From c936c319bd54f097cc1d75b1ee1c407d53215d71 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Mon, 10 Jan 2022 23:23:43 +0100
Subject: [PATCH] avcodec/mpegpicture: Decrease size of encoding_error array

The current size is AV_NUM_DATA_POINTERS (i.e. eight).
This number is chosen in order to minimize the amount of allocations
for AVFrame.extended_(data|buf) for audio; it is meaningless
for video for which four is sufficient. So decrease this array
in order to minimize what is copied in ff_mpeg_ref_picture()
and at the places that copy a whole MpegEncContext.

Also do the same for snowenc.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavcodec/mpegpicture.h   | 3 ++-
 libavcodec/mpegvideo_enc.c | 2 +-
 libavcodec/snow.h          | 4 +++-
 libavcodec/snowenc.c       | 2 +-
 4 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/libavcodec/mpegpicture.h b/libavcodec/mpegpicture.h
index 4bcd666797..a354c2a83c 100644
--- a/libavcodec/mpegpicture.h
+++ b/libavcodec/mpegpicture.h
@@ -29,6 +29,7 @@
 #include "motion_est.h"
 #include "thread.h"
 
+#define MPEGVIDEO_MAX_PLANES 4
 #define MAX_PICTURE_COUNT 36
 #define EDGE_WIDTH 16
 
@@ -88,7 +89,7 @@ typedef struct Picture {
     int reference;
     int shared;
 
-    uint64_t encoding_error[AV_NUM_DATA_POINTERS];
+    uint64_t encoding_error[MPEGVIDEO_MAX_PLANES];
 } Picture;
 
 /**
diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c
index afad9c8be1..35f0f79d4e 100644
--- a/libavcodec/mpegvideo_enc.c
+++ b/libavcodec/mpegvideo_enc.c
@@ -1792,7 +1792,7 @@ vbv_retry:
         }
         ff_side_data_set_encoder_stats(pkt, s->current_picture.f->quality,
                                        s->current_picture_ptr->encoding_error,
-                                       (avctx->flags&AV_CODEC_FLAG_PSNR) ? 4 : 0,
+                                       (avctx->flags&AV_CODEC_FLAG_PSNR) ? MPEGVIDEO_MAX_PLANES : 0,
                                        s->pict_type);
 
         if (avctx->flags & AV_CODEC_FLAG_PASS1)
diff --git a/libavcodec/snow.h b/libavcodec/snow.h
index 8795491cf3..f5beca66e9 100644
--- a/libavcodec/snow.h
+++ b/libavcodec/snow.h
@@ -35,6 +35,8 @@
 #include "mpegvideo.h"
 #include "h264qpel.h"
 
+#define SNOW_MAX_PLANES 4
+
 #define FF_ME_ITER 3
 
 #define MID_STATE 128
@@ -188,7 +190,7 @@ typedef struct SnowContext{
     AVMotionVector *avmv;
     unsigned avmv_size;
     int avmv_index;
-    uint64_t encoding_error[AV_NUM_DATA_POINTERS];
+    uint64_t encoding_error[SNOW_MAX_PLANES];
 
     int pred;
 }SnowContext;
diff --git a/libavcodec/snowenc.c b/libavcodec/snowenc.c
index 96b0d320bc..df31eb8132 100644
--- a/libavcodec/snowenc.c
+++ b/libavcodec/snowenc.c
@@ -1858,7 +1858,7 @@ redo_frame:
 
     ff_side_data_set_encoder_stats(pkt, s->current_picture->quality,
                                    s->encoding_error,
-                                   (s->avctx->flags&AV_CODEC_FLAG_PSNR) ? 4 : 0,
+                                   (s->avctx->flags&AV_CODEC_FLAG_PSNR) ? SNOW_MAX_PLANES : 0,
                                    s->current_picture->pict_type);
 
     pkt->size = ff_rac_terminate(c, 0);