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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 "onyxd_int.h"
13 #include "header.h"
14 #include "reconintra.h"
15 #include "reconintra4x4.h"
16 #include "recon.h"
17 #include "reconinter.h"
18 #include "dequantize.h"
19 #include "detokenize.h"
20 #include "invtrans.h"
21 #include "alloccommon.h"
22 #include "entropymode.h"
23 #include "quant_common.h"
24 #include "vpx_scale/vpxscale.h"
25 #include "vpx_scale/yv12extend.h"
26 #include "setupintrarecon.h"
27 
28 #include "decodemv.h"
29 #include "extend.h"
30 #include "vpx_mem/vpx_mem.h"
31 #include "idct.h"
32 #include "dequantize.h"
33 #include "predictdc.h"
34 #include "threading.h"
35 #include "decoderthreading.h"
36 #include "dboolhuff.h"
37 
38 #include <assert.h>
39 #include <stdio.h>
40 
vp8cx_init_de_quantizer(VP8D_COMP * pbi)41 void vp8cx_init_de_quantizer(VP8D_COMP *pbi)
42 {
43     int i;
44     int Q;
45     VP8_COMMON *const pc = & pbi->common;
46 
47     for (Q = 0; Q < QINDEX_RANGE; Q++)
48     {
49         pc->Y1dequant[Q][0] = (short)vp8_dc_quant(Q, pc->y1dc_delta_q);
50         pc->Y2dequant[Q][0] = (short)vp8_dc2quant(Q, pc->y2dc_delta_q);
51         pc->UVdequant[Q][0] = (short)vp8_dc_uv_quant(Q, pc->uvdc_delta_q);
52 
53         /* all the ac values = ; */
54         for (i = 1; i < 16; i++)
55         {
56             int rc = vp8_default_zig_zag1d[i];
57 
58             pc->Y1dequant[Q][rc] = (short)vp8_ac_yquant(Q);
59             pc->Y2dequant[Q][rc] = (short)vp8_ac2quant(Q, pc->y2ac_delta_q);
60             pc->UVdequant[Q][rc] = (short)vp8_ac_uv_quant(Q, pc->uvac_delta_q);
61         }
62     }
63 }
64 
mb_init_dequantizer(VP8D_COMP * pbi,MACROBLOCKD * xd)65 void mb_init_dequantizer(VP8D_COMP *pbi, MACROBLOCKD *xd)
66 {
67     int i;
68     int QIndex;
69     MB_MODE_INFO *mbmi = &xd->mode_info_context->mbmi;
70     VP8_COMMON *const pc = & pbi->common;
71 
72     /* Decide whether to use the default or alternate baseline Q value. */
73     if (xd->segmentation_enabled)
74     {
75         /* Abs Value */
76         if (xd->mb_segement_abs_delta == SEGMENT_ABSDATA)
77             QIndex = xd->segment_feature_data[MB_LVL_ALT_Q][mbmi->segment_id];
78 
79         /* Delta Value */
80         else
81         {
82             QIndex = pc->base_qindex + xd->segment_feature_data[MB_LVL_ALT_Q][mbmi->segment_id];
83             QIndex = (QIndex >= 0) ? ((QIndex <= MAXQ) ? QIndex : MAXQ) : 0;    /* Clamp to valid range */
84         }
85     }
86     else
87         QIndex = pc->base_qindex;
88 
89     /* Set up the block level dequant pointers */
90     for (i = 0; i < 16; i++)
91     {
92         xd->block[i].dequant = pc->Y1dequant[QIndex];
93     }
94 
95     for (i = 16; i < 24; i++)
96     {
97         xd->block[i].dequant = pc->UVdequant[QIndex];
98     }
99 
100     xd->block[24].dequant = pc->Y2dequant[QIndex];
101 
102 }
103 
104 #if CONFIG_RUNTIME_CPU_DETECT
105 #define RTCD_VTABLE(x) (&(pbi)->common.rtcd.x)
106 #else
107 #define RTCD_VTABLE(x) NULL
108 #endif
109 
110 /* skip_recon_mb() is Modified: Instead of writing the result to predictor buffer and then copying it
111  *  to dst buffer, we can write the result directly to dst buffer. This eliminates unnecessary copy.
112  */
skip_recon_mb(VP8D_COMP * pbi,MACROBLOCKD * xd)113 static void skip_recon_mb(VP8D_COMP *pbi, MACROBLOCKD *xd)
114 {
115     if (xd->frame_type == KEY_FRAME  ||  xd->mode_info_context->mbmi.ref_frame == INTRA_FRAME)
116     {
117 
118         vp8_build_intra_predictors_mbuv_s(xd);
119         vp8_build_intra_predictors_mby_s_ptr(xd);
120 
121     }
122     else
123     {
124         vp8_build_inter_predictors_mb_s(xd);
125     }
126 }
127 
clamp_mv_to_umv_border(MV * mv,const MACROBLOCKD * xd)128 static void clamp_mv_to_umv_border(MV *mv, const MACROBLOCKD *xd)
129 {
130     /* If the MV points so far into the UMV border that no visible pixels
131      * are used for reconstruction, the subpel part of the MV can be
132      * discarded and the MV limited to 16 pixels with equivalent results.
