1 | /* |
2 | Copyright (c) 2012, Broadcom Europe Ltd |
3 | All rights reserved. |
4 | |
5 | Redistribution and use in source and binary forms, with or without |
6 | modification, are permitted provided that the following conditions are met: |
7 | * Redistributions of source code must retain the above copyright |
8 | notice, this list of conditions and the following disclaimer. |
9 | * Redistributions in binary form must reproduce the above copyright |
10 | notice, this list of conditions and the following disclaimer in the |
11 | documentation and/or other materials provided with the distribution. |
12 | * Neither the name of the copyright holder nor the |
13 | names of its contributors may be used to endorse or promote products |
14 | derived from this software without specific prior written permission. |
15 | |
16 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |
17 | ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
18 | WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
19 | DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY |
20 | DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
21 | (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
22 | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
23 | ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
25 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | */ |
27 | |
28 | #include "containers/core/containers_bits.h" |
29 | #include "containers/core/containers_common.h" |
30 | |
31 | #ifdef ENABLE_CONTAINERS_LOG_FORMAT |
32 | #include "containers/core/containers_logging.h" |
33 | #endif |
34 | |
35 | /****************************************************************************** |
36 | Defines and constants. |
37 | ******************************************************************************/ |
38 | |
39 | #ifdef ENABLE_CONTAINERS_LOG_FORMAT |
40 | /** String used for indentation. If more spaces are needed, just add them. */ |
41 | #define INDENT_SPACES_STRING "> " |
42 | #define INDENT_SPACES_LENGTH (sizeof(INDENT_SPACES_STRING) - 1) |
43 | #endif /* ENABLE_CONTAINERS_LOG_FORMAT */ |
44 | |
45 | /****************************************************************************** |
46 | Type definitions |
47 | ******************************************************************************/ |
48 | |
49 | /****************************************************************************** |
50 | Function prototypes |
51 | ******************************************************************************/ |
52 | |
53 | /****************************************************************************** |
54 | Local Functions |
55 | ******************************************************************************/ |
56 | |
57 | #ifdef ENABLE_CONTAINERS_LOG_FORMAT |
58 | |
59 | /**************************************************************************//** |
60 | * Returns a string that indicates whether the bit stream is valid or not. |
61 | * |
62 | * \pre bit_stream is not NULL. |
63 | * |
64 | * \param bit_stream The bit stream object. |
65 | * \return A string indicating the validity of the stream. |
66 | */ |
67 | static const char * vc_container_bits_valid_str( VC_CONTAINER_BITS_T *bit_stream ) |
68 | { |
69 | return vc_container_bits_valid(bit_stream) ? "" : " - stream invalid" ; |
70 | } |
71 | |
72 | /**************************************************************************//** |
73 | * Returns a string of spaces the length of which is determined by the |
74 | * parameter. |
75 | * The length is limited to a certain size, above which a greater than symbol |
76 | * prefixes the maximum number of spaces. |
77 | * |
78 | * \param length The required length of the string. |
79 | * \return A string indicating the validity of the stream. |
80 | */ |
81 | static const char * vc_container_bits_indent_str(uint32_t length) |
