FFmpeg  4.4.5
cbs_mpeg2_syntax_template.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
20  MPEG2RawSequenceHeader *current)
21 {
23  int err, i;
24 
25  HEADER("Sequence Header");
26 
27  ui(8, sequence_header_code);
28 
29  uir(12, horizontal_size_value);
30  uir(12, vertical_size_value);
31 
32  mpeg2->horizontal_size = current->horizontal_size_value;
33  mpeg2->vertical_size = current->vertical_size_value;
34 
35  uir(4, aspect_ratio_information);
36  uir(4, frame_rate_code);
37  ui(18, bit_rate_value);
38 
39  marker_bit();
40 
41  ui(10, vbv_buffer_size_value);
42  ui(1, constrained_parameters_flag);
43 
44  ui(1, load_intra_quantiser_matrix);
45  if (current->load_intra_quantiser_matrix) {
46  for (i = 0; i < 64; i++)
47  uirs(8, intra_quantiser_matrix[i], 1, i);
48  }
49 
50  ui(1, load_non_intra_quantiser_matrix);
51  if (current->load_non_intra_quantiser_matrix) {
52  for (i = 0; i < 64; i++)
53  uirs(8, non_intra_quantiser_matrix[i], 1, i);
54  }
55 
56  return 0;
57 }
58 
60  MPEG2RawUserData *current)
61 {
62  size_t k;
63  int err;
64 
65  HEADER("User Data");
66 
67  ui(8, user_data_start_code);
68 
69 #ifdef READ
70  k = get_bits_left(rw);
71  av_assert0(k % 8 == 0);
72  current->user_data_length = k /= 8;
73  if (k > 0) {
74  current->user_data_ref = av_buffer_allocz(k + AV_INPUT_BUFFER_PADDING_SIZE);
75  if (!current->user_data_ref)
76  return AVERROR(ENOMEM);
77  current->user_data = current->user_data_ref->data;
78  }
79 #endif
80 
81  for (k = 0; k < current->user_data_length; k++)
82  uis(8, user_data[k], 1, k);
83 
84  return 0;
85 }
86 
89 {
91  int err;
92 
93  HEADER("Sequence Extension");
94 
95  ui(8, profile_and_level_indication);
96  ui(1, progressive_sequence);
97  ui(2, chroma_format);
98  ui(2, horizontal_size_extension);
99  ui(2, vertical_size_extension);
100 
101  mpeg2->horizontal_size = (mpeg2->horizontal_size & 0xfff) |
102  current->horizontal_size_extension << 12;
103  mpeg2->vertical_size = (mpeg2->vertical_size & 0xfff) |
104  current->vertical_size_extension << 12;
105  mpeg2->progressive_sequence = current->progressive_sequence;
106 
107  ui(12, bit_rate_extension);
108  marker_bit();
109  ui(8, vbv_buffer_size_extension);
110  ui(1, low_delay);
111  ui(2, frame_rate_extension_n);
112  ui(5, frame_rate_extension_d);
113 
114  return 0;
115 }
116 
119 {
120  int err;
121 
122  HEADER("Sequence Display Extension");
123 
124  ui(3, video_format);
125 
126  ui(1, colour_description);
127  if (current->colour_description) {
128 #ifdef READ
129 #define READ_AND_PATCH(name) do { \
130  ui(8, name); \
131  if (current->name == 0) { \
132  current->name = 2; \
133  av_log(ctx->log_ctx, AV_LOG_WARNING, "%s in a sequence display " \
134  "extension had the invalid value 0. Setting it to 2 " \
135  "(meaning unknown) instead.\n", #name); \
136  } \
137  } while (0)
138  READ_AND_PATCH(colour_primaries);
139  READ_AND_PATCH(transfer_characteristics);
140  READ_AND_PATCH(matrix_coefficients);
141 #undef READ_AND_PATCH
142 #else
143  uir(8, colour_primaries);
145  uir(8, matrix_coefficients);
146 #endif
147  } else {
148  infer(colour_primaries, 2);
150  infer(matrix_coefficients, 2);
151  }
152 
153  ui(14, display_horizontal_size);
154  marker_bit();
155  ui(14, display_vertical_size);
156 
157  return 0;
158 }
159 
162 {
163  int err;
164 
165  HEADER("Group of Pictures Header");
166 
167  ui(8, group_start_code);
168 
169  ui(25, time_code);
170  ui(1, closed_gop);
171  ui(1, broken_link);
172 
173  return 0;
174 }
175 
177  MPEG2RawExtraInformation *current,
178  const char *element_name, const char *marker_name)
179 {
180  int err;
181  size_t k;
182 #ifdef READ
183  GetBitContext start = *rw;
184  uint8_t bit;
185 
186  for (k = 0; nextbits(1, 1, bit); k++)
187  skip_bits(rw, 1 + 8);
188  current->extra_information_length = k;
189  if (k > 0) {
190  *rw = start;
191  current->extra_information_ref =
193  if (!current->extra_information_ref)
194  return AVERROR(ENOMEM);
195  current->extra_information = current->extra_information_ref->data;
196  }
197 #endif
198 
