1/*
2 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11
12#include "treereader.h"
13#include "vp8/common/entropymv.h"
14#include "vp8/common/entropymode.h"
15#include "onyxd_int.h"
16#include "vp8/common/findnearmv.h"
17
18#if CONFIG_DEBUG
19#include <assert.h>
20#endif
21static B_PREDICTION_MODE read_bmode(vp8_reader *bc, const vp8_prob *p)
22{
23    const int i = vp8_treed_read(bc, vp8_bmode_tree, p);
24
25    return (B_PREDICTION_MODE)i;
26}
27
28static MB_PREDICTION_MODE read_ymode(vp8_reader *bc, const vp8_prob *p)
29{
30    const int i = vp8_treed_read(bc, vp8_ymode_tree, p);
31
32    return (MB_PREDICTION_MODE)i;
33}
34
35static MB_PREDICTION_MODE read_kf_ymode(vp8_reader *bc, const vp8_prob *p)
36{
37    const int i = vp8_treed_read(bc, vp8_kf_ymode_tree, p);
38
39    return (MB_PREDICTION_MODE)i;
40}
41
42static MB_PREDICTION_MODE read_uv_mode(vp8_reader *bc, const vp8_prob *p)
43{
44    const int i = vp8_treed_read(bc, vp8_uv_mode_tree, p);
45
46    return (MB_PREDICTION_MODE)i;
47}
48
49static void read_kf_modes(VP8D_COMP *pbi, MODE_INFO *mi)
50{
51    vp8_reader *const bc = & pbi->mbc[8];
52    const int mis = pbi->common.mode_info_stride;
53
54    mi->mbmi.ref_frame = INTRA_FRAME;
55    mi->mbmi.mode = read_kf_ymode(bc, vp8_kf_ymode_prob);
56
57    if (mi->mbmi.mode == B_PRED)
58    {
59        int i = 0;
60        mi->mbmi.is_4x4 = 1;
61
62        do
63        {
64            const B_PREDICTION_MODE A = above_block_mode(mi, i, mis);
65            const B_PREDICTION_MODE L = left_block_mode(mi, i);
66
67            mi->bmi[i].as_mode =
68                read_bmode(bc, vp8_kf_bmode_prob [A] [L]);
69        }
70        while (++i < 16);
71    }
72
73    mi->mbmi.uv_mode = read_uv_mode(bc, vp8_kf_uv_mode_prob);
74}
75
76static int read_mvcomponent(vp8_reader *r, const MV_CONTEXT *mvc)
77{
78    const vp8_prob *const p = (const vp8_prob *) mvc;
79    int x = 0;
80
81    if (vp8_read(r, p [mvpis_short]))  /* Large */
82    {
83        int i = 0;
84
85        do
86        {
87            x += vp8_read(r, p [MVPbits + i]) << i;
88        }
89        while (++i < 3);
90
91        i = mvlong_width - 1;  /* Skip bit 3, which is sometimes implicit */
92
93        do
94        {
95            x += vp8_read(r, p [MVPbits + i]) << i;
96        }
97        while (--i > 3);
98
99        if (!(x & 0xFFF0)  ||  vp8_read(r, p [MVPbits + 3]))
100            x += 8;
101    }
102    else   /* small */
103        x = vp8_treed_read(r, vp8_small_mvtree, p + MVPshort);
104
105    if (x  &&  vp8_read(r, p [MVPsign]))
106        x = -x;
107
108    return x;
109}
110
111static void read_mv(vp8_reader *r, MV *mv, const MV_CONTEXT *mvc)
112{
113    mv->row = (short)(read_mvcomponent(r,   mvc) * 2);
114    mv->col = (short)(read_mvcomponent(r, ++mvc) * 2);
115}
116
117
118static void read_mvcontexts(vp8_reader *bc, MV_CONTEXT *mvc)
119{
120    int i = 0;
121
122    do
123    {
124        const vp8_prob *up = vp8_mv_update_probs[i].prob;
125        vp8_prob *p = (vp8_prob *)(mvc + i);
126        vp8_prob *const pstop = p + MVPcount;
127
128        do
129        {
130            if (vp8_read(bc, *up++))
131            {
132                const vp8_prob x = (vp8_prob)vp8_read_literal(bc, 7);
133
134                *p = x ? x << 1 : 1;
135            }
136        }
137        while (++p < pstop);
138    }
139    while (++i < 2);
140}
141
142static const unsigned char mbsplit_fill_count[4] = {8, 8, 4, 1};
143static const unsigned char mbsplit_fill_offset[4][16] = {
144    { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15},
145    { 0,  1,  4,  5,  8,  9, 12, 13,  2,  3,   6,  7, 10, 11, 14, 15},
146    { 0,  1,  4,  5,  2,  3,  6,  7,  8,  9,  12, 13, 10, 11, 14, 15},
147    { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15}