82 | { |
83 | uint32_t str_length = length; |
84 | |
85 | if (str_length > INDENT_SPACES_LENGTH) |
86 | str_length = INDENT_SPACES_LENGTH; |
87 | |
88 | return INDENT_SPACES_STRING + (INDENT_SPACES_LENGTH - str_length); |
89 | } |
90 | |
91 | #endif /* ENABLE_CONTAINERS_LOG_FORMAT */ |
92 | |
93 | /**************************************************************************//** |
94 | * Returns the number of consecutive zero bits in the stream. |
95 | * the zero bits are terminated either by a one bit, or the end of the stream. |
96 | * In the former case, the zero bits and the terminating one bit are removed |
97 | * from the stream. |
98 | * In the latter case, the stream becomes invalid. The stream also becomes |
99 | * invalid if there are not as many bits after the one bit as zero bits before |
100 | * it. |
101 | * If the stream is already or becomes invalid, zero is returned. |
102 | * |
103 | * \pre bit_stream is not NULL. |
104 | * |
105 | * \param bit_stream The bit stream object. |
106 | * \return The number of consecutive zero bits, or zero if the stream is |
107 | * invalid. |
108 | */ |
109 | static uint32_t vc_container_bits_get_leading_zero_bits( VC_CONTAINER_BITS_T *bit_stream ) |
110 | { |
111 | uint32_t leading_zero_bits; |
112 | uint32_t bits_left = vc_container_bits_available(bit_stream); |
113 | uint32_t bits; |
114 | uint8_t mask, current_byte; |
115 | |
116 | if (!bits_left) |
117 | return vc_container_bits_invalidate(bit_stream); |
118 | |
119 | /* Cache 'bits' field to avoid repeated pointer access */ |
120 | bits = bit_stream->bits; |
121 | if (bits) |
122 | { |
123 | current_byte = *bit_stream->buffer; |
124 | mask = 1 << (bits - 1); |
125 | } else { |
126 | /* Initialize variables to placate the compiler */ |
127 | current_byte = 0; |
128 | mask = 0; |
129 | } |
130 | |
131 | /* Scan for the first one bit, counting the number of zeroes. This gives the |
132 | * number of further bits after the one that are part of the value. See |
133 | * section 9.1 of ITU-T REC H.264 201003 for more details. */ |
134 | |
135 | for (leading_zero_bits = 0; leading_zero_bits < bits_left; leading_zero_bits++) |
136 | { |
137 | if (!bits) |
138 | { |
139 | if (!bit_stream->bytes) |
140 | return vc_container_bits_invalidate(bit_stream); |
141 | bit_stream->bytes--; |
142 | current_byte = *(++bit_stream->buffer); |
143 | bits = 8; |
144 | mask = 0x80; |
145 | } |
146 | |
147 | bits--; |
148 | bits_left--; |
149 | if (current_byte & mask) |
150 | break; /* Found the marker bit */ |
151 | |
152 | mask >>= 1; |
153 | } |
154 | |
155 | /* Check enough bits are left in the stream for the value. */ |
156 | if (leading_zero_bits > bits_left) |
157 | return vc_container_bits_invalidate(bit_stream); |
158 | |
159 | /* Return cached value of bits to the stream */ |
160 | bit_stream->bits = bits; |
161 | |
162 | return leading_zero_bits; |
163 | } |
164 | |
165 | /***************************************************************************** |
166 | Functions exported as part of the bit stream API |
167 | *****************************************************************************/ |
168 | |
169 | /*****************************************************************************/ |
170 | void vc_container_bits_init(VC_CONTAINER_BITS_T *bit_stream, |
171 | const uint8_t *buffer, |
172 | uint32_t available) |
173 | { |
174 | vc_container_assert(buffer && (buffer != (const uint8_t *)1)); |
175 | |
176 | /* Start with buffer pointing at the previous byte with no bits available |
177 | * to make the mathematics easier */ |
178 | bit_stream->buffer = buffer - 1; |
179 | bit_stream->bytes = available; |
180 | bit_stream->bits = 0; |
181 | } |
182 | |
183 | /*****************************************************************************/ |
