FFmpeg
mpeg4video.h
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1 /*
2  * MPEG-4 encoder/decoder internal header.
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #ifndef AVCODEC_MPEG4VIDEO_H
24 #define AVCODEC_MPEG4VIDEO_H
25 
26 #include <stdint.h>
27 
28 #include "get_bits.h"
29 #include "mpegvideo.h"
30 
31 // shapes
32 #define RECT_SHAPE 0
33 #define BIN_SHAPE 1
34 #define BIN_ONLY_SHAPE 2
35 #define GRAY_SHAPE 3
36 
37 #define SIMPLE_VO_TYPE 1
38 #define CORE_VO_TYPE 3
39 #define MAIN_VO_TYPE 4
40 #define NBIT_VO_TYPE 5
41 #define ARTS_VO_TYPE 10
42 #define ACE_VO_TYPE 12
43 #define SIMPLE_STUDIO_VO_TYPE 14
44 #define CORE_STUDIO_VO_TYPE 15
45 #define ADV_SIMPLE_VO_TYPE 17
46 
47 #define VOT_VIDEO_ID 1
48 #define VOT_STILL_TEXTURE_ID 2
49 
50 // aspect_ratio_info
51 #define EXTENDED_PAR 15
52 
53 //vol_sprite_usage / sprite_enable
54 #define STATIC_SPRITE 1
55 #define GMC_SPRITE 2
56 
57 #define MOTION_MARKER 0x1F001
58 #define DC_MARKER 0x6B001
59 
60 #define VOS_STARTCODE 0x1B0
61 #define USER_DATA_STARTCODE 0x1B2
62 #define GOP_STARTCODE 0x1B3
63 #define VISUAL_OBJ_STARTCODE 0x1B5
64 #define VOP_STARTCODE 0x1B6
65 #define SLICE_STARTCODE 0x1B7
66 #define EXT_STARTCODE 0x1B8
67 
68 #define QUANT_MATRIX_EXT_ID 0x3
69 
70 /* smaller packets likely don't contain a real frame */
71 #define MAX_NVOP_SIZE 19
72 
73 typedef struct Mpeg4DecContext {
75 
76  /// number of bits to represent the fractional part of time
78  int shape;
82  /// sprite trajectory points
83  uint16_t sprite_traj[4][2];
84  /// sprite shift [isChroma]
85  int sprite_shift[2];
86 
87  // reversible vlc
88  int rvlc;
89  /// could this stream contain resync markers
91  /// time distance of first I -> B, used for interlaced B-frames
92  int t_frame;
93 
94  int new_pred;
98 
99  /// QP above which the ac VLC should be used for intra dc
101 
102  /* bug workarounds */
107 
108  /// flag for having shown the warning about invalid Divx B-frames
110  /** does the stream contain the low_delay flag,
111  * used to work around buggy encoders. */
116 
117  int rgb;
119 
121  int16_t block[6][64],
122  int motion_x, int motion_y);
123 void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n,
124  int dir);
126 int ff_mpeg4_encode_picture_header(MpegEncContext *s, int picture_number);
127 
129  int header, int parse_only);
142 int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
143 
144 /**
145  * @return the mb_type
146  */
147 int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my);
148 
149 #if 0 //3IV1 is quite rare and it slows things down a tiny bit
150 #define IS_3IV1 s->codec_tag == AV_RL32("3IV1")
151 #else
152 #define IS_3IV1 0
153 #endif
154 
155 /**
156  * Predict the dc.
