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1 /******************************************************************************
2  *
3  * Copyright (C) 2015 The Android Open Source Project
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at:
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  *****************************************************************************
18  * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
19 */
20 /*!
21  ***************************************************************************
22  * \file ih264d_parse_mb_header.c
23  *
24  * \brief
25  *    This file contains context identifier encoding routines.
26  *
27  * \date
28  *    04/02/2003
29  *
30  * \author  NS
31  ***************************************************************************
32  */
33 #include <string.h>
34 #include "ih264d_structs.h"
35 #include "ih264d_bitstrm.h"
36 #include "ih264d_cabac.h"
37 #include "ih264_typedefs.h"
38 #include "ih264_macros.h"
39 #include "ih264_platform_macros.h"
40 #include "ih264d_defs.h"
41 #include "ih264d_error_handler.h"
42 #include "ih264d_tables.h"
43 #include "ih264d_debug.h"
44 #include "ih264d_defs.h"
45 #include "ih264d_defs.h"
46 #include "ih264d_mb_utils.h"
47 #include "ih264d_parse_mb_header.h"
48 #include "ih264d_defs.h"
49 
50 /*! < CtxtInc index 0 - CtxMbTypeI, CtxMbTypeSISuffix
51  index 1 - CtxMbTypePSuffix, CtxMbTypeBSuffix
52  */
53 
54 
55 
56 /*!
57  **************************************************************************
58  * \if Function name : ih264d_parse_mb_type_intra_cabac \endif
59  *
60  * \brief
61  *    This function decodes MB type using CABAC entropy coding mode.
62  *
63  * \return
64  *    MBType.
65  *
66  **************************************************************************
67  */
ih264d_parse_mb_type_intra_cabac(UWORD8 u1_inter,struct _DecStruct * ps_dec)68 UWORD8 ih264d_parse_mb_type_intra_cabac(UWORD8 u1_inter,
69                                         struct _DecStruct * ps_dec)
70 {
71     decoding_envirnoment_t * ps_cab_env = &ps_dec->s_cab_dec_env;
72     dec_bit_stream_t * ps_bitstrm = ps_dec->ps_bitstrm;
73     ctxt_inc_mb_info_t * ps_left_ctxt = ps_dec->p_left_ctxt_mb_info;
74     ctxt_inc_mb_info_t * ps_top_ctxt = ps_dec->p_top_ctxt_mb_info;
75     bin_ctxt_model_t *ps_mb_bin_ctxt = ps_dec->p_mb_type_t;
76     WORD8 u1_mb_type, u1_bin;
77     UWORD32 u4_cxt_inc;
78 
79     u4_cxt_inc = 0;
80     if(!u1_inter)
81     {
82         if(ps_left_ctxt != ps_dec->ps_def_ctxt_mb_info)
83             u4_cxt_inc += ((ps_left_ctxt->u1_mb_type != CAB_I4x4) ? 1 : 0);
84         if(ps_top_ctxt != ps_dec->ps_def_ctxt_mb_info)
85             u4_cxt_inc += ((ps_top_ctxt->u1_mb_type != CAB_I4x4) ? 1 : 0);
86     }
87     else
88     {
89         ps_mb_bin_ctxt = ps_mb_bin_ctxt + 3 + (ps_dec->u1_B << 1);
90     }
91 
92     /* b0 */
93     u1_mb_type = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt, ps_bitstrm,
94                                           ps_cab_env);
95     if(u1_mb_type)
96     {
97         /* I16x16 or I_PCM mode */
98         /* b1 */
99         u1_bin = ih264d_decode_terminate(ps_cab_env, ps_bitstrm);
100         if(u1_bin == 0)
101         {
102             /* I16x16 mode */
103             /* Read b2 and b3 */
104             u4_cxt_inc = (u1_inter) ? 0x021 : 0x043;
105 
106             u1_bin = ih264d_decode_bins(2, u4_cxt_inc, ps_mb_bin_ctxt, ps_bitstrm,
107                                         ps_cab_env);
108 
109             if(u1_bin & 0x01)
110                 u1_mb_type += 4;
111 
112             if(u1_bin & 0x02)
113                 u1_mb_type += 12;
114 
115             if(u1_bin & 0x01)
116             {
117                 /* since b3=1, Read three bins */
118                 u4_cxt_inc = (u1_inter) ? 0x0332 : 0x0765;
119                 u1_bin = (UWORD8)ih264d_decode_bins(3, u4_cxt_inc, ps_mb_bin_ctxt,
120                                                     ps_bitstrm, ps_cab_env);
121 
122             }
123             else
124             {
125                 /* Read two bins */
126                 u4_cxt_inc = (u1_inter) ? 0x033 : 0x076;
127                 u1_bin = (UWORD8)ih264d_decode_bins(2, u4_cxt_inc, ps_mb_bin_ctxt,
128                                                     ps_bitstrm, ps_cab_env);
129             }
130             u1_mb_type += u1_bin;
131         }
132         else
133         {
134             /* I_PCM mode */
135             /* b1=1 */
136             u1_mb_type = 25;
137         }
138     }
139     return (u1_mb_type);
140 }
141 
142 /*!
143  **************************************************************************
144  * \if Function name : ih264d_parse_mb_type_cabac \endif
145  *
146  * \brief
147  *    This function decodes MB type using CABAC entropy coding mode.
148  *
149  * \return
150  *    MBType.
