formats/format_pcm.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2006, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Flat, binary, ulaw PCM file format.
  22  * \arg File name extension: pcm, ulaw, ul, mu
  23  *
  24  * \ingroup formats
  25  */
  26
  27 #include "asterisk.h"
  28
  29 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  30
  31 #include <unistd.h>
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34 #include <stdlib.h>
  35 #include <sys/time.h>
  36 #include <stdio.h>
  37 #include <errno.h>
  38 #include <string.h>
  39
  40 #include "asterisk/lock.h"
  41 #include "asterisk/channel.h"
  42 #include "asterisk/file.h"
  43 #include "asterisk/logger.h"
  44 #include "asterisk/sched.h"
  45 #include "asterisk/module.h"
  46 #include "asterisk/endian.h"
  47 #include "asterisk/ulaw.h"
  48 #include "asterisk/alaw.h"
  49
  50 #define BUF_SIZE 160            /* 160 bytes, and same number of samples */
  51
  52 static char ulaw_silence[BUF_SIZE];
  53 static char alaw_silence[BUF_SIZE];
  54
  55 /* #define REALTIME_WRITE */    /* XXX does it work at all ? */
  56
  57 #ifdef REALTIME_WRITE
  58 struct pcm_desc {
  59         unsigned long start_time;
  60 };
  61
  62 /* Returns time in msec since system boot. */
  63 static unsigned long get_time(void)
  64 {
  65         struct tms buf;
  66         clock_t cur;
  67
  68         cur = times( &buf );
  69         if( cur < 0 ) {
  70                 ast_log( LOG_WARNING, "Cannot get current time\n" );
  71                 return 0;
  72         }
  73         return cur * 1000 / sysconf( _SC_CLK_TCK );
  74 }
  75
  76 static int pcma_open(struct ast_filestream *s)
  77 {
  78         if (s->fmt->format == AST_FORMAT_ALAW)
  79                 pd->starttime = get_time();
  80         return 0;
  81 }
  82
  83 static int pcma_rewrite(struct ast_filestream *s, const char *comment)
  84 {
  85         return pcma_open(s);
  86 }
  87 #endif
  88
  89 static struct ast_frame *pcm_read(struct ast_filestream *s, int *whennext)
  90 {
  91         int res;
  92
  93         /* Send a frame from the file to the appropriate channel */
  94
  95         s->fr.frametype = AST_FRAME_VOICE;
  96         s->fr.subclass = s->fmt->format;
  97         s->fr.mallocd = 0;
  98         AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
  99         if ((res = fread(s->fr.data, 1, s->fr.datalen, s->f)) < 1) {
 100                 if (res)
 101                         ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
 102                 return NULL;
 103         }
 104         s->fr.datalen = res;
 105         if (s->fmt->format == AST_FORMAT_G722)
 106                 *whennext = s->fr.samples = res * 2;
 107         else
 108                 *whennext = s->fr.samples = res;
 109         return &s->fr;
 110 }
 111
 112 static int pcm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 113 {
 114         off_t cur, max, offset = 0;
 115         int ret = -1;   /* assume error */
 116
 117         cur = ftello(fs->f);
 118         fseeko(fs->f, 0, SEEK_END);
 119         max = ftello(fs->f);
 120
 121         switch (whence) {
 122         case SEEK_SET:
 123                 offset = sample_offset;
 124                 break;
 125         case SEEK_END:
 126                 offset = max - sample_offset;
 127                 break;
 128         case SEEK_CUR:
 129         case SEEK_FORCECUR:
 130                 offset = cur + sample_offset;
 131                 break;
 132         default:
 133                 ast_log(LOG_WARNING, "invalid whence %d, assuming SEEK_SET\n", whence);
 134                 offset = sample_offset;
 135         }
 136         if (offset < 0) {
 137                 ast_log(LOG_WARNING, "negative offset %ld, resetting to 0\n", (long) offset);
 138                 offset = 0;
 139         }
 140         if (whence == SEEK_FORCECUR && offset > max) { /* extend the file */
 141                 size_t left = offset - max;
 142                 const char *src = (fs->fmt->format == AST_FORMAT_ALAW) ? alaw_silence : ulaw_silence;
 143
 144                 while (left) {
 145                         size_t written = fwrite(src, 1, (left > BUF_SIZE) ? BUF_SIZE : left, fs->f);
 146                         if (written == -1)
 147                                 break;  /* error */
 148                         left -= written;
