From ba6a5e7a3d4c372a98f910dda7e4d65847eda817 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Mon, 22 Aug 2022 20:33:32 +0200
Subject: [PATCH] avcodec/hevcdec: Move collocated_ref to HEVCContext

Only the collocated_ref of the current frame (i.e. HEVCContext.ref)
is ever used*, so move it to HEVCContext directly after ref.

*: This goes so far that collocated_ref was not even synced across
threads in case of frame-threading.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavcodec/hevc_mvs.c  | 2 +-
 libavcodec/hevc_refs.c | 5 ++---
 libavcodec/hevcdec.c   | 6 +++---
 libavcodec/hevcdec.h   | 2 +-
 4 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/libavcodec/hevc_mvs.c b/libavcodec/hevc_mvs.c
index c231797a57..0a8cc2c43d 100644
--- a/libavcodec/hevc_mvs.c
+++ b/libavcodec/hevc_mvs.c
@@ -227,7 +227,7 @@ static int temporal_luma_motion_vector(const HEVCContext *s, int x0, int y0,
     int availableFlagLXCol = 0;
     int colPic;
 
-    const HEVCFrame *ref = s->ref->collocated_ref;
+    const HEVCFrame *ref = s->collocated_ref;
 
     if (!ref) {
         memset(mvLXCol, 0, sizeof(*mvLXCol));
diff --git a/libavcodec/hevc_refs.c b/libavcodec/hevc_refs.c
index 793514e5d8..10fdeaf7ff 100644
--- a/libavcodec/hevc_refs.c
+++ b/libavcodec/hevc_refs.c
@@ -51,8 +51,6 @@ void ff_hevc_unref_frame(HEVCFrame *frame, int flags)
         frame->rpl_tab    = NULL;
         frame->refPicList = NULL;
 
-        frame->collocated_ref = NULL;
-
         ff_refstruct_unref(&frame->hwaccel_picture_private);
     }
 }
@@ -156,6 +154,7 @@ int ff_hevc_set_new_ref(HEVCContext *s, AVFrame **frame, int poc)
 
     *frame = ref->frame;
     s->ref = ref;
+    s->collocated_ref = NULL;
 
     if (s->sh.pic_output_flag)
         ref->flags = HEVC_FRAME_FLAG_OUTPUT | HEVC_FRAME_FLAG_SHORT_REF;
@@ -387,7 +386,7 @@ int ff_hevc_slice_rpl(HEVCContext *s)
 
         if (sh->collocated_list == list_idx &&
             sh->collocated_ref_idx < rpl->nb_refs)
-            s->ref->collocated_ref = rpl->ref[sh->collocated_ref_idx];
+            s->collocated_ref = rpl->ref[sh->collocated_ref_idx];
     }
 
     return 0;
diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index eb881c3ddb..b267f6ebcf 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -2920,7 +2920,7 @@ static int hevc_frame_start(HEVCContext *s)
 fail:
     if (s->ref)
         ff_hevc_unref_frame(s->ref, ~0);
-    s->ref = NULL;
+    s->ref = s->collocated_ref = NULL;
     return ret;
 }
 
@@ -3136,7 +3136,7 @@ static int decode_nal_units(HEVCContext *s, const uint8_t *buf, int length)
     int i, ret = 0;
     int eos_at_start = 1;
 
-    s->ref = NULL;
+    s->ref = s->collocated_ref = NULL;
     s->last_eos = s->eos;
     s->eos = 0;
     s->overlap = 0;
@@ -3351,7 +3351,7 @@ static int hevc_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
                    old, s->dovi_ctx.dv_profile);
     }
 
-    s->ref = NULL;
+    s->ref = s->collocated_ref = NULL;
     ret    = decode_nal_units(s, avpkt->data, avpkt->size);
     if (ret < 0)
         return ret;
diff --git a/libavcodec/hevcdec.h b/libavcodec/hevcdec.h
index 7f165b077d..6ef7d4f60f 100644
--- a/libavcodec/hevcdec.h
+++ b/libavcodec/hevcdec.h
@@ -413,7 +413,6 @@ typedef struct HEVCFrame {
     RefPicListTab **rpl_tab;
     int ctb_count;
     int poc;
-    struct HEVCFrame *collocated_ref;
 
     AVBufferRef *tab_mvf_buf;
     AVBufferRef *rpl_tab_buf;
@@ -529,6 +528,7 @@ typedef struct HEVCContext {
     enum HEVCNALUnitType nal_unit_type;
     int temporal_id;  ///< temporal_id_plus1 - 1
     HEVCFrame *ref;
+    HEVCFrame *collocated_ref;
     HEVCFrame DPB[32];
     int poc;
     int pocTid0;