133      *
134      * This limit kicks in at 19 pixels for the top and left edges, for
135      * the 16 pixels plus 3 taps right of the central pixel when subpel
136      * filtering. The bottom and right edges use 16 pixels plus 2 pixels
137      * left of the central pixel when filtering.
138      */
139     if (mv->col < (xd->mb_to_left_edge - (19 << 3)))
140         mv->col = xd->mb_to_left_edge - (16 << 3);
141     else if (mv->col > xd->mb_to_right_edge + (18 << 3))
142         mv->col = xd->mb_to_right_edge + (16 << 3);
143 
144     if (mv->row < (xd->mb_to_top_edge - (19 << 3)))
145         mv->row = xd->mb_to_top_edge - (16 << 3);
146     else if (mv->row > xd->mb_to_bottom_edge + (18 << 3))
147         mv->row = xd->mb_to_bottom_edge + (16 << 3);
148 }
149 
150 /* A version of the above function for chroma block MVs.*/
clamp_uvmv_to_umv_border(MV * mv,const MACROBLOCKD * xd)151 static void clamp_uvmv_to_umv_border(MV *mv, const MACROBLOCKD *xd)
152 {
153     mv->col = (2*mv->col < (xd->mb_to_left_edge - (19 << 3))) ? (xd->mb_to_left_edge - (16 << 3)) >> 1 : mv->col;
154     mv->col = (2*mv->col > xd->mb_to_right_edge + (18 << 3)) ? (xd->mb_to_right_edge + (16 << 3)) >> 1 : mv->col;
155 
156     mv->row = (2*mv->row < (xd->mb_to_top_edge - (19 << 3))) ? (xd->mb_to_top_edge - (16 << 3)) >> 1 : mv->row;
157     mv->row = (2*mv->row > xd->mb_to_bottom_edge + (18 << 3)) ? (xd->mb_to_bottom_edge + (16 << 3)) >> 1 : mv->row;
158 }
159 
clamp_mvs(MACROBLOCKD * xd)160 void clamp_mvs(MACROBLOCKD *xd)
161 {
162     if (xd->mode_info_context->mbmi.mode == SPLITMV)
163     {
164         int i;
165 
166         for (i=0; i<16; i++)
167             clamp_mv_to_umv_border(&xd->block[i].bmi.mv.as_mv, xd);
168         for (i=16; i<24; i++)
169             clamp_uvmv_to_umv_border(&xd->block[i].bmi.mv.as_mv, xd);
170     }
171     else
172     {
173         clamp_mv_to_umv_border(&xd->mode_info_context->mbmi.mv.as_mv, xd);
174         clamp_uvmv_to_umv_border(&xd->block[16].bmi.mv.as_mv, xd);
175     }
176 
177 }
178 
vp8_decode_macroblock(VP8D_COMP * pbi,MACROBLOCKD * xd)179 void vp8_decode_macroblock(VP8D_COMP *pbi, MACROBLOCKD *xd)
180 {
181     int eobtotal = 0;
182     int i, do_clamp = xd->mode_info_context->mbmi.need_to_clamp_mvs;
183 
184     if (xd->mode_info_context->mbmi.mb_skip_coeff)
185     {
186         vp8_reset_mb_tokens_context(xd);
187     }
188     else
189     {
190         eobtotal = vp8_decode_mb_tokens(pbi, xd);
191     }
192 
193     /* Perform temporary clamping of the MV to be used for prediction */
194     if (do_clamp)
195     {
196         clamp_mvs(xd);
197     }
198 
199     xd->mode_info_context->mbmi.dc_diff = 1;
200 
201     if (xd->mode_info_context->mbmi.mode != B_PRED && xd->mode_info_context->mbmi.mode != SPLITMV && eobtotal == 0)
202     {
203         xd->mode_info_context->mbmi.dc_diff = 0;
204         skip_recon_mb(pbi, xd);
205         return;
206     }
207 
208     if (xd->segmentation_enabled)
209         mb_init_dequantizer(pbi, xd);
210 
211     /* do prediction */
212     if (xd->frame_type == KEY_FRAME  ||  xd->mode_info_context->mbmi.ref_frame == INTRA_FRAME)
213     {
214         vp8_build_intra_predictors_mbuv(xd);
215 
216         if (xd->mode_info_context->mbmi.mode != B_PRED)
217         {
218             vp8_build_intra_predictors_mby_ptr(xd);
219         } else {
220             vp8_intra_prediction_down_copy(xd);
221         }
222     }
223     else
224     {
225         vp8_build_inter_predictors_mb(xd);
226     }
227 
228     /* dequantization and idct */
229     if (xd->mode_info_context->mbmi.mode != B_PRED && xd->mode_info_context->mbmi.mode != SPLITMV)
230     {
231         BLOCKD *b = &xd->block[24];
232         DEQUANT_INVOKE(&pbi->dequant, block)(b);
233 
234         /* do 2nd order transform on the dc block */
235         if (xd->eobs[24] > 1)
236         {
237             IDCT_INVOKE(RTCD_VTABLE(idct), iwalsh16)(&b->dqcoeff[0], b->diff);
238             ((int *)b->qcoeff)[0] = 0;
239             ((int *)b->qcoeff)[1] = 0;
240             ((int *)b->qcoeff)[2] = 0;
241             ((int *)b->qcoeff)[3] = 0;
242             ((int *)b->qcoeff)[4] = 0;
