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         *whennext = s->fr.samples = res;
 106         return &s->fr;
 107 }
 108
 109 static int pcm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 110 {
 111         off_t cur, max, offset = 0;
 112         int ret = -1;   /* assume error */
 113
 114         cur = ftello(fs->f);
 115         fseeko(fs->f, 0, SEEK_END);
 116         max = ftello(fs->f);
 117
 118         switch (whence) {
 119         case SEEK_SET:
 120                 offset = sample_offset;
 121                 break;
 122         case SEEK_END:
 123                 offset = max - sample_offset;
 124                 break;
 125         case SEEK_CUR:
 126         case SEEK_FORCECUR:
 127                 offset = cur + sample_offset;
 128                 break;
 129         default:
 130                 ast_log(LOG_WARNING, "invalid whence %d, assuming SEEK_SET\n", whence);
 131                 offset = sample_offset;
 132         }
 133         if (offset < 0) {
 134                 ast_log(LOG_WARNING, "negative offset %ld, resetting to 0\n", (long) offset);
 135                 offset = 0;
 136         }
 137         if (whence == SEEK_FORCECUR && offset > max) { /* extend the file */
 138                 size_t left = offset - max;
 139                 const char *src = (fs->fmt->format == AST_FORMAT_ALAW) ? alaw_silence : ulaw_silence;
 140
 141                 while (left) {
 142                         size_t written = fwrite(src, 1, (left > BUF_SIZE) ? BUF_SIZE : left, fs->f);
 143                         if (written == -1)
 144                                 break;  /* error */
 145                         left -= written;
 146                 }
 147                 ret = 0; /* successful */
 148         } else {
 149                 if (offset > max) {
 150                         ast_log(LOG_WARNING, "offset too large %ld, truncating to %ld\n", (long) offset, (long) max);
 151                         offset = max;
 152                 }
 153                 ret = fseeko(fs->f, offset, SEEK_SET);
 154         }
 155         return ret;
 156 }
 157
 158 static int pcm_trunc(struct ast_filestream *fs)
 159 {
 160         return ftruncate(fileno(fs->f), ftello(fs->f));
 161 }
 162
 163 static off_t pcm_tell(struct ast_filestream *fs)
 164 {
 165         return ftello(fs->f);
 166 }
 167
 168 static int pcm_write(struct ast_filestream *fs, struct ast_frame *f)
 169 {
 170         int res;
 171
 172         if (f->frametype != AST_FRAME_VOICE) {
 173                 ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
 174                 return -1;
 175         }
 176         if (f->subclass != fs->fmt->format) {
 177                 ast_log(LOG_WARNING, "Asked to write incompatible format frame (%d)!\n", f->subclass);
 178                 return -1;
 179         }
 180
 181 #ifdef REALTIME_WRITE
 182         if (s->fmt->format == AST_FORMAT_ALAW) {
 183                 struct pcm_desc *pd = (struct pcm_desc *)fs->private;
 184                 struct stat stat_buf;
 185                 unsigned long cur_time = get_time();
 186                 unsigned long fpos = ( cur_time - pd->start_time ) * 8; /* 8 bytes per msec */
 187                 /* Check if we have written to this position yet. If we have, then increment pos by one frame
 188                 *  for some degree of protection against receiving packets in the same clock tick.
 189                 */
 190
 191                 fstat(fileno(fs->f), &stat_buf );
 192                 if (stat_buf.st_size > fpos )
 193                         fpos += f->datalen;     /* Incrementing with the size of this current frame */
 194
 195                 if (stat_buf.st_size < fpos) {
 196                         /* fill the gap with 0x55 rather than 0. */
 197                         char buf[1024];
 198                         unsigned long cur, to_write;
 199
 200                         cur = stat_buf.st_size;
 201                         if (fseek(fs->f, cur, SEEK_SET) < 0) {
 202                                 ast_log( LOG_WARNING, "Cannot seek in file: %s\n", strerror(errno) );
 203                                 return -1;
 204                         }
 205                         memset(buf, 0x55, 512);
 206                         while (cur < fpos) {
 207                                 to_write = fpos - cur;
 208                                 if (to_write > sizeof(buf))
 209                                         to_write = sizeof(buf);
 210                                 fwrite(buf, 1, to_write, fs->f);
