From d1c52483aeeab5584a685146ab86f746cc941834 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Mon, 3 Mar 2025 02:36:55 +0100
Subject: [PATCH 12/77] avcodec/mjpegenc: Simplify allocating huffman table
Reuse the already computed value of macroblocks; use an array
instead of a switch, evaluate 64 * sizeof(MJpegHuffmanCode)
at compile-time.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
libavcodec/mjpegenc.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)
diff --git a/libavcodec/mjpegenc.c b/libavcodec/mjpegenc.c
index f34e89235d..6f9818baf2 100644
--- a/libavcodec/mjpegenc.c
+++ b/libavcodec/mjpegenc.c
@@ -277,25 +277,21 @@ fail:
return ret;
}
-static int alloc_huffman(MpegEncContext *s)
+static int alloc_huffman(MJPEGEncContext *const m2)
{
- MJpegContext *m = s->mjpeg_ctx;
- size_t num_mbs, num_blocks, num_codes;
- int blocks_per_mb;
-
- switch (s->chroma_format) {
- case CHROMA_420: blocks_per_mb = 6; break;
- case CHROMA_422: blocks_per_mb = 8; break;
- case CHROMA_444: blocks_per_mb = 12; break;
- default: av_assert0(0);
+ MJpegContext *const m = &m2->mjpeg;
+ MpegEncContext *const s = &m2->mpeg.s;
+ static const char blocks_per_mb[] = {
+ [CHROMA_420] = 6, [CHROMA_422] = 8, [CHROMA_444] = 12
};
+ size_t num_blocks, num_codes;
// Make sure we have enough space to hold this frame.
- num_mbs = s->mb_width * s->mb_height;
- num_blocks = num_mbs * blocks_per_mb;
+ num_blocks = s->mb_num * blocks_per_mb[s->chroma_format];
num_codes = num_blocks * 64;
- m->huff_buffer = av_malloc_array(num_codes, sizeof(MJpegHuffmanCode));
+ m->huff_buffer = av_malloc_array(num_codes,
+ 64 /* codes per MB */ * sizeof(MJpegHuffmanCode));
if (!m->huff_buffer)
return AVERROR(ENOMEM);
return 0;
@@ -369,7 +365,7 @@ static av_cold int mjpeg_encode_init(AVCodecContext *avctx)
m->huffman = HUFFMAN_TABLE_DEFAULT;
if (m->huffman == HUFFMAN_TABLE_OPTIMAL)
- return alloc_huffman(s);
+ return alloc_huffman(m2);
return 0;
}
--
2.45.2