243             ((int *)b->qcoeff)[5] = 0;
244             ((int *)b->qcoeff)[6] = 0;
245             ((int *)b->qcoeff)[7] = 0;
246         }
247         else
248         {
249             IDCT_INVOKE(RTCD_VTABLE(idct), iwalsh1)(&b->dqcoeff[0], b->diff);
250             ((int *)b->qcoeff)[0] = 0;
251         }
252 
253         DEQUANT_INVOKE (&pbi->dequant, dc_idct_add_y_block)
254                         (xd->qcoeff, xd->block[0].dequant,
255                          xd->predictor, xd->dst.y_buffer,
256                          xd->dst.y_stride, xd->eobs, xd->block[24].diff);
257     }
258     else if ((xd->frame_type == KEY_FRAME  ||  xd->mode_info_context->mbmi.ref_frame == INTRA_FRAME) && xd->mode_info_context->mbmi.mode == B_PRED)
259     {
260         for (i = 0; i < 16; i++)
261         {
262 
263             BLOCKD *b = &xd->block[i];
264             vp8_predict_intra4x4(b, b->bmi.mode, b->predictor);
265 
266             if (xd->eobs[i] > 1)
267             {
268                 DEQUANT_INVOKE(&pbi->dequant, idct_add)
269                     (b->qcoeff, b->dequant,  b->predictor,
270                     *(b->base_dst) + b->dst, 16, b->dst_stride);
271             }
272             else
273             {
274                 IDCT_INVOKE(RTCD_VTABLE(idct), idct1_scalar_add)
275                     (b->qcoeff[0] * b->dequant[0], b->predictor,
276                     *(b->base_dst) + b->dst, 16, b->dst_stride);
277                 ((int *)b->qcoeff)[0] = 0;
278             }
279         }
280 
281     }
282     else
283     {
284         DEQUANT_INVOKE (&pbi->dequant, idct_add_y_block)
285                         (xd->qcoeff, xd->block[0].dequant,
286                          xd->predictor, xd->dst.y_buffer,
287                          xd->dst.y_stride, xd->eobs);
288     }
289 
290     DEQUANT_INVOKE (&pbi->dequant, idct_add_uv_block)
291                     (xd->qcoeff+16*16, xd->block[16].dequant,
292                      xd->predictor+16*16, xd->dst.u_buffer, xd->dst.v_buffer,
293                      xd->dst.uv_stride, xd->eobs+16);
294 }
295 
296 
get_delta_q(vp8_reader * bc,int prev,int * q_update)297 static int get_delta_q(vp8_reader *bc, int prev, int *q_update)
298 {
299     int ret_val = 0;
300 
301     if (vp8_read_bit(bc))
302     {
303         ret_val = vp8_read_literal(bc, 4);
304 
305         if (vp8_read_bit(bc))
306             ret_val = -ret_val;
307     }
308 
309     /* Trigger a quantizer update if the delta-q value has changed */
310     if (ret_val != prev)
311         *q_update = 1;
312 
313     return ret_val;
314 }
315 
316 #ifdef PACKET_TESTING
317 #include <stdio.h>
318 FILE *vpxlog = 0;
319 #endif
320 
321 
322 
vp8_decode_mb_row(VP8D_COMP * pbi,VP8_COMMON * pc,int mb_row,MACROBLOCKD * xd)323 void vp8_decode_mb_row(VP8D_COMP *pbi,
324                        VP8_COMMON *pc,
325                        int mb_row,
326                        MACROBLOCKD *xd)
327 {
328 
329     int i;
330     int recon_yoffset, recon_uvoffset;
331     int mb_col;
332     int ref_fb_idx = pc->lst_fb_idx;
333     int dst_fb_idx = pc->new_fb_idx;
334     int recon_y_stride = pc->yv12_fb[ref_fb_idx].y_stride;
335     int recon_uv_stride = pc->yv12_fb[ref_fb_idx].uv_stride;
336 
337     vpx_memset(&pc->left_context, 0, sizeof(pc->left_context));
338     recon_yoffset = mb_row * recon_y_stride * 16;
339     recon_uvoffset = mb_row * recon_uv_stride * 8;
340     /* reset above block coeffs */
341 
342     xd->above_context = pc->above_context;
343     xd->up_available = (mb_row != 0);
344 
345     xd->mb_to_top_edge = -((mb_row * 16)) << 3;
346     xd->mb_to_bottom_edge = ((pc->mb_rows - 1 - mb_row) * 16) << 3;
347 
348     for (mb_col = 0; mb_col < pc->mb_cols; mb_col++)
349     {
350 
351         if (xd->mode_info_context->mbmi.mode == SPLITMV || xd->mode_info_context->mbmi.mode == B_PRED)
352         {
353             for (i = 0; i < 16; i++)
354             {
355                 BLOCKD *d = &xd->block[i];
356                 vpx_memcpy(&d->bmi, &xd->mode_info_context->bmi[i], sizeof(B_MODE_INFO));
357             }
358         }
359 
360         /* Distance of Mb to the various image edges.
