[FFmpeg-devel] [PATCH]lavc/dds: Fix GRAY8A decoding

[Paul B Mahol]

On 4/14/16, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> Paul B Mahol <onemda <at> gmail.com> writes:
>
>> > +        else if (bpp == 16 && r == 0xff00 && g == 0 &&
>> b == 0 && a == 0xff) {
>> > +            avctx->pix_fmt = AV_PIX_FMT_YA8;
>> > +            ctx->postproc = DDS_SWAP_ALPHA;
>>
>> Why? You disabled postproc lines bellow.
>
> I don't understand this comment:
> For GRAY8A, postproc depends on the exact mask.
>
>> > diff --git a/tests/ref/fate/dds-ya b/tests/ref/fate/dds-ya
>> > index d6527c6..01f7894 100644
>> > --- a/tests/ref/fate/dds-ya
>> > +++ b/tests/ref/fate/dds-ya
>> >  <at>  <at>  -1,2 +1,2  <at>  <at>
>> >  #tb 0: 1/25
>> > -0,          0,          0,        1,    28160, 0xd3981fcb
>> > +0,          0,          0,        1,    28160, 0x5aa41fcb
>>
>> I believe this shouldn't change
>
> I tend to disagree.
>
>> do you have explanation why it should change?
>
> Because I believe it is wrong.
>
> More important though: Why do you believe it is correct?
> Neither does the current code look correct nor do any of
> the two available samples look correct without the change.

Should be ok, but keep postproc step for case when y and a are swapped.
Thanks.

>
> Carl Eugen
>
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