184 | uint32_t vc_container_bits_invalidate( VC_CONTAINER_BITS_T *bit_stream ) |
185 | { |
186 | bit_stream->buffer = NULL; |
187 | return 0; |
188 | } |
189 | |
190 | /*****************************************************************************/ |
191 | bool vc_container_bits_valid(VC_CONTAINER_BITS_T *bit_stream) |
192 | { |
193 | return (bit_stream->buffer != NULL); |
194 | } |
195 | |
196 | /*****************************************************************************/ |
197 | void vc_container_bits_reset(VC_CONTAINER_BITS_T *bit_stream) |
198 | { |
199 | bit_stream->bytes = 0; |
200 | bit_stream->bits = 0; |
201 | } |
202 | |
203 | /*****************************************************************************/ |
204 | const uint8_t *vc_container_bits_current_pointer(const VC_CONTAINER_BITS_T *bit_stream) |
205 | { |
206 | const uint8_t *buffer = bit_stream->buffer; |
207 | |
208 | /* Only valid on byte boundaries, where buffer pointer has not been moved yet */ |
209 | vc_container_assert(!bit_stream->bits); |
210 | |
211 | return buffer ? (buffer + 1) : NULL; |
212 | } |
213 | |
214 | /*****************************************************************************/ |
215 | void vc_container_bits_copy_stream(VC_CONTAINER_BITS_T *dst, |
216 | const VC_CONTAINER_BITS_T *src) |
217 | { |
218 | memcpy(dst, src, sizeof(VC_CONTAINER_BITS_T)); |
219 | } |
220 | |
221 | /*****************************************************************************/ |
222 | uint32_t vc_container_bits_available(const VC_CONTAINER_BITS_T *bit_stream) |
223 | { |
224 | if (!bit_stream->buffer) |
225 | return 0; |
226 | return (bit_stream->bytes << 3) + bit_stream->bits; |
227 | } |
228 | |
229 | /*****************************************************************************/ |
230 | uint32_t vc_container_bits_bytes_available(const VC_CONTAINER_BITS_T *bit_stream) |
231 | { |
232 | if (!bit_stream->buffer) |
233 | return 0; |
234 | |
235 | vc_container_assert(!bit_stream->bits); |
236 | |
237 | return vc_container_bits_available(bit_stream) >> 3; |
238 | } |
239 | |
240 | /*****************************************************************************/ |
241 | void vc_container_bits_skip(VC_CONTAINER_BITS_T *bit_stream, |
242 | uint32_t bits_to_skip) |
243 | { |
244 | uint32_t have_bits; |
245 | uint32_t new_bytes; |
246 | |
247 | have_bits = vc_container_bits_available(bit_stream); |
248 | if (have_bits < bits_to_skip) |
249 | { |
250 | vc_container_bits_invalidate(bit_stream); |
251 | return; |
252 | } |
253 | |
254 | have_bits -= bits_to_skip; |
255 | new_bytes = have_bits >> 3; |
256 | bit_stream->bits = have_bits & 7; |
257 | bit_stream->buffer += (bit_stream->bytes - new_bytes); |
258 | bit_stream->bytes = new_bytes; |
259 | } |
260 | |
261 | /*****************************************************************************/ |
262 | void vc_container_bits_skip_bytes(VC_CONTAINER_BITS_T *bit_stream, |
263 | uint32_t bytes_to_skip) |
264 | { |
265 | /* Only valid on byte boundaries */ |
266 | vc_container_assert(!bit_stream->bits); |
267 | |
268 | vc_container_bits_skip(bit_stream, bytes_to_skip << 3); |
269 | } |
270 | |
271 | /*****************************************************************************/ |
272 | void vc_container_bits_reduce_bytes(VC_CONTAINER_BITS_T *bit_stream, |
273 | uint32_t bytes_to_reduce) |
274 | { |
275 | if (bit_stream->bytes >= bytes_to_reduce) |
276 | bit_stream->bytes -= bytes_to_reduce; |
277 | else |
278 | vc_container_bits_invalidate(bit_stream); |
279 | } |
280 | |
281 | /*****************************************************************************/ |
282 | void vc_container_bits_copy_bytes(VC_CONTAINER_BITS_T *bit_stream, |
283 | uint32_t bytes_to_copy, |
284 | uint8_t *dst) |
285 | { |
286 | vc_container_assert(!bit_stream->bits); |
287 | |
