From fb845ffdd335a1efd6dfd43e8adeb530397b348e Mon Sep 17 00:00:00 2001 From: "Ronald S. Bultje" Date: Tue, 15 Jan 2013 08:38:54 -0800 Subject: [PATCH] h264: add 3 pixels below for subpixel filter wait position If the motion vector is at a subpixel position, we need 3 pixels below the motion vector's wholepel position available, not 2, since the MC filter is a sixtap filter for the hpel position, and then a bilin filter for the qpel position. This patch fixes highly irreproducible (0.1%) fate failures in frame 2 and 4 of h264-conformance-cama2_vtc_b (e.g. first P-frame, first field, last line of MB x=40,y=2 and second field and last lines of MBs x=39-40, y=3). These used pre-loopfilter instead of post-loopfilter data because the await_progress() waited for one line too little in that field, and the motion vector of these particular MBs happened to align exactly to a position where that demonstrates the bug. CC: libav-stable@libav.org Signed-off-by: Luca Barbato --- libavcodec/h264.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/libavcodec/h264.c b/libavcodec/h264.c index 3298565d97..2a711bdfff 100644 --- a/libavcodec/h264.c +++ b/libavcodec/h264.c @@ -290,10 +290,11 @@ static inline int get_lowest_part_list_y(H264Context *h, Picture *pic, int n, int height, int y_offset, int list) { int raw_my = h->mv_cache[list][scan8[n]][1]; - int filter_height = (raw_my & 3) ? 2 : 0; + int filter_height_up = (raw_my & 3) ? 2 : 0; + int filter_height_down = (raw_my & 3) ? 3 : 0; int full_my = (raw_my >> 2) + y_offset; - int top = full_my - filter_height; - int bottom = full_my + filter_height + height; + int top = full_my - filter_height_up; + int bottom = full_my + filter_height_down + height; return FFMAX(abs(top), bottom); }