From 361b3c873ee011598e16397db699bbfe5c045d7c Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 18 Aug 2019 01:28:38 +0200 Subject: avcodec/pngdec: Optimize has_trns code add inner loop specialisations for 2 bpp and 4 bpp These are all cases for which i found testsamples. 30M cycles -> 5M cycles Testcase: fate-rgbapng-4816 Testcase: 16097/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APNG_fuzzer-5664690889293824 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/pngdec.c | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) (limited to 'libavcodec') diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c index cad5796545..2d6c1b218e 100644 --- a/libavcodec/pngdec.c +++ b/libavcodec/pngdec.c @@ -24,6 +24,7 @@ #include "libavutil/avassert.h" #include "libavutil/bprint.h" #include "libavutil/imgutils.h" +#include "libavutil/intreadwrite.h" #include "libavutil/stereo3d.h" #include "libavutil/mastering_display_metadata.h" @@ -1367,15 +1368,35 @@ exit_loop: for (y = 0; y < s->height; ++y) { uint8_t *row = &s->image_buf[s->image_linesize * y]; - /* since we're updating in-place, we have to go from right to left */ - for (x = s->width; x > 0; --x) { - uint8_t *pixel = &row[s->bpp * (x - 1)]; - memmove(pixel, &row[raw_bpp * (x - 1)], raw_bpp); + if (s->bpp == 2 && byte_depth == 1) { + uint8_t *pixel = &row[2 * s->width - 1]; + uint8_t *rowp = &row[1 * s->width - 1]; + int tcolor = s->transparent_color_be[0]; + for (x = s->width; x > 0; --x) { + *pixel-- = *rowp == tcolor ? 0 : 0xff; + *pixel-- = *rowp--; + } + } else if (s->bpp == 4 && byte_depth == 1) { + uint8_t *pixel = &row[4 * s->width - 1]; + uint8_t *rowp = &row[3 * s->width - 1]; + int tcolor = AV_RL24(s->transparent_color_be); + for (x = s->width; x > 0; --x) { + *pixel-- = AV_RL24(rowp-2) == tcolor ? 0 : 0xff; + *pixel-- = *rowp--; + *pixel-- = *rowp--; + *pixel-- = *rowp--; + } + } else { + /* since we're updating in-place, we have to go from right to left */ + for (x = s->width; x > 0; --x) { + uint8_t *pixel = &row[s->bpp * (x - 1)]; + memmove(pixel, &row[raw_bpp * (x - 1)], raw_bpp); - if (!memcmp(pixel, s->transparent_color_be, raw_bpp)) { - memset(&pixel[raw_bpp], 0, byte_depth); - } else { - memset(&pixel[raw_bpp], 0xff, byte_depth); + if (!memcmp(pixel, s->transparent_color_be, raw_bpp)) { + memset(&pixel[raw_bpp], 0, byte_depth); + } else { + memset(&pixel[raw_bpp], 0xff, byte_depth); + } } } } -- cgit v1.2.3