361          * These are specified to 8th pel as they are always compared to values that are in 1/8th pel units
362          */
363         xd->mb_to_left_edge = -((mb_col * 16) << 3);
364         xd->mb_to_right_edge = ((pc->mb_cols - 1 - mb_col) * 16) << 3;
365 
366         xd->dst.y_buffer = pc->yv12_fb[dst_fb_idx].y_buffer + recon_yoffset;
367         xd->dst.u_buffer = pc->yv12_fb[dst_fb_idx].u_buffer + recon_uvoffset;
368         xd->dst.v_buffer = pc->yv12_fb[dst_fb_idx].v_buffer + recon_uvoffset;
369 
370         xd->left_available = (mb_col != 0);
371 
372         /* Select the appropriate reference frame for this MB */
373         if (xd->mode_info_context->mbmi.ref_frame == LAST_FRAME)
374             ref_fb_idx = pc->lst_fb_idx;
375         else if (xd->mode_info_context->mbmi.ref_frame == GOLDEN_FRAME)
376             ref_fb_idx = pc->gld_fb_idx;
377         else
378             ref_fb_idx = pc->alt_fb_idx;
379 
380         xd->pre.y_buffer = pc->yv12_fb[ref_fb_idx].y_buffer + recon_yoffset;
381         xd->pre.u_buffer = pc->yv12_fb[ref_fb_idx].u_buffer + recon_uvoffset;
382         xd->pre.v_buffer = pc->yv12_fb[ref_fb_idx].v_buffer + recon_uvoffset;
383 
384         vp8_build_uvmvs(xd, pc->full_pixel);
385 
386         /*
387         if(pc->current_video_frame==0 &&mb_col==1 && mb_row==0)
388         pbi->debugoutput =1;
389         else
390         pbi->debugoutput =0;
391         */
392         vp8_decode_macroblock(pbi, xd);
393 
394 
395         recon_yoffset += 16;
396         recon_uvoffset += 8;
397 
398         ++xd->mode_info_context;  /* next mb */
399 
400         xd->above_context++;
401 
402     }
403 
404     /* adjust to the next row of mbs */
405     vp8_extend_mb_row(
406         &pc->yv12_fb[dst_fb_idx],
407         xd->dst.y_buffer + 16, xd->dst.u_buffer + 8, xd->dst.v_buffer + 8
408     );
409 
410     ++xd->mode_info_context;      /* skip prediction column */
411 }
412 
413 
read_partition_size(const unsigned char * cx_size)414 static unsigned int read_partition_size(const unsigned char *cx_size)
415 {
416     const unsigned int size =
417         cx_size[0] + (cx_size[1] << 8) + (cx_size[2] << 16);
418     return size;
419 }
420 
421 
setup_token_decoder(VP8D_COMP * pbi,const unsigned char * cx_data)422 static void setup_token_decoder(VP8D_COMP *pbi,
423                                 const unsigned char *cx_data)
424 {
425     int num_part;
426     int i;
427     VP8_COMMON          *pc = &pbi->common;
428     const unsigned char *user_data_end = pbi->Source + pbi->source_sz;
429     vp8_reader          *bool_decoder;
430     const unsigned char *partition;
431 
432     /* Parse number of token partitions to use */
433     pc->multi_token_partition = (TOKEN_PARTITION)vp8_read_literal(&pbi->bc, 2);
434     num_part = 1 << pc->multi_token_partition;
435 
436     /* Set up pointers to the first partition */
437     partition = cx_data;
438     bool_decoder = &pbi->bc2;
439 
440     if (num_part > 1)
441     {
442         CHECK_MEM_ERROR(pbi->mbc, vpx_malloc(num_part * sizeof(vp8_reader)));
443         bool_decoder = pbi->mbc;
444         partition += 3 * (num_part - 1);
445     }
446 
447     for (i = 0; i < num_part; i++)
448     {
449         const unsigned char *partition_size_ptr = cx_data + i * 3;
450         ptrdiff_t            partition_size;
451 
452         /* Calculate the length of this partition. The last partition
453          * size is implicit.