 211                                 cur += to_write;
 212                         }
 213                 }
 214
 215                 if (fseek(s->f, fpos, SEEK_SET) < 0) {
 216                         ast_log( LOG_WARNING, "Cannot seek in file: %s\n", strerror(errno) );
 217                         return -1;
 218                 }
 219         }
 220 #endif  /* REALTIME_WRITE */
 221
 222         if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
 223                 ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
 224                 return -1;
 225         }
 226         return 0;
 227 }
 228
 229 /* SUN .au support routines */
 230
 231 #define AU_HEADER_SIZE          24
 232 #define AU_HEADER(var)          uint32_t var[6]
 233
 234 #define AU_HDR_MAGIC_OFF        0
 235 #define AU_HDR_HDR_SIZE_OFF     1
 236 #define AU_HDR_DATA_SIZE_OFF    2
 237 #define AU_HDR_ENCODING_OFF     3
 238 #define AU_HDR_SAMPLE_RATE_OFF  4
 239 #define AU_HDR_CHANNELS_OFF     5
 240
 241 #define AU_ENC_8BIT_ULAW        1
 242
 243 #define AU_MAGIC 0x2e736e64
 244 #if __BYTE_ORDER == __BIG_ENDIAN
 245 #define htoll(b) (b)
 246 #define htols(b) (b)
 247 #define ltohl(b) (b)
 248 #define ltohs(b) (b)
 249 #else
 250 #if __BYTE_ORDER == __LITTLE_ENDIAN
 251 #define htoll(b)  \
 252           (((((b)      ) & 0xFF) << 24) | \
 253                ((((b) >>  8) & 0xFF) << 16) | \
 254                    ((((b) >> 16) & 0xFF) <<  8) | \
 255                    ((((b) >> 24) & 0xFF)      ))
 256 #define htols(b) \
 257           (((((b)      ) & 0xFF) << 8) | \
 258                    ((((b) >> 8) & 0xFF)      ))
 259 #define ltohl(b) htoll(b)
 260 #define ltohs(b) htols(b)
 261 #else
 262 #error "Endianess not defined"
 263 #endif
 264 #endif
 265
 266 static int check_header(FILE *f)
 267 {
 268         AU_HEADER(header);
 269         uint32_t magic;
 270         uint32_t hdr_size;
 271         uint32_t data_size;
 272         uint32_t encoding;
 273         uint32_t sample_rate;
 274         uint32_t channels;
 275
 276         if (fread(header, 1, AU_HEADER_SIZE, f) != AU_HEADER_SIZE) {
 277                 ast_log(LOG_WARNING, "Read failed (header)\n");
 278                 return -1;
 279         }
 280         magic = ltohl(header[AU_HDR_MAGIC_OFF]);
 281         if (magic != (uint32_t) AU_MAGIC) {
 282                 ast_log(LOG_WARNING, "Bad magic: 0x%x\n", magic);
 283         }
 284 /*      hdr_size = ltohl(header[AU_HDR_HDR_SIZE_OFF]);
 285         if (hdr_size < AU_HEADER_SIZE)*/
 286         hdr_size = AU_HEADER_SIZE;
 287 /*      data_size = ltohl(header[AU_HDR_DATA_SIZE_OFF]); */
 288         encoding = ltohl(header[AU_HDR_ENCODING_OFF]);
 289         if (encoding != AU_ENC_8BIT_ULAW) {
 290                 ast_log(LOG_WARNING, "Unexpected format: %d. Only 8bit ULAW allowed (%d)\n", encoding, AU_ENC_8BIT_ULAW);
 291                 return -1;
 292         }
 293         sample_rate = ltohl(header[AU_HDR_SAMPLE_RATE_OFF]);
 294         if (sample_rate != DEFAULT_SAMPLE_RATE) {
 295                 ast_log(LOG_WARNING, "Sample rate can only be 8000 not %d\n", sample_rate);
 296                 return -1;
 297         }
 298         channels = ltohl(header[AU_HDR_CHANNELS_OFF]);
 299         if (channels != 1) {
 300                 ast_log(LOG_WARNING, "Not in mono: channels=%d\n", channels);
 301                 return -1;
 302         }
 303         /* Skip to data */
 304         fseek(f, 0, SEEK_END);
 305         data_size = ftell(f) - hdr_size;
 306         if (fseek(f, hdr_size, SEEK_SET) == -1 ) {
 307                 ast_log(LOG_WARNING, "Failed to skip to data: %d\n", hdr_size);
 308                 return -1;
 309         }
 310         return data_size;
 311 }
 312
 313 static int update_header(FILE *f)
 314 {
 315         off_t cur, end;
 316         uint32_t datalen;
 317         int bytes;
 318
 319         cur = ftell(f);
 320         fseek(f, 0, SEEK_END);
 321         end = ftell(f);
 322         /* data starts 24 bytes in */
 323         bytes = end - AU_HEADER_SIZE;
 324         datalen = htoll(bytes);
 325
 326         if (cur < 0) {
 327                 ast_log(LOG_WARNING, "Unable to find our position\n");
 328                 return -1;
 329         }
 330         if (fseek(f, AU_HDR_DATA_SIZE_OFF * sizeof(uint32_t), SEEK_SET)) {
 331                 ast_log(LOG_WARNING, "Unable to set our position\n");
 332                 return -1;
 333         }
 334         if (fwrite(&datalen, 1, sizeof(datalen), f) != sizeof(datalen)) {