199  for (k = 0; k < current->extra_information_length; k++) {
200  bit(marker_name, 1);
201  xuia(8, element_name,
202  current->extra_information[k], 0, 255, 1, k);
203  }
204 
205  bit(marker_name, 0);
206 
207  return 0;
208 }
209 
211  MPEG2RawPictureHeader *current)
212 {
213  int err;
214 
215  HEADER("Picture Header");
216 
217  ui(8, picture_start_code);
218 
219  ui(10, temporal_reference);
220  uir(3, picture_coding_type);
221  ui(16, vbv_delay);
222 
223  if (current->picture_coding_type == 2 ||
224  current->picture_coding_type == 3) {
225  ui(1, full_pel_forward_vector);
226  ui(3, forward_f_code);
227  }
228 
229  if (current->picture_coding_type == 3) {
230  ui(1, full_pel_backward_vector);
231  ui(3, backward_f_code);
232  }
233 
234  CHECK(FUNC(extra_information)(ctx, rw, &current->extra_information_picture,
235  "extra_information_picture[k]", "extra_bit_picture"));
236 
237  return 0;
238 }
239 
242 {
244  int err;
245 
246  HEADER("Picture Coding Extension");
247 
248  uir(4, f_code[0][0]);
249  uir(4, f_code[0][1]);
250  uir(4, f_code[1][0]);
251  uir(4, f_code[1][1]);
252 
253  ui(2, intra_dc_precision);
254  ui(2, picture_structure);
255  ui(1, top_field_first);
256  ui(1, frame_pred_frame_dct);
257  ui(1, concealment_motion_vectors);
258  ui(1, q_scale_type);
259  ui(1, intra_vlc_format);
260  ui(1, alternate_scan);
261  ui(1, repeat_first_field);
262  ui(1, chroma_420_type);
263  ui(1, progressive_frame);
264 
265  if (mpeg2->progressive_sequence) {
266  if (current->repeat_first_field) {
267  if (current->top_field_first)
269  else
271  } else {
273  }
274  } else {
275  if (current->picture_structure == 1 || // Top field.
276  current->picture_structure == 2) { // Bottom field.
278  } else {
279  if (current->repeat_first_field)
281  else
283  }
284  }
285 
286  ui(1, composite_display_flag);
287  if (current->composite_display_flag) {
288  ui(1, v_axis);
289  ui(3, field_sequence);
290  ui(1, sub_carrier);
291  ui(7, burst_amplitude);
292  ui(8, sub_carrier_phase);
293  }
294 
295  return 0;
296 }
297 
300 {
301  int err, i;
302 
303  HEADER("Quant Matrix Extension");
304 
305  ui(1, load_intra_quantiser_matrix);
306  if (current->load_intra_quantiser_matrix) {
307  for (i = 0; i < 64; i++)
308  uirs(8, intra_quantiser_matrix[i], 1, i);
309  }
310 
311  ui(1, load_non_intra_quantiser_matrix);
312  if (current->load_non_intra_quantiser_matrix) {
313  for (i = 0; i < 64; i++)
314  uirs(8, non_intra_quantiser_matrix[i], 1, i);
315  }
316 
317  ui(1, load_chroma_intra_quantiser_matrix);
318  if (current->load_chroma_intra_quantiser_matrix) {
319  for (i = 0; i < 64; i++)
320  uirs(8, intra_quantiser_matrix[i], 1, i);
321  }
322 
323  ui(1, load_chroma_non_intra_quantiser_matrix);
324  if (current->load_chroma_non_intra_quantiser_matrix) {
325  for (i = 0; i < 64; i++)
326  uirs(8, chroma_non_intra_quantiser_matrix[i], 1, i);
327  }
328 
329  return 0;
330 }
331 
334 {
336  int err, i;
337 
338  HEADER("Picture Display Extension");
339 
340  for (i = 0; i < mpeg2->number_of_frame_centre_offsets; i++) {
341  sis(16, frame_centre_horizontal_offset[i], 1, i);
342  marker_bit();
343  sis(16, frame_centre_vertical_offset[i], 1, i);
344  marker_bit();
345  }
346 
347  return 0;
348 }
349 
351  MPEG2RawExtensionData *current)
352 {
353  int err;
354 
355  HEADER("Extension Data");
356 
357  ui(8, extension_start_code);
358  ui(4, extension_start_code_identifier);
359 
360  switch (current->extension_start_code_identifier) {
362  return FUNC(sequence_extension)
363  (ctx, rw, &current->data.sequence);
366  (ctx, rw, &current->data.sequence_display);
369  (ctx, rw, &current->data.quant_matrix);
372  (ctx, rw, &current->data.picture_display);
375  (ctx, rw, &current->data.picture_coding);
376  default:
377  av_log(ctx->log_ctx, AV_LOG_ERROR, "Extension ID %d not supported.\n",
378  current->extension_start_code_identifier);
379  return AVERROR_PATCHWELCOME;
380  }
381 }
382 
384  MPEG2RawSliceHeader *current)
385 {
387  int err;
388 
389  HEADER("Slice Header");
390 
391  ui(8, slice_vertical_position);
392 
393  if (mpeg2->vertical_size > 2800)