288 | if (bit_stream->bytes < bytes_to_copy) |
289 | { |
290 | /* Not enough data */ |
291 | vc_container_bits_invalidate(bit_stream); |
292 | return; |
293 | } |
294 | |
295 | /* When the number of bits is zero, the next byte to take is at buffer + 1 */ |
296 | memcpy(dst, bit_stream->buffer + 1, bytes_to_copy); |
297 | bit_stream->buffer += bytes_to_copy; |
298 | bit_stream->bytes -= bytes_to_copy; |
299 | } |
300 | |
301 | /*****************************************************************************/ |
302 | uint32_t vc_container_bits_read_u32(VC_CONTAINER_BITS_T *bit_stream, |
303 | uint32_t value_bits) |
304 | { |
305 | uint32_t value = 0; |
306 | uint32_t needed = value_bits; |
307 | uint32_t bits; |
308 | |
309 | vc_container_assert(value_bits <= 32); |
310 | |
311 | if (needed > vc_container_bits_available(bit_stream)) |
312 | return vc_container_bits_invalidate(bit_stream); |
313 | |
314 | bits = bit_stream->bits; |
315 | while (needed) |
316 | { |
317 | uint32_t take; |
318 | |
319 | if (!bits) |
320 | { |
321 | bit_stream->bytes--; |
322 | bit_stream->buffer++; |
323 | bits = 8; |
324 | } |
325 | |
326 | take = bits; |
327 | if (needed < take) take = needed; |
328 | |
329 | bits -= take; |
330 | needed -= take; |
331 | |
332 | value <<= take; |
333 | if (take == 8) |
334 | value |= *bit_stream->buffer; /* optimize whole byte case */ |
335 | else |
336 | value |= (*bit_stream->buffer >> bits) & ((1 << take) - 1); |
337 | } |
338 | |
339 | bit_stream->bits = bits; |
340 | return value; |
341 | } |
342 | |
343 | /*****************************************************************************/ |
344 | void vc_container_bits_skip_exp_golomb(VC_CONTAINER_BITS_T *bit_stream) |
345 | { |
346 | vc_container_bits_skip(bit_stream, vc_container_bits_get_leading_zero_bits(bit_stream)); |
347 | } |
348 | |
349 | /*****************************************************************************/ |
350 | uint32_t vc_container_bits_read_u32_exp_golomb(VC_CONTAINER_BITS_T *bit_stream) |
351 | { |
352 | uint32_t leading_zero_bits; |
353 | uint32_t codeNum; |
354 | |
355 | leading_zero_bits = vc_container_bits_get_leading_zero_bits(bit_stream); |
356 | |
357 | /* Anything bigger than 32 bits is definitely overflow */ |
358 | if (leading_zero_bits > 32) |
359 | return vc_container_bits_invalidate(bit_stream); |
360 | |
361 | codeNum = vc_container_bits_read_u32(bit_stream, leading_zero_bits); |
362 | |
363 | if (leading_zero_bits == 32) |
364 | { |
365 | /* If codeNum is non-zero, it would need 33 bits, so is also overflow */ |
366 | if (codeNum) |
367 | return vc_container_bits_invalidate(bit_stream); |
368 | |
369 | return 0xFFFFFFFF; |
370 | } |
371 | |
372 | return codeNum + (1 << leading_zero_bits) - 1; |
373 | } |
374 | |
375 | /*****************************************************************************/ |
376 | int32_t vc_container_bits_read_s32_exp_golomb(VC_CONTAINER_BITS_T *bit_stream) |
377 | { |
378 | uint32_t uval; |
379 | |
380 | uval = vc_container_bits_read_u32_exp_golomb(bit_stream); |
381 | |
382 | /* The signed Exp-Golomb code 0xFFFFFFFF cannot be represented as a signed 32-bit |
383 | * integer, because it should be one larger than the largest positive value. */ |
384 | if (uval == 0xFFFFFFFF) |
385 | return vc_container_bits_invalidate(bit_stream); |
386 | |
387 | /* Definition of conversion is |
388 | * s = ((-1)^(u + 1)) * Ceil(u / 2) |
389 | * where '^' is power, but this should be equivalent */ |
390 | return ((int32_t)((uval & 1) << 1) - 1) * (int32_t)((uval >> 1) + (uval & 1)); |
391 | } |
392 | |
393 | #ifdef ENABLE_CONTAINERS_LOG_FORMAT |
394 | |
395 | /*****************************************************************************/ |
396 | void vc_container_bits_log(VC_CONTAINER_T *p_ctx, |
397 | uint32_t indent, |
398 | const char *txt, |
