From 11d68061103257173a3c065b176cc84ad63885a7 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Thu, 27 Mar 2025 03:03:02 +0100
Subject: [PATCH] avcodec/mjpegenc: Don't allocate unnecessarily much memory
We need to allocate space for 64 coefficients per block;
24dbc4c2e82481f89d6fcacee1949e5038c5c2fc wanted to
perform the calculation 64*sizeof(MJpegHuffmanCode)
at compile time, yet in the end did it in a way that
made it allocate 64 times as much memory as needed.
Reported-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
libavcodec/mjpegenc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/libavcodec/mjpegenc.c b/libavcodec/mjpegenc.c
index 668065011c..214e2b0ec1 100644
--- a/libavcodec/mjpegenc.c
+++ b/libavcodec/mjpegenc.c
@@ -291,13 +291,12 @@ static int alloc_huffman(MJPEGEncContext *const m2)
static const char blocks_per_mb[] = {
[CHROMA_420] = 6, [CHROMA_422] = 8, [CHROMA_444] = 12
};
- size_t num_blocks, num_codes;
+ size_t num_blocks;
// Make sure we have enough space to hold this frame.
num_blocks = s->c.mb_num * blocks_per_mb[s->c.chroma_format];
- num_codes = num_blocks * 64;
- m->huff_buffer = av_malloc_array(num_codes,
+ m->huff_buffer = av_malloc_array(num_blocks,
64 /* codes per MB */ * sizeof(MJpegHuffmanCode));
if (!m->huff_buffer)
return AVERROR(ENOMEM);
--
2.45.2