vc1dec: Update destination pointers in context for fields

This replaces a large number of checks for the second field by
fixing the pointers when they are setup.

This should also fix I/BI field pictures.

Changes checksums for vc1_sa10143, the file becomes slightly closer
to what the reference decoder outputs.

Based on "vc1dec: the second field is written wrong to the picture"
by Sebastian Sandberg <sebastiand.sandberg@gmail.com>.

Signed-off-by: Martin Storsjö <martin@martin.st>

2 files changed, 38 insertions, 45 deletions

diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c
index f1dc10a..1238da2 100644
--- a/libavcodec/vc1dec.c
+++ b/libavcodec/vc1dec.c
@@ -73,6 +73,16 @@ enum Imode {
 };
 /** @} */ //imode defines
 
+static void init_block_index(VC1Context *v)
+{
+    MpegEncContext *s = &v->s;
+    ff_init_block_index(s);
+    if (v->field_mode && v->second_field) {
+        s->dest[0] += s->current_picture_ptr->f.linesize[0];
+        s->dest[1] += s->current_picture_ptr->f.linesize[1];
+        s->dest[2] += s->current_picture_ptr->f.linesize[2];
+    }
+}
 
 /** @} */ //Bitplane group
 
@@ -495,13 +505,8 @@ static void vc1_mc_1mv(VC1Context *v, int dir)
         srcY += s->mspel * (1 + s->linesize);
     }
 
-    if (v->field_mode && v->cur_field_type) {
-        off    = s->current_picture_ptr->f.linesize[0];
-        off_uv = s->current_picture_ptr->f.linesize[1];
-    } else {
-        off    = 0;
-        off_uv = 0;
-    }
+    off    = 0;
+    off_uv = 0;
     if (s->mspel) {
         dxy = ((my & 3) << 2) | (mx & 3);
         v->vc1dsp.put_vc1_mspel_pixels_tab[dxy](s->dest[0] + off    , srcY    , s->linesize, v->rnd);
@@ -631,8 +636,6 @@ static void vc1_mc_4mv_luma(VC1Context *v, int n, int dir)
         off = ((n > 1) ? s->linesize : 0) + (n & 1) * 8;
     else
         off = s->linesize * 4 * (n & 2) + (n & 1) * 8;
-    if (v->field_mode && v->cur_field_type)
-        off += s->current_picture_ptr->f.linesize[0];
 
     src_x = s->mb_x * 16 + (n & 1) * 8 + (mx >> 2);
     if (!fieldmv)
@@ -863,7 +866,7 @@ static void vc1_mc_4mv_chroma(VC1Context *v, int dir)
             srcU += s->current_picture_ptr->f.linesize[1];
             srcV += s->current_picture_ptr->f.linesize[2];
         }
-        off = v->cur_field_type ? s->current_picture_ptr->f.linesize[1] : 0;
+        off = 0;
     }
 
     if (v->rangeredfrm || (v->mv_mode == MV_PMODE_INTENSITY_COMP)
@@ -1930,13 +1933,8 @@ static void vc1_interp_mc(VC1Context *v)
         srcY += s->mspel * (1 + s->linesize);
     }
 
-    if (v->field_mode && v->cur_field_type) {
-        off    = s->current_picture_ptr->f.linesize[0];
-        off_uv = s->current_picture_ptr->f.linesize[1];
-    } else {
-        off    = 0;
-        off_uv = 0;
-    }
+    off    = 0;
+    off_uv = 0;
 
