[FFmpeg-devel] [PATCH v2 8/9] av1_parser: Use CBS parser interface

[Mark Thompson]

This simplifies the parser and improves performance by reducing the number
of allocations and eliminating redundant copies.
---
 libavcodec/av1_parser.c | 63 +++++++++--------------------------------
 1 file changed, 13 insertions(+), 50 deletions(-)

diff --git a/libavcodec/av1_parser.c b/libavcodec/av1_parser.c
index b916608d65..4a743d92d4 100644
--- a/libavcodec/av1_parser.c
+++ b/libavcodec/av1_parser.c
@@ -27,7 +27,7 @@
 
 typedef struct AV1ParseContext {
     CodedBitstreamContext *cbc;
-    CodedBitstreamFragment temporal_unit;
+    AV1RawFrameHeader frame_header;
     int parsed_extradata;
 } AV1ParseContext;
 
@@ -50,8 +50,10 @@ static int av1_parser_parse(AVCodecParserContext *ctx,
                             const uint8_t *data, int size)
 {
     AV1ParseContext *s = ctx->priv_data;
-    CodedBitstreamFragment *td = &s->temporal_unit;
     CodedBitstreamAV1Context *av1 = s->cbc->priv_data;
+    AV1RawSequenceHeader *seq;
+    AV1RawColorConfig *color;
+    AV1RawFrameHeader *frame;
     int ret;
 
     *out_data = data;
@@ -66,67 +68,35 @@ static int av1_parser_parse(AVCodecParserContext *ctx,
     if (avctx->extradata_size && !s->parsed_extradata) {
         s->parsed_extradata = 1;
 
-        ret = ff_cbs_read(s->cbc, td, avctx->extradata, avctx->extradata_size);
-        if (ret < 0) {
+        ret = ff_cbs_parse_headers(s->cbc, NULL,
+                                   avctx->extradata, avctx->extradata_size);
+        if (ret < 0)
             av_log(avctx, AV_LOG_WARNING, "Failed to parse extradata.\n");
-        }
-
-        ff_cbs_fragment_reset(s->cbc, td);
     }
 
-    ret = ff_cbs_read(s->cbc, td, data, size);
+    ret = ff_cbs_parse_headers(s->cbc, &s->frame_header, data, size);
     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Failed to parse temporal unit.\n");
         goto end;
     }
+    frame = &s->frame_header;
 
     if (!av1->sequence_header) {
         av_log(avctx, AV_LOG_ERROR, "No sequence header available\n");
         goto end;
     }
+    seq = av1->sequence_header;
+    color = &seq->color_config;
 
-    for (int i = 0; i < td->nb_units; i++) {
-        CodedBitstreamUnit *unit = &td->units[i];
-        AV1RawOBU *obu = unit->content;
-        AV1RawSequenceHeader *seq = av1->sequence_header;
-        AV1RawColorConfig *color = &seq->color_config;
-        AV1RawFrameHeader *frame;
-        int frame_type;
-
-        if (unit->type == AV1_OBU_FRAME)
-            frame = &obu->obu.frame.header;
-        else if (unit->type == AV1_OBU_FRAME_HEADER)
-            frame = &obu->obu.frame_header;
-        else
-            continue;
-
-        if (frame->show_existing_frame) {
-            AV1ReferenceFrameState *ref = &av1->ref[frame->frame_to_show_map_idx];
-
-            if (!ref->valid) {
-                av_log(avctx, AV_LOG_ERROR, "Invalid reference frame\n");
-                goto end;
-            }
-
-            ctx->width  = ref->frame_width;
-            ctx->height = ref->frame_height;
-            frame_type  = ref->frame_type;
-
-            ctx->key_frame = 0;
-        } else if (!frame->show_frame) {
-            continue;
-        } else {
             ctx->width  = av1->frame_width;
             ctx->height = av1->frame_height;
-            frame_type  = frame->frame_type;
 
-            ctx->key_frame = frame_type == AV1_FRAME_KEY;
-        }
+            ctx->key_frame = frame->frame_type == AV1_FRAME_KEY;
 
         avctx->profile = seq->seq_profile;
         avctx->level   = seq->seq_level_idx[0];
 
-        switch (frame_type) {
+        switch (frame->frame_type) {
         case AV1_FRAME_KEY:
         case AV1_FRAME_INTRA_ONLY:
             ctx->pict_type = AV_PICTURE_TYPE_I;
@@ -155,11 +125,8 @@ static int av1_parser_parse(AVCodecParserContext *ctx,
             break;
         }
         av_assert2(ctx->format != AV_PIX_FMT_NONE);
-    }
 
 end:
-    ff_cbs_fragment_reset(s->cbc, td);
-
     s->cbc->log_ctx = NULL;
 
     return size;
@@ -182,9 +149,6 @@ static av_cold int av1_parser_init(AVCodecParserContext *ctx)
     if (ret < 0)
         return ret;
 
-    s->cbc->decompose_unit_types    = (CodedBitstreamUnitType *)decompose_unit_types;
-    s->cbc->nb_decompose_unit_types = FF_ARRAY_ELEMS(decompose_unit_types);
-
     return 0;
 }
 
@@ -192,7 +156,6 @@ static void av1_parser_close(AVCodecParserContext *ctx)
 {
     AV1ParseContext *s = ctx->priv_data;
 
-    ff_cbs_fragment_free(s->cbc, &s->temporal_unit);
     ff_cbs_close(&s->cbc);
 }
 
-- 
2.20.1