xref: /third_party/ffmpeg/libavcodec/h263enc.h (revision cabdff1a)
1/*
2 * H.263 encoder 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_H263ENC_H
21#define AVCODEC_H263ENC_H
22
23#include <stdint.h>
24#include "h263data.h"
25#include "mpegvideoenc.h"
26
27void ff_h263_encode_init(MpegEncContext *s);
28void ff_h263_encode_picture_header(MpegEncContext *s, int picture_number);
29void ff_h263_encode_gob_header(MpegEncContext * s, int mb_line);
30void ff_h263_encode_mb(MpegEncContext *s,
31                       int16_t block[6][64],
32                       int motion_x, int motion_y);
33void ff_h263_encode_mba(MpegEncContext *s);
34
35void ff_init_qscale_tab(MpegEncContext *s);
36void ff_clean_h263_qscales(MpegEncContext *s);
37
38void ff_h263_encode_motion(PutBitContext *pb, int val, int f_code);
39
40
41static inline int h263_get_motion_length(int val, int f_code)
42{
43    int bit_size, code, sign;
44
45    if (val == 0) {
46        return 1; /* ff_mvtab[0][1] */
47    } else {
48        bit_size = f_code - 1;
49        /* modulo encoding */
50        val  = sign_extend(val, 6 + bit_size);
51        sign = val >> 31;
52        val  = (val ^ sign) - sign; /* val = FFABS(val) */
53        val--;
54        code = (val >> bit_size) + 1;
55
56        return ff_mvtab[code][1] + 1 + bit_size;
57    }
58}
59
60static inline void ff_h263_encode_motion_vector(MpegEncContext * s,
61                                                int x, int y, int f_code)
62{
63    if (s->avctx->flags2 & AV_CODEC_FLAG2_NO_OUTPUT) {
64        skip_put_bits(&s->pb,
65                      h263_get_motion_length(x, f_code) +
66                      h263_get_motion_length(y, f_code));
67    } else {
68        ff_h263_encode_motion(&s->pb, x, f_code);
69        ff_h263_encode_motion(&s->pb, y, f_code);
70    }
71}
72
73static inline int get_p_cbp(MpegEncContext * s,
74                      int16_t block[6][64],
75                      int motion_x, int motion_y){
76    int cbp;
77
78    if (s->mpv_flags & FF_MPV_FLAG_CBP_RD) {
79        int best_cbpy_score = INT_MAX;
80        int best_cbpc_score = INT_MAX;
81        int cbpc = (-1), cbpy = (-1);
82        const int offset = (s->mv_type == MV_TYPE_16X16 ? 0 : 16) + (s->dquant ? 8 : 0);
83        const int lambda = s->lambda2 >> (FF_LAMBDA_SHIFT - 6);
84
85        for (int i = 0; i < 4; i++) {
86            int score = ff_h263_inter_MCBPC_bits[i + offset] * lambda;
87            if (i & 1) score += s->coded_score[5];
88            if (i & 2) score += s->coded_score[4];
89
90            if (score < best_cbpc_score) {
91                best_cbpc_score = score;
92                cbpc = i;
93            }
94        }
95
96        for (int i = 0; i < 16; i++) {
97            int score= ff_h263_cbpy_tab[i ^ 0xF][1] * lambda;
98            if (i & 1) score += s->coded_score[3];
99            if (i & 2) score += s->coded_score[2];
100            if (i & 4) score += s->coded_score[1];
101            if (i & 8) score += s->coded_score[0];
102
103            if (score < best_cbpy_score) {
104                best_cbpy_score = score;
105                cbpy = i;
106            }
107        }
108        cbp = cbpc + 4 * cbpy;
109        if (!(motion_x | motion_y | s->dquant) && s->mv_type == MV_TYPE_16X16) {
110            if (best_cbpy_score + best_cbpc_score + 2 * lambda >= 0)
111                cbp= 0;
112        }
113
114        for (int i = 0; i < 6; i++) {
115            if (s->block_last_index[i] >= 0 && !((cbp >> (5 - i)) & 1)) {
116                s->block_last_index[i] = -1;
117                s->bdsp.clear_block(s->block[i]);
118            }
119        }
120    } else {
121        cbp = 0;
122        for (int i = 0; i < 6; i++) {
123            if (s->block_last_index[i] >= 0)
124                cbp |= 1 << (5 - i);
125        }
126    }
127    return cbp;
128}
129
130#endif
131