On Thu, 17 Jan 2019, Michael Niedermayer wrote:
On Wed, Jan 16, 2019 at 08:00:22PM +0100, Marton Balint wrote:
On Tue, 15 Jan 2019, Michael Niedermayer wrote:
On Sun, Dec 30, 2018 at 07:15:49PM +0100, Marton Balint wrote:
On Fri, 28 Dec 2018, Michael Niedermayer wrote:
On Wed, Dec 26, 2018 at 10:16:47PM +0100, Marton Balint wrote:
On Wed, 26 Dec 2018, Paul B Mahol wrote:
On 12/26/18, Michael Niedermayer <mich...@niedermayer.cc> wrote:
On Wed, Dec 26, 2018 at 04:32:17PM +0100, Paul B Mahol wrote:
On 12/25/18, Michael Niedermayer <mich...@niedermayer.cc> wrote:
Fixes: Timeout
Fixes:
11502/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WCMV_fuzzer-5664893810769920
Before: Executed
clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WCMV_fuzzer-5664893810769920
in 11294 ms
After : Executed
clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WCMV_fuzzer-5664893810769920
in 4249 ms
Found-by: continuous fuzzing process
https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc>
---
libavutil/imgutils.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/libavutil/imgutils.c b/libavutil/imgutils.c
index 4938a7ef67..cc38f1e878 100644
--- a/libavutil/imgutils.c
+++ b/libavutil/imgutils.c
@@ -529,6 +529,12 @@ static void memset_bytes(uint8_t *dst, size_t
dst_size,
uint8_t *clear,
}
} else if (clear_size == 4) {
uint32_t val = AV_RN32(clear);
+ uint64_t val8 = val * 0x100000001ULL;
+ for (; dst_size >= 32; dst_size -= 32) {
+ AV_WN64(dst , val8); AV_WN64(dst+ 8, val8);
+ AV_WN64(dst+16, val8); AV_WN64(dst+24, val8);
+ dst += 32;
+ }
for (; dst_size >= 4; dst_size -= 4) {
AV_WN32(dst, val);
dst += 4;
--
2.20.1
NAK, implement special memset function instead.
I can move the added loop into a seperate function, if thats what you
suggest ?
No, don't do that.
All the code is already in a "special" memset though, this is
memset_bytes()
I guess function is less useful if its static. So any duplicate should
be avoided in codebase.
Isn't av_memcpy_backptr does almost exactly what is needed here? That can
also be optimized further if needed.
av_memcpy_backptr() copies data with overlap, its more like a recursive
memmove().
So? As far as I see the memset_bytes function in imgutils.c can be replaced
with this:
if (clear_size > dst_size)
clear_size = dst_size;
memcpy(dst, clear, clear_size);
av_memcpy_backptr(dst + clear_size, clear_size, dst_size - clear_size);
I am not against an av_memset_bytes API addition, but I believe it should
share code with av_memcpy_backptr to avoid duplication.
ive implemented this, it does not seem to be really faster in the testcase
I guess it is not faster because you have not applied your original
optimalization to fill32 in libavutil/mem.c. Could you compare speed after
optimizing that the same way your original patch did it with imgutils
memset_bytes?
sure, that makes it faster:
Thanks, both patches LGTM.
Regards,
Marton
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