[FFmpeg-devel] [PATCH 31/92] Vulkan patchset part 1 - common code changes

[Anton Khirnov]

Quoting Anton Khirnov (2023-04-16 22:38:16)
> Quoting Lynne (2023-03-14 07:33:43)
> > From 61f412eea3fbcb1e2a8625796760c0e24fa3fb83 Mon Sep 17 00:00:00 2001
> > From: Lynne <dev at lynne.ee>
> > Date: Tue, 17 Jan 2023 05:01:45 +0100
> > Subject: [PATCH 27/92] h264dec: add hwaccel_params_buf
> > 
> > diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
> > index 0aee724c0d..6559593195 100644
> > --- a/libavcodec/h264dec.c
> > +++ b/libavcodec/h264dec.c
> > @@ -341,6 +341,7 @@ static av_cold int h264_decode_end(AVCodecContext *avctx)
> >      H264Context *h = avctx->priv_data;
> >      int i;
> >  
> > +    av_buffer_unref(&h->hwaccel_params_buf);
> >      ff_h264_remove_all_refs(h);
> >      ff_h264_free_tables(h);
> >  
> > @@ -470,6 +471,7 @@ static void h264_decode_flush(AVCodecContext *avctx)
> >  
> >      ff_h264_flush_change(h);
> >      ff_h264_sei_uninit(&h->sei);
> > +    av_buffer_unref(&h->hwaccel_params_buf);
> >  
> >      for (i = 0; i < H264_MAX_PICTURE_COUNT; i++)
> >          ff_h264_unref_picture(h, &h->DPB[i]);
> > @@ -669,6 +671,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size)
> >              avpriv_request_sample(avctx, "data partitioning");
> >              break;
> >          case H264_NAL_SEI:
> > +            av_buffer_unref(&h->hwaccel_params_buf);
> >              if (h->setup_finished) {
> >                  avpriv_request_sample(avctx, "Late SEI");
> >                  break;
> > @@ -682,6 +685,7 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size)
> >              break;
> >          case H264_NAL_SPS: {
> >              GetBitContext tmp_gb = nal->gb;
> > +            av_buffer_unref(&h->hwaccel_params_buf);
> >              if (avctx->hwaccel && avctx->hwaccel->decode_params) {
> >                  ret = avctx->hwaccel->decode_params(avctx,
> >                                                      nal->type,
> 
> Removed on SEI and SPS? That seems bizarre and highly arbitrary. Why
> specifically those two?

Found the explanation in the cover letter - I assume SEI is a mistake
and should really be PPS. The points where it is reset still seem highly
Vulkan-specific, so I think it'd be better for the decoder to set a flag
on seeing new parameter sets. Vulkan could would then check and clear
the flag as needed.

-- 
Anton Khirnov