PR #21313 opened by Ramiro Polla (ramiro) URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21313 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21313.patch
Minimize number of reads and simplify conditionals. Also use memchr(), as suggested by Andreas Rheinhardt <[email protected]> >From ab28b728b8a337f5f74e6b42239bdd1c8257dcba Mon Sep 17 00:00:00 2001 From: Ramiro Polla <[email protected]> Date: Tue, 23 Sep 2025 17:11:40 +0200 Subject: [PATCH] avcodec/mjpegdec: speed up find_marker() Minimize number of reads and simplify conditionals. Also use memchr(), as suggested by Andreas Rheinhardt <[email protected]> --- libavcodec/mjpegdec.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c index 05150e982c..cc05e87898 100644 --- a/libavcodec/mjpegdec.c +++ b/libavcodec/mjpegdec.c @@ -2193,17 +2193,19 @@ static int mjpeg_decode_com(MJpegDecodeContext *s) static int find_marker(const uint8_t **pbuf_ptr, const uint8_t *buf_end) { const uint8_t *buf_ptr; - unsigned int v, v2; int val; int skipped = 0; buf_ptr = *pbuf_ptr; - while (buf_end - buf_ptr > 1) { - v = *buf_ptr++; - v2 = *buf_ptr; - if ((v == 0xff) && (v2 >= SOF0) && (v2 <= COM) && buf_ptr < buf_end) { + while ((buf_ptr = memchr(buf_ptr, 0xff, buf_end - buf_ptr))) { + buf_ptr++; + while (buf_ptr < buf_end) { val = *buf_ptr++; - goto found; + if (val != 0xff) { + if ((val >= SOF0) && (val <= COM)) + goto found; + break; + } } skipped++; } -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
