View source for VP3 to Theora


== About ==


This is a quick guid to show how to transcode VP3 (usually with MP3) to Theora.

Now, this quick guide involves a lot of tools which are either experimental or are known to be buggy. Beware. Use with caution.

== NSV ==

If your Video is encapsulated in NSV you first need to remux it to AVI:

mencoder -oac copy -ovc copy -fafmttag 0x55 -o vp31.avi input.nsv

== Get the Theora code ==

Download the Theora source code (svn co http://svn.xiph.org/trunk/theora).

== Build the avi2vp3 tool ==

Go to theora/win32/experimental/transcoder/avi2vp3/

Compile the tool which will extract the VP3 data out of your AVI file: gcc *.c -o avi2vp3

== Build transcoder_example ==

Copy theora/win32/experimental/transcoder/transcoder_example.c to theora/examples/encoder_example.c - this will replace the usual Theora encoder example with the application creating a Theora stream from the raw VP3 data.


Configure your copy of Theora (run autogen.sh). This has a few dependencies. The configuration process will guide you. Be patient. Once configuration didn't complain because of missing dependencies: Invoke make.

After everything compiled you should rename the encoder_example binary (which is in the examples directory) to e.g. transcoder_example to avoid confusion.

== Process your videos ==

* Use avi2vp3 to convert your VP3 AVI. The input file *must* be named vp31.avi, the output file will always be outfile.vp3
* Use transcoder_example to create an Ogg Theora stream: transcoder_example outfile.vp3 > video.ogg
* Use e.g. mplayer to decode the audio in the AVI file: mplayer -vo null -ao pcm vp31.avi
* The audio will be in audiodump.wav. Encode it with e.g. oggenc: oggenc -q 1 audiodump.wav
* Now you need to combine video.ogg and audiodump.ogg. Use oggzmerge from the oggz-tools package (at least in Ubuntu it's oggz-tools): oggzmerge video.ogg audiodump.ogg > theora.ogg

theora.ogg now should be a valid Theora + Vorbis Ogg file. Congratulations!