Peter Ross pross at xvid.org
Wed Nov 21 12:45:24 CET 2012

On Wed, Nov 21, 2012 at 09:40:59AM +0000, Paul B Mahol wrote:
> On 11/21/12, Peter Ross <pross at xvid.org> wrote:
> > Currently the IFF bitmap decoder is split across two AV_CODEC_IDs.
> > Bitmaps with compression type 0 got to AV_CODEC_ID_IFF_ILBM, and
> > compression type 1 goes to AV_CODEC_ID_BYTERUN1.
> >
> > The compression type value is passed to the decoder via an extra-data
> > structure, so the separate AV_CODEC_IDs are not required. (Early
> > on this wasn't the case).
> >
> > How could the decoders be merged without breaking API compatibility.
> > There is at least one more compression type that I would like to add to
> > the IFF bitmap. Adding yet another AV_CODEC_ID for this would seem silly.
> And would make supporting ANIMs that may change (from one compression type to
> another impossible - like ilbm <-> byterun1 but I yet have to find such sample).
> Proposed solution: add new codec id and use it in our lavf, others keep just
> for compatibility sake.

Okay. The compression data structure could be sent via AVPacket.side_data[].
That would, in theory, support the ANIM use case.

-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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