[FFmpeg-devel] [PATCH] avcodec/allcodecs: add FFMPEG_PREFER_* env vars

wm4 nfxjfg at googlemail.com
Thu Apr 19 17:45:41 EEST 2018

On Thu, 19 Apr 2018 16:33:09 +0200
Hendrik Leppkes <h.leppkes at gmail.com> wrote:

> On Thu, Apr 19, 2018 at 12:40 PM, wm4 <nfxjfg at googlemail.com> wrote:
> >
> > Regarding this patch, personally I don't think using getenv() to
> > configure what is pretty much API semantics is acceptable. But a new
> > API function that restricts what codecs are used based on a string
> > argument might be ok. Then applications could use it to implement
> > codec selection control via environment or command line arguments or
> > something else.
> >
> >  
> I agree with no getenv, handling env variables in a library is an iffy concept.
> A new API  for that seems pretty weird as well, considering we already
> have functions to select codecs by name, which can be easily used for
> this purpose - the same way ffmpeg.c for example implements this.
> And if you need code changes anyway, might as well do it the way its intended.

I meant an API that can select the correct codec given a list of
decoders/encoders, and the actual codec. A codec list could for example
contain "h264,hevc,...", and of course you always want to pick "hevc"
if the input is HEVC. I don't think we have an API for this yet?

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