[M4IF Technotes] multiple audio tracks into an mp4 file

[nico.oorts]

Hi
>>I found what the problem was. It is not yet what I want it to be, but
>>for research it was sufficient. What I did first was different updates
>>of OD's at the time that I updated the scene. Now I update all the OD's
>>from the different tracks at time 0. The problem I have for the moment
>>is that all tracks internally start playing from time 0 and when I do an
>>update of the scene at time 15000, the second track is already playing
>>for 15s. This is probably because I update all the OD's at time 0.(??)
>>    
>>
>This is definitely a bug, it is not because you update an OD at some
>point in time that the associated medias should start at this same point
>in time. The starting and stopping of medias is controled by the scene.
>
>  
>
>>Now I am looking for a way to convert a textual description (something
>>like bifstext) into a BIFS and OD track, not immediatly an mp4 file.
>>(probably I need to use BIFSenc from the standard reference software?)
>>    
>>
>Yes you can do that or use mp4tool to create an mp4 file and then use
>the -export option of mp4tool to extract the tracks you want to have.
>The advantage of the second method is that you will get a file
>containing the media (bifs or od) plus a file containing the
>DecoderConfigDescriptor and a file containing some hints about the media
>AUs like DTS, CTS, size of the AU, RAP ...
>
Ik would like to do it with the mp4tool, the only problem is that 
mp4tool is proprietary and I want to build an application (in Eiffel or 
Java) which has as input some textual description of different tracks 
and time stamps and as output a mp4 file with the different tracks in it 
and starting from those time stamps. So I have to figure out if I'm 
going to use mp4tool or not.
>>I'm using Realplayer One with the envivio plugin, also winamp with an
>>mp4 plugin (only audio) and Quicktime 6.
>>    
>>
>I now that the Envivio plugin has some bugs regarding OD updates so that
>might explain the bug you had with the first scene.
>  
>
Nico