151  *
152  **************************************************************************
153  */
ih264d_parse_mb_type_cabac(struct _DecStruct * ps_dec)154 UWORD32 ih264d_parse_mb_type_cabac(struct _DecStruct * ps_dec)
155 {
156     const UWORD8 uc_slice_type = ps_dec->ps_cur_slice->u1_slice_type;
157     decoding_envirnoment_t *ps_cab_env = &ps_dec->s_cab_dec_env;
158     dec_bit_stream_t *ps_bitstrm = ps_dec->ps_bitstrm;
159     ctxt_inc_mb_info_t *ps_left_ctxt = ps_dec->p_left_ctxt_mb_info;
160     ctxt_inc_mb_info_t *ps_top_ctxt = ps_dec->p_top_ctxt_mb_info;
161     WORD8 c_ctxt_inc;
162     bin_ctxt_model_t *ps_mb_bin_ctxt = ps_dec->p_mb_type_t;
163     WORD8 u1_mb_type = 0, u1_bin;
164     UWORD32 u4_cxt_inc;
165 
166     INC_SYM_COUNT(ps_cab_env);
167 
168     c_ctxt_inc = 0;
169 
170     if(uc_slice_type == SI_SLICE)
171     {
172         /* b0 */
173         if(ps_left_ctxt != ps_dec->ps_def_ctxt_mb_info)
174             c_ctxt_inc += ((ps_left_ctxt->u1_mb_type != CAB_SI4x4) ? 1 : 0);
175         if(ps_top_ctxt != ps_dec->ps_def_ctxt_mb_info)
176             c_ctxt_inc += ((ps_top_ctxt->u1_mb_type != CAB_SI4x4) ? 1 : 0);
177 
178         u4_cxt_inc = c_ctxt_inc;
179         u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt, ps_bitstrm,
180                                            ps_cab_env);
181         if(u1_bin == 0)
182         {
183             /* SI MB */
184             u1_mb_type = 0;
185         }
186         else
187         {
188             u1_mb_type = 1 + ih264d_parse_mb_type_intra_cabac(0, ps_dec);
189         }
190     }
191     else if(uc_slice_type == P_SLICE)
192     {
193         /* P Slice */
194         /* b0 */
195         u4_cxt_inc = 0;
196         u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt, ps_bitstrm,
197                                            ps_cab_env);
198         if(!u1_bin)
199         {
200             /* Inter MB types */
201             /* b1 */
202             u4_cxt_inc = 0x01;
203             u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt,
204                                                ps_bitstrm, ps_cab_env);
205             /* b2 */
206             u4_cxt_inc = u1_bin + 2;
207             u1_mb_type = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt,
208                                                   ps_bitstrm, ps_cab_env);
209             u1_mb_type = (u1_bin << 1) + u1_mb_type;
210             if(u1_mb_type)
211                 u1_mb_type = 4 - u1_mb_type;
212         }
213         else
214         {
215             /* Intra Prefix 1 found */
216             /* Intra MB type */
217             u1_mb_type = 5 + ih264d_parse_mb_type_intra_cabac(1, ps_dec);
218         }
219     }
220     else if(uc_slice_type == B_SLICE)
221     {
222         WORD8 a, b;
223         /* B Slice */
224         /* b0 */
225         /* a = b = 0, if B slice and MB is a SKIP or B_DIRECT16x16 */
226         a = 0;
227         b = 0;
228         u1_mb_type = 0;
229         if(ps_left_ctxt != ps_dec->ps_def_ctxt_mb_info)
230             a = ((ps_left_ctxt->u1_mb_type & CAB_BD16x16_MASK) != CAB_BD16x16);
231         if(ps_top_ctxt != ps_dec->ps_def_ctxt_mb_info)
232             b = ((ps_top_ctxt->u1_mb_type & CAB_BD16x16_MASK) != CAB_BD16x16);
233 
234         u4_cxt_inc = a + b;
235 
236         u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt, ps_bitstrm,
237                                            ps_cab_env);
238 
239         if(u1_bin)
240         {
241 
242             /* b1 */
243             u4_cxt_inc = 0x03;
244             u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt,
245                                                ps_bitstrm, ps_cab_env);
246 
247             if(!u1_bin)
248             {
249                 /* b2 */
250                 u4_cxt_inc = 0x05;
251                 u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt,
252                                                    ps_bitstrm, ps_cab_env);
253 
254                 u1_mb_type = u1_bin + 1;
255             }
256             else
257             {
258                 u1_mb_type = 3;
259                 /* b2 */
260                 u4_cxt_inc = 0x04;
261                 u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt,
262                                                    ps_bitstrm, ps_cab_env);
263 
264                 if(u1_bin)
265                 {
266                     u1_mb_type += 8;
267                     /* b3 */
268                     u4_cxt_inc = 0x05;
269                     u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc, ps_mb_bin_ctxt,
270                                                        ps_bitstrm, ps_cab_env);
271 
272                     if(!u1_bin)
273                     {
274                         u1_mb_type++;
275                         /* b4, b5, b6 */
276                         u4_cxt_inc = 0x0555;
277                         u1_bin = (UWORD8)ih264d_decode_bins(3, u4_cxt_inc,
278                                                             ps_mb_bin_ctxt,
279                                                             ps_bitstrm,
280                                                             ps_cab_env);
281 
282 
283 
284                         u1_mb_type += u1_bin;
285                     }
286                     else
287                     {
288                         /* b4 */
289                         u4_cxt_inc = 0x05;
290                         u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc,
291                                                            ps_mb_bin_ctxt,
292                                                            ps_bitstrm,
293                                                            ps_cab_env);
294 
295                         if(u1_bin)
296                         {
297                             /* b5 */
298                             u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc,
299                                                                ps_mb_bin_ctxt,
300                                                                ps_bitstrm,
301                                                                ps_cab_env);
302 
303                             u1_mb_type += (u1_bin ? 11 : 0);
304                         }
305                         else
306                         {
307                             u1_mb_type = 20;
308                             /* b5 */
309                             u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc,
310                                                                ps_mb_bin_ctxt,
311                                                                ps_bitstrm,
312                                                                ps_cab_env);
313 
314                             if(!u1_bin)
315                             {
316                                 /* b6 */
317                                 u1_bin = (UWORD8)ih264d_decode_bin(u4_cxt_inc,
318                                                                    ps_mb_bin_ctxt,
319                                                                    ps_bitstrm,
320                                                                    ps_cab_env);
321 
322                                 u1_mb_type += u1_bin;
323                             }
324                             else
325                             {
326                                 /* Intra Prefix 111101 found */
327                                 /* Intra MB type */
328                                 u1_mb_type =
329                                                 23
330                                                                 + ih264d_parse_mb_type_intra_cabac(
331                                                                                 1,
332                                                                                 ps_dec);
333                             }
334                         }
335                     }
336                 }
337                 else
338                 {
339                     /* b3, b4, b5 */
340                     u4_cxt_inc = 0x0555;
341                     u1_bin = (UWORD8)ih264d_decode_bins(3, u4_cxt_inc,
342                                                         ps_mb_bin_ctxt, ps_bitstrm,
343                                                         ps_cab_env);
344 
345 
346 
347 
348                     u1_mb_type += u1_bin;
349                 }
350             }
351         }
352     }
353     return ((UWORD32)u1_mb_type);
354 }
355 
356 /*!
357  **************************************************************************
358  * \if Function name : DecSubMBType \endif
359  *
360  * \brief
361  *    This function decodes MB type using CABAC entropy coding mode.
362  *
363  * \return
364  *    MBType.
365  *
366  **************************************************************************
367  */
ih264d_parse_submb_type_cabac(const UWORD8 u1_slc_type_b,decoding_envirnoment_t * ps_cab_env,dec_bit_stream_t * ps_bitstrm,bin_ctxt_model_t * ps_sub_mb_cxt)368 UWORD32 ih264d_parse_submb_type_cabac(const UWORD8 u1_slc_type_b,
369                                       decoding_envirnoment_t * ps_cab_env,
370                                       dec_bit_stream_t * ps_bitstrm,
371                                       bin_ctxt_model_t * ps_sub_mb_cxt)
372 {
373     WORD8 u1_sub_mb_type, u1_bin;
374 
375     INC_SYM_COUNT(ps_cab_env);
376 
377     u1_sub_mb_type = 0;
378     u1_bin = (UWORD8)ih264d_decode_bin(0, ps_sub_mb_cxt, ps_bitstrm,
379                                        ps_cab_env);
380 
381     if(u1_slc_type_b ^ u1_bin)
382         return 0;
383 
384     if(!u1_slc_type_b)
385     {
386         /* P Slice */
387         u1_sub_mb_type = 1;
388         u1_bin = (UWORD8)ih264d_decode_bin(1, ps_sub_mb_cxt, ps_bitstrm,
389                                            ps_cab_env);
390         if(u1_bin == 1)
391         {
392             u1_bin = (UWORD8)ih264d_decode_bin(2, ps_sub_mb_cxt, ps_bitstrm,
393                                                ps_cab_env);
394             u1_sub_mb_type = (2 + (!u1_bin));
395         }
396 
397         return u1_sub_mb_type;
398     }
399     else
400     {
401         /* B Slice */
402 
403         /* b1 */
404         u1_bin = (UWORD8)ih264d_decode_bin(1, ps_sub_mb_cxt, ps_bitstrm,
405                                            ps_cab_env);
406         if(u1_bin)
407         {
408             /* b2 */
409             u1_bin = (UWORD8)ih264d_decode_bin(2, ps_sub_mb_cxt, ps_bitstrm,
410                                                ps_cab_env);
411             if(u1_bin)
412             {
413                 /* b3 */
414                 u1_sub_mb_type = 7;
415                 u1_bin = (UWORD8)ih264d_decode_bin(3, ps_sub_mb_cxt, ps_bitstrm,
416                                                    ps_cab_env);
417                 u1_sub_mb_type += u1_bin << 2;
418                 u1_bin = !u1_bin;
419                 /* b4 */
420                 if(u1_bin == 0)
421                 {
422                     u1_bin = ih264d_decode_bin(3, ps_sub_mb_cxt, ps_bitstrm,
423                                                ps_cab_env);
424                 }
425                 else
426                 {
427                     u1_bin = (UWORD8)ih264d_decode_bins(2, 0x33, ps_sub_mb_cxt,
428                                                         ps_bitstrm, ps_cab_env);
429                 }
430 
431                 return (u1_sub_mb_type + u1_bin);
432             }
433             else
434             {
435                 /* b3 */
436                 u1_bin = (UWORD8)ih264d_decode_bins(2, 0x33, ps_sub_mb_cxt,
437                                                     ps_bitstrm, ps_cab_env);
438                 return (3 + u1_bin);
439             }
440         }
441         else
442         {
443             /* b2 */
444             u1_bin = (UWORD8)ih264d_decode_bin(3, ps_sub_mb_cxt, ps_bitstrm,
445                                                ps_cab_env);
446             return (1 + u1_bin);
447         }
448     }
449 }
450 
451 /*!