394  ui(3, slice_vertical_position_extension);
395  if (mpeg2->scalable) {
396  if (mpeg2->scalable_mode == 0)
397  ui(7, priority_breakpoint);
398  }
399 
400  uir(5, quantiser_scale_code);
401 
402  if (nextbits(1, 1, current->slice_extension_flag)) {
403  ui(1, slice_extension_flag);
404  ui(1, intra_slice);
405  ui(1, slice_picture_id_enable);
406  ui(6, slice_picture_id);
407  }
408 
409  CHECK(FUNC(extra_information)(ctx, rw, &current->extra_information_slice,
410  "extra_information_slice[k]", "extra_bit_slice"));
411 
412  return 0;
413 }
414 
416  MPEG2RawSequenceEnd *current)
417 {
418  int err;
419 
420  HEADER("Sequence End");
421 
422  ui(8, sequence_end_code);
423 
424  return 0;
425 }
uint8_t
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
#define FUNC(a)
#define infer(name, value)
Definition: cbs_av1.c:720
#define RWContext
Definition: cbs_av1.c:673
#define HEADER(name)
Definition: cbs_av1.c:544
#define nextbits(width, compare, var)
Definition: cbs_mpeg2.c:121
#define ui(width, name)
Definition: cbs_mpeg2.c:43
#define bit(string, value)
Definition: cbs_mpeg2.c:58
#define marker_bit()
Definition: cbs_mpeg2.c:56
#define uirs(width, name, subs,...)
Definition: cbs_mpeg2.c:49
#define uis(width, name, subs,...)
Definition: cbs_mpeg2.c:47
#define xuia(width, string, var, range_min, range_max, subs,...)
Definition: cbs_mpeg2.c:108
#define sis(width, name, subs,...)
Definition: cbs_mpeg2.c:53
#define uir(width, name)
Definition: cbs_mpeg2.c:45
@ MPEG2_EXTENSION_SEQUENCE_DISPLAY
Definition: cbs_mpeg2.h:46
@ MPEG2_EXTENSION_PICTURE_CODING
Definition: cbs_mpeg2.h:51
@ MPEG2_EXTENSION_PICTURE_DISPLAY
Definition: cbs_mpeg2.h:50
@ MPEG2_EXTENSION_QUANT_MATRIX
Definition: cbs_mpeg2.h:47
@ MPEG2_EXTENSION_SEQUENCE
Definition: cbs_mpeg2.h:45
static int FUNC() picture_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawPictureHeader *current)
static int FUNC() user_data(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawUserData *current)
static int FUNC() group_of_pictures_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawGroupOfPicturesHeader *current)
static int FUNC() sequence_end(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSequenceEnd *current)
static int FUNC() sequence_display_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSequenceDisplayExtension *current)
static int FUNC() picture_display_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawPictureDisplayExtension *current)
static int FUNC() extension_data(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawExtensionData *current)
static int FUNC() picture_coding_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawPictureCodingExtension *current)
static int FUNC() slice_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSliceHeader *current)
static int FUNC() quant_matrix_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawQuantMatrixExtension *current)
static int FUNC() sequence_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSequenceExtension *current)
static int FUNC() sequence_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSequenceHeader *current)
static int FUNC() extra_information(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawExtraInformation *current, const char *element_name, const char *marker_name)
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:467
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
Definition: avcodec.h:215
AVBufferRef * av_buffer_allocz(buffer_size_t size)
Same as av_buffer_alloc(), except the returned buffer will be initialized to zero.
Definition: buffer.c:83
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
int i
Definition: input.c:407
static const struct TransferCharacteristics transfer_characteristics[AVCOL_TRC_NB]
void * priv_data
Format private data.
Definition: avformat.h:1260
Context structure for coded bitstream operations.
Definition: cbs.h:170
uint8_t number_of_frame_centre_offsets
Definition: cbs_mpeg2.h:227
#define av_log(a,...)
AVFormatContext * ctx
Definition: movenc.c:48
CHECK(-1) CHECK(-2) }} }} CHECK(1) CHECK(2) }} }} } if(diff0+diff1 > 0) temp -