/usr/include/pjmedia/circbuf.h is in libpjproject-dev 2.1.0.0.ast20130823-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 | /* $Id: circbuf.h 3664 2011-07-19 03:42:28Z nanang $ */
/*
* Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
* Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __PJMEDIA_CIRC_BUF_H__
#define __PJMEDIA_CIRC_BUF_H__
/**
* @file circbuf.h
* @brief Circular Buffer.
*/
#include <pj/assert.h>
#include <pj/errno.h>
#include <pj/pool.h>
#include <pjmedia/frame.h>
/**
* @defgroup PJMED_CIRCBUF Circular Buffer
* @ingroup PJMEDIA_FRAME_OP
* @brief Circular buffer manages read and write contiguous audio samples in a
* non-contiguous buffer as if the buffer were contiguous. This should give
* better performance than keeping contiguous samples in a contiguous buffer,
* since read/write operations will only update the pointers, instead of
* shifting audio samples.
*
* @{
*
* This section describes PJMEDIA's implementation of circular buffer.
*/
/* Algorithm checkings, for development purpose only */
#if 0
# define PJMEDIA_CIRC_BUF_CHECK(x) pj_assert(x)
#else
# define PJMEDIA_CIRC_BUF_CHECK(x)
#endif
PJ_BEGIN_DECL
/**
* Circular buffer structure
*/
typedef struct pjmedia_circ_buf {
pj_int16_t *buf; /**< The buffer */
unsigned capacity; /**< Buffer capacity, in samples */
pj_int16_t *start; /**< Pointer to the first sample */
unsigned len; /**< Audio samples length,
in samples */
} pjmedia_circ_buf;
/**
* Create the circular buffer.
*
* @param pool Pool where the circular buffer will be allocated
* from.
* @param capacity Capacity of the buffer, in samples.
* @param p_cb Pointer to receive the circular buffer instance.
*
* @return PJ_SUCCESS if the circular buffer has been
* created successfully, otherwise the appropriate
* error will be returned.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_create(pj_pool_t *pool,
unsigned capacity,
pjmedia_circ_buf **p_cb)
{
pjmedia_circ_buf *cbuf;
cbuf = PJ_POOL_ZALLOC_T(pool, pjmedia_circ_buf);
cbuf->buf = (pj_int16_t*) pj_pool_calloc(pool, capacity,
sizeof(pj_int16_t));
cbuf->capacity = capacity;
cbuf->start = cbuf->buf;
cbuf->len = 0;
*p_cb = cbuf;
return PJ_SUCCESS;
}
/**
* Reset the circular buffer.
*
* @param circbuf The circular buffer.
*
* @return PJ_SUCCESS when successful.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_reset(pjmedia_circ_buf *circbuf)
{
circbuf->start = circbuf->buf;
circbuf->len = 0;
return PJ_SUCCESS;
}
/**
* Get the circular buffer length, it is number of samples buffered in the
* circular buffer.
*
* @param circbuf The circular buffer.
*
* @return The buffer length.
*/
PJ_INLINE(unsigned) pjmedia_circ_buf_get_len(pjmedia_circ_buf *circbuf)
{
return circbuf->len;
}
/**
* Set circular buffer length. This is useful when audio buffer is manually
* manipulated by the user, e.g: shrinked, expanded.
*
* @param circbuf The circular buffer.
* @param len The new buffer length.
*/
PJ_INLINE(void) pjmedia_circ_buf_set_len(pjmedia_circ_buf *circbuf,
unsigned len)
{
PJMEDIA_CIRC_BUF_CHECK(len <= circbuf->capacity);
circbuf->len = len;
}
/**
* Advance the read pointer of circular buffer. This function will discard
* the skipped samples while advancing the read pointer, thus reducing
* the buffer length.
*
* @param circbuf The circular buffer.
* @param count Distance from current read pointer, can only be
* possitive number, in samples.
*
* @return PJ_SUCCESS when successful, otherwise
* the appropriate error will be returned.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_adv_read_ptr(pjmedia_circ_buf *circbuf,
unsigned count)
{
if (count >= circbuf->len)
return pjmedia_circ_buf_reset(circbuf);
PJMEDIA_CIRC_BUF_CHECK(count <= circbuf->len);
circbuf->start += count;
if (circbuf->start >= circbuf->buf + circbuf->capacity)
circbuf->start -= circbuf->capacity;
circbuf->len -= count;
return PJ_SUCCESS;
}
/**
* Advance the write pointer of circular buffer. Since write pointer is always
* pointing to a sample after the end of sample, so this function also means
* increasing the buffer length.