452  **************************************************************************
453  * \if Function name : ih264d_parse_ref_idx_cabac \endif
454  *
455  * \brief
456  *    This function decodes Reference Index using CABAC entropy coding mode.
457  *
458  * \return
459  *    None
460  *
461  **************************************************************************
462  */
ih264d_parse_ref_idx_cabac(const UWORD8 u1_num_part,const UWORD8 u1_b2,const UWORD8 u1_max_ref_minus1,const UWORD8 u1_mb_mode,WORD8 * pi1_ref_idx,WORD8 * const pi1_lft_cxt,WORD8 * const pi1_top_cxt,decoding_envirnoment_t * const ps_cab_env,dec_bit_stream_t * const ps_bitstrm,bin_ctxt_model_t * const ps_ref_cxt)463 WORD32 ih264d_parse_ref_idx_cabac(const UWORD8 u1_num_part,
464                                 const UWORD8 u1_b2,
465                                 const UWORD8 u1_max_ref_minus1,
466                                 const UWORD8 u1_mb_mode,
467                                 WORD8 * pi1_ref_idx,
468                                 WORD8 * const pi1_lft_cxt,
469                                 WORD8 * const pi1_top_cxt,
470                                 decoding_envirnoment_t * const ps_cab_env,
471                                 dec_bit_stream_t * const ps_bitstrm,
472                                 bin_ctxt_model_t * const ps_ref_cxt)
473 {
474     UWORD8 u1_a, u1_b;
475     UWORD32 u4_cxt_inc;
476     UWORD8 u1_blk_no, u1_i, u1_idx_lft, u1_idx_top;
477     WORD8 i1_ref_idx;
478 
479     for(u1_blk_no = 0, u1_i = 0; u1_i < u1_num_part; u1_i++, pi1_ref_idx++)
480     {
481         u1_idx_lft = ((u1_blk_no & 0x02) >> 1) + u1_b2;
482         u1_idx_top = (u1_blk_no & 0x01) + u1_b2;
483         i1_ref_idx = *pi1_ref_idx;
484 
485         if(i1_ref_idx > 0)
486         {
487             u1_a = pi1_lft_cxt[u1_idx_lft] > 0;
488             u1_b = pi1_top_cxt[u1_idx_top] > 0;
489 
490             u4_cxt_inc = u1_a + (u1_b << 1);
491             u4_cxt_inc = (u4_cxt_inc | 0x55540);
492 
493             i1_ref_idx = (WORD8)ih264d_decode_bins_unary(32, u4_cxt_inc,
494                                                          ps_ref_cxt, ps_bitstrm,
495                                                          ps_cab_env);
496 
497             if((i1_ref_idx > u1_max_ref_minus1) || (i1_ref_idx < 0))
498             {
499                 return ERROR_REF_IDX;
500             }
501 
502             *pi1_ref_idx = i1_ref_idx;
503 
504             INC_SYM_COUNT(ps_cab_env);
505 
506         }
507 
508         /* Storing Reference Idx Information */
509         pi1_lft_cxt[u1_idx_lft] = i1_ref_idx;
510         pi1_top_cxt[u1_idx_top] = i1_ref_idx;
511         u1_blk_no = u1_blk_no + 1 + (u1_mb_mode & 0x01);
512     }
513     /* if(!u1_sub_mb) */
514     if(u1_num_part != 4)
515     {
516         pi1_lft_cxt[(!(u1_mb_mode & 0x1)) + u1_b2] = pi1_lft_cxt[u1_b2];
517         pi1_top_cxt[(!(u1_mb_mode & 0x2)) + u1_b2] = pi1_top_cxt[u1_b2];
518     }
519     return OK;
520 }
521 
522 /*!
523  **************************************************************************
524  * \if Function name : ih264d_parse_mb_qp_delta_cabac \endif
525  *
526  * \brief
527  *    This function decodes MB Qp delta using CABAC entropy coding mode.
528  *
529  * \return
530  *    None
531  *
532  **************************************************************************
533  */
ih264d_parse_mb_qp_delta_cabac(struct _DecStruct * ps_dec,WORD8 * pi1_mb_qp_delta)534 WORD32 ih264d_parse_mb_qp_delta_cabac(struct _DecStruct * ps_dec,
535                                       WORD8 *pi1_mb_qp_delta)
536 {
537     decoding_envirnoment_t * ps_cab_env = &ps_dec->s_cab_dec_env;
538     dec_bit_stream_t * ps_bitstrm = ps_dec->ps_bitstrm;
539 
540     UWORD8 u1_code_num;
541     bin_ctxt_model_t *ps_mb_qp_delta_ctxt = ps_dec->p_mb_qp_delta_t;
542     UWORD32 u4_cxt_inc;
543 
544     INC_SYM_COUNT(ps_cab_env);
545 
546     u4_cxt_inc = (!(!(ps_dec->i1_prev_mb_qp_delta)));
547 
548     u1_code_num = 0;
549     u4_cxt_inc = (u4_cxt_inc | 0x33320);
550     /* max number of bins = 53,
551      since Range for MbQpDelta= -26 to +25 inclusive, UNARY code */
552     u1_code_num = ih264d_decode_bins_unary(32, u4_cxt_inc, ps_mb_qp_delta_ctxt,
553                                           ps_bitstrm, ps_cab_env);
554     if(u1_code_num == 32)
555     {
556         /* Read remaining 21 bins */
557         UWORD8 uc_codeNumX;
558         u4_cxt_inc = 0x33333;
559         uc_codeNumX = ih264d_decode_bins_unary(21, u4_cxt_inc, ps_mb_qp_delta_ctxt,
560                                                ps_bitstrm, ps_cab_env);
561         u1_code_num = u1_code_num + uc_codeNumX;
562     }
563 
564     *pi1_mb_qp_delta = (u1_code_num + 1) >> 1;
565     /* Table 9.3: If code_num is even Syntax Element has -ve value */
566     if(!(u1_code_num & 0x01))
567         *pi1_mb_qp_delta = -(*pi1_mb_qp_delta);
568 
569     /* Range of MbQpDelta= -26 to +25 inclusive */
570     if((*pi1_mb_qp_delta < -26) || (*pi1_mb_qp_delta > 25))
571         return ERROR_INV_RANGE_QP_T;
572     ps_dec->i1_prev_mb_qp_delta = *pi1_mb_qp_delta;
573     return OK;
574 }
575 /*!
