From 19c3df0cd6ddc21a666e67a0c98b7823a2730003 Mon Sep 17 00:00:00 2001 From: Jerome Borsboom Date: Sat, 28 Apr 2018 17:15:32 +0200 Subject: [PATCH] avcodec/vc1: fix mquant calculation In vc1_decode_i_blocks_adv mquant needs to be reset to its default value for each macroblock, instead of once at the beginning of the slice. DQPROFILE specifies which macroblocks can have an alternative quantizer step size. When DQPROFILE specifies edges, the selection is applicable to the edges of the picture. Slice edges are not selected by DQPROFILE. Signed-off-by: Jerome Borsboom Signed-off-by: Michael Niedermayer --- libavcodec/vc1_block.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c index 7cabe49eda..ace1b3eedb 100644 --- a/libavcodec/vc1_block.c +++ b/libavcodec/vc1_block.c @@ -177,7 +177,7 @@ static void vc1_put_signed_blocks_clamped(VC1Context *v) edges = 15; \ if ((edges&1) && !s->mb_x) \ mquant = -v->altpq; \ - if ((edges&2) && s->first_slice_line) \ + if ((edges&2) && !s->mb_y) \ mquant = -v->altpq; \ if ((edges&4) && s->mb_x == (s->mb_width - 1)) \ mquant = -v->altpq; \ @@ -2626,7 +2626,7 @@ static void vc1_decode_i_blocks_adv(VC1Context *v) int cbp, val; uint8_t *coded_val; int mb_pos; - int mquant = v->pq; + int mquant; int mqdiff; GetBitContext *gb = &s->gb; @@ -2671,6 +2671,7 @@ static void vc1_decode_i_blocks_adv(VC1Context *v) init_block_index(v); for (;s->mb_x < s->mb_width; s->mb_x++) { int16_t (*block)[64] = v->block[v->cur_blk_idx]; + mquant = v->pq; ff_update_block_index(s); s->bdsp.clear_blocks(block[0]); mb_pos = s->mb_x + s->mb_y * s->mb_stride;