From ae591aeea58d64399b8281be31dacec0de85ae04 Mon Sep 17 00:00:00 2001 From: "Ronald S. Bultje" Date: Tue, 14 Feb 2012 12:40:19 -0800 Subject: [PATCH] vc1: prevent using last_frame as a reference for I/P first frame. Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind CC: libav-stable@libav.org --- libavcodec/vc1dec.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c index c66260996f..e48aabcfb2 100644 --- a/libavcodec/vc1dec.c +++ b/libavcodec/vc1dec.c @@ -478,7 +478,10 @@ static void vc1_mc_1mv(VC1Context *v, int dir) int dxy, mx, my, uvmx, uvmy, src_x, src_y, uvsrc_x, uvsrc_y; int off, off_uv; int v_edge_pos = s->v_edge_pos >> v->field_mode; - if (!v->field_mode && !v->s.last_picture.f.data[0]) + + if ((!v->field_mode || + (v->ref_field_type[dir] == 1 && v->cur_field_type == 1)) && + !v->s.last_picture.f.data[0]) return; mx = s->mv[dir][0][0]; @@ -690,7 +693,9 @@ static void vc1_mc_4mv_luma(VC1Context *v, int n, int dir) int fieldmv = (v->fcm == ILACE_FRAME) ? v->blk_mv_type[s->block_index[n]] : 0; int v_edge_pos = s->v_edge_pos >> v->field_mode; - if (!v->field_mode && !v->s.last_picture.f.data[0]) + if ((!v->field_mode || + (v->ref_field_type[dir] == 1 && v->cur_field_type == 1)) && + !v->s.last_picture.f.data[0]) return; mx = s->mv[dir][n][0]; @@ -946,6 +951,8 @@ static void vc1_mc_4mv_chroma(VC1Context *v, int dir) if (dominant) chroma_ref_type = !v->cur_field_type; } + if (v->field_mode && chroma_ref_type == 1 && v->cur_field_type == 1 && !v->s.last_picture.f.data[0]) + return; s->current_picture.f.motion_val[1][s->block_index[0] + v->blocks_off][0] = tx; s->current_picture.f.motion_val[1][s->block_index[0] + v->blocks_off][1] = ty; uvmx = (tx + ((tx & 3) == 3)) >> 1;