576  **************************************************************************
577  * \if Function name : ih264d_parse_chroma_pred_mode_cabac \endif
578  *
579  * \brief
580  *    This function decodes Chroma Pred mode using CABAC entropy coding mode.
581  *
582  * \return
583  *    None
584  *
585  **************************************************************************
586  */
ih264d_parse_chroma_pred_mode_cabac(struct _DecStruct * ps_dec)587 WORD8 ih264d_parse_chroma_pred_mode_cabac(struct _DecStruct * ps_dec)
588 {
589     decoding_envirnoment_t * ps_cab_env = &ps_dec->s_cab_dec_env;
590     dec_bit_stream_t * ps_bitstrm = ps_dec->ps_bitstrm;
591     ctxt_inc_mb_info_t * ps_left_ctxt = ps_dec->p_left_ctxt_mb_info;
592     ctxt_inc_mb_info_t * ps_top_ctxt = ps_dec->p_top_ctxt_mb_info;
593     WORD8 i1_chroma_pred_mode, a, b;
594     UWORD32 u4_cxt_inc;
595 
596     INC_SYM_COUNT(ps_cab_env);
597 
598     /* Binarization is TU and Cmax=3 */
599     i1_chroma_pred_mode = 0;
600     a = 0;
601     b = 0;
602 
603     a = ((ps_left_ctxt->u1_intra_chroma_pred_mode != 0) ? 1 : 0);
604 
605     b = ((ps_top_ctxt->u1_intra_chroma_pred_mode != 0) ? 1 : 0);
606     u4_cxt_inc = a + b;
607 
608     u4_cxt_inc = (u4_cxt_inc | 0x330);
609 
610     i1_chroma_pred_mode = ih264d_decode_bins_tunary(
611                     3, u4_cxt_inc, ps_dec->p_intra_chroma_pred_mode_t,
612                     ps_bitstrm, ps_cab_env);
613 
614     return (i1_chroma_pred_mode);
615 }
616 
617 /*****************************************************************************/
618 /*                                                                           */
619 /*  Function Name : ih264d_parse_transform8x8flag_cabac                                     */
620 /*                                                                           */
621 /*  Description   :                                                          */
622 /*  Inputs        :                                                          */
623 /*                                                                           */
624 /*                                                                           */
625 /*  Returns       :                                                          */
626 /*                                                                           */
627 /*  Revision History:                                                        */
628 /*                                                                           */
629 /*         DD MM YYYY   Author(s)       Changes (Describe the changes made)  */
630 /*                      Rajasekhar      Creation                             */
631 /*                                                                           */
632 /*****************************************************************************/
ih264d_parse_transform8x8flag_cabac(struct _DecStruct * ps_dec,dec_mb_info_t * ps_cur_mb_info)633 UWORD8 ih264d_parse_transform8x8flag_cabac(struct _DecStruct * ps_dec,
634                                            dec_mb_info_t * ps_cur_mb_info)
635 {
636     decoding_envirnoment_t * ps_cab_env = &ps_dec->s_cab_dec_env;
637     dec_bit_stream_t * ps_bitstrm = ps_dec->ps_bitstrm;
638     ctxt_inc_mb_info_t * ps_left_ctxt = ps_dec->p_left_ctxt_mb_info;
639     ctxt_inc_mb_info_t * ps_top_ctxt = ps_dec->p_top_ctxt_mb_info;
640     UWORD8 u1_transform_8x8flag;
641     UWORD8 u1_mb_ngbr_avail = ps_cur_mb_info->u1_mb_ngbr_availablity;
642 
643     WORD8 a, b;
644     UWORD32 u4_cxt_inc;
645 
646     /* for calculating the context increment for transform8x8 u4_flag */
647     /* it reads transform8x8 u4_flag of the neighbors through */
648 
649     /* Binarization is FLC */
650     a = 0;
651     b = 0;
652 
653     if(u1_mb_ngbr_avail & LEFT_MB_AVAILABLE_MASK)
654     {
655         a = ps_left_ctxt->u1_transform8x8_ctxt;
656     }
657     if(u1_mb_ngbr_avail & TOP_MB_AVAILABLE_MASK)
658     {
659         b = ps_top_ctxt->u1_transform8x8_ctxt;
660 
661     }
662 
663     u4_cxt_inc = a + b;
664 
665     u1_transform_8x8flag = ih264d_decode_bin(
666                     u4_cxt_inc, ps_dec->s_high_profile.ps_transform8x8_flag,
667                     ps_bitstrm, ps_cab_env);
668 
669     return (u1_transform_8x8flag);
670 }
671 
672 /*!
673  **************************************************************************
674  * \if Function name : ih264d_read_intra_pred_modes_cabac \endif
675  *
676  * \brief
677  *    Reads the intra pred mode related values of I4x4 MB from bitstream.
678  *
679  *    This function will read the prev intra pred mode flags and
680  *    stores it in pu1_prev_intra4x4_pred_mode_flag. If the u4_flag
681  *    indicates that most probable mode is not intra pred mode, then
682  *    the rem_intra4x4_pred_mode is read and stored in
683  *    pu1_rem_intra4x4_pred_mode array.
