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
25
26
27 #define HEADER(name) do { \
28 ff_cbs_trace_header(ctx, name); \
29 } while (0)
30
31 #define CHECK(call) do { \
32 err = (call); \
33 if (err < 0) \
34 return err; \
35 } while (0)
36
37 #define FUNC_NAME(rw, codec, name) cbs_ ## codec ## _ ## rw ## _ ## name
38 #define FUNC_MPEG2(rw, name) FUNC_NAME(rw, mpeg2, name)
39 #define FUNC(name) FUNC_MPEG2(READWRITE, name)
40
41 #define SUBSCRIPTS(subs, ...) (subs > 0 ? ((int[subs + 1]){ subs, __VA_ARGS__ }) : NULL)
42
43 #define uir(width, name) \
44 xui(width, name, current->name, 1, MAX_UINT_BITS(width), 0, )
45 #define uis(width, name, subs, ...) \
46 xui(width, name, current->name, 0, MAX_UINT_BITS(width), subs, __VA_ARGS__)
47 #define uirs(width, name, subs, ...) \
48 xui(width, name, current->name, 1, MAX_UINT_BITS(width), subs, __VA_ARGS__)
49 #define xui(width, name, var, range_min, range_max, subs, ...) \
50 xuia(width, #name, var, range_min, range_max, subs, __VA_ARGS__)
51 #define sis(width, name, subs, ...) \
52 xsi(width, name, current->name, subs, __VA_ARGS__)
53
54 #define marker_bit() \
55 bit("marker_bit", 1)
56 #define bit(string, value) do { \
57 av_unused uint32_t bit = value; \
58 xuia(1, string, bit, value, value, 0, ); \
59 } while (0)
60
61
63 #define READWRITE read
64 #define RWContext GetBitContext
65
66 #define ui(width, name) do { \
67 uint32_t value; \
68 CHECK(ff_cbs_read_simple_unsigned(ctx, rw, width, #name, \
69 &value)); \
70 current->name = value; \
71 } while (0)
72 #define xuia(width, string, var, range_min, range_max, subs, ...) do { \
73 uint32_t value; \
74 CHECK(ff_cbs_read_unsigned(ctx, rw, width, string, \
75 SUBSCRIPTS(subs, __VA_ARGS__), \
76 &value, range_min, range_max)); \
77 var = value; \
78 } while (0)
79
80 #define xsi(width, name, var, subs, ...) do { \
81 int32_t value; \
82 CHECK(ff_cbs_read_signed(ctx, rw, width, #name, \
83 SUBSCRIPTS(subs, __VA_ARGS__), &value, \
84 MIN_INT_BITS(width), \
85 MAX_INT_BITS(width))); \
86 var = value; \
87 } while (0)
88
89 #define nextbits(width, compare, var) \
90 (get_bits_left(rw) >= width && \
91 (var = show_bits(rw, width)) == (compare))
92
93 #define infer(name, value) do { \
94 current->name = value; \
95 } while (0)
96
98
99 #undef READ
100 #undef READWRITE
101 #undef RWContext
102 #undef ui
103 #undef xuia
104 #undef xsi
105 #undef nextbits
106 #undef infer
107
108
110 #define READWRITE write
111 #define RWContext PutBitContext
112
113 #define ui(width, name) do { \
114 CHECK(ff_cbs_write_simple_unsigned(ctx, rw, width, #name, \
115 current->name)); \
116 } while (0)
117
118 #define xuia(width, string, var, range_min, range_max, subs, ...) do { \
119 CHECK(ff_cbs_write_unsigned(ctx, rw, width, string, \
120 SUBSCRIPTS(subs, __VA_ARGS__), \
121 var, range_min, range_max)); \
122 } while (0)
123
124 #define xsi(width, name, var, subs, ...) do { \
125 CHECK(ff_cbs_write_signed(ctx, rw, width, #name, \
126 SUBSCRIPTS(subs, __VA_ARGS__), var, \
127 MIN_INT_BITS(width), \
128 MAX_INT_BITS(width))); \
129 } while (0)
130
131 #define nextbits(width, compare, var) (var)
132
133 #define infer(name, value) do { \
134 if (current->name != (value)) { \
135 av_log(ctx->log_ctx, AV_LOG_WARNING, "Warning: " \
136 "%s does not match inferred value: " \
137 "%"PRId64", but should be %"PRId64".\n", \
138 #name, (int64_t)current->name, (int64_t)(value)); \
139 } \
140 } while (0)
141
143
144 #undef WRITE
145 #undef READWRITE
146 #undef RWContext
147 #undef ui
148 #undef xuia
149 #undef xsi
150 #undef nextbits
151 #undef infer
152
153
157 {
158 const uint8_t *start;
160 int err;
161
165 // No start code found.
