FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
h263.c
Go to the documentation of this file.
1 /*
2  * H263/MPEG4 backend for encoder and decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * H263+ support.
5  * Copyright (c) 2001 Juan J. Sierralta P
6  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 /**
26  * @file
27  * h263/mpeg4 codec.
28  */
29 
30 #include <limits.h>
31 
32 #include "avcodec.h"
33 #include "mpegvideo.h"
34 #include "h263.h"
35 #include "h263data.h"
36 #include "mathops.h"
37 #include "unary.h"
38 #include "flv.h"
39 #include "mpeg4video.h"
40 
41 
42 uint8_t ff_h263_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
43 
44 
45 void ff_h263_update_motion_val(MpegEncContext * s){
46  const int mb_xy = s->mb_y * s->mb_stride + s->mb_x;
47  //FIXME a lot of that is only needed for !low_delay
48  const int wrap = s->b8_stride;
49  const int xy = s->block_index[0];
50 
51  s->current_picture.mbskip_table[mb_xy] = s->mb_skipped;
52 
53  if(s->mv_type != MV_TYPE_8X8){
54  int motion_x, motion_y;
55  if (s->mb_intra) {
56  motion_x = 0;
57  motion_y = 0;
58  } else if (s->mv_type == MV_TYPE_16X16) {
59  motion_x = s->mv[0][0][0];
60  motion_y = s->mv[0][0][1];
61  } else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
62  int i;
63  motion_x = s->mv[0][0][0] + s->mv[0][1][0];
64  motion_y = s->mv[0][0][1] + s->mv[0][1][1];
65  motion_x = (motion_x>>1) | (motion_x&1);
66  for(i=0; i<2; i++){
67  s->p_field_mv_table[i][0][mb_xy][0]= s->mv[0][i][0];
68  s->p_field_mv_table[i][0][mb_xy][1]= s->mv[0][i][1];
69  }
70  s->current_picture.ref_index[0][4*mb_xy ] =
71  s->current_picture.ref_index[0][4*mb_xy + 1] = s->field_select[0][0];
72  s->current_picture.ref_index[0][4*mb_xy + 2] =
73  s->current_picture.ref_index[0][4*mb_xy + 3] = s->field_select[0][1];
74  }
75 
76  /* no update if 8X8 because it has been done during parsing */
77  s->current_picture.motion_val[0][xy][0] = motion_x;
78  s->current_picture.motion_val[0][xy][1] = motion_y;
79  s->current_picture.motion_val[0][xy + 1][0] = motion_x;
80  s->current_picture.motion_val[0][xy + 1][1] = motion_y;
81  s->current_picture.motion_val[0][xy + wrap][0] = motion_x;
82  s->current_picture.motion_val[0][xy + wrap][1] = motion_y;
83  s->current_picture.motion_val[0][xy + 1 + wrap][0] = motion_x;
84  s->current_picture.motion_val[0][xy + 1 + wrap][1] = motion_y;
85  }
86 
87  if(s->encoding){ //FIXME encoding MUST be cleaned up
88  if (s->mv_type == MV_TYPE_8X8)
89  s->current_picture.mb_type[mb_xy] = MB_TYPE_L0 | MB_TYPE_8x8;
90  else if(s->mb_intra)
91  s->current_picture.mb_type[mb_xy] = MB_TYPE_INTRA;
92  else
93  s->current_picture.mb_type[mb_xy] = MB_TYPE_L0 | MB_TYPE_16x16;
94  }
95 }
96 
97 int ff_h263_pred_dc(MpegEncContext * s, int n, int16_t **dc_val_ptr)
98 {
99  int x, y, wrap, a, c, pred_dc;
100  int16_t *dc_val;
101 
102  /* find prediction */
103  if (n < 4) {
104  x = 2 * s->mb_x + (n & 1);
105  y = 2 * s->mb_y + ((n & 2) >> 1);
106  wrap = s->b8_stride;
107  dc_val = s->dc_val[0];
108  } else {
109  x = s->mb_x;
110  y = s->mb_y;
111  wrap = s->mb_stride;
112  dc_val = s->dc_val[n - 4 + 1];
113  }
114  /* B C
115  * A X
116  */
117  a = dc_val[(x - 1) + (y) * wrap];
118  c = dc_val[(x) + (y - 1) * wrap];
119 
120  /* No prediction outside GOB boundary */
121  if(s->first_slice_line && n!=3){
122  if(n!=2) c= 1024;
123  if(n!=1 && s->mb_x == s->resync_mb_x) a= 1024;
124  }
125  /* just DC prediction */
126  if (a != 1024 && c != 1024)
