2 * This file is part of FFmpeg.
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.
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.
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
19 static int FUNC(sequence_header)(CodedBitstreamContext *ctx, RWContext *rw,
20 MPEG2RawSequenceHeader *current)
22 CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
25 HEADER("Sequence Header");
27 ui(8, sequence_header_code);
29 uir(12, horizontal_size_value);
30 uir(12, vertical_size_value);
32 mpeg2->horizontal_size = current->horizontal_size_value;
33 mpeg2->vertical_size = current->vertical_size_value;
35 uir(4, aspect_ratio_information);
36 uir(4, frame_rate_code);
37 ui(18, bit_rate_value);
41 ui(10, vbv_buffer_size_value);
42 ui(1, constrained_parameters_flag);
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);
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);
59 static int FUNC(user_data)(CodedBitstreamContext *ctx, RWContext *rw,
60 MPEG2RawUserData *current)
67 ui(8, user_data_start_code);
70 k = get_bits_left(rw);
71 av_assert0(k % 8 == 0);
72 current->user_data_length = k /= 8;
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;
81 for (k = 0; k < current->user_data_length; k++)
82 uis(8, user_data[k], 1, k);
87 static int FUNC(sequence_extension)(CodedBitstreamContext *ctx, RWContext *rw,
88 MPEG2RawSequenceExtension *current)
90 CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
93 HEADER("Sequence Extension");
95 ui(8, profile_and_level_indication);
96 ui(1, progressive_sequence);
98 ui(2, horizontal_size_extension);
99 ui(2, vertical_size_extension);
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;
107 ui(12, bit_rate_extension);
109 ui(8, vbv_buffer_size_extension);
111 ui(2, frame_rate_extension_n);
112 ui(5, frame_rate_extension_d);
117 static int FUNC(sequence_display_extension)(CodedBitstreamContext *ctx, RWContext *rw,
118 MPEG2RawSequenceDisplayExtension *current)
122 HEADER("Sequence Display Extension");
126 ui(1, colour_description);
127 if (current->colour_description) {
129 #define READ_AND_PATCH(name) do { \
131 if (current->name == 0) { \
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); \
138 READ_AND_PATCH(colour_primaries);
139 READ_AND_PATCH(transfer_characteristics);
140 READ_AND_PATCH(matrix_coefficients);
141 #undef READ_AND_PATCH
143 uir(8, colour_primaries);
144 uir(8, transfer_characteristics);
145 uir(8, matrix_coefficients);
148 infer(colour_primaries, 2);
149 infer(transfer_characteristics, 2);
150 infer(matrix_coefficients, 2);
153 ui(14, display_horizontal_size);
155 ui(14, display_vertical_size);
160 static int FUNC(group_of_pictures_header)(CodedBitstreamContext *ctx, RWContext *rw,
161 MPEG2RawGroupOfPicturesHeader *current)
165 HEADER("Group of Pictures Header");
167 ui(8, group_start_code);
176 static int FUNC(extra_information)(CodedBitstreamContext *ctx, RWContext *rw,
177 MPEG2RawExtraInformation *current,
178 const char *element_name, const char *marker_name)
183 GetBitContext start = *rw;
186 for (k = 0; nextbits(1, 1, bit); k++)
187 skip_bits(rw, 1 + 8);
188 current->extra_information_length = k;
191 current->extra_information_ref =
192 av_buffer_allocz(k + AV_INPUT_BUFFER_PADDING_SIZE);
193 if (!current->extra_information_ref)
194 return AVERROR(ENOMEM);
195 current->extra_information = current->extra_information_ref->data;
199 for (k = 0; k < current->extra_information_length; k++) {
201 xuia(8, element_name,
202 current->extra_information[k], 0, 255, 1, k);
210 static int FUNC(picture_header)(CodedBitstreamContext *ctx, RWContext *rw,
211 MPEG2RawPictureHeader *current)
215 HEADER("Picture Header");
217 ui(8, picture_start_code);
219 ui(10, temporal_reference);
220 uir(3, picture_coding_type);
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);
229 if (current->picture_coding_type == 3) {
230 ui(1, full_pel_backward_vector);
231 ui(3, backward_f_code);
234 CHECK(FUNC(extra_information)(ctx, rw, ¤t->extra_information_picture,
235 "extra_information_picture[k]", "extra_bit_picture"));
240 static int FUNC(picture_coding_extension)(CodedBitstreamContext *ctx, RWContext *rw,
241 MPEG2RawPictureCodingExtension *current)
243 CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
246 HEADER("Picture Coding Extension");
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]);
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);
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);
265 if (mpeg2->progressive_sequence) {
266 if (current->repeat_first_field) {
267 if (current->top_field_first)
268 mpeg2->number_of_frame_centre_offsets = 3;
270 mpeg2->number_of_frame_centre_offsets = 2;
272 mpeg2->number_of_frame_centre_offsets = 1;
275 if (current->picture_structure == 1 || // Top field.
