[FFmpeg-devel] [PATCH 4/5] aptx: implement the aptX HD bluetooth codec

Carl Eugen Hoyos ceffmpeg at gmail.com
Mon Jan 8 14:27:16 EET 2018


2018-01-08 11:32 GMT+01:00 Hendrik Leppkes <h.leppkes at gmail.com>:
> On Mon, Jan 8, 2018 at 1:38 AM, Rostislav Pehlivanov
> <atomnuker at gmail.com> wrote:
>>
>> That's okay - for encoding switch the profile depending on both the
>> avctx->profile setting and the samplerate and list all supported
>> samplerates for all profiles in the AVCodec structure. We do something
>> similar in the AAC encoder where we pick different settings depending on
>> the profile and change the profile depending on the settings listed.
>> If there's an overlap, pick a sane default unless the user forces a profile
>> using profile:a. If forced and the samplerate isn't supported - error out
>> and let the user know.
>> For decoding set the profile via the demuxer. There doesn't have to be just
>> one demuxer for a codec. If there are major changes in how you parse
>> profiles go ahead and make a new one which sets the codec ID and the
>> profile.
>>
>
> I don't think there is any precedent for "profile" being mandatory for
> a decoder to work, so that might be iffy. Decoders usually set
> profile, don't require it.
> ie. from the docs:
> * - decoding: Set by libavcodec.
>
> There is plenty precedent for using "codec_tag" however, so that may
> be a better choice - and can hold the tag from the "container" as-is
> as well.

While I don't understand why even having more than one codec_id for
the same codec (which afaiu isn't the case here) would be an issue, I
don't think we should invent codec_tags unless necessary.

Carl Eugen


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