454          */
455         if (i < num_part - 1)
456         {
457             partition_size = read_partition_size(partition_size_ptr);
458         }
459         else
460         {
461             partition_size = user_data_end - partition;
462         }
463 
464         if (partition + partition_size > user_data_end
465             || partition + partition_size < partition)
466             vpx_internal_error(&pc->error, VPX_CODEC_CORRUPT_FRAME,
467                                "Truncated packet or corrupt partition "
468                                "%d length", i + 1);
469 
470         if (vp8dx_start_decode(bool_decoder, IF_RTCD(&pbi->dboolhuff),
471                                partition, partition_size))
472             vpx_internal_error(&pc->error, VPX_CODEC_MEM_ERROR,
473                                "Failed to allocate bool decoder %d", i + 1);
474 
475         /* Advance to the next partition */
476         partition += partition_size;
477         bool_decoder++;
478     }
479 
480     /* Clamp number of decoder threads */
481     if (pbi->decoding_thread_count > num_part - 1)
482         pbi->decoding_thread_count = num_part - 1;
483 }
484 
485 
stop_token_decoder(VP8D_COMP * pbi)486 static void stop_token_decoder(VP8D_COMP *pbi)
487 {
488     int i;
489     VP8_COMMON *pc = &pbi->common;
490 
491     if (pc->multi_token_partition != ONE_PARTITION)
492         vpx_free(pbi->mbc);
493 }
494 
init_frame(VP8D_COMP * pbi)495 static void init_frame(VP8D_COMP *pbi)
496 {
497     VP8_COMMON *const pc = & pbi->common;
498     MACROBLOCKD *const xd  = & pbi->mb;
499 
500     if (pc->frame_type == KEY_FRAME)
501     {
502         /* Various keyframe initializations */
503         vpx_memcpy(pc->fc.mvc, vp8_default_mv_context, sizeof(vp8_default_mv_context));
504 
505         vp8_init_mbmode_probs(pc);
506 
507         vp8_default_coef_probs(pc);
508         vp8_kf_default_bmode_probs(pc->kf_bmode_prob);
509 
510         /* reset the segment feature data to 0 with delta coding (Default state). */
511         vpx_memset(xd->segment_feature_data, 0, sizeof(xd->segment_feature_data));
512         xd->mb_segement_abs_delta = SEGMENT_DELTADATA;
513 
514         /* reset the mode ref deltasa for loop filter */
515         vpx_memset(xd->ref_lf_deltas, 0, sizeof(xd->ref_lf_deltas));
516         vpx_memset(xd->mode_lf_deltas, 0, sizeof(xd->mode_lf_deltas));
517 
518         /* All buffers are implicitly updated on key frames. */
519         pc->refresh_golden_frame = 1;
520         pc->refresh_alt_ref_frame = 1;
521         pc->copy_buffer_to_gf = 0;
522         pc->copy_buffer_to_arf = 0;
523 
524         /* Note that Golden and Altref modes cannot be used on a key frame so
525          * ref_frame_sign_bias[] is undefined and meaningless
526          */
527         pc->ref_frame_sign_bias[GOLDEN_FRAME] = 0;
528         pc->ref_frame_sign_bias[ALTREF_FRAME] = 0;
529     }
530     else
531     {
532         if (!pc->use_bilinear_mc_filter)
533             pc->mcomp_filter_type = SIXTAP;
534         else
535             pc->mcomp_filter_type = BILINEAR;
536 
537         /* To enable choice of different interploation filters */
538         if (pc->mcomp_filter_type == SIXTAP)
539         {
540             xd->subpixel_predict      = SUBPIX_INVOKE(RTCD_VTABLE(subpix), sixtap4x4);
541             xd->subpixel_predict8x4   = SUBPIX_INVOKE(RTCD_VTABLE(subpix), sixtap8x4);
542             xd->subpixel_predict8x8   = SUBPIX_INVOKE(RTCD_VTABLE(subpix), sixtap8x8);
543             xd->subpixel_predict16x16 = SUBPIX_INVOKE(RTCD_VTABLE(subpix), sixtap16x16);
544         }
545         else
546         {
547             xd->subpixel_predict      = SUBPIX_INVOKE(RTCD_VTABLE(subpix), bilinear4x4);
548             xd->subpixel_predict8x4   = SUBPIX_INVOKE(RTCD_VTABLE(subpix), bilinear8x4);
549             xd->subpixel_predict8x8   = SUBPIX_INVOKE(RTCD_VTABLE(subpix), bilinear8x8);
550             xd->subpixel_predict16x16 = SUBPIX_INVOKE(RTCD_VTABLE(subpix), bilinear16x16);
551         }
552     }
553 
554     xd->left_context = &pc->left_context;
555     xd->mode_info_context = pc->mi;
556     xd->frame_type = pc->frame_type;
557     xd->mode_info_context->mbmi.mode = DC_PRED;