     if (s->mspel) {
         dxy = ((my & 3) << 2) | (mx & 3);
@@ -3940,7 +3938,6 @@ static int vc1_decode_p_mb_intfi(VC1Context *v)
                 continue;
             v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
             off  = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
-            off += v->cur_field_type ? ((i & 4) ? s->current_picture_ptr->f.linesize[1] : s->current_picture_ptr->f.linesize[0]) : 0;
             s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, (i & 4) ? s->uvlinesize : s->linesize);
             // TODO: loop filter
         }
@@ -3987,8 +3984,6 @@ static int vc1_decode_p_mb_intfi(VC1Context *v)
             dst_idx += i >> 2;
             val = ((cbp >> (5 - i)) & 1);
             off = (i & 4) ? 0 : (i & 1) * 8 + (i & 2) * 4 * s->linesize;
-            if (v->cur_field_type)
-                off += (i & 4) ? s->current_picture_ptr->f.linesize[1] : s->current_picture_ptr->f.linesize[0];
             if (val) {
                 pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                          first_block, s->dest[dst_idx] + off,
@@ -4217,7 +4212,6 @@ static void vc1_decode_b_mb_intfi(VC1Context *v)
                 for (j = 0; j < 64; j++)
                     s->block[i][j] <<= 1;
             off  = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
-            off += v->cur_field_type ? ((i & 4) ? s->current_picture_ptr->f.linesize[1] : s->current_picture_ptr->f.linesize[0]) : 0;
             s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, (i & 4) ? s->uvlinesize : s->linesize);
             // TODO: yet to perform loop filter
         }
@@ -4299,8 +4293,6 @@ static void vc1_decode_b_mb_intfi(VC1Context *v)
             dst_idx += i >> 2;
             val = ((cbp >> (5 - i)) & 1);
             off = (i & 4) ? 0 : (i & 1) * 8 + (i & 2) * 4 * s->linesize;
-            if (v->cur_field_type)
-                off += (i & 4) ? s->current_picture_ptr->f.linesize[1] : s->current_picture_ptr->f.linesize[0];
             if (val) {
                 vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                    first_block, s->dest[dst_idx] + off,
@@ -4359,7 +4351,7 @@ static void vc1_decode_i_blocks(VC1Context *v)
     s->first_slice_line = 1;
     for (s->mb_y = 0; s->mb_y < s->end_mb_y; s->mb_y++) {
         s->mb_x = 0;
-        ff_init_block_index(s);
+        init_block_index(v);
         for (; s->mb_x < v->end_mb_x; s->mb_x++) {
             uint8_t *dst[6];
             ff_update_block_index(s);
@@ -4499,13 +4491,13 @@ static void vc1_decode_i_blocks_adv(VC1Context *v)
     s->mb_y             = s->start_mb_y;
     if (s->start_mb_y) {
         s->mb_x = 0;
-        ff_init_block_index(s);
+        init_block_index(v);
         memset(&s->coded_block[s->block_index[0] - s->b8_stride], 0,
                (1 + s->b8_stride) * sizeof(*s->coded_block));
     }
     for (; s->mb_y < s->end_mb_y; s->mb_y++) {
         s->mb_x = 0;
-        ff_init_block_index(s);
+        init_block_index(v);
         for (;s->mb_x < s->mb_width; s->mb_x++) {
             int16_t (*block)[64] = v->block[v->cur_blk_idx];
             ff_update_block_index(s);
@@ -4576,7 +4568,8 @@ static void vc1_decode_i_blocks_adv(VC1Context *v)
 
     /* raw bottom MB row */
     s->mb_x = 0;
-    ff_init_block_index(s);
+    init_block_index(v);
+
     for (;s->mb_x < s->mb_width; s->mb_x++) {
         ff_update_block_index(s);
         vc1_put_signed_blocks_clamped(v);
@@ -4625,7 +4618,7 @@ static void vc1_decode_p_blocks(VC1Context *v)
     memset(v->cbp_base, 0, sizeof(v->cbp_base[0])*2*s->mb_stride);
     for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
         s->mb_x = 0;
-        ff_init_block_index(s);
+        init_block_index(v);
         for (; s->mb_x < s->mb_width; s->mb_x++) {
             ff_update_block_index(s);
 
@@ -4653,7 +4646,7 @@ static void vc1_decode_p_blocks(VC1Context *v)
     }
     if (apply_loop_filter) {
         s->mb_x = 0;
-        ff_init_block_index(s);
+        init_block_index(v);
         for (; s->mb_x < s->mb_width; s->mb_x++) {
             ff_update_block_index(s);
             vc1_apply_p_loop_filter(v);
@@ -4697,7 +4690,7 @@ static void vc1_decode_b_blocks(VC1Context *v)
     s->first_slice_line = 1;
     for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
         s->mb_x = 0;
-        ff_init_block_index(s);
+        init_block_index(v);
         for (; s->mb_x < s->mb_width; s->mb_x++) {
             ff_update_block_index(s);
 
