ffmpeg | branch: master | Niklas Haas <g...@haasn.dev> | Wed Sep 27 15:16:51 2023 +0200| [338a5fcdbe9571e6f22817a111621259d83f2e59] | committer: Niklas Haas
lavc/h274: fix PRNG definition The spec specifies x^31 + x^3 + 1 as the polynomial, but the diagram in Figure 1-1 omits the +1 offset. The initial implementation was based on the diagram, but this is wrong (produces subtly incorrect results). > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=338a5fcdbe9571e6f22817a111621259d83f2e59 --- libavcodec/h274.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/h274.c b/libavcodec/h274.c index a69f941142..fc111cdb50 100644 --- a/libavcodec/h274.c +++ b/libavcodec/h274.c @@ -38,7 +38,7 @@ static void prng_shift(uint32_t *state) { // Primitive polynomial x^31 + x^3 + 1 (modulo 2) uint32_t x = *state; - uint8_t feedback = (x >> 2) ^ (x >> 30); + uint8_t feedback = 1u ^ (x >> 2) ^ (x >> 30); *state = (x << 1) | (feedback & 1u); } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
