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

[mypopy at gmail.com]

On Mon, Aug 17, 2020 at 7:08 PM Joose Sainio <joose.sainio at tuni.fi> wrote:
>
> On 7.8.2020 5.40, mypopy at gmail.com wrote:
> > On Sun, Jul 26, 2020 at 8:45 PM Jun Zhao <mypopydev at gmail.com> 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
> >> +
> >> + ff_side_data_set_encoder_stats(avpkt, frame_info.qp * FF_QP2LAMBDA,
> >> NULL, 0, pict_type);
> >> +
> >> +#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;
> >> }
> >>
> >> --
> >> 2.7.4
> >>
> > ping ?
> Sorry, I forgot I was subscribed to the list on the old organization
> so the message didn't go through originally.
>
> In terms of Kvazaar this seems ok but the QP to lambda conversion will
> result
> in vastly different lambda value than what Kvazaar would have used
> internally (and in fact the FF_QP2LAMBDA macro states it is for h.263).
> I can't comment whether this is problem on the ffmpeg side.
>
> The correct formula for hevc/h.265 would be
> lambda = 0.57 * pow(2.0, (qp - 12 / 3.0))
This is the other issue, I think, will try to fix it.
>
> - Joose
>