[FFmpeg-devel] [PATCH][RFC] avcodec/avutil: Add timeline side data

wm4 nfxjfg at googlemail.com
Tue Apr 3 19:26:28 EEST 2018

On Tue, 3 Apr 2018 17:06:03 +0100
Derek Buitenhuis <derek.buitenhuis at gmail.com> wrote:

> On 4/3/2018 4:15 AM, wm4 wrote:
> > So I think all what you've been writing can be reduced to: should this
> > really be side data, or would it be better to just make it a new
> > AVStream field.  
> I don't really have an opinion on this one way or another.
> Do others?

Uh no idea. One angle:

The idea with AVStream side data is that it can be attached as AVPacket
side data. So if an API user is fine with treating all kinds of side
data per AVPacket, it can call av_format_inject_global_side_data() and
ignore AVStream side data. Basically, you could ask the question
whether this kind of side data makes sense as per-AVPacket, and if not,
then it should be AVStream side data. Maybe.

Another angle is that the API better because side data would not add
yet another AVStream field. It makes the API more discoverable: the API
user can easily detect an unsupported side data type and handle it as
soon as he has a sample, instead of having to go over every AVStream
field during the initial implementation, and wondering what the hell it
does (and things going wrong when not handling explicitly). I probably
didn't word that too well, but I hope you get what I mean.

More information about the ffmpeg-devel mailing list