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
19static int FUNC(sequence_header)(CodedBitstreamContext *ctx, RWContext *rw,
20                                 MPEG2RawSequenceHeader *current)
21{
22    CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
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
59static int FUNC(user_data)(CodedBitstreamContext *ctx, RWContext *rw,
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
87static int FUNC(sequence_extension)(CodedBitstreamContext *ctx, RWContext *rw,
88                                    MPEG2RawSequenceExtension *current)
89{
90    CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
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
117static int FUNC(sequence_display_extension)(CodedBitstreamContext *ctx, RWContext *rw,
118                                            MPEG2RawSequenceDisplayExtension *current)
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);
144        uir(8, transfer_characteristics);
145        uir(8, matrix_coefficients);
146#endif
147    } else {
148        infer(colour_primaries,         2);
149        infer(transfer_characteristics, 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
160static int FUNC(group_of_pictures_header)(CodedBitstreamContext *ctx, RWContext *rw,
161                                          MPEG2RawGroupOfPicturesHeader *current)
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
176static int FUNC(extra_information)(CodedBitstreamContext *ctx, RWContext *rw,
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 =
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;
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
210static int FUNC(picture_header)(CodedBitstreamContext *ctx, RWContext *rw,
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
240static int FUNC(picture_coding_extension)(CodedBitstreamContext *ctx, RWContext *rw,
241                                          MPEG2RawPictureCodingExtension *current)
242{
243    CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
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)
268                mpeg2->number_of_frame_centre_offsets = 3;
269            else
270                mpeg2->number_of_frame_centre_offsets = 2;
271        } else {
272            mpeg2->number_of_frame_centre_offsets = 1;
273        }
274    } else {
275        if (current->picture_structure == 1 || // Top field.
276            current->picture_structure == 2) { // Bottom field.
277            mpeg2->number_of_frame_centre_offsets = 1;
278        } else {
279            if (current->repeat_first_field)
280                mpeg2->number_of_frame_centre_offsets = 3;
281            else
282                mpeg2->number_of_frame_centre_offsets = 2;
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
298static int FUNC(quant_matrix_extension)(CodedBitstreamContext *ctx, RWContext *rw,
299                                        MPEG2RawQuantMatrixExtension *current)
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
332static int FUNC(picture_display_extension)(CodedBitstreamContext *ctx, RWContext *rw,
333                                           MPEG2RawPictureDisplayExtension *current)
334{
335    CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
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
350static int FUNC(extension_data)(CodedBitstreamContext *ctx, RWContext *rw,
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) {
361    case MPEG2_EXTENSION_SEQUENCE:
362        return FUNC(sequence_extension)
363            (ctx, rw, &current->data.sequence);
364    case MPEG2_EXTENSION_SEQUENCE_DISPLAY:
365        return FUNC(sequence_display_extension)
366            (ctx, rw, &current->data.sequence_display);
367    case MPEG2_EXTENSION_QUANT_MATRIX:
368        return FUNC(quant_matrix_extension)
369            (ctx, rw, &current->data.quant_matrix);
370    case MPEG2_EXTENSION_PICTURE_DISPLAY:
371        return FUNC(picture_display_extension)
372            (ctx, rw, &current->data.picture_display);
373    case MPEG2_EXTENSION_PICTURE_CODING:
374        return FUNC(picture_coding_extension)
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
383static int FUNC(slice_header)(CodedBitstreamContext *ctx, RWContext *rw,
384                              MPEG2RawSliceHeader *current)
385{
386    CodedBitstreamMPEG2Context *mpeg2 = ctx->priv_data;
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
415static int FUNC(sequence_end)(CodedBitstreamContext *ctx, RWContext *rw,
416                              MPEG2RawSequenceEnd *current)
417{
418    int err;
419
420    HEADER("Sequence End");
421
422    ui(8, sequence_end_code);
423
424    return 0;
425}
426