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 <jerome.borsboom@carpalis.nl>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c
index 7cabe49edae7ada3ac91e217a73e32051850a9f8..ace1b3eedb632c7027d9964f1f23d36a353717b5 100644 (file)
--- 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;