157  * encoding quantized level -> quantized diff
158  * decoding quantized diff -> quantized level
159  * @param n block index (0-3 are luma, 4-5 are chroma)
160  * @param dir_ptr pointer to an integer where the prediction direction will be stored
161  */
162 static inline int ff_mpeg4_pred_dc(MpegEncContext *s, int n, int level,
163  int *dir_ptr, int encoding)
164 {
165  int a, b, c, wrap, pred, scale, ret;
166  int16_t *dc_val;
167 
168  /* find prediction */
169  if (n < 4)
170  scale = s->y_dc_scale;
171  else
172  scale = s->c_dc_scale;
173  if (IS_3IV1)
174  scale = 8;
175 
176  wrap = s->block_wrap[n];
177  dc_val = s->dc_val[0] + s->block_index[n];
178 
179  /* B C
180  * A X
181  */
182  a = dc_val[-1];
183  b = dc_val[-1 - wrap];
184  c = dc_val[-wrap];
185 
186  /* outside slice handling (we can't do that by memset as we need the
187  * dc for error resilience) */
188  if (s->first_slice_line && n != 3) {
189  if (n != 2)
190  b = c = 1024;
191  if (n != 1 && s->mb_x == s->resync_mb_x)
192  b = a = 1024;
193  }
194  if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1) {
195  if (n == 0 || n == 4 || n == 5)
196  b = 1024;
197  }
198 
199  if (abs(a - b) < abs(b - c)) {
200  pred = c;
201  *dir_ptr = 1; /* top */
202  } else {
203  pred = a;
204  *dir_ptr = 0; /* left */
205  }
206  /* we assume pred is positive */
207  pred = FASTDIV((pred + (scale >> 1)), scale);
208 
209  if (encoding) {
210  ret = level - pred;
211  } else {
212  level += pred;
213  ret = level;
214  }
215  level *= scale;
216  if (level & (~2047)) {
217  if (!s->encoding && (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE))) {
218  if (level < 0) {
219  av_log(s->avctx, AV_LOG_ERROR,
220  "dc<0 at %dx%d\n", s->mb_x, s->mb_y);
221  return AVERROR_INVALIDDATA;
222  }
223  if (level > 2048 + scale) {
224  av_log(s->avctx, AV_LOG_ERROR,
225  "dc overflow at %dx%d\n", s->mb_x, s->mb_y);
226  return AVERROR_INVALIDDATA;
227  }
228  }
229  if (level < 0)
230  level = 0;
231  else if (!(s->workaround_bugs & FF_BUG_DC_CLIP))
232  level = 2047;
233  }
234  dc_val[0] = level;
235 
236  return ret;
237 }
238 
239 #endif /* AVCODEC_MPEG4VIDEO_H */
FF_BUG_DC_CLIP
#define FF_BUG_DC_CLIP
Definition: avcodec.h:1263
ff_mpeg4_workaround_bugs
int ff_mpeg4_workaround_bugs(AVCodecContext *avctx)
Definition: mpeg4videodec.c:2732
level
uint8_t level
Definition: svq3.c:202
Mpeg4DecContext::vol_sprite_usage
int vol_sprite_usage
Definition: mpeg4video.h:79
ff_mpeg4_encode_video_packet_header
void ff_mpeg4_encode_video_packet_header(MpegEncContext *s)
Definition: mpeg4videoenc.c:1364
Mpeg4DecContext::showed_packed_warning
int showed_packed_warning
flag for having shown the warning about invalid Divx B-frames
Definition: mpeg4video.h:109
ff_mpeg4_merge_partitions
void ff_mpeg4_merge_partitions(MpegEncContext *s)
Definition: mpeg4videoenc.c:1338
b
#define b
Definition: input.c:40
Mpeg4DecContext::rvlc
int rvlc
Definition: mpeg4video.h:88
ff_mpeg4_decode_video_packet_header
int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
Decode the next video packet.
Definition: mpeg4videodec.c:448
Mpeg4DecContext::new_pred
int new_pred
Definition: mpeg4video.h:94
mpegvideo.h
ff_mpeg4_init_direct_mv
void ff_mpeg4_init_direct_mv(MpegEncContext *s)
Definition: mpeg4video.c:83
ff_set_mpeg4_time
void ff_set_mpeg4_time(MpegEncContext *s)
Definition: mpeg4videoenc.c:876
ff_mpeg4_decode_partitions
int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx)
Decode the first and second partition.
Definition: mpeg4videodec.c:978
wrap
#define wrap(func)
Definition: neontest.h:65
GetBitContext
Definition: get_bits.h:62
scale
static av_always_inline float scale(float x, float s)
Definition: vf_v360.c:1388
ff_mpeg4_encode_mb
void ff_mpeg4_encode_mb(MpegEncContext *s, int16_t block[6][64], int motion_x, int motion_y)
Definition: mpeg4videoenc.c:478
AV_EF_BITSTREAM
#define AV_EF_BITSTREAM
detect bitstream specification deviations
Definition: avcodec.h:1333
ff_mpeg4_encode_picture_header
int ff_mpeg4_encode_picture_header(MpegEncContext *s, int picture_number)
Definition: mpeg4videoenc.c:1061
ff_mpeg4_decode_studio_slice_header
int ff_mpeg4_decode_studio_slice_header(Mpeg4DecContext *ctx)
Decode the next video packet.
