From 571e4055dc241f8b4556a27b49691edc02edf10b Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Thu, 30 Jun 2022 20:36:53 +0200
Subject: [PATCH] avcodec/pthread_slice: Reuse buffer if possible

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavcodec/pthread_slice.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavcodec/pthread_slice.c b/libavcodec/pthread_slice.c
index 756cc59dbf..a4d31c6f4d 100644
--- a/libavcodec/pthread_slice.c
+++ b/libavcodec/pthread_slice.c
@@ -242,9 +242,11 @@ int ff_slice_thread_allocz_entries(AVCodecContext *avctx, int count)
     if (avctx->active_thread_type & FF_THREAD_SLICE)  {
         SliceThreadContext *p = avctx->internal->thread_ctx;
 
-        if (p->entries) {
-            av_freep(&p->entries);
+        if (p->entries_count == count) {
+            memset(p->entries, 0, p->entries_count * sizeof(*p->entries));
+            return 0;
         }
+        av_freep(&p->entries);
 
         p->entries       = av_calloc(count, sizeof(*p->entries));
         if (!p->entries) {