558     xd->mode_info_stride = pc->mode_info_stride;
559 }
560 
vp8_decode_frame(VP8D_COMP * pbi)561 int vp8_decode_frame(VP8D_COMP *pbi)
562 {
563     vp8_reader *const bc = & pbi->bc;
564     VP8_COMMON *const pc = & pbi->common;
565     MACROBLOCKD *const xd  = & pbi->mb;
566     const unsigned char *data = (const unsigned char *)pbi->Source;
567     const unsigned char *const data_end = data + pbi->source_sz;
568     ptrdiff_t first_partition_length_in_bytes;
569 
570     int mb_row;
571     int i, j, k, l;
572     const int *const mb_feature_data_bits = vp8_mb_feature_data_bits;
573 
574     if (data_end - data < 3)
575         vpx_internal_error(&pc->error, VPX_CODEC_CORRUPT_FRAME,
576                            "Truncated packet");
577     pc->frame_type = (FRAME_TYPE)(data[0] & 1);
578     pc->version = (data[0] >> 1) & 7;
579     pc->show_frame = (data[0] >> 4) & 1;
580     first_partition_length_in_bytes =
581         (data[0] | (data[1] << 8) | (data[2] << 16)) >> 5;
582     data += 3;
583 
584     if (data + first_partition_length_in_bytes > data_end
585         || data + first_partition_length_in_bytes < data)
586         vpx_internal_error(&pc->error, VPX_CODEC_CORRUPT_FRAME,
587                            "Truncated packet or corrupt partition 0 length");
588     vp8_setup_version(pc);
589 
590     if (pc->frame_type == KEY_FRAME)
591     {
592         const int Width = pc->Width;
593         const int Height = pc->Height;
594 
595         /* vet via sync code */
596         if (data[0] != 0x9d || data[1] != 0x01 || data[2] != 0x2a)
597             vpx_internal_error(&pc->error, VPX_CODEC_UNSUP_BITSTREAM,
598                                "Invalid frame sync code");
599 
600         pc->Width = (data[3] | (data[4] << 8)) & 0x3fff;
601         pc->horiz_scale = data[4] >> 6;
602         pc->Height = (data[5] | (data[6] << 8)) & 0x3fff;
603         pc->vert_scale = data[6] >> 6;
604         data += 7;
605 
606         if (Width != pc->Width  ||  Height != pc->Height)
607         {
608             int prev_mb_rows = pc->mb_rows;
609 
610             if (pc->Width <= 0)
611             {
612                 pc->Width = Width;
613                 vpx_internal_error(&pc->error, VPX_CODEC_CORRUPT_FRAME,
614                                    "Invalid frame width");
615             }
616 
617             if (pc->Height <= 0)
618             {
619                 pc->Height = Height;
620                 vpx_internal_error(&pc->error, VPX_CODEC_CORRUPT_FRAME,
621                                    "Invalid frame height");
622             }
623 
624             if (vp8_alloc_frame_buffers(pc, pc->Width, pc->Height))
625                 vpx_internal_error(&pc->error, VPX_CODEC_MEM_ERROR,
626                                    "Failed to allocate frame buffers");
627 
628 #if CONFIG_MULTITHREAD
629             if (pbi->b_multithreaded_rd)
630                 vp8mt_alloc_temp_buffers(pbi, pc->Width, prev_mb_rows);
631 #endif
632         }
633     }
634 
635     if (pc->Width == 0 || pc->Height == 0)
636     {
637         return -1;
638     }
639 
640     init_frame(pbi);
641 
642     if (vp8dx_start_decode(bc, IF_RTCD(&pbi->dboolhuff),
643                            data, data_end - data))
644         vpx_internal_error(&pc->error, VPX_CODEC_MEM_ERROR,
645                            "Failed to allocate bool decoder 0");
646     if (pc->frame_type == KEY_FRAME) {
647         pc->clr_type    = (YUV_TYPE)vp8_read_bit(bc);
648         pc->clamp_type  = (CLAMP_TYPE)vp8_read_bit(bc);
649     }
650 
651     /* Is segmentation enabled */
652     xd->segmentation_enabled = (unsigned char)vp8_read_bit(bc);
653 
654     if (xd->segmentation_enabled)
655     {
656         /* Signal whether or not the segmentation map is being explicitly updated this frame. */
657         xd->update_mb_segmentation_map = (unsigned char)vp8_read_bit(bc);
658         xd->update_mb_segmentation_data = (unsigned char)vp8_read_bit(bc);
659 
660         if (xd->update_mb_segmentation_data)
661         {
662             xd->mb_segement_abs_delta = (unsigned char)vp8_read_bit(bc);
663 
664             vpx_memset(xd->segment_feature_data, 0, sizeof(xd->segment_feature_data));
665 
666             /* For each segmentation feature (Quant and loop filter level) */