148};
149
150
151static void mb_mode_mv_init(VP8D_COMP *pbi)
152{
153    vp8_reader *const bc = & pbi->mbc[8];
154    MV_CONTEXT *const mvc = pbi->common.fc.mvc;
155
156#if CONFIG_ERROR_CONCEALMENT
157    /* Default is that no macroblock is corrupt, therefore we initialize
158     * mvs_corrupt_from_mb to something very big, which we can be sure is
159     * outside the frame. */
160    pbi->mvs_corrupt_from_mb = UINT_MAX;
161#endif
162    /* Read the mb_no_coeff_skip flag */
163    pbi->common.mb_no_coeff_skip = (int)vp8_read_bit(bc);
164
165    pbi->prob_skip_false = 0;
166    if (pbi->common.mb_no_coeff_skip)
167        pbi->prob_skip_false = (vp8_prob)vp8_read_literal(bc, 8);
168
169    if(pbi->common.frame_type != KEY_FRAME)
170    {
171        pbi->prob_intra = (vp8_prob)vp8_read_literal(bc, 8);
172        pbi->prob_last  = (vp8_prob)vp8_read_literal(bc, 8);
173        pbi->prob_gf    = (vp8_prob)vp8_read_literal(bc, 8);
174
175        if (vp8_read_bit(bc))
176        {
177            int i = 0;
178
179            do
180            {
181                pbi->common.fc.ymode_prob[i] =
182                    (vp8_prob) vp8_read_literal(bc, 8);
183            }
184            while (++i < 4);
185        }
186
187        if (vp8_read_bit(bc))
188        {
189            int i = 0;
190
191            do
192            {
193                pbi->common.fc.uv_mode_prob[i] =
194                    (vp8_prob) vp8_read_literal(bc, 8);
195            }
196            while (++i < 3);
197        }
198
199        read_mvcontexts(bc, mvc);
200    }
201}
202
203const vp8_prob vp8_sub_mv_ref_prob3 [8][VP8_SUBMVREFS-1] =
204{
205    { 147, 136, 18 },   /* SUBMVREF_NORMAL          */
206    { 223, 1  , 34 },   /* SUBMVREF_LEFT_ABOVE_SAME */
207    { 106, 145, 1  },   /* SUBMVREF_LEFT_ZED        */
208    { 208, 1  , 1  },   /* SUBMVREF_LEFT_ABOVE_ZED  */
209    { 179, 121, 1  },   /* SUBMVREF_ABOVE_ZED       */
210    { 223, 1  , 34 },   /* SUBMVREF_LEFT_ABOVE_SAME */
211    { 179, 121, 1  },   /* SUBMVREF_ABOVE_ZED       */
212    { 208, 1  , 1  }    /* SUBMVREF_LEFT_ABOVE_ZED  */
213};
214
215static
216const vp8_prob * get_sub_mv_ref_prob(const int left, const int above)
217{
218    int lez = (left == 0);
219    int aez = (above == 0);
220    int lea = (left == above);
221    const vp8_prob * prob;
222
223    prob = vp8_sub_mv_ref_prob3[(aez << 2) |
224                                (lez << 1) |
225                                (lea)];
226
227    return prob;
228}
229
230static void decode_split_mv(vp8_reader *const bc, MODE_INFO *mi,
231                        const MODE_INFO *left_mb, const MODE_INFO *above_mb,
232                        MB_MODE_INFO *mbmi, int_mv best_mv,
233                        MV_CONTEXT *const mvc, int mb_to_left_edge,
234                        int mb_to_right_edge, int mb_to_top_edge,
235                        int mb_to_bottom_edge)
236{
237    int s;      /* split configuration (16x8, 8x16, 8x8, 4x4) */
238    int num_p;  /* number of partitions in the split configuration
239                  (see vp8_mbsplit_count) */
240    int j = 0;
241
242    s = 3;
243    num_p = 16;
244    if( vp8_read(bc, 110) )
245    {
246        s = 2;
247        num_p = 4;
248        if( vp8_read(bc, 111) )
249        {
250            s = vp8_read(bc, 150);
251            num_p = 2;
252        }
253    }
254
255    do  /* for each subset j */
256    {
257        int_mv leftmv, abovemv;
258        int_mv blockmv;
259        int k;  /* first block in subset j */
260
261        const vp8_prob *prob;
262        k = vp8_mbsplit_offset[s][j];
263
264        if (!(k & 3))
265        {
266            /* On L edge, get from MB to left of us */
267            if(left_mb->mbmi.mode != SPLITMV)
