FFmpeg  4.1.11
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  }
148 
149  ui(14, display_horizontal_size);
150  marker_bit();
151  ui(14, display_vertical_size);
152 
153  return 0;
154 }
155 
158 {
159  int err;
160 
161  HEADER("Group of Pictures Header");
162 
163  ui(8, group_start_code);
164 
165  ui(25, time_code);
166  ui(1, closed_gop);
167  ui(1, broken_link);
168 
169  return 0;
170 }
171 
173  MPEG2RawPictureHeader *current)
174 {
175  int err;
176 
177  HEADER("Picture Header");
178 
179  ui(8, picture_start_code);
180 
181  ui(10, temporal_reference);
182  uir(3, picture_coding_type);
183  ui(16, vbv_delay);
184 
185  if (current->picture_coding_type == 2 ||
186  current->picture_coding_type == 3) {
187  ui(1, full_pel_forward_vector);
188  ui(3, forward_f_code);
189  }
190 
191  if (current->picture_coding_type == 3) {
192  ui(1, full_pel_backward_vector);
193  ui(3, backward_f_code);
194  }
195 
196  ui(1, extra_bit_picture);
197 
198  return 0;
199 }
200 
203 {
205  int err;
206 
207  HEADER("Picture Coding Extension");
208 
209  uir(4, f_code[0][0]);
210  uir(4, f_code[0][1]);
211  uir(4, f_code[1][0]);
212  uir(4, f_code[1][1]);
213 
214  ui(2, intra_dc_precision);
215  ui(2, picture_structure);
216  ui(1, top_field_first);
217  ui(1, frame_pred_frame_dct);
218  ui(1, concealment_motion_vectors);
219  ui(1, q_scale_type);
220  ui(1, intra_vlc_format);
221  ui(1, alternate_scan);
222  ui(1, repeat_first_field);
223  ui(1, chroma_420_type);
224  ui(1, progressive_frame);
225 
226  if (mpeg2->progressive_sequence) {
227  if (current->repeat_first_field) {
228  if (current->top_field_first)
230  else
232  } else {
234  }
235  } else {
236  if (current->picture_structure == 1 || // Top field.
237  current->picture_structure == 2) { // Bottom field.
239  } else {
240  if (current->repeat_first_field)
242  else
244  }
245  }
246 
247  ui(1, composite_display_flag);
248  if (current->composite_display_flag) {
249  ui(1, v_axis);
250  ui(3, field_sequence);
251  ui(1, sub_carrier);
252  ui(7, burst_amplitude);
253  ui(8, sub_carrier_phase);
254  }
255 
256  return 0;
257 }
258 
261 {
262  int err, i;
263 
264  HEADER("Quant Matrix Extension");
265 
266  ui(1, load_intra_quantiser_matrix);
267  if (current->load_intra_quantiser_matrix) {
268  for (i = 0; i < 64; i++)
269  uirs(8, intra_quantiser_matrix[i], 1, i);
270  }
271 
272  ui(1, load_non_intra_quantiser_matrix);
273  if (current->load_non_intra_quantiser_matrix) {
274  for (i = 0; i < 64; i++)
275  uirs(8, non_intra_quantiser_matrix[i], 1, i);
276  }
277 
278  ui(1, load_chroma_intra_quantiser_matrix);
279  if (current->load_chroma_intra_quantiser_matrix) {
280  for (i = 0; i < 64; i++)
281  uirs(8, intra_quantiser_matrix[i], 1, i);
282  }
283 
284  ui(1, load_chroma_non_intra_quantiser_matrix);
285  if (current->load_chroma_non_intra_quantiser_matrix) {
286  for (i = 0; i < 64; i++)
287  uirs(8, chroma_non_intra_quantiser_matrix[i], 1, i);
288  }
289 
290  return 0;
291 }
292 
295 {
297  int err, i;
298 
299  HEADER("Picture Display Extension");
300 
301  for (i = 0; i < mpeg2->number_of_frame_centre_offsets; i++) {
302  sis(16, frame_centre_horizontal_offset[i], 1, i);
303  marker_bit();
304  sis(16, frame_centre_vertical_offset[i], 1, i);
305  marker_bit();
306  }
307 
308  return 0;
309 }
310 
312  MPEG2RawExtensionData *current)
313 {
314  int err;
315 
316  HEADER("Extension Data");
317 
318  ui(8, extension_start_code);
319  ui(4, extension_start_code_identifier);
320 
321  switch (current->extension_start_code_identifier) {
322  case 1:
323  return FUNC(sequence_extension)
324  (ctx, rw, &current->data.sequence);
325  case 2:
327  (ctx, rw, &current->data.sequence_display);
328  case 3:
330  (ctx, rw, &current->data.quant_matrix);
331  case 7:
333  (ctx, rw, &current->data.picture_display);
334  case 8:
336  (ctx, rw, &current->data.picture_coding);
337  default:
338  av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid extension ID %d.\n",
339  current->extension_start_code_identifier);
340  return AVERROR_INVALIDDATA;
341  }
342 }
343 
345  MPEG2RawSliceHeader *current)
346 {
348  int err;
349 
350  HEADER("Slice Header");
351 
352  ui(8, slice_vertical_position);
353 
354  if (mpeg2->vertical_size > 2800)