684  *
685  *
686  * \return
687  *    0 on success and Error code otherwise
688  *
689  **************************************************************************
690  */
ih264d_read_intra_pred_modes_cabac(dec_struct_t * ps_dec,UWORD8 * pu1_prev_intra4x4_pred_mode_flag,UWORD8 * pu1_rem_intra4x4_pred_mode,UWORD8 u1_tran_form8x8)691 WORD32 ih264d_read_intra_pred_modes_cabac(dec_struct_t * ps_dec,
692                                           UWORD8 * pu1_prev_intra4x4_pred_mode_flag,
693                                           UWORD8 * pu1_rem_intra4x4_pred_mode,
694                                           UWORD8 u1_tran_form8x8)
695 {
696     WORD32 i4x4_luma_blk_idx = 0;
697     dec_bit_stream_t * ps_bitstrm = ps_dec->ps_bitstrm;
698     decoding_envirnoment_t * ps_cab_env = &ps_dec->s_cab_dec_env;
699     bin_ctxt_model_t *ps_ctxt_ipred_luma_mpm, *ps_ctx_ipred_luma_rm;
700     WORD32 i4_rem_intra4x4_pred_mode;
701     UWORD32 u4_prev_intra4x4_pred_mode_flag;
702     UWORD32 u4_code_int_range, u4_code_int_val_ofst;
703     const UWORD32 *pu4_table = (const UWORD32 *)ps_cab_env->cabac_table;
704 
705     ps_ctxt_ipred_luma_mpm = ps_dec->p_prev_intra4x4_pred_mode_flag_t;
706     ps_ctx_ipred_luma_rm = ps_dec->p_rem_intra4x4_pred_mode_t;
707     SWITCHOFFTRACE;
708 
709     i4x4_luma_blk_idx = (0 == u1_tran_form8x8) ? 16 : 4;
710 
711     u4_code_int_range = ps_cab_env->u4_code_int_range;
712     u4_code_int_val_ofst = ps_cab_env->u4_code_int_val_ofst;
713 
714     do
715     {
716 
717         DECODE_ONE_BIN_MACRO(ps_ctxt_ipred_luma_mpm, u4_code_int_range,
718                              u4_code_int_val_ofst, pu4_table, ps_bitstrm,
719                              u4_prev_intra4x4_pred_mode_flag)
720         *pu1_prev_intra4x4_pred_mode_flag = u4_prev_intra4x4_pred_mode_flag;
721 
722         i4_rem_intra4x4_pred_mode = -1;
723         if(!u4_prev_intra4x4_pred_mode_flag)
724         {
725 
726             /*inlining DecodeDecisionBins_FLC*/
727 
728             {
729 
730                 UWORD8 u1_max_bins = 3;
731                 UWORD32 u4_value;
732                 UWORD32 u4_symbol, i;
733 
734                 i = 0;
735                 u4_value = 0;
736 
737                 do
738                 {
739 
740                     DECODE_ONE_BIN_MACRO(ps_ctx_ipred_luma_rm, u4_code_int_range,
741                                          u4_code_int_val_ofst, pu4_table,
742                                          ps_bitstrm, u4_symbol)
743 
744                     INC_BIN_COUNT(ps_cab_env);INC_DECISION_BINS(ps_cab_env);
745 
746                     u4_value = u4_value | (u4_symbol << i);
747 
748                     i++;
749                 }
750                 while(i < u1_max_bins);
751 
752                 i4_rem_intra4x4_pred_mode = (u4_value);
753 
754             }
755 
756         }
757 
758         (*pu1_rem_intra4x4_pred_mode) = i4_rem_intra4x4_pred_mode;
759 
760         COPYTHECONTEXT("intra4x4_pred_mode", i4_rem_intra4x4_pred_mode);
761 
762         pu1_prev_intra4x4_pred_mode_flag++;
763         pu1_rem_intra4x4_pred_mode++;
764 
765         i4x4_luma_blk_idx--;
766     }
767     while(i4x4_luma_blk_idx);
768 
769     ps_cab_env->u4_code_int_range = u4_code_int_range;
770     ps_cab_env->u4_code_int_val_ofst = u4_code_int_val_ofst;
771 
772     return (0);
773 
774 }
775 
776 /*!
777  **************************************************************************
778  * \if Function name : ih264d_parse_ctx_cbp_cabac \endif
779  *
780  * \brief
781  *    This function decodes CtxCbpLuma and CtxCbpChroma (CBP of a Macroblock).
782  *    using CABAC entropy coding mode.
783  *
784  * \return
785  *    CBP of a MB.
786  *
787  **************************************************************************
788  */
ih264d_parse_ctx_cbp_cabac(struct _DecStruct * ps_dec)789 UWORD32 ih264d_parse_ctx_cbp_cabac(struct _DecStruct * ps_dec)
790 {
791 
792     UWORD32 u4_cxt_inc;
793     decoding_envirnoment_t * ps_cab_env = &ps_dec->s_cab_dec_env;
794     dec_bit_stream_t * ps_bitstrm = ps_dec->ps_bitstrm;
795     ctxt_inc_mb_info_t * ps_left_ctxt = ps_dec->p_left_ctxt_mb_info;
796     ctxt_inc_mb_info_t * ps_top_ctxt = ps_dec->p_top_ctxt_mb_info;
797     bin_ctxt_model_t *ps_ctxt_cbp_luma = ps_dec->p_cbp_luma_t, *ps_bin_ctxt;
798     WORD8 c_Cbp; //,i,j;
799     UWORD32 u4_code_int_range, u4_code_int_val_ofst;
800     UWORD32 u4_offset, *pu4_buffer;
801     const UWORD32 *pu4_table = (const UWORD32 *)ps_cab_env->cabac_table;
802 
803     INC_SYM_COUNT(ps_cab_env);
804 
805 
806 
807     /* CBP Luma, FL, Cmax = 15, L = 4 */
808     u4_cxt_inc = (!((ps_top_ctxt->u1_cbp >> 2) & 0x01)) << 1;
809     u4_cxt_inc += !((ps_left_ctxt->u1_cbp >> 1) & 0x01);
810 
811     u4_offset = ps_bitstrm->u4_ofst;
812     pu4_buffer = ps_bitstrm->pu4_buffer;
813 
814     u4_code_int_range = ps_cab_env->u4_code_int_range;
815     u4_code_int_val_ofst = ps_cab_env->u4_code_int_val_ofst;
816     /*renormalize to ensure there 23 bits more in the u4_code_int_val_ofst*/
817     {
818         UWORD32 u4_clz, read_bits;
819 
820         u4_clz = CLZ(u4_code_int_range);
821         FLUSHBITS(u4_offset, u4_clz)
822         NEXTBITS(read_bits, u4_offset, pu4_buffer, 23)
823         u4_code_int_range = u4_code_int_range << u4_clz;
824         u4_code_int_val_ofst = (u4_code_int_val_ofst << u4_clz) | read_bits;
825     }
826 
827     ps_bin_ctxt = ps_ctxt_cbp_luma + u4_cxt_inc;
828 
829     /*inlining DecodeDecision_onebin without renorm*/
830     {
831 
832         UWORD32 u4_qnt_int_range, u4_int_range_lps;
833         UWORD32 u4_symbol, u1_mps_state;
834         UWORD32 table_lookup;
835         UWORD32 u4_clz;
836 
837         u1_mps_state = (ps_bin_ctxt->u1_mps_state);
838 
839         u4_clz = CLZ(u4_code_int_range);
840         u4_qnt_int_range = u4_code_int_range << u4_clz;
841         u4_qnt_int_range = (u4_qnt_int_range >> 29) & 0x3;
842 
843         table_lookup = pu4_table[(u1_mps_state << 2) + u4_qnt_int_range];
844         u4_int_range_lps = table_lookup & 0xff;
845 
846         u4_int_range_lps = u4_int_range_lps << (23 - u4_clz);
847         u4_code_int_range = u4_code_int_range - u4_int_range_lps;
848 
849         u4_symbol = ((u1_mps_state >> 6) & 0x1);
850 
851         /*if mps*/
852         u1_mps_state = (table_lookup >> 8) & 0x7F;
853 
854         CHECK_IF_LPS(u4_code_int_range, u4_code_int_val_ofst, u4_symbol,
855                      u4_int_range_lps, u1_mps_state, table_lookup)
856 
857         INC_BIN_COUNT(ps_cab_env);
858 
859         ps_bin_ctxt->u1_mps_state = u1_mps_state;
860 
861         c_Cbp = u4_symbol;
862 
863     }
864 
865     u4_cxt_inc = (!((ps_top_ctxt->u1_cbp >> 3) & 0x01)) << 1;
866     u4_cxt_inc += !(c_Cbp & 0x01);
867     ps_bin_ctxt = ps_ctxt_cbp_luma + u4_cxt_inc;
868     /*inlining DecodeDecision_onebin without renorm*/
869 
870     {
871 
872         UWORD32 u4_qnt_int_range, u4_int_range_lps;
873         UWORD32 u4_symbol, u1_mps_state;
874         UWORD32 table_lookup;
875         UWORD32 u4_clz;
876 
877         u1_mps_state = (ps_bin_ctxt->u1_mps_state);
878 
879         u4_clz = CLZ(u4_code_int_range);
880         u4_qnt_int_range = u4_code_int_range << u4_clz;
881         u4_qnt_int_range = (u4_qnt_int_range >> 29) & 0x3;
882 