268                leftmv.as_int =  left_mb->mbmi.mv.as_int;
269            else
270                leftmv.as_int =  (left_mb->bmi + k + 4 - 1)->mv.as_int;
271        }
272        else
273            leftmv.as_int =  (mi->bmi + k - 1)->mv.as_int;
274
275        if (!(k >> 2))
276        {
277            /* On top edge, get from MB above us */
278            if(above_mb->mbmi.mode != SPLITMV)
279                abovemv.as_int =  above_mb->mbmi.mv.as_int;
280            else
281                abovemv.as_int =  (above_mb->bmi + k + 16 - 4)->mv.as_int;
282        }
283        else
284            abovemv.as_int = (mi->bmi + k - 4)->mv.as_int;
285
286        prob = get_sub_mv_ref_prob(leftmv.as_int, abovemv.as_int);
287
288        if( vp8_read(bc, prob[0]) )
289        {
290            if( vp8_read(bc, prob[1]) )
291            {
292                blockmv.as_int = 0;
293                if( vp8_read(bc, prob[2]) )
294                {
295                    blockmv.as_mv.row = read_mvcomponent(bc, &mvc[0]) * 2;
296                    blockmv.as_mv.row += best_mv.as_mv.row;
297                    blockmv.as_mv.col = read_mvcomponent(bc, &mvc[1]) * 2;
298                    blockmv.as_mv.col += best_mv.as_mv.col;
299                }
300            }
301            else
302            {
303                blockmv.as_int = abovemv.as_int;
304            }
305        }
306        else
307        {
308            blockmv.as_int = leftmv.as_int;
309        }
310
311        mbmi->need_to_clamp_mvs |= vp8_check_mv_bounds(&blockmv,
312                                                  mb_to_left_edge,
313                                                  mb_to_right_edge,
314                                                  mb_to_top_edge,
315                                                  mb_to_bottom_edge);
316
317        {
318            /* Fill (uniform) modes, mvs of jth subset.
319             Must do it here because ensuing subsets can
320             refer back to us via "left" or "above". */
321            const unsigned char *fill_offset;
322            unsigned int fill_count = mbsplit_fill_count[s];
323
324            fill_offset = &mbsplit_fill_offset[s]
325                             [(unsigned char)j * mbsplit_fill_count[s]];
326
327            do {
328                mi->bmi[ *fill_offset].mv.as_int = blockmv.as_int;
329                fill_offset++;
330            }while (--fill_count);
331        }
332
333    }
334    while (++j < num_p);
335
336    mbmi->partitioning = s;
337}
338
339static void read_mb_modes_mv(VP8D_COMP *pbi, MODE_INFO *mi, MB_MODE_INFO *mbmi)
340{
341    vp8_reader *const bc = & pbi->mbc[8];
342    mbmi->ref_frame = (MV_REFERENCE_FRAME) vp8_read(bc, pbi->prob_intra);
343    if (mbmi->ref_frame)    /* inter MB */
344    {
345        enum {CNT_INTRA, CNT_NEAREST, CNT_NEAR, CNT_SPLITMV};
346        int cnt[4];
347        int *cntx = cnt;
348        int_mv near_mvs[4];
349        int_mv *nmv = near_mvs;
350        const int mis = pbi->mb.mode_info_stride;
351        const MODE_INFO *above = mi - mis;
352        const MODE_INFO *left = mi - 1;
353        const MODE_INFO *aboveleft = above - 1;
354        int *ref_frame_sign_bias = pbi->common.ref_frame_sign_bias;
355
356        mbmi->need_to_clamp_mvs = 0;
357
358        if (vp8_read(bc, pbi->prob_last))
359        {
360            mbmi->ref_frame =
361                (MV_REFERENCE_FRAME)((int)(2 + vp8_read(bc, pbi->prob_gf)));
362        }
363
364        /* Zero accumulators */
365        nmv[0].as_int = nmv[1].as_int = nmv[2].as_int = 0;
366        cnt[0] = cnt[1] = cnt[2] = cnt[3] = 0;
367
368        /* Process above */
369        if (above->mbmi.ref_frame != INTRA_FRAME)
370        {
371            if (above->mbmi.mv.as_int)