 149                 }
 150                 ret = 0; /* successful */
 151         } else {
 152                 if (offset > max) {
 153                         ast_log(LOG_WARNING, "offset too large %ld, truncating to %ld\n", (long) offset, (long) max);
 154                         offset = max;
 155                 }
 156                 ret = fseeko(fs->f, offset, SEEK_SET);
 157         }
 158         return ret;
 159 }
 160
 161 static int pcm_trunc(struct ast_filestream *fs)
 162 {
 163         return ftruncate(fileno(fs->f), ftello(fs->f));
 164 }
 165
 166 static off_t pcm_tell(struct ast_filestream *fs)
 167 {
 168         return ftello(fs->f);
 169 }
 170
 171 static int pcm_write(struct ast_filestream *fs, struct ast_frame *f)
 172 {
 173         int res;
 174
 175         if (f->frametype != AST_FRAME_VOICE) {
 176                 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
 177                 return -1;
 178         }
 179         if (f->subclass != fs->fmt->format) {
 180                 ast_log(LOG_WARNING, "Asked to write incompatible format frame (%d)!\n", f->subclass);
 181                 return -1;
 182         }
 183
 184 #ifdef REALTIME_WRITE
 185         if (s->fmt->format == AST_FORMAT_ALAW) {
 186                 struct pcm_desc *pd = (struct pcm_desc *)fs->_private;
 187                 struct stat stat_buf;
 188                 unsigned long cur_time = get_time();
 189                 unsigned long fpos = ( cur_time - pd->start_time ) * 8; /* 8 bytes per msec */
 190                 /* Check if we have written to this position yet. If we have, then increment pos by one frame
 191                 *  for some degree of protection against receiving packets in the same clock tick.
 192                 */
 193
 194                 fstat(fileno(fs->f), &stat_buf );
 195                 if (stat_buf.st_size > fpos )
 196                         fpos += f->datalen;     /* Incrementing with the size of this current frame */
 197
 198                 if (stat_buf.st_size < fpos) {
 199                         /* fill the gap with 0x55 rather than 0. */
 200                         char buf[1024];
 201                         unsigned long cur, to_write;
 202
 203                         cur = stat_buf.st_size;
 204                         if (fseek(fs->f, cur, SEEK_SET) < 0) {
 205                                 ast_log( LOG_WARNING, "Cannot seek in file: %s\n", strerror(errno) );
 206                                 return -1;
 207                         }
 208                         memset(buf, 0x55, 512);
 209                         while (cur < fpos) {
 210                                 to_write = fpos - cur;
 211                                 if (to_write > sizeof(buf))
 212                                         to_write = sizeof(buf);
 213                                 fwrite(buf, 1, to_write, fs->f);
 214                                 cur += to_write;
 215                         }
 216                 }
 217
 218                 if (fseek(s->f, fpos, SEEK_SET) < 0) {
 219                         ast_log( LOG_WARNING, "Cannot seek in file: %s\n", strerror(errno) );
 220                         return -1;
 221                 }
 222         }
 223 #endif  /* REALTIME_WRITE */
 224
 225         if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
 226                 ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
 227                 return -1;
 228         }
 229         return 0;
 230 }
 231
 232 /* SUN .au support routines */
 233
 234 #define AU_HEADER_SIZE          24
 235 #define AU_HEADER(var)          uint32_t var[6]
 236
 237 #define AU_HDR_MAGIC_OFF        0
 238 #define AU_HDR_HDR_SIZE_OFF     1
 239 #define AU_HDR_DATA_SIZE_OFF    2
 240 #define AU_HDR_ENCODING_OFF     3
 241 #define AU_HDR_SAMPLE_RATE_OFF  4
 242 #define AU_HDR_CHANNELS_OFF     5
 243
 244 #define AU_ENC_8BIT_ULAW        1
 245
 246 #define AU_MAGIC 0x2e736e64
 247 #if __BYTE_ORDER == __BIG_ENDIAN
 248 #define htoll(b) (b)
 249 #define htols(b) (b)
 250 #define ltohl(b) (b)
 251 #define ltohs(b) (b)
 252 #else
 253 #if __BYTE_ORDER == __LITTLE_ENDIAN
 254 #define htoll(b)  \
 255           (((((b)      ) & 0xFF) << 24) | \
 256                ((((b) >>  8) & 0xFF) << 16) | \
 257                    ((((b) >> 16) & 0xFF) <<  8) | \
 258                    ((((b) >> 24) & 0xFF)      ))