355  ui(3, slice_vertical_position_extension);
356  if (mpeg2->scalable) {
357  if (mpeg2->scalable_mode == 0)
358  ui(7, priority_breakpoint);
359  }
360 
361  uir(5, quantiser_scale_code);
362 
363  if (nextbits(1, 1, current->slice_extension_flag)) {
364  ui(1, slice_extension_flag);
365  ui(1, intra_slice);
366  ui(1, slice_picture_id_enable);
367  ui(6, slice_picture_id);
368 
369  {
370  size_t k;
371 #ifdef READ
373  uint8_t bit;
374  start = *rw;
375  for (k = 0; nextbits(1, 1, bit); k++)
376  skip_bits(rw, 8);
377  current->extra_information_length = k;
378  if (k > 0) {
379  *rw = start;
380  current->extra_information_ref =
381  av_buffer_alloc(current->extra_information_length);
382  if (!current->extra_information_ref)
383  return AVERROR(ENOMEM);
384  current->extra_information = current->extra_information_ref->data;
385  for (k = 0; k < current->extra_information_length; k++) {
386  xui(1, extra_bit_slice, bit, 1, 1, 0);
387  xui(8, extra_information_slice[k],
388  current->extra_information[k], 0, 255, 1, k);
389  }
390  }
391 #else
392  for (k = 0; k < current->extra_information_length; k++) {
393  xui(1, extra_bit_slice, 1, 1, 1, 0);
394  xui(8, extra_information_slice[k],
395  current->extra_information[k], 0, 255, 1, k);
396  }
397 #endif
398  }
399  }
400  ui(1, extra_bit_slice);
401 
402  return 0;
403 }
#define nextbits(width, compare, var)
Definition: cbs_mpeg2.c:117
static int FUNC() picture_coding_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawPictureCodingExtension *current)
uint8_t number_of_frame_centre_offsets
Definition: cbs_mpeg2.h:221
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define RWContext
Definition: cbs_av1.c:710
static int FUNC() extension_data(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawExtensionData *current)
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
uint8_t
static int FUNC() picture_display_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawPictureDisplayExtension *current)
#define HEADER(name)
Definition: cbs_av1.c:582
#define xui(width, name, var, range_min, range_max, subs,...)
Definition: cbs_mpeg2.c:100
#define av_log(a,...)
#define uirs(width, name, subs,...)
Definition: cbs_mpeg2.c:49
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:814
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:258
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define FUNC(a)
#define AVERROR(e)
Definition: error.h:43
#define sis(width, name, subs,...)
Definition: cbs_mpeg2.c:51
static int FUNC() sequence_display_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSequenceDisplayExtension *current)
static int FUNC() quant_matrix_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawQuantMatrixExtension *current)
#define uir(width, name)
Definition: cbs_mpeg2.c:45
static int FUNC() picture_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawPictureHeader *current)
static const struct TransferCharacteristics transfer_characteristics[AVCOL_TRC_NB]
static int FUNC() user_data(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawUserData *current)
AVFormatContext * ctx
Definition: movenc.c:48
static int FUNC() slice_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSliceHeader *current)
static int FUNC() sequence_extension(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSequenceExtension *current)
#define marker_bit()
Definition: cbs_mpeg2.c:113
#define uis(width, name, subs,...)
Definition: cbs_mpeg2.c:47
static int FUNC() sequence_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawSequenceHeader *current)
AVBufferRef * av_buffer_alloc(int size)
Allocate an AVBuffer of the given size using av_malloc().
Definition: buffer.c:67
AVBufferRef * av_buffer_allocz(int size)
Same as av_buffer_alloc(), except the returned buffer will be initialized to zero.
Definition: buffer.c:83
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:460
Context structure for coded bitstream operations.
Definition: cbs.h:159
#define ui(width, name)
Definition: cbs_mpeg2.c:43
static int FUNC() group_of_pictures_header(CodedBitstreamContext *ctx, RWContext *rw, MPEG2RawGroupOfPicturesHeader *current)
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:782
void * priv_data
Format private data.
Definition: avformat.h:1379
void INT64 start
Definition: avisynth_c.h:690