[FFmpeg-devel] [PATCH 1/4] avcodec/proresdec2: change profile only if it is unknown

[Paul B Mahol]

On 12/7/18, Michael Niedermayer <michael at niedermayer.cc> wrote:
> On Fri, Dec 07, 2018 at 10:28:09AM +0100, Paul B Mahol wrote:
>> On 12/7/18, Michael Niedermayer <michael at niedermayer.cc> wrote:
>> > On Wed, Dec 05, 2018 at 09:22:48PM +0100, Paul B Mahol wrote:
>> >> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>> >> ---
>> >>  libavcodec/proresdec2.c | 51
>> >> ++++++++++++++++++++++-------------------
>> >>  1 file changed, 27 insertions(+), 24 deletions(-)
>> >>
>> >> diff --git a/libavcodec/proresdec2.c b/libavcodec/proresdec2.c
>> >> index 8581d797fb..80a76bbba1 100644
>> >> --- a/libavcodec/proresdec2.c
>> >> +++ b/libavcodec/proresdec2.c
>> >> @@ -140,32 +140,35 @@ static av_cold int decode_init(AVCodecContext
>> >> *avctx)
>> >>@@ -140,6 +140,7 @@ static av_cold int decode_init(AVCodecContext
>> >> *avctx)
>> >>
>> >>     avctx->bits_per_raw_sample = 10;
>> >>
>> >>+    if (avctx->profile == FF_PROFILE_UNKNOWN) {
>> >>         switch (avctx->codec_tag) {
>> >>         case MKTAG('a','p','c','o'):
>> >>             avctx->profile = FF_PROFILE_PRORES_PROXY;
>> >>@@ -155,16 +156,18 @@ static av_cold int decode_init(AVCodecContext
>> >> *avctx)
>> >>             break;
>> >>         case MKTAG('a','p','4','h'):
>> >>             avctx->profile = FF_PROFILE_PRORES_4444;
>> >>-        avctx->bits_per_raw_sample = 12;
>> >>             break;
>> >>         case MKTAG('a','p','4','x'):
>> >>             avctx->profile = FF_PROFILE_PRORES_XQ;
>> >>-        avctx->bits_per_raw_sample = 12;
>> >>             break;
>> >>         default:
>> >>-        avctx->profile = FF_PROFILE_UNKNOWN;
>> >>             av_log(avctx, AV_LOG_WARNING, "Unknown prores profile
>> >> %d\n",
>> >> avctx->codec_tag);
>> >>         }
>> >>+    }
>> >>+
>> >>+    if (avctx->profile == FF_PROFILE_PRORES_XQ ||
>> >>+        avctx->profile == FF_PROFILE_PRORES_4444)
>> >>+        avctx->bits_per_raw_sample = 12;
>> >
>> > with this it would be possible to have 12bit output while the profile
>> > is set to one having 10bits and vice versa ?
>>
>> No, and neither with previous code.
>>
>> > maybe the profile should only be left if it is compatible with the
>> > decoder output
>>
>> I do not follow.
>
> I may have misunderstood the intend of the patch
> please document what this fixes in the commit message.
>
> AVCodecContext.profile is for decoding set by the decoder.
> (thats how its documented in avcodec.h)
>
> So the obvious thought that this is about not overriding a profile
> set by the user(app) or demuxer might have been flawed on my side
> as that seems not possible in the API as it is documented

You missed fact that profile is set via codecpar (which is than copied
to codec context), never in codec context directly.

Once again, what you want to change?