[libav-devel] [PATCH 2/2] vaapi_h265: Mark unused entries in RefPicList[01] as explicitly invalid

Mark Thompson sw at jkqxz.net
Wed Dec 20 12:57:27 CET 2017


On 18/12/17 01:59, Jun Zhao wrote:
> On 2017/12/18 4:05, Mark Thompson wrote:
>> The iHD driver looks at entries beyond num_ref_idx_l[01]_active_minus1
>> for unknown reasons.
>> ---
>> This still isn't enough to actually work for encoding H.265 with the iHD driver on Skylake.  It can generate output with this rather than crashing, but the output is still wrong (though it does resemble the input somewhat).
>>
>> It also seems to like inserting emulation prevention bytes everywhere in slice headers after the first, so it breaks totally if AUDs are present.
> I think the root cause for HECV enc can't work in SKL is iHD have a
> limitation for
> max_transform_hierarchy_depth_inter/max_transform_hierarchy_depth_intra,
> you can apply the patch in
> https://github.com/mypopydev/FFmpeg/commit/fb35b6167d16d1acb81d0c82e19293c7cf97a574,
> then re-try h265 ENC with iHD in SKL. Tks.

I'm not sure that can be a hardware limitation, since it does work with the i965 driver on the same hardware.

If it really is different then I think something will need to be added to VAAPI itself to query these parameters (certainly all the transform size stuff, possibly more).  Currently we use values suitable for i965 because it was the only working driver when the code was written, but once there is a second driver we need some way to choose between them.

- Mark

>>
>>  libavcodec/vaapi_encode_h265.c | 21 +++++++++++++++++++--
>>  1 file changed, 19 insertions(+), 2 deletions(-)
>>
>> diff --git a/libavcodec/vaapi_encode_h265.c b/libavcodec/vaapi_encode_h265.c
>> index a9853a3aa..813d4f944 100644
>> --- a/libavcodec/vaapi_encode_h265.c
>> +++ b/libavcodec/vaapi_encode_h265.c
>> @@ -767,8 +767,6 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
>>  
>>          .num_ref_idx_l0_active_minus1 = sh->num_ref_idx_l0_active_minus1,
>>          .num_ref_idx_l1_active_minus1 = sh->num_ref_idx_l1_active_minus1,
>> -        .ref_pic_list0[0]             = vpic->reference_frames[0],
>> -        .ref_pic_list1[0]             = vpic->reference_frames[1],
>>  
>>          .luma_log2_weight_denom         = sh->luma_log2_weight_denom,
>>          .delta_chroma_log2_weight_denom = sh->delta_chroma_log2_weight_denom,
>> @@ -802,6 +800,25 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
>>          },
>>      };
>>  
>> +    for (i = 0; i < FF_ARRAY_ELEMS(vslice->ref_pic_list0); i++) {
>> +        vslice->ref_pic_list0[i].picture_id = VA_INVALID_ID;
>> +        vslice->ref_pic_list0[i].flags      = VA_PICTURE_HEVC_INVALID;
>> +        vslice->ref_pic_list1[i].picture_id = VA_INVALID_ID;
>> +        vslice->ref_pic_list1[i].flags      = VA_PICTURE_HEVC_INVALID;
>> +    }
>> +
>> +    av_assert0(pic->nb_refs <= 2);
>> +    if (pic->nb_refs >= 1) {
>> +        // Backward reference for P- or B-frame.
>> +        av_assert0(pic->type == PICTURE_TYPE_P ||
>> +                   pic->type == PICTURE_TYPE_B);
>> +        vslice->ref_pic_list0[0] = vpic->reference_frames[0];
>> +    }
>> +    if (pic->nb_refs >= 2) {
>> +        // Forward reference for B-frame.
>> +        av_assert0(pic->type == PICTURE_TYPE_B);
>> +        vslice->ref_pic_list1[0] = vpic->reference_frames[1];
>> +    }
>>  
>>      return 0;
>>  }
> 



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