127  pred_dc = (a + c) >> 1;
128  else if (a != 1024)
129  pred_dc = a;
130  else
131  pred_dc = c;
132 
133  /* we assume pred is positive */
134  *dc_val_ptr = &dc_val[x + y * wrap];
135  return pred_dc;
136 }
137 
138 void ff_h263_loop_filter(MpegEncContext * s){
139  int qp_c;
140  const int linesize = s->linesize;
141  const int uvlinesize= s->uvlinesize;
142  const int xy = s->mb_y * s->mb_stride + s->mb_x;
143  uint8_t *dest_y = s->dest[0];
144  uint8_t *dest_cb= s->dest[1];
145  uint8_t *dest_cr= s->dest[2];
146 
147 // if(s->pict_type==AV_PICTURE_TYPE_B && !s->readable) return;
148 
149  /*
150  Diag Top
151  Left Center
152  */
153  if (!IS_SKIP(s->current_picture.mb_type[xy])) {
154  qp_c= s->qscale;
155  s->dsp.h263_v_loop_filter(dest_y+8*linesize , linesize, qp_c);
156  s->dsp.h263_v_loop_filter(dest_y+8*linesize+8, linesize, qp_c);
157  }else
158  qp_c= 0;
159 
160  if(s->mb_y){
161  int qp_dt, qp_tt, qp_tc;
162 
163  if (IS_SKIP(s->current_picture.mb_type[xy - s->mb_stride]))
164  qp_tt=0;
165  else
166  qp_tt = s->current_picture.qscale_table[xy - s->mb_stride];
167 
168  if(qp_c)
169  qp_tc= qp_c;
170  else
171  qp_tc= qp_tt;
172 
173  if(qp_tc){
174  const int chroma_qp= s->chroma_qscale_table[qp_tc];
175  s->dsp.h263_v_loop_filter(dest_y , linesize, qp_tc);
176  s->dsp.h263_v_loop_filter(dest_y+8, linesize, qp_tc);
177 
178  s->dsp.h263_v_loop_filter(dest_cb , uvlinesize, chroma_qp);
179  s->dsp.h263_v_loop_filter(dest_cr , uvlinesize, chroma_qp);
180  }
181 
182  if(qp_tt)
183  s->dsp.h263_h_loop_filter(dest_y-8*linesize+8 , linesize, qp_tt);
184 
185  if(s->mb_x){
186  if (qp_tt || IS_SKIP(s->current_picture.mb_type[xy - 1 - s->mb_stride]))
187  qp_dt= qp_tt;
188  else
189  qp_dt = s->current_picture.qscale_table[xy - 1 - s->mb_stride];
190 
191  if(qp_dt){
192  const int chroma_qp= s->chroma_qscale_table[qp_dt];
193  s->dsp.h263_h_loop_filter(dest_y -8*linesize , linesize, qp_dt);
194  s->dsp.h263_h_loop_filter(dest_cb-8*uvlinesize, uvlinesize, chroma_qp);
195  s->dsp.h263_h_loop_filter(dest_cr-8*uvlinesize, uvlinesize, chroma_qp);
196  }
197  }
198  }
199 
200  if(qp_c){
201  s->dsp.h263_h_loop_filter(dest_y +8, linesize, qp_c);
202  if(s->mb_y + 1 == s->mb_height)
203  s->dsp.h263_h_loop_filter(dest_y+8*linesize+8, linesize, qp_c);
204  }
205 
206  if(s->mb_x){
207  int qp_lc;
208  if (qp_c || IS_SKIP(s->current_picture.mb_type[xy - 1]))
209  qp_lc= qp_c;
210  else
211  qp_lc = s->current_picture.qscale_table[xy - 1];
212 
213  if(qp_lc){
214  s->dsp.h263_h_loop_filter(dest_y, linesize, qp_lc);
215  if(s->mb_y + 1 == s->mb_height){
216  const int chroma_qp= s->chroma_qscale_table[qp_lc];
217  s->dsp.h263_h_loop_filter(dest_y +8* linesize, linesize, qp_lc);
218  s->dsp.h263_h_loop_filter(dest_cb , uvlinesize, chroma_qp);
219  s->dsp.h263_h_loop_filter(dest_cr , uvlinesize, chroma_qp);
220  }
221  }
222  }
223 }
224 
225 void ff_h263_pred_acdc(MpegEncContext * s, int16_t *block, int n)
226 {
227  int x, y, wrap, a, c, pred_dc, scale, i;
228  int16_t *dc_val, *ac_val, *ac_val1;
229 
230  /* find prediction */
231  if (n < 4) {
232  x = 2 * s->mb_x + (n & 1);
233  y = 2 * s->mb_y + (n>> 1);
234  wrap = s->b8_stride;
235  dc_val = s->dc_val[0];
236  ac_val = s->ac_val[0][0];
237  scale = s->y_dc_scale;
238  } else {
239  x = s->mb_x;
240  y = s->mb_y;
241  wrap = s->mb_stride;
242  dc_val = s->dc_val[n - 4 + 1];
243  ac_val = s->ac_val[n - 4 + 1][0];
244  scale = s->c_dc_scale;
245  }
246 
