[FFmpeg-cvslog] avcodec/vvc_parser: Don't store state unnecessarily

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Thu Jun 29 23:29:18 2023 +0200| [0009cbe11d0a57da447ad9234c57f98701e8553b] | committer: Andreas Rheinhardt

avcodec/vvc_parser: Don't store state unnecessarily

VVCParserContext.au_info is only used once (and in a read-only manner);
but this happens immediately after au_info has been completely
overwritten. Therefore one can just the src structure used to overwrite
au_info directly and remove au_info.

This also means that the whole referencing and unreferncing of au_info
(which duplicates AVBufferRefs CodedBitstreamH266Context and is
therefore of dubious gain) can be removed, as can the AVBufferRef*
contained in PuInfo; this also removes a certain uglyness: Sometimes
these AVBufferRef* were ownership pointers and sometimes not.

Reviewed-by: James Almer <jamrial at gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0009cbe11d0a57da447ad9234c57f98701e8553b
---

 libavcodec/vvc_parser.c | 63 +------------------------------------------------
 1 file changed, 1 insertion(+), 62 deletions(-)

diff --git a/libavcodec/vvc_parser.c b/libavcodec/vvc_parser.c
index efea833565..69696eef57 100644
--- a/libavcodec/vvc_parser.c
+++ b/libavcodec/vvc_parser.c
@@ -29,11 +29,6 @@
 #define IS_H266_SLICE(nut) (nut <= VVC_RASL_NUT || (nut >= VVC_IDR_W_RADL && nut <= VVC_GDR_NUT))
 
 typedef struct PuInfo {
-    AVBufferRef *sps_ref;
-    AVBufferRef *pps_ref;
-    AVBufferRef *slice_ref;
-    AVBufferRef *ph_ref;
-
     const H266RawPPS *pps;
     const H266RawSPS *sps;
     const H266RawPH *ph;
@@ -53,7 +48,6 @@ typedef struct VVCParserContext {
 
     CodedBitstreamFragment picture_unit;
 
-    PuInfo   au_info;
     AVPacket au;
     AVPacket last_au;
 
@@ -150,41 +144,6 @@ static int get_pict_type(const CodedBitstreamFragment *pu)
     return has_p ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
 }
 
-static void pu_info_unref(PuInfo *info)
-{
-    av_buffer_unref(&info->slice_ref);
-    av_buffer_unref(&info->ph_ref);
-    av_buffer_unref(&info->pps_ref);
-    av_buffer_unref(&info->sps_ref);
-    info->slice = NULL;
-    info->ph = NULL;
-    info->pps = NULL;
-    info->sps = NULL;
-    info->pic_type = AV_PICTURE_TYPE_NONE;
-}
-
-static int pu_info_ref(PuInfo *dest, const PuInfo *src)
-{
-    pu_info_unref(dest);
-    dest->sps_ref = av_buffer_ref(src->sps_ref);
-    dest->pps_ref = av_buffer_ref(src->pps_ref);
-    if (src->ph_ref)
-        dest->ph_ref = av_buffer_ref(src->ph_ref);
-    dest->slice_ref = av_buffer_ref(src->slice_ref);
-    if (!dest->sps_ref || !dest->pps_ref || (src->ph_ref && !dest->ph_ref)
-        || !dest->slice_ref) {
-        pu_info_unref(dest);
-        return AVERROR(ENOMEM);
-    }
-
-    dest->sps = src->sps;
-    dest->pps = src->pps;
-    dest->ph = src->ph;
-    dest->slice = src->slice;
-    dest->pic_type = src->pic_type;
-    return 0;
-}
-
 static void set_parser_ctx(AVCodecParserContext *s, AVCodecContext *avctx,
                            const PuInfo *pu)
 {
@@ -241,20 +200,6 @@ static void set_parser_ctx(AVCodecParserContext *s, AVCodecContext *avctx,
     }
 }
 
-static int set_ctx(AVCodecParserContext *s, AVCodecContext *avctx,
-                   const PuInfo *next_pu)
-{
-    VVCParserContext *ctx = s->priv_data;
-
-    int ret = pu_info_ref(&ctx->au_info, next_pu);
-    if (ret < 0)
-        return ret;
-
-    set_parser_ctx(s, avctx, &ctx->au_info);
-
-    return 0;
-}
-
 //8.3.1 Decoding process for picture order count.
 //VTM did not follow the spec, and it's much simpler than spec.
 //We follow the VTM.
@@ -338,10 +283,8 @@ static int get_pu_info(PuInfo *info, const CodedBitstreamH266Context *h266,
             continue;
         if ( nal->nal_unit_type == VVC_PH_NUT ) {
             info->ph = pu->units[i].content;
-            info->ph_ref = pu->units[i].content_ref;
         } else if (IS_H266_SLICE(nal->nal_unit_type)) {
             info->slice = pu->units[i].content;
-            info->slice_ref = pu->units[i].content_ref;
             if (info->slice->header.sh_picture_header_in_slice_header_flag)
                 info->ph = &info->slice->header.sh_picture_header;
             if (!info->ph) {
@@ -365,7 +308,6 @@ static int get_pu_info(PuInfo *info, const CodedBitstreamH266Context *h266,
         ret = AVERROR_INVALIDDATA;
         goto error;
     }
-    info->pps_ref = h266->pps_ref[info->ph->ph_pic_parameter_set_id];
     info->sps = h266->sps[info->pps->pps_seq_parameter_set_id];
     if (!info->sps) {
         av_log(logctx, AV_LOG_ERROR, "SPS id %d is not avaliable.\n",
@@ -373,7 +315,6 @@ static int get_pu_info(PuInfo *info, const CodedBitstreamH266Context *h266,
         ret = AVERROR_INVALIDDATA;
         goto error;
     }
-    info->sps_ref = h266->sps_ref[info->pps->pps_seq_parameter_set_id];
     info->pic_type = get_pict_type(pu);
     return 0;
   error:
@@ -430,8 +371,7 @@ static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
         goto end;
     }
     if (is_au_start(ctx, &info, avctx)) {
-        if ((ret = set_ctx(s, avctx, &info)) < 0)
-            goto end;
+        set_parser_ctx(s, avctx, &info);
         av_packet_move_ref(&ctx->last_au, &ctx->au);
     } else {
         ret = 1; //not a completed au
@@ -560,7 +500,6 @@ static void vvc_parser_close(AVCodecParserContext *s)
 {
     VVCParserContext *ctx = s->priv_data;
 
-    pu_info_unref(&ctx->au_info);
     av_packet_unref(&ctx->au);
     av_packet_unref(&ctx->last_au);
     ff_cbs_fragment_free(&ctx->picture_unit);