[Libav-user] Codec Specific Options

[wm4]

On Tue, 3 Feb 2015 22:59:20 +0000 (UTC)
Lyndon Hill <emptystate-at-yahoo.co.uk at ffmpeg.org> wrote:

> Hi
> Is there an example to show the recommended way one should set codec specific options ? In the included examples both av_dict_set() and av_opt_set_xxx() are used.
> 
> Also is there a way to choose codec asides from the AV_CODEC_ID_XXX... enumeration ? For example, there are two ProRes codecs but there is only one AV_CODEC_ID_PRORES - how do I select ?
> Finally, is there any documentation for codec options or do you have to read the source ?
> Thanks
> 

Something like:

AVCodec *codec = avcodec_find_decoder_by_name(name);
AVCodecContext *ctx = avcodec_alloc_context3(codec);

You still need to set the codec ID on the context, which in this case
forces the format, not the decoder.