167 }
168
169 do {
171 const uint8_t *end;
172 size_t unit_size;
173
174 // Reset start_code to ensure that avpriv_find_start_code()
175 // really reads a new start code and does not reuse the old
176 // start code in any way (as e.g. happens when there is a
177 // Sequence End unit at the very end of a packet).
181
182 // start points to the byte containing the start_code_identifier
183 // (may be the last byte of fragment->data); end points to the byte
184 // following the byte containing the start code identifier (or to
185 // the end of fragment->data).
187 // Unit runs from start to the beginning of the start code
188 // pointed to by end (including any padding zeroes).
189 unit_size = (end - 4) - start;
190 } else {
191 // We didn't find a start code, so this is the final unit.
192 unit_size = end - start;
193 }
194
195 err = ff_cbs_append_unit_data(frag, unit_type, (uint8_t*)start,
197 if (err < 0)
198 return err;
199
200 start = end;
201
202 // Do we have a further unit to add to the fragment?
204
205 return 0;
206 }
207
210 {
212 int err;
213
215 if (err < 0)
216 return err;
217
218 err = ff_cbs_alloc_unit_content(
ctx, unit);
219 if (err < 0)
220 return err;
221
225
226 err = cbs_mpeg2_read_slice_header(
ctx, &gbc, &slice->
header);
227 if (err < 0)
228 return err;
229
232
235
241
243
244 } else {
245 switch (unit->
type) {
246 #define START(start_code, type, read_func, free_func) \
247 case start_code: \
248 { \
249 type *header = unit->content; \
250 err = cbs_mpeg2_read_ ## read_func(ctx, &gbc, header); \
251 if (err < 0) \
252 return err; \
253 } \
254 break;
267 #undef START
268 default:
270 }
271 }
272
273 return 0;
274 }
275
279 {
280 int err;
281
282 switch (unit->
type) {
283 #define START(start_code, type, func) \
284 case start_code: \
285 err = cbs_mpeg2_write_ ## func(ctx, pbc, unit->content); \
286 break;
294 #undef START
295 default:
297 "code %02"PRIx32
".\n", unit->
type);
299 }
300
301 return err;
302 }
303
307 {
309 int err;
310
311 err = cbs_mpeg2_write_slice_header(
ctx, pbc, &slice->
header);
312 if (err < 0)
313 return err;
314
318
321
324
325 // First copy the remaining bits of the first byte
329
331 // If the writer is aligned at this point,
332 // memcpy can be used to improve performance.
333 // This is the normal case.
337 } else {
338 // If not, we have to copy manually:
339 for (; rest > 3; rest -= 4,
pos += 4)
341
342 for (; rest; rest--,
pos++)
344
345 // Align with zeros
347 }
348 }
349
350 return 0;
351 }
352
356 {
359 else
361 }
362
365 {
369
373
378
379 dp = 0;
382
386
389 }
390
392
396
397 return 0;
398 }
399
402 extra_information_picture.extra_information),
403
404 {
406 .unit_type.range.start = 0x01,
407 .unit_type.range.end = 0xaf,
408
411 .
type.ref = { .nb_offsets = 2,
414 },
415
418
423
425 };
426
429
431
433
438 };