667             for (i = 0; i < MB_LVL_MAX; i++)
668             {
669                 for (j = 0; j < MAX_MB_SEGMENTS; j++)
670                 {
671                     /* Frame level data */
672                     if (vp8_read_bit(bc))
673                     {
674                         xd->segment_feature_data[i][j] = (signed char)vp8_read_literal(bc, mb_feature_data_bits[i]);
675 
676                         if (vp8_read_bit(bc))
677                             xd->segment_feature_data[i][j] = -xd->segment_feature_data[i][j];
678                     }
679                     else
680                         xd->segment_feature_data[i][j] = 0;
681                 }
682             }
683         }
684 
685         if (xd->update_mb_segmentation_map)
686         {
687             /* Which macro block level features are enabled */
688             vpx_memset(xd->mb_segment_tree_probs, 255, sizeof(xd->mb_segment_tree_probs));
689 
690             /* Read the probs used to decode the segment id for each macro block. */
691             for (i = 0; i < MB_FEATURE_TREE_PROBS; i++)
692             {
693                 /* If not explicitly set value is defaulted to 255 by memset above */
694                 if (vp8_read_bit(bc))
695                     xd->mb_segment_tree_probs[i] = (vp8_prob)vp8_read_literal(bc, 8);
696             }
697         }
698     }
699 
700     /* Read the loop filter level and type */
701     pc->filter_type = (LOOPFILTERTYPE) vp8_read_bit(bc);
702     pc->filter_level = vp8_read_literal(bc, 6);
703     pc->sharpness_level = vp8_read_literal(bc, 3);
704 
705     /* Read in loop filter deltas applied at the MB level based on mode or ref frame. */
706     xd->mode_ref_lf_delta_update = 0;
707     xd->mode_ref_lf_delta_enabled = (unsigned char)vp8_read_bit(bc);
708 
709     if (xd->mode_ref_lf_delta_enabled)
710     {
711         /* Do the deltas need to be updated */
712         xd->mode_ref_lf_delta_update = (unsigned char)vp8_read_bit(bc);
713 
714         if (xd->mode_ref_lf_delta_update)
715         {
716             /* Send update */
717             for (i = 0; i < MAX_REF_LF_DELTAS; i++)
718             {
719                 if (vp8_read_bit(bc))
720                 {
721                     /*sign = vp8_read_bit( bc );*/
722                     xd->ref_lf_deltas[i] = (signed char)vp8_read_literal(bc, 6);
723 
724                     if (vp8_read_bit(bc))        /* Apply sign */
725                         xd->ref_lf_deltas[i] = xd->ref_lf_deltas[i] * -1;
726                 }
727             }
728 
729             /* Send update */
730             for (i = 0; i < MAX_MODE_LF_DELTAS; i++)
731             {
732                 if (vp8_read_bit(bc))
733                 {
734                     /*sign = vp8_read_bit( bc );*/
735                     xd->mode_lf_deltas[i] = (signed char)vp8_read_literal(bc, 6);
736 
737                     if (vp8_read_bit(bc))        /* Apply sign */
738                         xd->mode_lf_deltas[i] = xd->mode_lf_deltas[i] * -1;
739                 }
740             }
741         }
742     }
743 
744     setup_token_decoder(pbi, data + first_partition_length_in_bytes);
745     xd->current_bc = &pbi->bc2;
746 
747     /* Read the default quantizers. */
748     {
749         int Q, q_update;
750 
751         Q = vp8_read_literal(bc, 7);  /* AC 1st order Q = default */
752         pc->base_qindex = Q;
753         q_update = 0;
754         pc->y1dc_delta_q = get_delta_q(bc, pc->y1dc_delta_q, &q_update);
755         pc->y2dc_delta_q = get_delta_q(bc, pc->y2dc_delta_q, &q_update);
756         pc->y2ac_delta_q = get_delta_q(bc, pc->y2ac_delta_q, &q_update);
757         pc->uvdc_delta_q = get_delta_q(bc, pc->uvdc_delta_q, &q_update);
758         pc->uvac_delta_q = get_delta_q(bc, pc->uvac_delta_q, &q_update);
759 
760         if (q_update)
761             vp8cx_init_de_quantizer(pbi);
762 
763         /* MB level dequantizer setup */
764         mb_init_dequantizer(pbi, &pbi->mb);
765     }
766 
767     /* Determine if the golden frame or ARF buffer should be updated and how.
768      * For all non key frames the GF and ARF refresh flags and sign bias
769      * flags must be set explicitly.