Definition: mpeg4videodec.c:549
Mpeg4DecContext::sprite_brightness_change
int sprite_brightness_change
Definition: mpeg4video.h:80
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
s
#define s(width, name)
Definition: cbs_vp9.c:257
Mpeg4DecContext::cplx_estimation_trash_b
int cplx_estimation_trash_b
Definition: mpeg4video.h:115
ctx
AVFormatContext * ctx
Definition: movenc.c:48
get_bits.h
ff_mpeg4_stuffing
void ff_mpeg4_stuffing(PutBitContext *pbc)
add MPEG-4 stuffing bits (01...1)
Definition: mpeg4videoenc.c:866
PutBitContext
Definition: put_bits.h:49
Mpeg4DecContext::rgb
int rgb
Definition: mpeg4video.h:117
Mpeg4DecContext::shape
int shape
Definition: mpeg4video.h:78
Mpeg4DecContext::cplx_estimation_trash_i
int cplx_estimation_trash_i
Definition: mpeg4video.h:113
abs
#define abs(x)
Definition: cuda_runtime.h:35
Mpeg4DecContext
Definition: mpeg4video.h:73
FASTDIV
#define FASTDIV(a, b)
Definition: mathops.h:202
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
Mpeg4DecContext::scalability
int scalability
Definition: mpeg4video.h:96
Mpeg4DecContext::t_frame
int t_frame
time distance of first I -> B, used for interlaced B-frames
Definition: mpeg4video.h:92
Mpeg4DecContext::divx_version
int divx_version
Definition: mpeg4video.h:103
ff_mpeg4_decode_picture_header
int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb, int header, int parse_only)
Decode MPEG-4 headers.
Definition: mpeg4videodec.c:3235
ff_mpeg4_set_direct_mv
int ff_mpeg4_set_direct_mv(MpegEncContext *s, int mx, int my)
Definition: mpeg4video.c:129
Mpeg4DecContext::lavc_build
int lavc_build
Definition: mpeg4video.h:106
ff_mpeg4_pred_dc
static int ff_mpeg4_pred_dc(MpegEncContext *s, int n, int level, int *dir_ptr, int encoding)
Predict the dc.
Definition: mpeg4video.h:162
Mpeg4DecContext::sprite_shift
int sprite_shift[2]
sprite shift [isChroma]
Definition: mpeg4video.h:85
header
static const uint8_t header[24]
Definition: sdr2.c:67
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
ff_mpeg4_pred_ac
void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n, int dir)
Predict the ac.
Definition: mpeg4videodec.c:74
Mpeg4DecContext::sprite_traj
uint16_t sprite_traj[4][2]
sprite trajectory points
Definition: mpeg4video.h:83
Mpeg4DecContext::cplx_estimation_trash_p
int cplx_estimation_trash_p
Definition: mpeg4video.h:114
ff_clean_mpeg4_qscales
void ff_clean_mpeg4_qscales(MpegEncContext *s)
modify mb_type & qscale so that encoding is actually possible in MPEG-4
Definition: mpeg4videoenc.c:216
ff_mpeg4_get_video_packet_prefix_length
int ff_mpeg4_get_video_packet_prefix_length(MpegEncContext *s)
Definition: mpeg4video.c:42
Mpeg4DecContext::time_increment_bits
int time_increment_bits
number of bits to represent the fractional part of time
Definition: mpeg4video.h:77
Mpeg4DecContext::num_sprite_warping_points
int num_sprite_warping_points
Definition: mpeg4video.h:81
Mpeg4DecContext::use_intra_dc_vlc
int use_intra_dc_vlc
Definition: mpeg4video.h:97
ff_mpeg4_init_partitions
void ff_mpeg4_init_partitions(MpegEncContext *s)
Definition: mpeg4videoenc.c:1325
Mpeg4DecContext::vol_control_parameters
int vol_control_parameters
does the stream contain the low_delay flag, used to work around buggy encoders.
Definition: mpeg4video.h:112
ret
ret
Definition: filter_design.txt:187
pred
static const float pred[4]
Definition: siprdata.h:259
ff_mpeg4_frame_end
int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
Definition: mpeg4videodec.c:3393
ff_mpeg4_clean_buffers
void ff_mpeg4_clean_buffers(MpegEncContext *s)
Definition: mpeg4video.c:57
AVCodecContext
main external API structure.
Definition: avcodec.h:383
Mpeg4DecContext::m
MpegEncContext m
Definition: mpeg4video.h:74
Mpeg4DecContext::resync_marker
int resync_marker
could this stream contain resync markers
Definition: mpeg4video.h:90
Mpeg4DecContext::enhancement_type
int enhancement_type
Definition: mpeg4video.h:95
AV_EF_AGGRESSIVE
#define AV_EF_AGGRESSIVE
consider things that a sane encoder should not do as an error
Definition: avcodec.h:1340
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
Mpeg4DecContext::divx_build
int divx_build
Definition: mpeg4video.h:104
Mpeg4DecContext::xvid_build
int xvid_build
Definition: mpeg4video.h:105
MpegEncContext
MpegEncContext.
Definition: mpegvideo.h:69
Mpeg4DecContext::intra_dc_threshold
int intra_dc_threshold
QP above which the ac VLC should be used for intra dc.
Definition: mpeg4video.h:100
IS_3IV1
#define IS_3IV1
Definition: mpeg4video.h:152