372            {
373                (++nmv)->as_int = above->mbmi.mv.as_int;
374                mv_bias(ref_frame_sign_bias[above->mbmi.ref_frame],
375                        mbmi->ref_frame, nmv, ref_frame_sign_bias);
376                ++cntx;
377            }
378
379            *cntx += 2;
380        }
381
382        /* Process left */
383        if (left->mbmi.ref_frame != INTRA_FRAME)
384        {
385            if (left->mbmi.mv.as_int)
386            {
387                int_mv this_mv;
388
389                this_mv.as_int = left->mbmi.mv.as_int;
390                mv_bias(ref_frame_sign_bias[left->mbmi.ref_frame],
391                        mbmi->ref_frame, &this_mv, ref_frame_sign_bias);
392
393                if (this_mv.as_int != nmv->as_int)
394                {
395                    (++nmv)->as_int = this_mv.as_int;
396                    ++cntx;
397                }
398
399                *cntx += 2;
400            }
401            else
402                cnt[CNT_INTRA] += 2;
403        }
404
405        /* Process above left */
406        if (aboveleft->mbmi.ref_frame != INTRA_FRAME)
407        {
408            if (aboveleft->mbmi.mv.as_int)
409            {
410                int_mv this_mv;
411
412                this_mv.as_int = aboveleft->mbmi.mv.as_int;
413                mv_bias(ref_frame_sign_bias[aboveleft->mbmi.ref_frame],
414                        mbmi->ref_frame, &this_mv, ref_frame_sign_bias);
415
416                if (this_mv.as_int != nmv->as_int)
417                {
418                    (++nmv)->as_int = this_mv.as_int;
419                    ++cntx;
420                }
421
422                *cntx += 1;
423            }
424            else
425                cnt[CNT_INTRA] += 1;
426        }
427
428        if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_INTRA]] [0]) )
429        {
430
431            /* If we have three distinct MV's ... */
432            /* See if above-left MV can be merged with NEAREST */
433            cnt[CNT_NEAREST] += ( (cnt[CNT_SPLITMV] > 0) &
434                (nmv->as_int == near_mvs[CNT_NEAREST].as_int));
435
436            /* Swap near and nearest if necessary */
437            if (cnt[CNT_NEAR] > cnt[CNT_NEAREST])
438            {
439                int tmp;
440                tmp = cnt[CNT_NEAREST];
441                cnt[CNT_NEAREST] = cnt[CNT_NEAR];
442                cnt[CNT_NEAR] = tmp;
443                tmp = near_mvs[CNT_NEAREST].as_int;
444                near_mvs[CNT_NEAREST].as_int = near_mvs[CNT_NEAR].as_int;
445                near_mvs[CNT_NEAR].as_int = tmp;
446            }
447
448            if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_NEAREST]] [1]) )
449            {
450
451                if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_NEAR]] [2]) )
452                {
453                    int mb_to_top_edge;
454                    int mb_to_bottom_edge;
455                    int mb_to_left_edge;
456                    int mb_to_right_edge;
457                    MV_CONTEXT *const mvc = pbi->common.fc.mvc;
458                    int near_index;
459
460                    mb_to_top_edge = pbi->mb.mb_to_top_edge;
461                    mb_to_bottom_edge = pbi->mb.mb_to_bottom_edge;
462                    mb_to_top_edge -= LEFT_TOP_MARGIN;
463                    mb_to_bottom_edge += RIGHT_BOTTOM_MARGIN;
464                    mb_to_right_edge = pbi->mb.mb_to_right_edge;
465                    mb_to_right_edge += RIGHT_BOTTOM_MARGIN;
466                    mb_to_left_edge = pbi->mb.mb_to_left_edge;
467                    mb_to_left_edge -= LEFT_TOP_MARGIN;
468
469                    /* Use near_mvs[0] to store the "best" MV */
470                    near_index = CNT_INTRA +