 259 #define htols(b) \
 260           (((((b)      ) & 0xFF) << 8) | \
 261                    ((((b) >> 8) & 0xFF)      ))
 262 #define ltohl(b) htoll(b)
 263 #define ltohs(b) htols(b)
 264 #else
 265 #error "Endianess not defined"
 266 #endif
 267 #endif
 268
 269 static int check_header(FILE *f)
 270 {
 271         AU_HEADER(header);
 272         uint32_t magic;
 273         uint32_t hdr_size;
 274         uint32_t data_size;
 275         uint32_t encoding;
 276         uint32_t sample_rate;
 277         uint32_t channels;
 278
 279         if (fread(header, 1, AU_HEADER_SIZE, f) != AU_HEADER_SIZE) {
 280                 ast_log(LOG_WARNING, "Read failed (header)\n");
 281                 return -1;
 282         }
 283         magic = ltohl(header[AU_HDR_MAGIC_OFF]);
 284         if (magic != (uint32_t) AU_MAGIC) {
 285                 ast_log(LOG_WARNING, "Bad magic: 0x%x\n", magic);
 286         }
 287 /*      hdr_size = ltohl(header[AU_HDR_HDR_SIZE_OFF]);
 288         if (hdr_size < AU_HEADER_SIZE)*/
 289         hdr_size = AU_HEADER_SIZE;
 290 /*      data_size = ltohl(header[AU_HDR_DATA_SIZE_OFF]); */
 291         encoding = ltohl(header[AU_HDR_ENCODING_OFF]);
 292         if (encoding != AU_ENC_8BIT_ULAW) {
 293                 ast_log(LOG_WARNING, "Unexpected format: %d. Only 8bit ULAW allowed (%d)\n", encoding, AU_ENC_8BIT_ULAW);
 294                 return -1;
 295         }
 296         sample_rate = ltohl(header[AU_HDR_SAMPLE_RATE_OFF]);
 297         if (sample_rate != DEFAULT_SAMPLE_RATE) {
 298                 ast_log(LOG_WARNING, "Sample rate can only be 8000 not %d\n", sample_rate);
 299                 return -1;
 300         }
 301         channels = ltohl(header[AU_HDR_CHANNELS_OFF]);
 302         if (channels != 1) {
 303                 ast_log(LOG_WARNING, "Not in mono: channels=%d\n", channels);
 304                 return -1;
 305         }
 306         /* Skip to data */
 307         fseek(f, 0, SEEK_END);
 308         data_size = ftell(f) - hdr_size;
 309         if (fseek(f, hdr_size, SEEK_SET) == -1 ) {
 310                 ast_log(LOG_WARNING, "Failed to skip to data: %d\n", hdr_size);
 311                 return -1;
 312         }
 313         return data_size;
 314 }
 315
 316 static int update_header(FILE *f)
 317 {
 318         off_t cur, end;
 319         uint32_t datalen;
 320         int bytes;
 321
 322         cur = ftell(f);
 323         fseek(f, 0, SEEK_END);
 324         end = ftell(f);
 325         /* data starts 24 bytes in */
 326         bytes = end - AU_HEADER_SIZE;
 327         datalen = htoll(bytes);
 328
 329         if (cur < 0) {
 330                 ast_log(LOG_WARNING, "Unable to find our position\n");
 331                 return -1;
 332         }
 333         if (fseek(f, AU_HDR_DATA_SIZE_OFF * sizeof(uint32_t), SEEK_SET)) {
 334                 ast_log(LOG_WARNING, "Unable to set our position\n");
 335                 return -1;
 336         }
 337         if (fwrite(&datalen, 1, sizeof(datalen), f) != sizeof(datalen)) {
 338                 ast_log(LOG_WARNING, "Unable to set write file size\n");
 339                 return -1;
 340         }
 341         if (fseek(f, cur, SEEK_SET)) {
 342                 ast_log(LOG_WARNING, "Unable to return to position\n");
 343                 return -1;
 344         }
 345         return 0;
 346 }
 347
 348 static int write_header(FILE *f)
 349 {
 350         AU_HEADER(header);
 351
 352         header[AU_HDR_MAGIC_OFF] = htoll((uint32_t) AU_MAGIC);
 353         header[AU_HDR_HDR_SIZE_OFF] = htoll(AU_HEADER_SIZE);
 354         header[AU_HDR_DATA_SIZE_OFF] = 0;
 355         header[AU_HDR_ENCODING_OFF] = htoll(AU_ENC_8BIT_ULAW);
 356         header[AU_HDR_SAMPLE_RATE_OFF] = htoll(DEFAULT_SAMPLE_RATE);
 357         header[AU_HDR_CHANNELS_OFF] = htoll(1);
 358
 359         /* Write an au header, ignoring sizes which will be filled in later */
 360         fseek(f, 0, SEEK_SET);
 361         if (fwrite(header, 1, AU_HEADER_SIZE, f) != AU_HEADER_SIZE) {
 362                 ast_log(LOG_WARNING, "Unable to write header\n");
 363                 return -1;
 364         }
 365         return 0;
 366 }
 367
 368 static int au_open(struct ast_filestream *s)
 369 {
 370         if (check_header(s->f) < 0)
 371                 return -1;
 372         return 0;
 373 }
 374
 375 static int au_rewrite(struct ast_filestream *s, const char *comment)