399 | VC_CONTAINER_BITS_T *bit_stream, |
400 | VC_CONTAINER_BITS_LOG_OP_T op, |
401 | uint32_t length) |
402 | { |
403 | const char *valid_str = vc_container_bits_valid_str(bit_stream); |
404 | const char *indent_str = vc_container_bits_indent_str(indent); |
405 | |
406 | switch (op) |
407 | { |
408 | case VC_CONTAINER_BITS_LOG_SKIP: |
409 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: %u bits skipped%s" , indent_str, txt, length, valid_str); |
410 | break; |
411 | case VC_CONTAINER_BITS_LOG_SKIP_BYTES: |
412 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: %u bytes skipped%s" , indent_str, txt, length, valid_str); |
413 | break; |
414 | case VC_CONTAINER_BITS_LOG_COPY_BYTES: |
415 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: %u bytes copied%s" , indent_str, txt, length, valid_str); |
416 | break; |
417 | case VC_CONTAINER_BITS_LOG_REDUCE_BYTES: |
418 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: %u bytes reduced%s" , indent_str, txt, length, valid_str); |
419 | break; |
420 | case VC_CONTAINER_BITS_LOG_EG_SKIP: |
421 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: Exp-Golomb value skipped%s" , indent_str, txt, valid_str); |
422 | break; |
423 | default: |
424 | /* Unexpected operation. Check bit stream logging macros */ |
425 | vc_container_assert(0); |
426 | } |
427 | } |
428 | |
429 | /*****************************************************************************/ |
430 | uint32_t vc_container_bits_log_u32(VC_CONTAINER_T *p_ctx, |
431 | uint32_t indent, |
432 | const char *txt, |
433 | VC_CONTAINER_BITS_T *bit_stream, |
434 | VC_CONTAINER_BITS_LOG_OP_T op, |
435 | uint32_t length, |
436 | uint32_t value) |
437 | { |
438 | const char *valid_str = vc_container_bits_valid_str(bit_stream); |
439 | const char *indent_str = vc_container_bits_indent_str(indent); |
440 | |
441 | switch (op) |
442 | { |
443 | case VC_CONTAINER_BITS_LOG_U8: |
444 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: 0x%02x (%u) in %u bits%s" , indent_str, txt, value, value, length, valid_str); |
445 | break; |
446 | case VC_CONTAINER_BITS_LOG_U16: |
447 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: 0x%04x (%u) in %u bits%s" , indent_str, txt, value, value, length, valid_str); |
448 | break; |
449 | case VC_CONTAINER_BITS_LOG_U32: |
450 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: 0x%08x (%u) in %u bits%s" , indent_str, txt, value, value, length, valid_str); |
451 | break; |
452 | case VC_CONTAINER_BITS_LOG_EG_U32: |
453 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: 0x%08x (%u) unsigned Exp-Golomb%s" , indent_str, txt, value, value, valid_str); |
454 | break; |
455 | default: |
456 | /* Unexpected operation. Check bit stream logging macros */ |
457 | vc_container_assert(0); |
458 | } |
459 | |
460 | return value; |
461 | } |
462 | |
463 | /*****************************************************************************/ |
464 | int32_t vc_container_bits_log_s32(VC_CONTAINER_T *p_ctx, |
465 | uint32_t indent, |
466 | const char *txt, |
467 | VC_CONTAINER_BITS_T *bit_stream, |
468 | VC_CONTAINER_BITS_LOG_OP_T op, |
469 | uint32_t length, |
470 | int32_t value) |
471 | { |
472 | const char *valid_str = vc_container_bits_valid_str(bit_stream); |
473 | const char *indent_str = vc_container_bits_indent_str(indent); |
474 | |
475 | VC_CONTAINER_PARAM_UNUSED(length); |
476 | |
477 | switch (op) |
478 | { |
479 | case VC_CONTAINER_BITS_LOG_EG_S32: |
480 | vc_container_log(p_ctx, VC_CONTAINER_LOG_FORMAT, "%s%s: 0x%08x (%d) signed Exp-Golomb%s" , indent_str, txt, value, value, valid_str); |
481 | break; |
482 | default: |
483 | /* Unexpected operation. Check bit stream logging macros */ |
484 | vc_container_assert(0); |
485 | } |
486 | |
487 | return value; |
488 | } |
489 | |
490 | #endif /* ENABLE_CONTAINERS_LOG_FORMAT */ |
491 | |