*
* @param circbuf The circular buffer.
* @param count Distance from current write pointer, can only be
* possitive number, in samples.
*
* @return PJ_SUCCESS when successful, otherwise
* the appropriate error will be returned.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_adv_write_ptr(pjmedia_circ_buf *circbuf,
unsigned count)
{
if (count + circbuf->len > circbuf->capacity)
return PJ_ETOOBIG;
circbuf->len += count;
return PJ_SUCCESS;
}
/**
* Get the real buffer addresses containing the audio samples.
*
* @param circbuf The circular buffer.
* @param reg1 Pointer to store the first buffer address.
* @param reg1_len Pointer to store the length of the first buffer,
* in samples.
* @param reg2 Pointer to store the second buffer address.
* @param reg2_len Pointer to store the length of the second buffer,
* in samples.
*/
PJ_INLINE(void) pjmedia_circ_buf_get_read_regions(pjmedia_circ_buf *circbuf,
pj_int16_t **reg1,
unsigned *reg1_len,
pj_int16_t **reg2,
unsigned *reg2_len)
{
*reg1 = circbuf->start;
*reg1_len = circbuf->len;
if (*reg1 + *reg1_len > circbuf->buf + circbuf->capacity) {
*reg1_len = circbuf->buf + circbuf->capacity - circbuf->start;
*reg2 = circbuf->buf;
*reg2_len = circbuf->len - *reg1_len;
} else {
*reg2 = NULL;
*reg2_len = 0;
}
PJMEDIA_CIRC_BUF_CHECK(*reg1_len != 0 || (*reg1_len == 0 &&
circbuf->len == 0));
PJMEDIA_CIRC_BUF_CHECK(*reg1_len + *reg2_len == circbuf->len);
}
/**
* Get the real buffer addresses that is empty or writeable.
*
* @param circbuf The circular buffer.
* @param reg1 Pointer to store the first buffer address.
* @param reg1_len Pointer to store the length of the first buffer,
* in samples.
* @param reg2 Pointer to store the second buffer address.
* @param reg2_len Pointer to store the length of the second buffer,
* in samples.
*/
PJ_INLINE(void) pjmedia_circ_buf_get_write_regions(pjmedia_circ_buf *circbuf,
pj_int16_t **reg1,
unsigned *reg1_len,
pj_int16_t **reg2,
unsigned *reg2_len)
{
*reg1 = circbuf->start + circbuf->len;
if (*reg1 >= circbuf->buf + circbuf->capacity)
*reg1 -= circbuf->capacity;
*reg1_len = circbuf->capacity - circbuf->len;
if (*reg1 + *reg1_len > circbuf->buf + circbuf->capacity) {
*reg1_len = circbuf->buf + circbuf->capacity - *reg1;
*reg2 = circbuf->buf;
*reg2_len = circbuf->start - circbuf->buf;
} else {
*reg2 = NULL;
*reg2_len = 0;
}
PJMEDIA_CIRC_BUF_CHECK(*reg1_len != 0 || (*reg1_len == 0 &&
circbuf->len == 0));
PJMEDIA_CIRC_BUF_CHECK(*reg1_len + *reg2_len == circbuf->capacity -
circbuf->len);
}
/**
* Read audio samples from the circular buffer.
*
* @param circbuf The circular buffer.
* @param data Buffer to store the read audio samples.
* @param count Number of samples being read.
*
* @return PJ_SUCCESS when successful, otherwise
* the appropriate error will be returned.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_read(pjmedia_circ_buf *circbuf,
pj_int16_t *data,
unsigned count)
{
pj_int16_t *reg1, *reg2;
unsigned reg1cnt, reg2cnt;
/* Data in the buffer is less than requested */
if (count > circbuf->len)
return PJ_ETOOBIG;
pjmedia_circ_buf_get_read_regions(circbuf, ®1, ®1cnt,
®2, ®2cnt);
if (reg1cnt >= count) {
pjmedia_copy_samples(data, reg1, count);
} else {
pjmedia_copy_samples(data, reg1, reg1cnt);
pjmedia_copy_samples(data + reg1cnt, reg2, count - reg1cnt);
}
return pjmedia_circ_buf_adv_read_ptr(circbuf, count);
}
/**
* Write audio samples to the circular buffer.
