[FFmpeg-devel] [PATCH v2 11/12] lavc/vaapi_decode: use dynamic frame pool for output frames with libva2

[Mark Thompson]

On 26/01/2024 07:25, Xiang, Haihao wrote:
> On Wo, 2023-12-20 at 15:10 +0800, Xiang, Haihao wrote:
>> From: Haihao Xiang <haihao.xiang at intel.com>
>>
>> This allows a downstream element stores more frames from VAAPI
>> decoders and fixes error in get_buffer()
>>
>> $ ffmpeg -hwaccel vaapi -hwaccel_output_format vaapi -i input_100frames.mp4 \
>>   -vf reverse -an -f null -
>> ...
>> [h264 @ 0x557a075a1400] get_buffer() failed
>> [h264 @ 0x557a075a1400] thread_get_buffer() failed
>> [h264 @ 0x557a075a1400] decode_slice_header error
>> [h264 @ 0x557a075a1400] no frame!
>>
>> Signed-off-by: Haihao Xiang <haihao.xiang at intel.com>
>> ---
>>   libavcodec/vaapi_decode.c | 36 ++++++++++++++++++++----------------
>>   1 file changed, 20 insertions(+), 16 deletions(-)
>>
>> diff --git a/libavcodec/vaapi_decode.c b/libavcodec/vaapi_decode.c
>> index ceac769c52..8cc29e96f9 100644
>> --- a/libavcodec/vaapi_decode.c
>> +++ b/libavcodec/vaapi_decode.c
>> @@ -601,22 +601,26 @@ static int vaapi_decode_make_config(AVCodecContext
>> *avctx,
>>           if (err < 0)
>>               goto fail;
>>   
>> -        frames->initial_pool_size = 1;
>> -        // Add per-codec number of surfaces used for storing reference
>> frames.
>> -        switch (avctx->codec_id) {
>> -        case AV_CODEC_ID_H264:
>> -        case AV_CODEC_ID_HEVC:
>> -        case AV_CODEC_ID_AV1:
>> -            frames->initial_pool_size += 16;
>> -            break;
>> -        case AV_CODEC_ID_VP9:
>> -            frames->initial_pool_size += 8;
>> -            break;
>> -        case AV_CODEC_ID_VP8:
>> -            frames->initial_pool_size += 3;
>> -            break;
>> -        default:
>> -            frames->initial_pool_size += 2;
>> +        if (CONFIG_VAAPI_1)
>> +            frames->initial_pool_size = 0;
>> +        else {
>> +            frames->initial_pool_size = 1;
>> +            // Add per-codec number of surfaces used for storing reference
>> frames.
>> +            switch (avctx->codec_id) {
>> +            case AV_CODEC_ID_H264:
>> +            case AV_CODEC_ID_HEVC:
>> +            case AV_CODEC_ID_AV1:
>> +                frames->initial_pool_size += 16;
>> +                break;
>> +            case AV_CODEC_ID_VP9:
>> +                frames->initial_pool_size += 8;
>> +                break;
>> +            case AV_CODEC_ID_VP8:
>> +                frames->initial_pool_size += 3;
>> +                break;
>> +            default:
>> +                frames->initial_pool_size += 2;
>> +            }
>>           }
>>       }
>>   
> 
> Hi Mark,
> 
> Do you have any comment about dynamic frame pool used in vaapi ?

Are we completely sure that there are no driver/hardware combinations which rely on this still used?

I note that the D3D12 implementation in ffmpeg is currently incomplete and does not work on some hardware because it only supports dynamic pools (non-array textures), which makes me wonder whether changing this would cause the same problem for VAAPI.

Thanks,

- Mark