp4toavi.pl), se pueden convertir en un solo paso todos los archivos MP4 y FLV en un directorio al formato AVI (XVID/MP3).
# Convert MP4/FLV files into AVI (XVID/MP3)
# @author José Miguel Cotrino
# @date 01.03.2010
#
use strict;my $dir = $ARGV[0];
my $tmp = «tmp.js»;
if( !defined($dir) or $dir eq «» ) {
die «Please specify a directory where to look for MP4/FLV files»;
}
print «Parsing MP4/FLV files at $dir…\n«;
foreach my $file (<$dir/*>) {
if( $file =~ m/\.mp4$/ ) {
process($file,«mp4»);
} elsif( $file =~ m/\.flv$/ ) {
process($file,«flv»);
}
}
exit 0;
sub process($$) {
my($source,$format) = @_;
my $target = $source;
$target =~ s/\.$format$/\.avi/;
print «Converting \»$source\» into \»$target\»…\n«;
open(SCRIPT, «>$tmp»);
print SCRIPT <<SCRIPTEND;
//AD
//–automatically built–
var app = new Avidemux();
// Load the file
app.forceUnpack();
app.load(«$source»);
app.rebuildIndex();
//** Video Codec conf **
app.video.codecPlugin(«92B544BE-59A3-4720-86F0-6AD5A2526FD2», «Xvid», «CQ=4», «<?xml version=’1.0′?><XvidConfig><presetConfiguration><name><default></name><type>default</type></presetConfiguration><XvidOptions><threads>0</threads><vui><sarAsInput>false</sarAsInput><sarHeight>1</sarHeight><sarWidth>1</sarWidth></vui><motionEstimation>low</motionEstimation><rdo>dct</rdo><bFrameRdo>false</bFrameRdo><chromaMotionEstimation>false</chromaMotionEstimation><qPel>false</qPel><gmc>false</gmc><turboMode>false</turboMode><chromaOptimiser>false</chromaOptimiser><fourMv>false</fourMv><cartoon>false</cartoon><greyscale>false</greyscale><interlaced>none</interlaced><frameDropRatio>0</frameDropRatio><maxIframeInterval>0</maxIframeInterval><maxBframes>0</maxBframes><bFrameSensitivity>0</bFrameSensitivity><closedGop>false</closedGop><packed>false</packed><quantImin>2</quantImin><quantPmin>2</quantPmin><quantBmin>2</quantBmin><quantImax>31</quantImax><quantPmax>31</quantPmax><quantBmax>31</quantBmax><quantBratio>150</quantBratio><quantBoffset>100</quantBoffset><quantType>h.263</quantType><intraMatrix><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value><value>8</value></intraMatrix><interMatrix><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value><value>1</value></interMatrix><trellis>false</trellis><singlePass><reactionDelayFactor>0</reactionDelayFactor><averagingQuantiserPeriod>0</averagingQuantiserPeriod><smoother>0</smoother></singlePass><twoPass><keyFrameBoost>0</keyFrameBoost><maxKeyFrameReduceBitrate>0</maxKeyFrameReduceBitrate><keyFrameBitrateThreshold>0</keyFrameBitrateThreshold><overflowControlStrength>5</overflowControlStrength><maxOverflowImprovement>5</maxOverflowImprovement><maxOverflowDegradation>5</maxOverflowDegradation><aboveAverageCurveCompression>0</aboveAverageCurveCompression><belowAverageCurveCompression>0</belowAverageCurveCompression><vbvBufferSize>0</vbvBufferSize><maxVbvBitrate>0</maxVbvBitrate><vbvPeakBitrate>0</vbvPeakBitrate></twoPass></XvidOptions></XvidConfig>»);
//** Audio **
app.audio.reset();
app.audio.codec(«Lame»,128,20,»80 00 00 00 00 00 00 00 01 00 00 00 02 00 00 00 00 00 00 00 «);
app.audio.normalizeMode=0;
app.audio.normalizeValue=0;
app.audio.delay=0;
app.audio.mixer=»NONE»;
app.setContainer(«AVI»);
app.save(«$target»);
app.exit();
//End of script
SCRIPTEND
close(SCRIPT);
system(«avidemux –force-alt-h264 –run $tmp»);
unlink($tmp);
}
Para ejecutarlo, basta con:
perl mp4toavi.pl /directory_con_mp4s
Actualización: he cambiado el código para que funciona con Avidemux 2.5.1.
