On Sat, Mar 25, 2006 at 03:45:43PM +0200, Oded Shimon wrote:
- Is file_id_string desirable? There was a question about this at one point and I don't know if it was resolved. I don't really care one way or the other.
I'm leaning both ways. It's slightly more complex, but it allows for ex. mplayer to probe without having to seek back after probing (mplayer is very dumb about this...)
Umm, reading main header startcode will work just as well for probing.
- version 2 must be incremented for freeze/final.
IMO 2 for freeze, 3 for final. By the time spec is finalized should be
IMO 3 for freeze. 2 has been all the constantly-changing versions for the past year and we need a way to distinguish them and reject the old files during the freeze while people are testing. Also if there are no changes (no unfreeze) then we can keep 3 after final too!
about same time nutmerge can give 100% compliant nut files. Also, is there any rule about if a certaion version number means it is non backwards compatible? Like, if version is 4 then the demuxer should not even bother trying demuxing the file?
After final, nut will ALWAYS be compatible, forever. This is why freeze/final is so important! New version numbers will just indicate new additional semantics, etc. Maybe they're not even needed at all..
- We need a spec for what goes in the fourcc field, especially for audio, but it may also be an issue for video. Are XVID, DIVX, DX50, etc. valid or is MP4S the only valid MPEG4-ASP fourcc?
seperate from freeze/finalizing...
No it's not.
- The correct spec for decode_delay is still missing. It just says "decode_delay MUST NOT be set higher than necessary for a codec." which is ambiguous and actually incorrect in the case of an mpeg4 stream without low_delay but with no B frames actually present. I've drafted possible wordings for a correct requirement on IRC before and I think Michael has written a corrected version too.
send a patch?
OK..
- Michael's guidelines about what a demuxer should do for reading info do not seem to have been committed in full.
I didn't quite follow that whole discussion so not sure whats missing.
OK I'll check.. Rich