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h263.h
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1 /*
2  * H263 internal header
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 #ifndef AVCODEC_H263_H
21 #define AVCODEC_H263_H
22 
23 #include <stdint.h>
24 #include "libavutil/rational.h"
25 #include "get_bits.h"
26 #include "mpegvideo.h"
27 #include "rl.h"
28 
29 // The defines below define the number of bits that are read at once for
30 // reading vlc values. Changing these may improve speed and data cache needs
31 // be aware though that decreasing them may need the number of stages that is
32 // passed to get_vlc* to be increased.
33 #define INTRA_MCBPC_VLC_BITS 6
34 #define INTER_MCBPC_VLC_BITS 7
35 #define CBPY_VLC_BITS 6
36 #define TEX_VLC_BITS 9
37 
38 extern const AVRational ff_h263_pixel_aspect[16];
39 extern const uint8_t ff_h263_cbpy_tab[16][2];
40 
41 extern const uint8_t ff_cbpc_b_tab[4][2];
42 
43 extern const uint8_t ff_mvtab[33][2];
44 
45 extern const uint8_t ff_h263_intra_MCBPC_code[9];
46 extern const uint8_t ff_h263_intra_MCBPC_bits[9];
47 
48 extern const uint8_t ff_h263_inter_MCBPC_code[28];
49 extern const uint8_t ff_h263_inter_MCBPC_bits[28];
50 extern const uint8_t ff_h263_mbtype_b_tab[15][2];
51 
54 extern VLC ff_h263_cbpy_vlc;
55 
57 
59 
60 extern const uint16_t ff_h263_format[8][2];
61 extern const uint8_t ff_modified_quant_tab[2][32];
62 extern const uint16_t ff_mba_max[6];
63 extern const uint8_t ff_mba_length[7];
64 
66 
68 
69 
70 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code);
74  void *data, int *got_frame,
75  AVPacket *avpkt);
78  int16_t block[6][64],
79  int motion_x, int motion_y);
80 void ff_h263_encode_picture_header(MpegEncContext *s, int picture_number);
81 void ff_h263_encode_gob_header(MpegEncContext * s, int mb_line);
82 int16_t *ff_h263_pred_motion(MpegEncContext * s, int block, int dir,
83  int *px, int *py);
85 void ff_h263_decode_init_vlc(void);
93 int ff_h263_pred_dc(MpegEncContext * s, int n, int16_t **dc_val_ptr);
94 void ff_h263_pred_acdc(MpegEncContext * s, int16_t *block, int n);
95 
96 
97 /**
98  * Print picture info if FF_DEBUG_PICT_INFO is set.
99  */
101 
104  int16_t block[6][64]);
105 
106 /**
107  * Return the value of the 3bit "source format" syntax element.
108  * This represents some standard picture dimensions or indicates that
109  * width&height are explicitly stored later.
110  */
112 
117 void ff_h263_encode_motion(MpegEncContext * s, int val, int f_code);
118 
119 
120 static inline int h263_get_motion_length(MpegEncContext * s, int val, int f_code){
121  int l, bit_size, code;
122 
123  if (val == 0) {
124  return ff_mvtab[0][1];
125  } else {
126  bit_size = f_code - 1;
127  /* modulo encoding */
128  l= INT_BIT - 6 - bit_size;
129  val = (val<<l)>>l;
130  val--;
131  code = (val >> bit_size) + 1;
132 
133  return ff_mvtab[code][1] + 1 + bit_size;
134  }
135 }
136 
137 static inline void ff_h263_encode_motion_vector(MpegEncContext * s, int x, int y, int f_code){
138  if(s->flags2 & CODEC_FLAG2_NO_OUTPUT){
139  skip_put_bits(&s->pb,
140  h263_get_motion_length(s, x, f_code)
141  +h263_get_motion_length(s, y, f_code));
142  }else{
143  ff_h263_encode_motion(s, x, f_code);
144  ff_h263_encode_motion(s, y, f_code);
145  }
146 }
147 
148 static inline int get_p_cbp(MpegEncContext * s,
149  int16_t block[6][64],
150  int motion_x, int motion_y){
151  int cbp, i;
152 
153  if (s->mpv_flags & FF_MPV_FLAG_CBP_RD) {
154  int best_cbpy_score= INT_MAX;
155  int best_cbpc_score= INT_MAX;
156  int cbpc = (-1), cbpy= (-1);
157  const int offset= (s->mv_type==MV_TYPE_16X16 ? 0 : 16) + (s->dquant ? 8 : 0);
158  const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
159 
160  for(i=0; i<4; i++){
161  int score= ff_h263_inter_MCBPC_bits[i + offset] * lambda;
162  if(i&1) score += s->coded_score[5];
163  if(i&2) score += s->coded_score[4];
164 
165  if(score < best_cbpc_score){
166  best_cbpc_score= score;
167  cbpc= i;
168  }
169  }
170 
171  for(i=0; i<16; i++){
172  int score= ff_h263_cbpy_tab[i ^ 0xF][1] * lambda;
173  if(i&1) score += s->coded_score[3];
174  if(i&2) score += s->coded_score[2];
175  if(i&4) score += s->coded_score[1];
176  if(i&8) score += s->coded_score[0];
177 
178  if(score < best_cbpy_score){
179  best_cbpy_score= score;
180  cbpy= i;
181  }
182  }
183  cbp= cbpc + 4*cbpy;
184  if ((motion_x | motion_y | s->dquant) == 0 && s->mv_type==MV_TYPE_16X16){
185  if(best_cbpy_score + best_cbpc_score + 2*lambda >= 0)
186  cbp= 0;
187  }
188 
189  for (i = 0; i < 6; i++) {
190  if (s->block_last_index[i] >= 0 && ((cbp >> (5 - i))&1)==0 ){
191  s->block_last_index[i]= -1;
192  s->dsp.clear_block(s->block[i]);
193  }
194  }
195  }else{
196  cbp= 0;
197  for (i = 0; i < 6; i++) {
198  if (s->block_last_index[i] >= 0)
199  cbp |= 1 << (5 - i);
200  }
201  }
202  return cbp;
203 }
204 
205 static inline void memsetw(short *tab, int val, int n)
206 {
207  int i;
208  for(i=0;i<n;i++)
209  tab[i] = val;
210 }
211 
212 #endif /* AVCODEC_H263_H */