[FFmpeg-devel] [PATCH] [RFC] avformat/options_table: do not merge sidedata by default

Reimar Döffinger Reimar.Doeffinger at gmx.de
Thu Nov 21 00:48:24 CET 2013


On Wed, Nov 20, 2013 at 10:11:32PM +0100, wm4 wrote:
> I agree that it would be better if there was no side data. But if you
> look at the way things were done before, side data is a clear
> improvement. (Before, decoders just updated the fields in the
> AVStream's AVCodecContext struct, and it was hard to tell after which
> packet the fields had to be updated, and a general pain to any software
> that used a new AVCodecContext instead of AVStream.codec.)

Um, no, not quite. Some demuxers actually came up with a bitstream
format that avoided the issue instead.

> I'll just say that I think merging out-of-band data into the payload is
> inelegant, because if it weren't, the designers of the codec would have
> put it in-band as well.

Well, there are other options like the developers were working in
a very special environment. Or they just didn't feel like
actually designing things well.
Just because somebody designed something doesn't mean they
did a good job with it.
Though this automated merging we do is certainly not particularly
good.
Anyway I think I'll just try to put up my two main points:
1) From my side, do the change if you think it improves things (not sure
what I think).
   It's just a matter of setting a flag anyway to get back.
2) If you care about side data, I'd appreciate some improvements like
   making sure we don't drop critical data.
   Also in general some easy way to find out what side data actually
   is important and which is just metadata and similar clutter would be
   useful.


More information about the ffmpeg-devel mailing list