[FFmpeg-devel] [PATCH v2 2/2] lavc/vaapi_av1: Avoid sending the same slice buffer multiple times

[David Rosca]

When there are multiple tiles in one slice buffer, use multiple slice
params to avoid sending the same slice buffer multiple times and thus
increasing the bitstream size the driver will need to upload to hw.
---
v2: Avoid allocations every slice.

 libavcodec/vaapi_av1.c | 47 +++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/libavcodec/vaapi_av1.c b/libavcodec/vaapi_av1.c
index 4a90db1e09..4ee33a3ae3 100644
--- a/libavcodec/vaapi_av1.c
+++ b/libavcodec/vaapi_av1.c
@@ -19,6 +19,7 @@
  */
 
 #include "libavutil/frame.h"
+#include "libavutil/mem.h"
 #include "hwaccel_internal.h"
 #include "vaapi_decode.h"
 #include "internal.h"
@@ -42,6 +43,9 @@ typedef struct VAAPIAV1DecContext {
     */
     VAAPIAV1FrameRef ref_tab[AV1_NUM_REF_FRAMES];
     AVFrame *tmp_frame;
+
+    int nb_slice_params;
+    VASliceParameterBufferAV1 *slice_params;
 } VAAPIAV1DecContext;
 
 static VASurfaceID vaapi_av1_surface_id(AV1Frame *vf)
@@ -97,6 +101,8 @@ static int vaapi_av1_decode_uninit(AVCodecContext *avctx)
     for (int i = 0; i < FF_ARRAY_ELEMS(ctx->ref_tab); i++)
         av_frame_free(&ctx->ref_tab[i].frame);
 
+    av_freep(&ctx->slice_params);
+
     return ff_vaapi_decode_uninit(avctx);
 }
 
@@ -393,13 +399,24 @@ static int vaapi_av1_decode_slice(AVCodecContext *avctx,
 {
     const AV1DecContext *s = avctx->priv_data;
     VAAPIDecodePicture *pic = s->cur_frame.hwaccel_picture_private;
-    VASliceParameterBufferAV1 slice_param;
-    int err = 0;
+    VAAPIAV1DecContext *ctx = avctx->internal->hwaccel_priv_data;
+    int err, nb_params;
+
+    nb_params = s->tg_end - s->tg_start + 1;
+    if (ctx->nb_slice_params < nb_params) {
+        ctx->slice_params = av_realloc_array(ctx->slice_params,
+                                             nb_params,
+                                             sizeof(*ctx->slice_params));
+        if (!ctx->slice_params) {
+            ctx->nb_slice_params = 0;
+            err = AVERROR(ENOMEM);
+            goto fail;
+        }
+        ctx->nb_slice_params = nb_params;
+    }
 
     for (int i = s->tg_start; i <= s->tg_end; i++) {
-        memset(&slice_param, 0, sizeof(VASliceParameterBufferAV1));
-
-        slice_param = (VASliceParameterBufferAV1) {
+        ctx->slice_params[i - s->tg_start] = (VASliceParameterBufferAV1) {
             .slice_data_size   = s->tile_group_info[i].tile_size,
             .slice_data_offset = s->tile_group_info[i].tile_offset,
             .slice_data_flag   = VA_SLICE_DATA_FLAG_ALL,
@@ -408,18 +425,20 @@ static int vaapi_av1_decode_slice(AVCodecContext *avctx,
             .tg_start          = s->tg_start,
             .tg_end            = s->tg_end,
         };
-
-        err = ff_vaapi_decode_make_slice_buffer(avctx, pic, &slice_param, 1,
-                                                sizeof(VASliceParameterBufferAV1),
-                                                buffer,
-                                                size);
-        if (err) {
-            ff_vaapi_decode_cancel(avctx, pic);
-            return err;
-        }
     }
 
+    err = ff_vaapi_decode_make_slice_buffer(avctx, pic, ctx->slice_params, nb_params,
+                                            sizeof(VASliceParameterBufferAV1),
+                                            buffer,
+                                            size);
+    if (err)
+        goto fail;
+
     return 0;
+
+fail:
+    ff_vaapi_decode_cancel(avctx, pic);
+    return err;
 }
 
 const FFHWAccel ff_av1_vaapi_hwaccel = {
-- 
2.45.0