247  ac_val += ((y) * wrap + (x)) * 16;
248  ac_val1 = ac_val;
249 
250  /* B C
251  * A X
252  */
253  a = dc_val[(x - 1) + (y) * wrap];
254  c = dc_val[(x) + (y - 1) * wrap];
255 
256  /* No prediction outside GOB boundary */
257  if(s->first_slice_line && n!=3){
258  if(n!=2) c= 1024;
259  if(n!=1 && s->mb_x == s->resync_mb_x) a= 1024;
260  }
261 
262  if (s->ac_pred) {
263  pred_dc = 1024;
264  if (s->h263_aic_dir) {
265  /* left prediction */
266  if (a != 1024) {
267  ac_val -= 16;
268  for(i=1;i<8;i++) {
269  block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
270  }
271  pred_dc = a;
272  }
273  } else {
274  /* top prediction */
275  if (c != 1024) {
276  ac_val -= 16 * wrap;
277  for(i=1;i<8;i++) {
278  block[s->dsp.idct_permutation[i ]] += ac_val[i + 8];
279  }
280  pred_dc = c;
281  }
282  }
283  } else {
284  /* just DC prediction */
285  if (a != 1024 && c != 1024)
286  pred_dc = (a + c) >> 1;
287  else if (a != 1024)
288  pred_dc = a;
289  else
290  pred_dc = c;
291  }
292 
293  /* we assume pred is positive */
294  block[0]=block[0]*scale + pred_dc;
295 
296  if (block[0] < 0)
297  block[0] = 0;
298  else
299  block[0] |= 1;
300 
301  /* Update AC/DC tables */
302  dc_val[(x) + (y) * wrap] = block[0];
303 
304  /* left copy */
305  for(i=1;i<8;i++)
306  ac_val1[i ] = block[s->dsp.idct_permutation[i<<3]];
307  /* top copy */
308  for(i=1;i<8;i++)
309  ac_val1[8 + i] = block[s->dsp.idct_permutation[i ]];
310 }
311 
312 int16_t *ff_h263_pred_motion(MpegEncContext * s, int block, int dir,
313  int *px, int *py)
314 {
315  int wrap;
316  int16_t *A, *B, *C, (*mot_val)[2];
317  static const int off[4]= {2, 1, 1, -1};
318 
319  wrap = s->b8_stride;
320  mot_val = s->current_picture.motion_val[dir] + s->block_index[block];
321 
322  A = mot_val[ - 1];
323  /* special case for first (slice) line */
324  if (s->first_slice_line && block<3) {
325  // we can't just change some MVs to simulate that as we need them for the B frames (and ME)
326  // and if we ever support non rectangular objects than we need to do a few ifs here anyway :(
327  if(block==0){ //most common case
328  if(s->mb_x == s->resync_mb_x){ //rare
329  *px= *py = 0;
330  }else if(s->mb_x + 1 == s->resync_mb_x && s->h263_pred){ //rare
331  C = mot_val[off[block] - wrap];
332  if(s->mb_x==0){
333  *px = C[0];
334  *py = C[1];
335  }else{
336  *px = mid_pred(A[0], 0, C[0]);
337  *py = mid_pred(A[1], 0, C[1]);
338  }
339  }else{
340  *px = A[0];
341  *py = A[1];
342  }
343  }else if(block==1){
344  if(s->mb_x + 1 == s->resync_mb_x && s->h263_pred){ //rare
345  C = mot_val[off[block] - wrap];
346  *px = mid_pred(A[0], 0, C[0]);
347  *py = mid_pred(A[1], 0, C[1]);
348  }else{
349  *px = A[0];
350  *py = A[1];
351  }
352  }else{ /* block==2*/
353  B = mot_val[ - wrap];
354  C = mot_val[off[block] - wrap];
355  if(s->mb_x == s->resync_mb_x) //rare
356  A[0]=A[1]=0;
357 
358  *px = mid_pred(A[0], B[0], C[0]);
359  *py = mid_pred(A[1], B[1], C[1]);
360  }
361  } else {
362  B = mot_val[ - wrap];
363  C = mot_val[off[block] - wrap];
364  *px = mid_pred(A[0], B[0], C[0]);
365  *py = mid_pred(A[1], B[1], C[1]);
366  }
367  return *mot_val;
368 }
369 
370 
371 /**
372  * Get the GOB height based on picture height.
373  */
374 int ff_h263_get_gob_height(MpegEncContext *s){
375  if (s->height <= 400)
376  return 1;
377  else if (s->height <= 800)
378  return 2;
379  else
380  return 4;
381 }
Generated on Wed Jul 10 2013 23:47:58 for FFmpeg by   doxygen 1.8.2