883         table_lookup = pu4_table[(u1_mps_state << 2) + u4_qnt_int_range];
884         u4_int_range_lps = table_lookup & 0xff;
885 
886         u4_int_range_lps = u4_int_range_lps << (23 - u4_clz);
887         u4_code_int_range = u4_code_int_range - u4_int_range_lps;
888 
889         u4_symbol = ((u1_mps_state >> 6) & 0x1);
890 
891         /*if mps*/
892         u1_mps_state = (table_lookup >> 8) & 0x7F;
893 
894         CHECK_IF_LPS(u4_code_int_range, u4_code_int_val_ofst, u4_symbol,
895                      u4_int_range_lps, u1_mps_state, table_lookup)
896 
897         INC_BIN_COUNT(ps_cab_env);
898 
899         ps_bin_ctxt->u1_mps_state = u1_mps_state;
900 
901         c_Cbp |= u4_symbol << 1;
902 
903     }
904 
905     u4_cxt_inc = (!(c_Cbp & 0x01)) << 1;
906     u4_cxt_inc += !((ps_left_ctxt->u1_cbp >> 3) & 0x01);
907     ps_bin_ctxt = ps_ctxt_cbp_luma + u4_cxt_inc;
908     /*inlining DecodeDecision_onebin without renorm*/
909 
910     {
911 
912         UWORD32 u4_qnt_int_range, u4_int_range_lps;
913         UWORD32 u4_symbol, u1_mps_state;
914         UWORD32 table_lookup;
915         UWORD32 u4_clz;
916 
917         u1_mps_state = (ps_bin_ctxt->u1_mps_state);
918 
919         u4_clz = CLZ(u4_code_int_range);
920         u4_qnt_int_range = u4_code_int_range << u4_clz;
921         u4_qnt_int_range = (u4_qnt_int_range >> 29) & 0x3;
922 
923         table_lookup = pu4_table[(u1_mps_state << 2) + u4_qnt_int_range];
924         u4_int_range_lps = table_lookup & 0xff;
925 
926         u4_int_range_lps = u4_int_range_lps << (23 - u4_clz);
927         u4_code_int_range = u4_code_int_range - u4_int_range_lps;
928 
929         u4_symbol = ((u1_mps_state >> 6) & 0x1);
930 
931         /*if mps*/
932         u1_mps_state = (table_lookup >> 8) & 0x7F;
933 
934         CHECK_IF_LPS(u4_code_int_range, u4_code_int_val_ofst, u4_symbol,
935                      u4_int_range_lps, u1_mps_state, table_lookup)
936 
937         INC_BIN_COUNT(ps_cab_env);
938 
939         ps_bin_ctxt->u1_mps_state = u1_mps_state;
940 
941         c_Cbp |= u4_symbol << 2;
942 
943     }
944 
945     u4_cxt_inc = (!((c_Cbp >> 1) & 0x01)) << 1;
946     u4_cxt_inc += !((c_Cbp >> 2) & 0x01);
947     ps_bin_ctxt = ps_ctxt_cbp_luma + u4_cxt_inc;
948     /*inlining DecodeDecision_onebin without renorm*/
949 
950     {
951 
952         UWORD32 u4_qnt_int_range, u4_int_range_lps;
953         UWORD32 u4_symbol, u1_mps_state;
954         UWORD32 table_lookup;
955         UWORD32 u4_clz;
956 
957         u1_mps_state = (ps_bin_ctxt->u1_mps_state);
958 
959         u4_clz = CLZ(u4_code_int_range);
960         u4_qnt_int_range = u4_code_int_range << u4_clz;
961         u4_qnt_int_range = (u4_qnt_int_range >> 29) & 0x3;
962 
963         table_lookup = pu4_table[(u1_mps_state << 2) + u4_qnt_int_range];
964         u4_int_range_lps = table_lookup & 0xff;
965 
966         u4_int_range_lps = u4_int_range_lps << (23 - u4_clz);
967         u4_code_int_range = u4_code_int_range - u4_int_range_lps;
968 
969         u4_symbol = ((u1_mps_state >> 6) & 0x1);
970 
971         /*if mps*/
972         u1_mps_state = (table_lookup >> 8) & 0x7F;
973 
974         CHECK_IF_LPS(u4_code_int_range, u4_code_int_val_ofst, u4_symbol,
975                      u4_int_range_lps, u1_mps_state, table_lookup)
976 
977         INC_BIN_COUNT(ps_cab_env);
978 
979         ps_bin_ctxt->u1_mps_state = u1_mps_state;
980 
981         c_Cbp |= u4_symbol << 3;
982 
983     }
984 
985     if(u4_code_int_range < ONE_RIGHT_SHIFTED_BY_8)
986     {
987 
988         RENORM_RANGE_OFFSET(u4_code_int_range, u4_code_int_val_ofst, u4_offset,
989                             pu4_buffer)
990 
991     }
992 
993     {
994         UWORD32 u4_cxt_inc;
995         WORD8 a, b, c, d;
996         bin_ctxt_model_t *p_CtxtCbpChroma = ps_dec->p_cbp_chroma_t;
997 
998         /* CBP Chroma, TU, Cmax = 2 */
999         a = 0;
1000         b = 0;
1001         c = 0;
1002         d = 0;
1003 
1004         {
1005             a = (ps_top_ctxt->u1_cbp > 15) ? 2 : 0;
1006             c = (ps_top_ctxt->u1_cbp > 31) ? 2 : 0;
1007         }
1008 
1009         {
1010             b = (ps_left_ctxt->u1_cbp > 15) ? 1 : 0;
1011             d = (ps_left_ctxt->u1_cbp > 31) ? 1 : 0;
1012         }
1013         u4_cxt_inc = a + b;
1014         u4_cxt_inc = (u4_cxt_inc | ((4 + c + d) << 4));
1015 
1016         /*inlining ih264d_decode_bins_tunary */
1017 
1018         {
1019 
1020             UWORD8 u1_max_bins = 2;
1021             UWORD32 u4_ctx_inc = u4_cxt_inc;
1022 
1023             UWORD32 u4_value;
1024             UWORD32 u4_symbol;
1025             UWORD8 u4_ctx_Inc;
1026             bin_ctxt_model_t *ps_bin_ctxt;
1027             u4_value = 0;
1028 
1029             do
1030             {
1031                 u4_ctx_Inc = u4_ctx_inc & 0xF;
1032                 u4_ctx_inc = u4_ctx_inc >> 4;
1033 
1034                 ps_bin_ctxt = p_CtxtCbpChroma + u4_ctx_Inc;
1035                 /*inlining DecodeDecision_onebin*/
1036                 {
1037 
1038                     UWORD32 u4_qnt_int_range, u4_int_range_lps;
1039 
1040                     UWORD32 u1_mps_state;
1041                     UWORD32 table_lookup;
1042                     UWORD32 u4_clz;
1043 
1044                     u1_mps_state = (ps_bin_ctxt->u1_mps_state);
1045 
1046                     u4_clz = CLZ(u4_code_int_range);
1047                     u4_qnt_int_range = u4_code_int_range << u4_clz;
1048                     u4_qnt_int_range = (u4_qnt_int_range >> 29) & 0x3;
1049 
1050                     table_lookup = pu4_table[(u1_mps_state << 2)
1051                                     + u4_qnt_int_range];
1052                     u4_int_range_lps = table_lookup & 0xff;
1053 
1054                     u4_int_range_lps = u4_int_range_lps << (23 - u4_clz);
1055                     u4_code_int_range = u4_code_int_range - u4_int_range_lps;
1056 
1057                     u4_symbol = ((u1_mps_state >> 6) & 0x1);
1058 
1059                     /*if mps*/
1060                     u1_mps_state = (table_lookup >> 8) & 0x7F;
1061 
1062                     CHECK_IF_LPS(u4_code_int_range, u4_code_int_val_ofst,
1063                                  u4_symbol, u4_int_range_lps, u1_mps_state,
1064                                  table_lookup)
1065 
1066                     if(u4_code_int_range < ONE_RIGHT_SHIFTED_BY_8)
1067                     {
1068                         RENORM_RANGE_OFFSET(u4_code_int_range,
1069                                             u4_code_int_val_ofst, u4_offset,
1070                                             pu4_buffer)
1071                     }
1072                     ps_bin_ctxt->u1_mps_state = u1_mps_state;
1073                 }
1074 
1075                 INC_BIN_COUNT(ps_cab_env);INC_DECISION_BINS(
1076                                 ps_cab_env);
1077 
1078                 u4_value++;
1079             }
1080             while((u4_value < u1_max_bins) & (u4_symbol));
1081 
1082             u4_value = u4_value - 1 + u4_symbol;
1083 
1084             a = (u4_value);
1085 
1086         }
1087 
1088 c_Cbp = (c_Cbp | (a << 4));
1089 }
1090 
1091 ps_bitstrm->u4_ofst = u4_offset;
1092 
1093 ps_cab_env->u4_code_int_range = u4_code_int_range;
1094 ps_cab_env->u4_code_int_val_ofst = u4_code_int_val_ofst;
1095 
1096 return (c_Cbp);
1097 }
1098 
1099 /*!
