[Tremor] cleanly modifying vorbis-tools to use tremor

[Michael Smith]

On 6/2/05, Jolan Luff <jolan at protection.cx> wrote:
> hi,
> 
> i'm running openbsd on my zaurus c3000 (http://www.openbsd.org/zaurus.html
> for more information).  i used the patches from:
> 
> http://cvsweb.netbsd.org/bsdweb.cgi/pkgsrc/audio/tremor-tools/patches/
> 
> to convert ogg123 from vorbis-tools 1.0 to use tremor.  i tried 1.0.1
> but the build infrastructure had changed dramatically and i was having
> problems converting the above patches.  when i run "igg123" ld.so
> complains about a size mismatch, probably because of finding the same
> symbol in both libvorbisidec and libvorbis and the object files only
> store their size and the size is not the same.
> 
> is there any way to make the idec decoder ABI compatible with the normal
> decoder? i see that ov_read takes different arguments and ov_time_seek
> is int64 in tremor as opposed to a double with regular vorbis.  is it
> not advantageous to merge tremor into libvorbis proper and implement
> some flavor selection at the decoder level?  i can see how tremor being
> separate may be helpful for embedded audio hardware developers, but
> there are going to more multi-functional arm based devices which require
> an integer only decoder in order to play oggs in realtime.

As you've noted, the libraries aren't even API compatible - so ABI
compatibility definately isn't possible. The API is neccesarily
different in some cases, since the entire point of having a fixed
point decoder is to avoid floating point, and the reference
implementation uses floating point extensively. Merging the two would
be neither practical nor useful.

I guess I'm just not understanding why you're linking to libvorbis as
well as tremor - can't you just link to tremor? Or are there functions
you need in libvorbis that aren't in tremor? (if that's the case, then
they're probably simple ones that would be easy to add). This just
sounds like you didn't make the appropriate build changes everywhere.

Mike