@@ -4734,7 +4727,7 @@ static void vc1_decode_skip_blocks(VC1Context *v)
     s->first_slice_line = 1;
     for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
         s->mb_x = 0;
-        ff_init_block_index(s);
+        init_block_index(v);
         ff_update_block_index(s);
         memcpy(s->dest[0], s->last_picture.f.data[0] + s->mb_y * 16 * s->linesize,   s->linesize   * 16);
         memcpy(s->dest[1], s->last_picture.f.data[1] + s->mb_y *  8 * s->uvlinesize, s->uvlinesize *  8);
diff --git a/tests/ref/fate/vc1_sa10143 b/tests/ref/fate/vc1_sa10143
index 0d2e697..6a5137f 100644
--- a/tests/ref/fate/vc1_sa10143
+++ b/tests/ref/fate/vc1_sa10143
@@ -1,31 +1,31 @@
 #tb 0: 1/25
 0,          0,          0,        1,   518400, 0x89407f55
-0,          2,          2,        1,   518400, 0x1480849d
+0,          2,          2,        1,   518400, 0x8611849c
 0,          3,          3,        1,   518400, 0x0e69ff59
-0,          4,          4,        1,   518400, 0x00d6db06
+0,          4,          4,        1,   518400, 0xf31adb03
 0,          5,          5,        1,   518400, 0x1a5b6a69
-0,          6,          6,        1,   518400, 0xc1a1232e
+0,          6,          6,        1,   518400, 0x6ae6232e
 0,          7,          7,        1,   518400, 0x9a4e3c54
-0,          8,          8,        1,   518400, 0x04122b44
+0,          8,          8,        1,   518400, 0xe5852b45
 0,          9,          9,        1,   518400, 0x0fcfeebc
-0,         10,         10,        1,   518400, 0xc7882dc1
+0,         10,         10,        1,   518400, 0x06e22dc3
 0,         11,         11,        1,   518400, 0x9d79df09
-0,         12,         12,        1,   518400, 0xff6b716f
+0,         12,         12,        1,   518400, 0xcb2c716f
 0,         13,         13,        1,   518400, 0x638a8746
-0,         14,         14,        1,   518400, 0x07572efb
+0,         14,         14,        1,   518400, 0xf7032efd
 0,         15,         15,        1,   518400, 0x306f6cef
-0,         16,         16,        1,   518400, 0xd7602518
+0,         16,         16,        1,   518400, 0xe83d2518
 0,         17,         17,        1,   518400, 0x49ab5bf5
-0,         18,         18,        1,   518400, 0x3c736b6c
+0,         18,         18,        1,   518400, 0x6b336b6f
 0,         19,         19,        1,   518400, 0x95ae00c9
-0,         20,         20,        1,   518400, 0x7b9ab64e
+0,         20,         20,        1,   518400, 0x68ddb64f
 0,         21,         21,        1,   518400, 0x5205ea68
-0,         22,         22,        1,   518400, 0xb486e618
+0,         22,         22,        1,   518400, 0xb088e617
 0,         23,         23,        1,   518400, 0xa3217616
-0,         24,         24,        1,   518400, 0xc66bbc56
+0,         24,         24,        1,   518400, 0x1723bc53
 0,         25,         25,        1,   518400, 0xf024872a
-0,         26,         26,        1,   518400, 0x97d2a8ba
+0,         26,         26,        1,   518400, 0x2e81a8bb
 0,         27,         27,        1,   518400, 0xa3a2418e
-0,         28,         28,        1,   518400, 0x08460005
+0,         28,         28,        1,   518400, 0xb7beffed
 0,         29,         29,        1,   518400, 0x50fb6c94
 0,         30,         30,        1,   518400, 0x5584bb40