1100  **************************************************************************
1101  * \if Function name : ih264d_get_mvd_cabac \endif
1102  *
1103  * \brief
1104  *    This function decodes Horz and Vert mvd_l0 and mvd_l1 using CABAC entropy
1105  *    coding mode as defined in 9.3.2.3.
1106  *
1107  * \return
1108  *    None
1109  *
1110  **************************************************************************
1111  */
ih264d_get_mvd_cabac(UWORD8 u1_sub_mb,UWORD8 u1_b2,UWORD8 u1_part_wd,UWORD8 u1_part_ht,UWORD8 u1_dec_mvd,dec_struct_t * ps_dec,mv_pred_t * ps_mv)1112 void ih264d_get_mvd_cabac(UWORD8 u1_sub_mb,
1113                           UWORD8 u1_b2,
1114                           UWORD8 u1_part_wd,
1115                           UWORD8 u1_part_ht,
1116                           UWORD8 u1_dec_mvd,
1117                           dec_struct_t *ps_dec,
1118                           mv_pred_t *ps_mv)
1119 {
1120     UWORD8 u1_abs_mvd_x = 0, u1_abs_mvd_y = 0;
1121     UWORD8 u1_sub_mb_x, u1_sub_mb_y;
1122     UWORD8 *pu1_top_mv_ctxt, *pu1_lft_mv_ctxt;
1123     WORD16 *pi2_mv;
1124 
1125     u1_sub_mb_x = (UWORD8)(u1_sub_mb & 0x03);
1126     u1_sub_mb_y = (UWORD8)(u1_sub_mb >> 2);
1127     pu1_top_mv_ctxt = &ps_dec->ps_curr_ctxt_mb_info->u1_mv[u1_sub_mb_x][u1_b2];
1128     pu1_lft_mv_ctxt = &ps_dec->pu1_left_mv_ctxt_inc[u1_sub_mb_y][u1_b2];
1129     pi2_mv = &ps_mv->i2_mv[u1_b2];
1130 
1131     if(u1_dec_mvd)
1132     {
1133         WORD16 i2_mv_x, i2_mv_y;
1134         WORD32 i2_temp;
1135         {
1136             decoding_envirnoment_t * ps_cab_env = &ps_dec->s_cab_dec_env;
1137             dec_bit_stream_t * ps_bitstrm = ps_dec->ps_bitstrm;
1138             UWORD16 u2_abs_mvd_x_a, u2_abs_mvd_x_b, u2_abs_mvd_y_a,
1139                             u2_abs_mvd_y_b;
1140 
1141             u2_abs_mvd_x_b = (UWORD16)pu1_top_mv_ctxt[0];
1142             u2_abs_mvd_y_b = (UWORD16)pu1_top_mv_ctxt[1];
1143             u2_abs_mvd_x_a = (UWORD16)pu1_lft_mv_ctxt[0];
1144             u2_abs_mvd_y_a = (UWORD16)pu1_lft_mv_ctxt[1];
1145 
1146             i2_temp = u2_abs_mvd_x_a + u2_abs_mvd_x_b;
1147 
1148             i2_mv_x = ih264d_parse_mvd_cabac(ps_bitstrm, ps_cab_env,
1149                                              ps_dec->p_mvd_x_t, i2_temp);
1150 
1151             i2_temp = u2_abs_mvd_y_a + u2_abs_mvd_y_b;
1152 
1153             i2_mv_y = ih264d_parse_mvd_cabac(ps_bitstrm, ps_cab_env,
1154                                              ps_dec->p_mvd_y_t, i2_temp);
1155         }
1156 
1157         /***********************************************************************/
1158         /* Store the abs_mvd_values in cabac contexts                          */
1159         /* The follownig code can be easily optimzed if mvX, mvY clip values   */
1160         /* are packed in 16 bits follwed by memcpy                             */
1161         /***********************************************************************/
1162         u1_abs_mvd_x = CLIP3(0, 127, ABS(i2_mv_x));
1163         u1_abs_mvd_y = CLIP3(0, 127, ABS(i2_mv_y));
1164 
1165         COPYTHECONTEXT("MVD", i2_mv_x);COPYTHECONTEXT("MVD", i2_mv_y);
1166 
1167         /* Storing Mv residuals */
1168         pi2_mv[0] = i2_mv_x;
1169         pi2_mv[1] = i2_mv_y;
1170     }
1171 
1172     /***************************************************************/
1173     /* Store abs_mvd_values cabac contexts                         */
1174     /***************************************************************/
1175     {
1176         UWORD8 u1_i;
1177         for(u1_i = 0; u1_i < u1_part_wd; u1_i++, pu1_top_mv_ctxt += 4)
1178         {
1179             pu1_top_mv_ctxt[0] = u1_abs_mvd_x;
1180             pu1_top_mv_ctxt[1] = u1_abs_mvd_y;
1181         }
1182 
1183         for(u1_i = 0; u1_i < u1_part_ht; u1_i++, pu1_lft_mv_ctxt += 4)
1184         {
1185             pu1_lft_mv_ctxt[0] = u1_abs_mvd_x;
1186             pu1_lft_mv_ctxt[1] = u1_abs_mvd_y;
1187         }
1188     }
1189 }
1190 
1191 /*****************************************************************************/
1192 /*                                                                           */
1193 /*  Function Name : ih264d_parse_mvd_cabac                                                  */
1194 /*                                                                           */
1195 /*  Description   : This cabac function decodes the mvd in a given direction */
1196 /*                  direction ( x or y ) as defined in 9.3.2.3.              */
1197 /*                                                                           */
1198 /*  Inputs        : 1. pointer to Bitstream                                  */
1199 /*                  2. pointer to cabac decoding environmnet                 */
1200 /*                  3. pointer to Mvd context                                */
1201 /*                  4. abs(Top mvd) = u2_abs_mvd_b                           */
1202 /*                  5. abs(left mvd)= u2_abs_mvd_a                           */
1203 /*                                                                           */
1204 /*  Processing    : see section 9.3.2.3 of the standard                      */
1205 /*                                                                           */
1206 /*  Outputs       : i2_mvd                                                   */
1207 /*  Returns       : i2_mvd                                                   */
1208 /*                                                                           */
1209 /*  Issues        : none                                                     */
