[FFmpeg-devel] [PATCH 1/2] avcodec/pthread_frame: Remove ff_thread_release_buffer()

[Andreas Rheinhardt]

Anton Khirnov:
> Quoting Andreas Rheinhardt (2023-10-20 16:33:06)
>> diff --git a/libavcodec/av1dec.c b/libavcodec/av1dec.c
>> index c02408548c..1a4339b346 100644
>> --- a/libavcodec/av1dec.c
>> +++ b/libavcodec/av1dec.c
>> @@ -636,9 +636,9 @@ static int get_pixel_format(AVCodecContext *avctx)
>>      return 0;
>>  }
>>  
>> -static void av1_frame_unref(AVCodecContext *avctx, AV1Frame *f)
>> +static void av1_frame_unref(AV1Frame *f)
>>  {
>> -    ff_thread_release_buffer(avctx, f->f);
>> +    av_frame_unref(f->f);
>>      ff_refstruct_unref(&f->hwaccel_picture_private);
>>      ff_refstruct_unref(&f->header_ref);
>>      f->raw_frame_header = NULL;
>> @@ -689,7 +689,7 @@ static int av1_frame_ref(AVCodecContext *avctx, AV1Frame *dst, const AV1Frame *s
>>      return 0;
>>  
>>  fail:
>> -    av1_frame_unref(avctx, dst);
>> +    av1_frame_unref(dst);
>>      return AVERROR(ENOMEM);
>>  }
>>  
>> @@ -699,12 +699,15 @@ static av_cold int av1_decode_free(AVCodecContext *avctx)
>>      AV1RawMetadataITUTT35 itut_t35;
>>  
>>      for (int i = 0; i < FF_ARRAY_ELEMS(s->ref); i++) {
>> -        av1_frame_unref(avctx, &s->ref[i]);
>> -        av_frame_free(&s->ref[i].f);
>> +        if (s->ref[i].f) {
> 
> Wouldn't it be simpler and more consistent to check for the frame's
> existence in av1_frame_unref()?
> 

The frame being NULL is a very exceptional scenario: It can only happen
if init failed. In this case it is clear that the AV1Frame is blank and
need not be unreferenced at all. Given that av1_frame_unref() is not
called infrequently, why should it check all the time for this
exceptional scenario? It seems better to handle this case in the only
codepath that needs to handle this.

>> +            av1_frame_unref(&s->ref[i]);
>> +            av_frame_free(&s->ref[i].f);
>> +        }
>> +    }
>> +    if (s->cur_frame.f) {
>> +        av1_frame_unref(&s->cur_frame);
>> +        av_frame_free(&s->cur_frame.f);
>>      }
>> -    av1_frame_unref(avctx, &s->cur_frame);
>> -    av_frame_free(&s->cur_frame.f);
>> -
>>      ff_refstruct_unref(&s->seq_ref);
>>      ff_refstruct_unref(&s->header_ref);
>>      ff_refstruct_unref(&s->cll_ref);
> 
> LGTM otherwise.
>