 376 {
 377         if (write_header(s->f))
 378                 return -1;
 379         return 0;
 380 }
 381
 382 /* XXX check this, probably incorrect */
 383 static int au_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 384 {
 385         off_t min, max, cur;
 386         long offset = 0, bytes;
 387
 388         if (fs->fmt->format == AST_FORMAT_G722)
 389                 bytes = sample_offset / 2;
 390         else
 391                 bytes = sample_offset;
 392
 393         min = AU_HEADER_SIZE;
 394         cur = ftello(fs->f);
 395         fseek(fs->f, 0, SEEK_END);
 396         max = ftello(fs->f);
 397
 398         if (whence == SEEK_SET)
 399                 offset = bytes + min;
 400         else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
 401                 offset = bytes + cur;
 402         else if (whence == SEEK_END)
 403                 offset = max - bytes;
 404         if (whence != SEEK_FORCECUR) {
 405                 offset = (offset > max) ? max : offset;
 406         }
 407
 408         /* always protect the header space. */
 409         offset = (offset < min) ? min : offset;
 410
 411         return fseeko(fs->f, offset, SEEK_SET);
 412 }
 413
 414 static int au_trunc(struct ast_filestream *fs)
 415 {
 416         if (ftruncate(fileno(fs->f), ftell(fs->f)))
 417                 return -1;
 418         return update_header(fs->f);
 419 }
 420
 421 static off_t au_tell(struct ast_filestream *fs)
 422 {
 423         off_t offset = ftello(fs->f);
 424         return offset - AU_HEADER_SIZE;
 425 }
 426
 427 static const struct ast_format alaw_f = {
 428         .name = "alaw",
 429         .exts = "alaw|al",
 430         .format = AST_FORMAT_ALAW,
 431         .write = pcm_write,
 432         .seek = pcm_seek,
 433         .trunc = pcm_trunc,
 434         .tell = pcm_tell,
 435         .read = pcm_read,
 436         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 437 #ifdef REALTIME_WRITE
 438         .open = pcma_open,
 439         .rewrite = pcma_rewrite,
 440         .desc_size = sizeof(struct pcm_desc),
 441 #endif
 442 };
 443
 444 static const struct ast_format pcm_f = {
 445         .name = "pcm",
 446         .exts = "pcm|ulaw|ul|mu",
 447         .format = AST_FORMAT_ULAW,
 448         .write = pcm_write,
 449         .seek = pcm_seek,
 450         .trunc = pcm_trunc,
 451         .tell = pcm_tell,
 452         .read = pcm_read,
 453         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 454 };
 455
 456 static const struct ast_format g722_f = {
 457         .name = "g722",
 458         .exts = "g722",
 459         .format = AST_FORMAT_G722,
 460         .write = pcm_write,
 461         .seek = pcm_seek,
 462         .trunc = pcm_trunc,
 463         .tell = pcm_tell,
 464         .read = pcm_read,
 465         .buf_size = (BUF_SIZE * 2) + AST_FRIENDLY_OFFSET,
 466 };
 467
 468 static const struct ast_format au_f = {
 469         .name = "au",
 470         .exts = "au",
 471         .format = AST_FORMAT_ULAW,
 472         .open = au_open,
 473         .rewrite = au_rewrite,
 474         .write = pcm_write,
 475         .seek = au_seek,
 476         .trunc = au_trunc,
 477         .tell = au_tell,
 478         .read = pcm_read,
 479         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,     /* this many shorts */
 480 };
 481
 482 static int load_module(void)
 483 {
 484         int index;
 485
 486         /* XXX better init ? */
 487         for (index = 0; index < (sizeof(ulaw_silence) / sizeof(ulaw_silence[0])); index++)
 488                 ulaw_silence[index] = AST_LIN2MU(0);
 489         for (index = 0; index < (sizeof(alaw_silence) / sizeof(alaw_silence[0])); index++)
 490                 alaw_silence[index] = AST_LIN2A(0);
 491
 492         return ast_format_register(&pcm_f)
 493                 || ast_format_register(&alaw_f)
 494                 || ast_format_register(&au_f)
 495                 || ast_format_register(&g722_f);
 496 }
 497
 498 static int unload_module(void)
 499 {
 500         return ast_format_unregister(pcm_f.name)
 501                 || ast_format_unregister(alaw_f.name)
 502                 || ast_format_unregister(au_f.name)
 503                 || ast_format_unregister(g722_f.name);
 504 }
 505
 506 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw/Sun uLaw/ALaw 8KHz (PCM,PCMA,AU), G.722 16Khz");