[FFmpeg-devel] [RFC] Expose more legal encoding parameters from AVCodec

Stefano Sabatini stefano.sabatini-lala
Mon Apr 7 16:35:27 CEST 2008

Hi all,

AVCodec already contains the capabilities, pix_fmts and
supported_framerates fields, which tell (if specified) some of the
parameters which are supported for encoding/decoding.

I would like to extend such features, for example to expose: 
* a more verbose description of the codec, similiar to the
  long_description already implemented in libavformat.  Also relevant
  is [1].

* valid sizes for the video streams, for example as in the case of
  H263 which only supports a limited legal set of sizes

* legal audio samplerates (e.g. as in MP2)

* others?

This would be useful both for the command line user (if we provide
some way to convey this information to the user, I'm thinking for
example to extend ffprobe for this) and in a scenario of adaptive
encoding, where you have to programmatically choose which parameters
is better to use in function of the available
storage/computing/bandwidth resources, and reimplementing this in
every application doesn't sound that good.

If maintainers see this like a good idea I could start to elaborate
more on this.

Best regards.

[1] http://thread.gmane.org/47CE6BC2.3030609 at olebyn.nu
Stefano Sabatini
Linux user number 337176 (see http://counter.li.org)

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