276 current->picture_structure == 2) { // Bottom field.
277 mpeg2->number_of_frame_centre_offsets = 1;
279 if (current->repeat_first_field)
280 mpeg2->number_of_frame_centre_offsets = 3;
282 mpeg2->number_of_frame_centre_offsets = 2;
286 ui(1, composite_display_flag);
287 if (current->composite_display_flag) {
289 ui(3, field_sequence);
291 ui(7, burst_amplitude);
292 ui(8, sub_carrier_phase);
298 static int FUNC(quant_matrix_extension)(CodedBitstreamContext *ctx, RWContext *rw,
299 MPEG2RawQuantMatrixExtension *current)
303 HEADER("Quant Matrix Extension");
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);
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);
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);
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);
332 static int FUNC(picture_display_extension)(CodedBitstreamContext *ctx, RWContext *rw,
333 MPEG2RawPictureDisplayExtension *current)
335 CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
338 HEADER("Picture Display Extension");
340 for (i = 0; i < mpeg2->number_of_frame_centre_offsets; i++) {
341 sis(16, frame_centre_horizontal_offset[i], 1, i);
343 sis(16, frame_centre_vertical_offset[i], 1, i);
350 static int FUNC(extension_data)(CodedBitstreamContext *ctx, RWContext *rw,
351 MPEG2RawExtensionData *current)
355 HEADER("Extension Data");
357 ui(8, extension_start_code);
358 ui(4, extension_start_code_identifier);
360 switch (current->extension_start_code_identifier) {
361 case MPEG2_EXTENSION_SEQUENCE:
362 return FUNC(sequence_extension)
363 (ctx, rw, ¤t->data.sequence);
364 case MPEG2_EXTENSION_SEQUENCE_DISPLAY:
365 return FUNC(sequence_display_extension)
366 (ctx, rw, ¤t->data.sequence_display);
367 case MPEG2_EXTENSION_QUANT_MATRIX:
368 return FUNC(quant_matrix_extension)
369 (ctx, rw, ¤t->data.quant_matrix);
370 case MPEG2_EXTENSION_PICTURE_DISPLAY:
371 return FUNC(picture_display_extension)
372 (ctx, rw, ¤t->data.picture_display);
373 case MPEG2_EXTENSION_PICTURE_CODING:
374 return FUNC(picture_coding_extension)
375 (ctx, rw, ¤t->data.picture_coding);
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;
383 static int FUNC(slice_header)(CodedBitstreamContext *ctx, RWContext *rw,
384 MPEG2RawSliceHeader *current)
386 CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
389 HEADER("Slice Header");
391 ui(8, slice_vertical_position);
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);
400 uir(5, quantiser_scale_code);
402 if (nextbits(1, 1, current->slice_extension_flag)) {
403 ui(1, slice_extension_flag);
405 ui(1, slice_picture_id_enable);
406 ui(6, slice_picture_id);
409 CHECK(FUNC(extra_information)(ctx, rw, ¤t->extra_information_slice,
410 "extra_information_slice[k]", "extra_bit_slice"));
415 static int FUNC(sequence_end)(CodedBitstreamContext *ctx, RWContext *rw,
416 MPEG2RawSequenceEnd *current)
420 HEADER("Sequence End");
422 ui(8, sequence_end_code);