1 /*
2  * H.263 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 "h263data.h"
28 #include "rl.h"
29 
30 #define FF_ASPECT_EXTENDED 15
31 #define INT_BIT (CHAR_BIT * sizeof(int))
32 
33 // The defines below define the number of bits that are read at once for
34 // reading vlc values. Changing these may improve speed and data cache needs
35 // be aware though that decreasing them may need the number of stages that is
36 // passed to get_vlc* to be increased.
37 #define H263_MV_VLC_BITS     9
38 #define INTRA_MCBPC_VLC_BITS 6
39 #define INTER_MCBPC_VLC_BITS 7
40 #define CBPY_VLC_BITS 6
41 #define TEX_VLC_BITS 9
42 
43 #define H263_GOB_HEIGHT(h) ((h) <= 400 ? 1 : (h) <= 800 ? 2 : 4)
44 
45 extern VLC ff_h263_intra_MCBPC_vlc;
46 extern VLC ff_h263_inter_MCBPC_vlc;
47 extern VLC ff_h263_cbpy_vlc;
48 extern VLC ff_h263_mv_vlc;
49 
50 extern const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[];
51 
52 
53 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code);
54 av_const int ff_h263_aspect_to_info(AVRational aspect);
55 int ff_h263_decode_init(AVCodecContext *avctx);
56 int ff_h263_decode_frame(AVCodecContext *avctx,
57                              void *data, int *got_frame,
58                              AVPacket *avpkt);
59 int ff_h263_decode_end(AVCodecContext *avctx);
60 void ff_h263_encode_mb(MpegEncContext *s,
61                        int16_t block[6][64],
62                        int motion_x, int motion_y);
63 void ff_h263_encode_picture_header(MpegEncContext *s, int picture_number);
64 void ff_h263_encode_gob_header(MpegEncContext * s, int mb_line);
65 int16_t *ff_h263_pred_motion(MpegEncContext * s, int block, int dir,
66                              int *px, int *py);
67 void ff_h263_encode_init(MpegEncContext *s);
68 void ff_h263_decode_init_vlc(void);
69 int ff_h263_decode_picture_header(MpegEncContext *s);
70 int ff_h263_decode_gob_header(MpegEncContext *s);
71 void ff_h263_update_motion_val(MpegEncContext * s);
72 void ff_h263_loop_filter(MpegEncContext * s);
73 int ff_h263_decode_mba(MpegEncContext *s);
74 void ff_h263_encode_mba(MpegEncContext *s);
75 void ff_init_qscale_tab(MpegEncContext *s);
76 int ff_h263_pred_dc(MpegEncContext * s, int n, int16_t **dc_val_ptr);
77 void ff_h263_pred_acdc(MpegEncContext * s, int16_t *block, int n);
78 
79 
80 /**
81  * Print picture info if FF_DEBUG_PICT_INFO is set.
82  */
83 void ff_h263_show_pict_info(MpegEncContext *s);
84 
85 int ff_intel_h263_decode_picture_header(MpegEncContext *s);
86 int ff_h263_decode_mb(MpegEncContext *s,
87                       int16_t block[6][64]);
88 
89 /**
90  * Return the value of the 3-bit "source format" syntax element.
91  * This represents some standard picture dimensions or indicates that
92  * width&height are explicitly stored later.
93  */
94 int av_const h263_get_picture_format(int width, int height);
95 
96 void ff_clean_h263_qscales(MpegEncContext *s);
97 int ff_h263_resync(MpegEncContext *s);
98 void ff_h263_encode_motion(PutBitContext *pb, int val, int f_code);
99 
100 
h263_get_motion_length(int val,int f_code)101 static inline int h263_get_motion_length(int val, int f_code){
102     int l, bit_size, code;
103 
104     if (val == 0) {
105         return ff_mvtab[0][1];
106     } else {
107         bit_size = f_code - 1;
108         /* modulo encoding */
109         l= INT_BIT - 6 - bit_size;
110         val = (val<<l)>>l;
111         val--;
112         code = (val >> bit_size) + 1;
113 
114         return ff_mvtab[code][1] + 1 + bit_size;
115     }
116 }
117 
ff_h263_encode_motion_vector(MpegEncContext * s,int x,int y,int f_code)118 static inline void ff_h263_encode_motion_vector(MpegEncContext * s, int x, int y, int f_code){
119     if (s->avctx->flags2 & AV_CODEC_FLAG2_NO_OUTPUT) {
120         skip_put_bits(&s->pb,
121             h263_get_motion_length(x, f_code)
122            +h263_get_motion_length(y, f_code));
123     }else{
124         ff_h263_encode_motion(&s->pb, x, f_code);
125         ff_h263_encode_motion(&s->pb, y, f_code);
126     }
127 }
128 
get_p_cbp(MpegEncContext * s,int16_t block[6][64],int motion_x,int motion_y)129 static inline int get_p_cbp(MpegEncContext * s,
130                       int16_t block[6][64],
131                       int motion_x, int motion_y){
132     int cbp, i;
133 
134     if (s->mpv_flags & FF_MPV_FLAG_CBP_RD) {
135         int best_cbpy_score= INT_MAX;
136         int best_cbpc_score= INT_MAX;
137         int cbpc = (-1), cbpy= (-1);
138         const int offset= (s->mv_type==MV_TYPE_16X16 ? 0 : 16) + (s->dquant ? 8 : 0);
139         const int lambda= s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
140 
141         for(i=0; i<4; i++){
142             int score= ff_h263_inter_MCBPC_bits[i + offset] * lambda;
143             if(i&1) score += s->coded_score[5];
144             if(i&2) score += s->coded_score[4];
145 
146             if(score < best_cbpc_score){
147                 best_cbpc_score= score;
148                 cbpc= i;
149             }
150         }
151 
152         for(i=0; i<16; i++){
153             int score= ff_h263_cbpy_tab[i ^ 0xF][1] * lambda;
154             if(i&1) score += s->coded_score[3];
155             if(i&2) score += s->coded_score[2];
156             if(i&4) score += s->coded_score[1];
157             if(i&8) score += s->coded_score[0];
158 
159             if(score < best_cbpy_score){
160                 best_cbpy_score= score;
161                 cbpy= i;
162             }
163         }
164         cbp= cbpc + 4*cbpy;
165         if ((motion_x | motion_y | s->dquant) == 0 && s->mv_type==MV_TYPE_16X16){
166             if(best_cbpy_score + best_cbpc_score + 2*lambda >= 0)
167                 cbp= 0;
168         }
169 
170         for (i = 0; i < 6; i++) {
171             if (s->block_last_index[i] >= 0 && ((cbp >> (5 - i))&1)==0 ){
172                 s->block_last_index[i]= -1;
173                 s->bdsp.clear_block(s->block[i]);
174             }
175         }
176     }else{
177         cbp= 0;
178         for (i = 0; i < 6; i++) {
179             if (s->block_last_index[i] >= 0)
180                 cbp |= 1 << (5 - i);
181         }
182     }
183     return cbp;
184 }
185 
186 #endif /* AVCODEC_H263_H */
187