471                        (cnt[CNT_NEAREST] >= cnt[CNT_INTRA]);
472
473                    vp8_clamp_mv2(&near_mvs[near_index], &pbi->mb);
474
475                    cnt[CNT_SPLITMV] = ((above->mbmi.mode == SPLITMV)
476                                        + (left->mbmi.mode == SPLITMV)) * 2
477                                       + (aboveleft->mbmi.mode == SPLITMV);
478
479                    if( vp8_read(bc, vp8_mode_contexts [cnt[CNT_SPLITMV]] [3]) )
480                    {
481                        decode_split_mv(bc, mi, left, above,
482                                                    mbmi,
483                                                    near_mvs[near_index],
484                                                    mvc, mb_to_left_edge,
485                                                    mb_to_right_edge,
486                                                    mb_to_top_edge,
487                                                    mb_to_bottom_edge);
488                        mbmi->mv.as_int = mi->bmi[15].mv.as_int;
489                        mbmi->mode =  SPLITMV;
490                        mbmi->is_4x4 = 1;
491                    }
492                    else
493                    {
494                        int_mv *const mbmi_mv = & mbmi->mv;
495                        read_mv(bc, &mbmi_mv->as_mv, (const MV_CONTEXT *) mvc);
496                        mbmi_mv->as_mv.row += near_mvs[near_index].as_mv.row;
497                        mbmi_mv->as_mv.col += near_mvs[near_index].as_mv.col;
498
499                        /* Don't need to check this on NEARMV and NEARESTMV
500                         * modes since those modes clamp the MV. The NEWMV mode
501                         * does not, so signal to the prediction stage whether
502                         * special handling may be required.
503                         */
504                        mbmi->need_to_clamp_mvs =
505                            vp8_check_mv_bounds(mbmi_mv, mb_to_left_edge,
506                                                mb_to_right_edge,
507                                                mb_to_top_edge,
508                                                mb_to_bottom_edge);
509                        mbmi->mode =  NEWMV;
510                    }
511                }
512                else
513                {
514                    mbmi->mode =  NEARMV;
515                    mbmi->mv.as_int = near_mvs[CNT_NEAR].as_int;
516                    vp8_clamp_mv2(&mbmi->mv, &pbi->mb);
517                }
518            }
519            else
520            {
521                mbmi->mode =  NEARESTMV;
522                mbmi->mv.as_int = near_mvs[CNT_NEAREST].as_int;
523                vp8_clamp_mv2(&mbmi->mv, &pbi->mb);
524            }
525        }
526        else
527        {
528            mbmi->mode =  ZEROMV;
529            mbmi->mv.as_int = 0;
530        }
531
532#if CONFIG_ERROR_CONCEALMENT
533        if(pbi->ec_enabled && (mbmi->mode != SPLITMV))
534        {
535            mi->bmi[ 0].mv.as_int =
536            mi->bmi[ 1].mv.as_int =
537            mi->bmi[ 2].mv.as_int =
538            mi->bmi[ 3].mv.as_int =
539            mi->bmi[ 4].mv.as_int =
540            mi->bmi[ 5].mv.as_int =
541            mi->bmi[ 6].mv.as_int =
542            mi->bmi[ 7].mv.as_int =
543            mi->bmi[ 8].mv.as_int =
544            mi->bmi[ 9].mv.as_int =
545            mi->bmi[10].mv.as_int =
546            mi->bmi[11].mv.as_int =
547            mi->bmi[12].mv.as_int =
548            mi->bmi[13].mv.as_int =
549            mi->bmi[14].mv.as_int =
550            mi->bmi[15].mv.as_int = mbmi->mv.as_int;
551        }
552#endif
553    }
554    else
555    {
556        /* required for left and above block mv */