*
* @param circbuf The circular buffer.
* @param data Audio samples to be written.
* @param count Number of samples being written.
*
* @return PJ_SUCCESS when successful, otherwise
* the appropriate error will be returned.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_write(pjmedia_circ_buf *circbuf,
pj_int16_t *data,
unsigned count)
{
pj_int16_t *reg1, *reg2;
unsigned reg1cnt, reg2cnt;
/* Data to write is larger than buffer can store */
if (count > circbuf->capacity - circbuf->len)
return PJ_ETOOBIG;
pjmedia_circ_buf_get_write_regions(circbuf, ®1, ®1cnt,
®2, ®2cnt);
if (reg1cnt >= count) {
pjmedia_copy_samples(reg1, data, count);
} else {
pjmedia_copy_samples(reg1, data, reg1cnt);
pjmedia_copy_samples(reg2, data + reg1cnt, count - reg1cnt);
}
return pjmedia_circ_buf_adv_write_ptr(circbuf, count);
}
/**
* Copy audio samples from the circular buffer without changing its state.
*
* @param circbuf The circular buffer.
* @param start_idx Starting sample index to be copied.
* @param data Buffer to store the read audio samples.
* @param count Number of samples being read.
*
* @return PJ_SUCCESS when successful, otherwise
* the appropriate error will be returned.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_copy(pjmedia_circ_buf *circbuf,
unsigned start_idx,
pj_int16_t *data,
unsigned count)
{
pj_int16_t *reg1, *reg2;
unsigned reg1cnt, reg2cnt;
/* Data in the buffer is less than requested */
if (count + start_idx > circbuf->len)
return PJ_ETOOBIG;
pjmedia_circ_buf_get_read_regions(circbuf, ®1, ®1cnt,
®2, ®2cnt);
if (reg1cnt > start_idx) {
unsigned tmp_len;
tmp_len = reg1cnt - start_idx;
if (tmp_len > count)
tmp_len = count;
pjmedia_copy_samples(data, reg1 + start_idx, tmp_len);
if (tmp_len < count)
pjmedia_copy_samples(data + tmp_len, reg2, count - tmp_len);
} else {
pjmedia_copy_samples(data, reg2 + start_idx - reg1cnt, count);
}
return PJ_SUCCESS;
}
/**
* Pack the buffer so the first sample will be in the beginning of the buffer.
* This will also make the buffer contiguous.
*
* @param circbuf The circular buffer.
*
* @return PJ_SUCCESS when successful, otherwise
* the appropriate error will be returned.
*/
PJ_INLINE(pj_status_t) pjmedia_circ_buf_pack_buffer(pjmedia_circ_buf *circbuf)
{
pj_int16_t *reg1, *reg2;
unsigned reg1cnt, reg2cnt;
unsigned gap;
pjmedia_circ_buf_get_read_regions(circbuf, ®1, ®1cnt,
®2, ®2cnt);
/* Check if not contigue */
if (reg2cnt != 0) {
/* Check if no space left to roll the buffer
* (or should this function provide temporary buffer?)
*/
gap = circbuf->capacity - pjmedia_circ_buf_get_len(circbuf);
if (gap == 0)
return PJ_ETOOBIG;
/* Roll buffer left using the gap until reg2cnt == 0 */
do {
if (gap > reg2cnt)
gap = reg2cnt;
pjmedia_move_samples(reg1 - gap, reg1, reg1cnt);
pjmedia_copy_samples(reg1 + reg1cnt - gap, reg2, gap);
if (gap < reg2cnt)
pjmedia_move_samples(reg2, reg2 + gap, reg2cnt - gap);
reg1 -= gap;
reg1cnt += gap;
reg2cnt -= gap;
} while (reg2cnt > 0);
}
/* Finally, Shift samples to the left edge */
if (reg1 != circbuf->buf)
pjmedia_move_samples(circbuf->buf, reg1,
pjmedia_circ_buf_get_len(circbuf));
circbuf->start = circbuf->buf;
return PJ_SUCCESS;
}
PJ_END_DECL
/**
* @}
*/
#endif
|