| Message ID | 20240212162755.43790-1-mattias.wadman@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel,v1] avcodec/h2645_parse: Don't treat 0x000002 as a start code and truncate | expand |
| Context | Check | Description |
|---|---|---|
| yinshiyou/make_loongarch64 | success | Make finished |
| yinshiyou/make_fate_loongarch64 | fail | Make fate failed |
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | fail | Make fate failed |
diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c index 28db465059..d54bdd53c2 100644 --- a/libavcodec/h2645_parse.c +++ b/libavcodec/h2645_parse.c @@ -40,8 +40,9 @@ int ff_h2645_extract_rbsp(const uint8_t *src, int length, nal->skipped_bytes = 0; #define STARTCODE_TEST \ - if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) { \ - if (src[i + 2] != 3 && src[i + 2] != 0) { \ + if (i + 2 < length && src[i + 1] == 0 && \ + (src[i + 2] == 3 || src[i + 2] == 1)) { \ + if (src[i + 2] == 1) { \ /* startcode, so we must be past the end */ \ length = i; \ } \
According to ITU-T H.265 7.4.2.1 this byte sequence should not appear in a NAL unit but in practice in rare cases it seems it does, possibly due to buggy encoders. Other players like VLC and Quicktime seem to be fine with it. Currently when this sequence is found it is treated as if the next start code has been found and the NAL unit gets truncated. This change limits the code to only look for first start code 0x0000001 or first escape 0x000003. Sadly i can't share the original source file with the issue but the first 80 bytes of the NAL unit looks like this: │00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f│0123456789abcdef│ 0x00000│00 00 00 01 02 01 d0 bc 57 a1 b8 44 70 01 00 0b│........W..Dp...│ 0x00010│80 2e 00 c2 6c ec 3e b9 e3 03 fb 91 2e d2 43 cb│....l.>.......C.│ 0x00020│1d 2c 00 00 02 00 02 00 5c 93 72 6f 31 76 18 00│.,......\.ro1v..│ 0x00030│08 38 aa b1 4c 33 3f fd 08 cb 77 9b d4 3c db 02│.8..L3?...w..<..│ 0x00040│a2 04 73 15 75 de 3b c4 67 c0 8f ca ad 31 f1 99│..s.u.;.g....1..│ --- libavcodec/h2645_parse.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)