557        mbmi->mv.as_int = 0;
558
559        /* MB is intra coded */
560        if ((mbmi->mode = read_ymode(bc, pbi->common.fc.ymode_prob)) == B_PRED)
561        {
562            int j = 0;
563            mbmi->is_4x4 = 1;
564            do
565            {
566                mi->bmi[j].as_mode = read_bmode(bc, pbi->common.fc.bmode_prob);
567            }
568            while (++j < 16);
569        }
570
571        mbmi->uv_mode = read_uv_mode(bc, pbi->common.fc.uv_mode_prob);
572    }
573
574}
575
576static void read_mb_features(vp8_reader *r, MB_MODE_INFO *mi, MACROBLOCKD *x)
577{
578    /* Is segmentation enabled */
579    if (x->segmentation_enabled && x->update_mb_segmentation_map)
580    {
581        /* If so then read the segment id. */
582        if (vp8_read(r, x->mb_segment_tree_probs[0]))
583            mi->segment_id =
584                (unsigned char)(2 + vp8_read(r, x->mb_segment_tree_probs[2]));
585        else
586            mi->segment_id =
587                (unsigned char)(vp8_read(r, x->mb_segment_tree_probs[1]));
588    }
589}
590
591static void decode_mb_mode_mvs(VP8D_COMP *pbi, MODE_INFO *mi,
592                               MB_MODE_INFO *mbmi)
593{
594    /* Read the Macroblock segmentation map if it is being updated explicitly
595     * this frame (reset to 0 above by default)
596     * By default on a key frame reset all MBs to segment 0
597     */
598    if (pbi->mb.update_mb_segmentation_map)
599        read_mb_features(&pbi->mbc[8], &mi->mbmi, &pbi->mb);
600    else if(pbi->common.frame_type == KEY_FRAME)
601        mi->mbmi.segment_id = 0;
602
603    /* Read the macroblock coeff skip flag if this feature is in use,
604     * else default to 0 */
605    if (pbi->common.mb_no_coeff_skip)
606        mi->mbmi.mb_skip_coeff = vp8_read(&pbi->mbc[8], pbi->prob_skip_false);
607    else
608        mi->mbmi.mb_skip_coeff = 0;
609
610    mi->mbmi.is_4x4 = 0;
611    if(pbi->common.frame_type == KEY_FRAME)
612        read_kf_modes(pbi, mi);
613    else
614        read_mb_modes_mv(pbi, mi, &mi->mbmi);
615
616}
617
618void vp8_decode_mode_mvs(VP8D_COMP *pbi)
619{
620    MODE_INFO *mi = pbi->common.mi;
621    int mb_row = -1;
622    int mb_to_right_edge_start;
623
624    mb_mode_mv_init(pbi);
625
626    pbi->mb.mb_to_top_edge = 0;
627    pbi->mb.mb_to_bottom_edge = ((pbi->common.mb_rows - 1) * 16) << 3;
628    mb_to_right_edge_start = ((pbi->common.mb_cols - 1) * 16) << 3;
629
630    while (++mb_row < pbi->common.mb_rows)
631    {
632        int mb_col = -1;
633
634        pbi->mb.mb_to_left_edge =  0;
635        pbi->mb.mb_to_right_edge = mb_to_right_edge_start;
636
637        while (++mb_col < pbi->common.mb_cols)
638        {
639#if CONFIG_ERROR_CONCEALMENT
640            int mb_num = mb_row * pbi->common.mb_cols + mb_col;
641#endif
642
643            decode_mb_mode_mvs(pbi, mi, &mi->mbmi);
644
645#if CONFIG_ERROR_CONCEALMENT
646            /* look for corruption. set mvs_corrupt_from_mb to the current
647             * mb_num if the frame is corrupt from this macroblock. */
648            if (vp8dx_bool_error(&pbi->mbc[8]) && mb_num <
649                (int)pbi->mvs_corrupt_from_mb)
650            {
651                pbi->mvs_corrupt_from_mb = mb_num;
652                /* no need to continue since the partition is corrupt from
653                 * here on.
654                 */
655                return;
656            }
657#endif
658
659            pbi->mb.mb_to_left_edge -= (16 << 3);
660            pbi->mb.mb_to_right_edge -= (16 << 3);
661            mi++;       /* next macroblock */
662        }
663        pbi->mb.mb_to_top_edge -= (16 << 3);
664        pbi->mb.mb_to_bottom_edge -= (16 << 3);
665
666        mi++;           /* skip left predictor each row */
667    }
668}
669