FFmpeg
h263enc.h
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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 
28 void ff_h263_encode_picture_header(MpegEncContext *s, int picture_number);
29 void ff_h263_encode_gob_header(MpegEncContext * s, int mb_line);
31  int16_t block[6][64],
32  int motion_x, int motion_y);
34 
37 
38 void ff_h263_encode_motion(PutBitContext *pb, int val, int f_code);
39 
40 
41 static 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 
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 
73 static 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
MV_TYPE_16X16
#define MV_TYPE_16X16
1 vector for the whole mb
Definition: mpegvideo.h:263
ff_h263_encode_mba
void ff_h263_encode_mba(MpegEncContext *s)
Definition: ituh263enc.c:871
h263data.h
mpegvideoenc.h
FF_LAMBDA_SHIFT
#define FF_LAMBDA_SHIFT
Definition: avutil.h:225
val
static double val(void *priv, double ch)
Definition: aeval.c:77
FF_MPV_FLAG_CBP_RD
#define FF_MPV_FLAG_CBP_RD
Definition: mpegvideoenc.h:42
ff_h263_encode_motion_vector
static void ff_h263_encode_motion_vector(MpegEncContext *s, int x, int y, int f_code)
Definition: h263enc.h:60
AV_CODEC_FLAG2_NO_OUTPUT
#define AV_CODEC_FLAG2_NO_OUTPUT
Skip bitstream encoding.
Definition: avcodec.h:307
s
#define s(width, name)
Definition: cbs_vp9.c:256
get_p_cbp
static int get_p_cbp(MpegEncContext *s, int16_t block[6][64], int motion_x, int motion_y)
Definition: h263enc.h:73
skip_put_bits
static void skip_put_bits(PutBitContext *s, int n)
Skip the given number of bits.
Definition: put_bits.h:392
PutBitContext
Definition: put_bits.h:50
h263_get_motion_length
static int h263_get_motion_length(int val, int f_code)
Definition: h263enc.h:41
ff_init_qscale_tab
void ff_init_qscale_tab(MpegEncContext *s)
init s->current_picture.qscale_table from s->lambda_table
Definition: mpegvideo_enc.c:236
ff_clean_h263_qscales
void ff_clean_h263_qscales(MpegEncContext *s)
modify qscale so that encoding is actually possible in H.263 (limit difference to -2....
Definition: ituh263enc.c:272
ff_h263_encode_picture_header
void ff_h263_encode_picture_header(MpegEncContext *s, int picture_number)
Definition: ituh263enc.c:108
ff_h263_cbpy_tab
const uint8_t ff_h263_cbpy_tab[16][2]
Definition: h263data.c:82
offset
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Definition: writing_filters.txt:86
ff_h263_encode_mb
void ff_h263_encode_mb(MpegEncContext *s, int16_t block[6][64], int motion_x, int motion_y)
Definition: ituh263enc.c:494
ff_h263_inter_MCBPC_bits
const uint8_t ff_h263_inter_MCBPC_bits[28]
Definition: h263data.c:47
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
code
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
Definition: filter_design.txt:178
ff_h263_encode_init
void ff_h263_encode_init(MpegEncContext *s)
Definition: ituh263enc.c:816
ff_h263_encode_gob_header
void ff_h263_encode_gob_header(MpegEncContext *s, int mb_line)
Encode a group of blocks header.
Definition: ituh263enc.c:246
ff_mvtab
const uint8_t ff_mvtab[33][2]
Definition: h263data.c:88
sign_extend
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:133
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
ff_h263_encode_motion
void ff_h263_encode_motion(PutBitContext *pb, int val, int f_code)
Definition: ituh263enc.c:692
MpegEncContext
MpegEncContext.
Definition: mpegvideo.h:70