[FFmpeg-devel] [PATCH 3/5] lavc/libkvazaar: export encoded frame stats

[Mark Thompson]

On 26/07/2020 13:26, Jun Zhao wrote:
> From: Jun Zhao <barryjzhao at tencent.com>
> 
> Export choosen pict_type and qp.
> 
> Signed-off-by: Jun Zhao <barryjzhao at tencent.com>
> ---
>   libavcodec/libkvazaar.c | 30 ++++++++++++++++++++++++++++++
>   1 file changed, 30 insertions(+)
> 
> diff --git a/libavcodec/libkvazaar.c b/libavcodec/libkvazaar.c
> index 71c9c8f..9032547 100644
> --- a/libavcodec/libkvazaar.c
> +++ b/libavcodec/libkvazaar.c
> @@ -37,6 +37,7 @@
>   
>   #include "avcodec.h"
>   #include "internal.h"
> +#include "packet_internal.h"
>   
>   typedef struct LibkvazaarContext {
>       const AVClass *class;
> @@ -170,6 +171,7 @@ static int libkvazaar_encode(AVCodecContext *avctx,
>       kvz_data_chunk *data_out = NULL;
>       uint32_t len_out = 0;
>       int retval = 0;
> +    int pict_type;
>   
>       *got_packet_ptr = 0;
>   
> @@ -257,6 +259,34 @@ static int libkvazaar_encode(AVCodecContext *avctx,
>               avpkt->flags |= AV_PKT_FLAG_KEY;
>           }
>   
> +        switch (frame_info.slice_type) {
> +        case KVZ_SLICE_I:
> +            pict_type = AV_PICTURE_TYPE_I;
> +            break;
> +        case KVZ_SLICE_P:
> +            pict_type = AV_PICTURE_TYPE_P;
> +            break;
> +        case KVZ_SLICE_B:
> +            pict_type = AV_PICTURE_TYPE_B;
> +            break;
> +        default:
> +            av_log(avctx, AV_LOG_ERROR, "Unknown picture type encountered.\n");
> +            return AVERROR_EXTERNAL;
> +        }
> +#if FF_API_CODED_FRAME
> +FF_DISABLE_DEPRECATION_WARNINGS
> +        avctx->coded_frame->pict_type = pict_type;
> +FF_ENABLE_DEPRECATION_WARNINGS
> +#endif

Is there some value to setting the deprecated fields?  They will disappear on the next version bump, which probably isn't very far away.

> +
> +        ff_side_data_set_encoder_stats(avpkt, frame_info.qp * FF_QP2LAMBDA, NULL, 0, pict_type);

I'm not familiar with kvazaar - is the QP value here actually reflective of the global quality in a useful way?  The documentation is not very good...

(Your following patch for OpenH264 uses a field "AverageFrameQP", which has an much more usefully-suggestive name.)

Zero is a valid QP value, but you shouldn't be passing it here.  Possibly it needs some more scaling to get the range to [1, FF_LAMDBA_MAX].

> +
> +#if FF_API_CODED_FRAME
> +FF_DISABLE_DEPRECATION_WARNINGS
> +        avctx->coded_frame->quality = frame_info.qp * FF_QP2LAMBDA;
> +FF_ENABLE_DEPRECATION_WARNINGS
> +#endif
> +
>           *got_packet_ptr = 1;
>       }
>   
>
- Mark