From 5da8b522c85c2fb877917c1df6388312803fb36e Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Sun, 23 Oct 2022 14:42:24 +0200
Subject: [PATCH] avformat/mux: Don't call ff_toupper4() unnecessarily

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavformat/mux.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavformat/mux.c b/libavformat/mux.c
index 5d89458f82..a7517dae0a 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -148,6 +148,7 @@ static int validate_codec_tag(AVFormatContext *s, AVStream *st)
 {
     const AVCodecTag *avctag;
     enum AVCodecID id = AV_CODEC_ID_NONE;
+    unsigned uppercase_tag = ff_toupper4(st->codecpar->codec_tag);
     int64_t tag  = -1;
 
     /**
@@ -159,7 +160,7 @@ static int validate_codec_tag(AVFormatContext *s, AVStream *st)
     for (int n = 0; s->oformat->codec_tag[n]; n++) {
         avctag = s->oformat->codec_tag[n];
         while (avctag->id != AV_CODEC_ID_NONE) {
-            if (ff_toupper4(avctag->tag) == ff_toupper4(st->codecpar->codec_tag)) {
+            if (ff_toupper4(avctag->tag) == uppercase_tag) {
                 id = avctag->id;
                 if (id == st->codecpar->codec_id)
                     return 1;