770      */
771     if (pc->frame_type != KEY_FRAME)
772     {
773         /* Should the GF or ARF be updated from the current frame */
774         pc->refresh_golden_frame = vp8_read_bit(bc);
775         pc->refresh_alt_ref_frame = vp8_read_bit(bc);
776 
777         /* Buffer to buffer copy flags. */
778         pc->copy_buffer_to_gf = 0;
779 
780         if (!pc->refresh_golden_frame)
781             pc->copy_buffer_to_gf = vp8_read_literal(bc, 2);
782 
783         pc->copy_buffer_to_arf = 0;
784 
785         if (!pc->refresh_alt_ref_frame)
786             pc->copy_buffer_to_arf = vp8_read_literal(bc, 2);
787 
788         pc->ref_frame_sign_bias[GOLDEN_FRAME] = vp8_read_bit(bc);
789         pc->ref_frame_sign_bias[ALTREF_FRAME] = vp8_read_bit(bc);
790     }
791 
792     pc->refresh_entropy_probs = vp8_read_bit(bc);
793     if (pc->refresh_entropy_probs == 0)
794     {
795         vpx_memcpy(&pc->lfc, &pc->fc, sizeof(pc->fc));
796     }
797 
798     pc->refresh_last_frame = pc->frame_type == KEY_FRAME  ||  vp8_read_bit(bc);
799 
800     if (0)
801     {
802         FILE *z = fopen("decodestats.stt", "a");
803         fprintf(z, "%6d F:%d,G:%d,A:%d,L:%d,Q:%d\n",
804                 pc->current_video_frame,
805                 pc->frame_type,
806                 pc->refresh_golden_frame,
807                 pc->refresh_alt_ref_frame,
808                 pc->refresh_last_frame,
809                 pc->base_qindex);
810         fclose(z);
811     }
812 
813 
814     {
815         /* read coef probability tree */
816 
817         for (i = 0; i < BLOCK_TYPES; i++)
818             for (j = 0; j < COEF_BANDS; j++)
819                 for (k = 0; k < PREV_COEF_CONTEXTS; k++)
820                     for (l = 0; l < MAX_ENTROPY_TOKENS - 1; l++)
821                     {
822 
823                         vp8_prob *const p = pc->fc.coef_probs [i][j][k] + l;
824 
825                         if (vp8_read(bc, vp8_coef_update_probs [i][j][k][l]))
826                         {
827                             *p = (vp8_prob)vp8_read_literal(bc, 8);
828 
829                         }
830                     }
831     }
832 
833     vpx_memcpy(&xd->pre, &pc->yv12_fb[pc->lst_fb_idx], sizeof(YV12_BUFFER_CONFIG));
834     vpx_memcpy(&xd->dst, &pc->yv12_fb[pc->new_fb_idx], sizeof(YV12_BUFFER_CONFIG));
835 
836     /* set up frame new frame for intra coded blocks */
837     if (!(pbi->b_multithreaded_rd) || pc->multi_token_partition == ONE_PARTITION || !(pc->filter_level))
838         vp8_setup_intra_recon(&pc->yv12_fb[pc->new_fb_idx]);
839 
840     vp8_setup_block_dptrs(xd);
841 
842     vp8_build_block_doffsets(xd);
843 
844     /* clear out the coeff buffer */
845     vpx_memset(xd->qcoeff, 0, sizeof(xd->qcoeff));
846 
847     /* Read the mb_no_coeff_skip flag */
848     pc->mb_no_coeff_skip = (int)vp8_read_bit(bc);
849 
850 
851     vp8_decode_mode_mvs(pbi);
852 
853     vpx_memset(pc->above_context, 0, sizeof(ENTROPY_CONTEXT_PLANES) * pc->mb_cols);
854 
855     vpx_memcpy(&xd->block[0].bmi, &xd->mode_info_context->bmi[0], sizeof(B_MODE_INFO));
856 
857     if (pbi->b_multithreaded_rd && pc->multi_token_partition != ONE_PARTITION)
858     {
859         vp8mt_decode_mb_rows(pbi, xd);
860         if(pbi->common.filter_level)
861         {
862             /*vp8_mt_loop_filter_frame(pbi);*/ /*cm, &pbi->mb, cm->filter_level);*/
863 
864             pc->last_frame_type = pc->frame_type;
865             pc->last_filter_type = pc->filter_type;
866             pc->last_sharpness_level = pc->sharpness_level;
867         }
868         vp8_yv12_extend_frame_borders_ptr(&pc->yv12_fb[pc->new_fb_idx]);    /*cm->frame_to_show);*/
869     }
870     else
871     {
872         int ibc = 0;
873         int num_part = 1 << pc->multi_token_partition;
874 
875         /* Decode the individual macro block */
876         for (mb_row = 0; mb_row < pc->mb_rows; mb_row++)
877         {
878 
879             if (num_part > 1)
880             {
881                 xd->current_bc = & pbi->mbc[ibc];
882                 ibc++;
883 
884                 if (ibc == num_part)
885                     ibc = 0;
886             }
887 
888             vp8_decode_mb_row(pbi, pc, mb_row, xd);
889         }
890     }
891 
892 
893     stop_token_decoder(pbi);
894 
895     /* vpx_log("Decoder: Frame Decoded, Size Roughly:%d bytes  \n",bc->pos+pbi->bc2.pos); */
896 
897     /* If this was a kf or Gf note the Q used */
898     if ((pc->frame_type == KEY_FRAME) ||
899          pc->refresh_golden_frame || pc->refresh_alt_ref_frame)
900     {
901         pc->last_kf_gf_q = pc->base_qindex;
902     }
903 
904     if (pc->refresh_entropy_probs == 0)
905     {
906         vpx_memcpy(&pc->fc, &pc->lfc, sizeof(pc->fc));
907     }
908 
909 #ifdef PACKET_TESTING
910     {
911         FILE *f = fopen("decompressor.VP8", "ab");
912         unsigned int size = pbi->bc2.pos + pbi->bc.pos + 8;
913         fwrite((void *) &size, 4, 1, f);
914         fwrite((void *) pbi->Source, size, 1, f);
915         fclose(f);
916     }
917 #endif
918 
919     return 0;
920 }
921