[FFmpeg-devel] [PATCH 3/4] avcodec/decode: Set KEY flag+pict_type generically for intra-only codecs

[Andreas Rheinhardt]

Tomas Härdin:
> tor 2024-05-09 klockan 04:04 +0200 skrev Andreas Rheinhardt:
>> This commit is the analog of 3f11eac75741888c7b2b6f93c458766f2613bab5
>> for decoding: It sets the AV_FRAME_FLAG_KEY and (for video decoders)
>> also pict_type to AV_PICTURE_TYPE_I. It furthermore stops setting
>> audio frames as always being key frames -- it is wrong for e.g.
>> TrueHD/MLP. The latter also affects TAK and DFPWM.
>>
>> The change already improves output for several decoders where
>> it has been forgotten to set e.g. pict_type like speedhq, wnv1
>> or tiff. The latter is the reason for the change to the exif-image-
>> tiff
>> FATE test reference file.
>>
>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
>> ---
>>  libavcodec/decode.c            | 29 +++++++++++++++++++++++++++--
>>  libavcodec/pthread_frame.c     | 17 ++++++++++++++---
>>  tests/ref/fate/exif-image-tiff |  2 +-
>>  3 files changed, 42 insertions(+), 6 deletions(-)
>>
>> diff --git a/libavcodec/decode.c b/libavcodec/decode.c
>> index d031b1ca17..0ca5344ef5 100644
>> --- a/libavcodec/decode.c
>> +++ b/libavcodec/decode.c
>> @@ -57,6 +57,20 @@
>>  typedef struct DecodeContext {
>>      AVCodecInternal avci;
>>  
>> +    /**
>> +     * This is set to AV_FRAME_FLAG_KEY for decoders of intra-only
>> formats
>> +     * (those whose codec descriptor has AV_CODEC_PROP_INTRA_ONLY
>> set)
>> +     * to set the flag generically.
>> +     */
>> +    int intra_only_flag;
>> +
>> +    /**
>> +     * This is set to AV_PICTURE_TYPE_I for intra only video
>> decoders
>> +     * and to AV_PICTURE_TYPE_NONE for other decoders. It is used to
>> set
>> +     * the AVFrame's pict_type before the decoder receives it.
>> +     */
>> +    enum AVPictureType initial_pict_type;
> 
> Carrying this around as state seems unnecessary when a small static
> function could do the same?
> 

The aim of this is to avoid branches for every frame.

- Andreas