From 616e9d24137d34fba02ebd159d5a7186aaf53eca Mon Sep 17 00:00:00 2001 From: Niklas Haas Date: Wed, 27 Sep 2023 15:39:00 +0200 Subject: [PATCH] lavc/h274: correct grain DB indices The spec specified indices in the order [x][y], but our code follows the traditional C convention of [y][x]. This was not correctly account for when calculating the base index of the grain database access. --- libavcodec/h274.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libavcodec/h274.c b/libavcodec/h274.c index fc111cdb50..2388826d54 100644 --- a/libavcodec/h274.c +++ b/libavcodec/h274.c @@ -259,11 +259,11 @@ int ff_h274_apply_film_grain(AVFrame *out_frame, const AVFrame *in_frame, // only advanced in 16x16 blocks, so use a nested loop for (int y = 0; y < height; y += 16) { for (int x = 0; x < width; x += 16) { - uint16_t y_offset = (seed >> 16) % 52; - uint16_t x_offset = (seed & 0xFFFF) % 56; + uint16_t x_offset = (seed >> 16) % 52; + uint16_t y_offset = (seed & 0xFFFF) % 56; const int invert = (seed & 0x1); - y_offset &= 0xFFFC; - x_offset &= 0xFFF8; + x_offset &= 0xFFFC; + y_offset &= 0xFFF8; prng_shift(&seed); for (int yy = 0; yy < 16 && y+yy < height; yy += 8) {