1210 /*                                                                           */
1211 /*  Revision History:                                                        */
1212 /*                                                                           */
1213 /*         DD MM YYYY   Author(s)       Changes (Describe the changes made)  */
1214 /*         16 06 2005   Jay          Draft                                   */
1215 /*                                                                           */
1216 /*****************************************************************************/
ih264d_parse_mvd_cabac(dec_bit_stream_t * ps_bitstrm,decoding_envirnoment_t * ps_cab_env,bin_ctxt_model_t * p_ctxt_mvd,UWORD32 i4_temp)1217 WORD16 ih264d_parse_mvd_cabac(dec_bit_stream_t * ps_bitstrm,
1218                               decoding_envirnoment_t * ps_cab_env,
1219                               bin_ctxt_model_t * p_ctxt_mvd,
1220                               UWORD32 i4_temp)
1221 
1222 {
1223     WORD8 k;
1224     WORD16 i2_suf;
1225     WORD16 i2_mvd;
1226     UWORD16 u2_abs_mvd;
1227     UWORD32 u4_ctx_inc;
1228     UWORD32 u4_prefix;
1229     const UWORD32 *pu4_table = (const UWORD32 *)ps_cab_env->cabac_table;
1230     UWORD32 u4_code_int_range, u4_code_int_val_ofst;
1231 
1232     /*  if mvd < 9                                                  */
1233     /*  mvd =  Prefix                                                   */
1234     /*  else                                                            */
1235     /*  mvd = Prefix + Suffix                                           */
1236     /*  decode sign bit                                                 */
1237     /*  Prefix TU decoding Cmax =Ucoff and Suffix 3rd order Exp-Golomb  */
1238 
1239     u2_abs_mvd = (UWORD16)i4_temp;
1240     u4_ctx_inc = 1;
1241 
1242     if(u2_abs_mvd < 3)
1243         u4_ctx_inc = 0;
1244     else if(u2_abs_mvd > 32)
1245         u4_ctx_inc = 2;
1246 
1247     u4_ctx_inc = (u4_ctx_inc | 0x65430);
1248 
1249     /*inlining modified version of ih264d_decode_bins_unary*/
1250 
1251     {
1252         UWORD8 u1_max_bins = 9;
1253         UWORD32 u4_value;
1254         UWORD32 u4_symbol;
1255         bin_ctxt_model_t *ps_bin_ctxt;
1256         UWORD32 u4_ctx_Inc;
1257 
1258         u4_value = 0;
1259         u4_code_int_range = ps_cab_env->u4_code_int_range;
1260         u4_code_int_val_ofst = ps_cab_env->u4_code_int_val_ofst;
1261 
1262         do
1263         {
1264             u4_ctx_Inc = u4_ctx_inc & 0xf;
1265             u4_ctx_inc = u4_ctx_inc >> 4;
1266 
1267             ps_bin_ctxt = p_ctxt_mvd + u4_ctx_Inc;
1268 
1269             DECODE_ONE_BIN_MACRO(ps_bin_ctxt, u4_code_int_range,
1270                                  u4_code_int_val_ofst, pu4_table, ps_bitstrm,
1271                                  u4_symbol)
1272 
1273             INC_BIN_COUNT(ps_cab_env);INC_DECISION_BINS(ps_cab_env);
1274 
1275             u4_value++;
1276 
1277         }
1278         while(u4_symbol && u4_value < 5);
1279 
1280         ps_bin_ctxt = p_ctxt_mvd + 6;
1281 
1282         if(u4_symbol && (u4_value < u1_max_bins))
1283         {
1284 
1285             do
1286             {
1287 
1288                 DECODE_ONE_BIN_MACRO(ps_bin_ctxt, u4_code_int_range,
1289                                      u4_code_int_val_ofst, pu4_table,
1290                                      ps_bitstrm, u4_symbol)
1291 
1292                 INC_BIN_COUNT(ps_cab_env);INC_DECISION_BINS(ps_cab_env);
1293                 u4_value++;
1294             }
1295             while(u4_symbol && (u4_value < u1_max_bins));
1296 
1297         }
1298 
1299         ps_cab_env->u4_code_int_range = u4_code_int_range;
1300         ps_cab_env->u4_code_int_val_ofst = u4_code_int_val_ofst;
1301         u4_value = u4_value - 1 + u4_symbol;
1302         u4_prefix = (u4_value);
1303     }
1304 
1305     i2_mvd = u4_prefix;
1306 
1307     if(i2_mvd == 9)
1308     {
1309         /* Read Suffix */
1310         k = ih264d_decode_bypass_bins_unary(ps_cab_env, ps_bitstrm);
1311         i2_suf = (1 << k) - 1;
1312         k = k + 3;
1313         i2_suf = (i2_suf << 3);
1314         i2_mvd += i2_suf;
1315         i2_suf = ih264d_decode_bypass_bins(ps_cab_env, k, ps_bitstrm);
1316         i2_mvd += i2_suf;
1317     }
1318     /* Read Sign bit */
1319     if(!i2_mvd)
1320         return (i2_mvd);
1321 
1322     else
1323     {
1324         UWORD32 u4_code_int_val_ofst, u4_code_int_range;
1325 
1326         u4_code_int_val_ofst = ps_cab_env->u4_code_int_val_ofst;
1327         u4_code_int_range = ps_cab_env->u4_code_int_range;
1328 
1329         if(u4_code_int_range < ONE_RIGHT_SHIFTED_BY_9)
1330         {
1331             UWORD32 *pu4_buffer, u4_offset;
1332 
1333             pu4_buffer = ps_bitstrm->pu4_buffer;
1334             u4_offset = ps_bitstrm->u4_ofst;
1335 
1336             RENORM_RANGE_OFFSET(u4_code_int_range, u4_code_int_val_ofst,
1337                                 u4_offset, pu4_buffer)
1338             ps_bitstrm->u4_ofst = u4_offset;
1339         }
1340 
1341         u4_code_int_range = u4_code_int_range >> 1;
1342 
1343         if(u4_code_int_val_ofst >= u4_code_int_range)
1344         {
1345             /* S=1 */
1346             u4_code_int_val_ofst -= u4_code_int_range;
1347             i2_mvd = (-i2_mvd);
1348         }
1349 
1350         ps_cab_env->u4_code_int_val_ofst = u4_code_int_val_ofst;
1351         ps_cab_env->u4_code_int_range = u4_code_int_range;
1352 
1353         return (i2_mvd);
1354 
1355     }
1356 }
1357