Sunday, November 16, 2008

PS3 MP4 Encoding with Linux

After a lot of reading, searching, and trial and error, I have come up with a fairly simple way to convert video and audio content into an h264 and aac stream. The stream is packed into an MP4 file and can be streamed to a PS3 via a media server such as MediaTomb.

The following scripts makes it a pretty automated process. It relies on mencoder, and MP4Box. I have been using it to convert DVD vob files into smaller MP4 files, with nearly the same quality. I can't actually tell a difference from the original DVD source.


mencoder -v \
$1 \
-alang en \
-ovc x264 -x264encopts $ENCOPTS:pass=1:turbo=1 \
-ofps 24000/1001 \
-vobsubout "$3_subtitles" -vobsuboutindex 0 -slang en \
-passlogfile "$3.log" \
-oac copy \
-o /dev/null

mencoder -v \
$1 \
-alang en \
-ovc x264 -x264encopts $ENCOPTS:pass=2 \
-oac faac -faacopts object=1:tns:quality=150 \
-passlogfile "$3.log" \
-ofps 24000/1001 \
-o "$3.avi"

MP4Box -aviraw video "$3.avi"

MP4Box -aviraw audio "$3.avi"

mv "$3_audio.raw" "$3_audio.aac"

rm "$3.mp4"

MP4Box -isma -hint -add "$3_video.h264#Video:fps=23.976" -add "$3_audio.aac" "$3.mp4"

rm "$3_video.h264" "$3_audio.aac"

Running the script involves something like...

./ Terminator2.vob 3800 Terminator2

The first argument is the source file, the second is the target bitrate, and the 3rd is the target file. I do not put an extension on the target as the script will do this. A bitrate of 3800 seems high enough to produce an encode that looks nearly identical to the source DVD.

You will probably need to tweak the VIDEOFILTER crop filter according to your video source. You can run mplayer on your source using -vf cropdetect to determine the correct cropping arguments. Of course you can also change the ENCOPTS to your liking, although I find the current options acceptable.

Once the oncode is finished you have a nice MP4 file. The avi file is left after the encode in-case something go wrong so you don't have to re-encode the source. If everything goes ok, you can delete this file.

Let me know what you think.

EDIT: The PS3 seems to be picky about the video resolutions, be careful when cropping to strange resolutions. I'll try to investigate this more, as I ran into a problem with a cropped wide screen video. Removing or tweaking the crop made a short test encode work.

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