 335                 ast_log(LOG_WARNING, "Unable to set write file size\n");
 336                 return -1;
 337         }
 338         if (fseek(f, cur, SEEK_SET)) {
 339                 ast_log(LOG_WARNING, "Unable to return to position\n");
 340                 return -1;
 341         }
 342         return 0;
 343 }
 344
 345 static int write_header(FILE *f)
 346 {
 347         AU_HEADER(header);
 348
 349         header[AU_HDR_MAGIC_OFF] = htoll((uint32_t) AU_MAGIC);
 350         header[AU_HDR_HDR_SIZE_OFF] = htoll(AU_HEADER_SIZE);
 351         header[AU_HDR_DATA_SIZE_OFF] = 0;
 352         header[AU_HDR_ENCODING_OFF] = htoll(AU_ENC_8BIT_ULAW);
 353         header[AU_HDR_SAMPLE_RATE_OFF] = htoll(DEFAULT_SAMPLE_RATE);
 354         header[AU_HDR_CHANNELS_OFF] = htoll(1);
 355
 356         /* Write an au header, ignoring sizes which will be filled in later */
 357         fseek(f, 0, SEEK_SET);
 358         if (fwrite(header, 1, AU_HEADER_SIZE, f) != AU_HEADER_SIZE) {
 359                 ast_log(LOG_WARNING, "Unable to write header\n");
 360                 return -1;
 361         }
 362         return 0;
 363 }
 364
 365 static int au_open(struct ast_filestream *s)
 366 {
 367         if (check_header(s->f) < 0)
 368                 return -1;
 369         return 0;
 370 }
 371
 372 static int au_rewrite(struct ast_filestream *s, const char *comment)
 373 {
 374         if (write_header(s->f))
 375                 return -1;
 376         return 0;
 377 }
 378
 379 /* XXX check this, probably incorrect */
 380 static int au_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
 381 {
 382         off_t min, max, cur;
 383         long offset = 0, samples;
 384
 385         samples = sample_offset;
 386         min = AU_HEADER_SIZE;
 387         cur = ftello(fs->f);
 388         fseek(fs->f, 0, SEEK_END);
 389         max = ftello(fs->f);
 390         if (whence == SEEK_SET)
 391                 offset = samples + min;
 392         else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
 393                 offset = samples + cur;
 394         else if (whence == SEEK_END)
 395                 offset = max - samples;
 396         if (whence != SEEK_FORCECUR) {
 397                 offset = (offset > max) ? max : offset;
 398         }
 399         /* always protect the header space. */
 400         offset = (offset < min) ? min : offset;
 401         return fseeko(fs->f, offset, SEEK_SET);
 402 }
 403
 404 static int au_trunc(struct ast_filestream *fs)
 405 {
 406         if (ftruncate(fileno(fs->f), ftell(fs->f)))
 407                 return -1;
 408         return update_header(fs->f);
 409 }
 410
 411 static off_t au_tell(struct ast_filestream *fs)
 412 {
 413         off_t offset = ftello(fs->f);
 414         return offset - AU_HEADER_SIZE;
 415 }
 416
 417 static const struct ast_format alaw_f = {
 418         .name = "alaw",
 419         .exts = "alaw|al",
 420         .format = AST_FORMAT_ALAW,
 421         .write = pcm_write,
 422         .seek = pcm_seek,
 423         .trunc = pcm_trunc,
 424         .tell = pcm_tell,
 425         .read = pcm_read,
 426         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 427 #ifdef REALTIME_WRITE
 428         .open = pcma_open,
 429         .rewrite = pcma_rewrite,
 430         .desc_size = sizeof(struct pcm_desc),
 431 #endif
 432 };
 433
 434 static const struct ast_format pcm_f = {
 435         .name = "pcm",
 436         .exts = "pcm|ulaw|ul|mu",
 437         .format = AST_FORMAT_ULAW,
 438         .write = pcm_write,
 439         .seek = pcm_seek,
 440         .trunc = pcm_trunc,
 441         .tell = pcm_tell,
 442         .read = pcm_read,
 443         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
 444 };
 445
 446 static const struct ast_format g722_f = {
 447         .name = "g722",
 448         .exts = "g722",
 449         .format = AST_FORMAT_G722,
 450         .write = pcm_write,
 451         .seek = pcm_seek,
 452         .trunc = pcm_trunc,
 453         .tell = pcm_tell,
 454         .read = pcm_read,
 455         .buf_size = (BUF_SIZE * 2) + AST_FRIENDLY_OFFSET,
 456 };
 457
 458 static const struct ast_format au_f = {
 459         .name = "au",
 460         .exts = "au",
 461         .format = AST_FORMAT_ULAW,
 462         .open = au_open,
 463         .rewrite = au_rewrite,
 464         .write = pcm_write,
 465         .seek = au_seek,
 466         .trunc = au_trunc,
 467         .tell = au_tell,
 468         .read = pcm_read,
 469         .buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,     /* this many shorts */
 470 };
 471
 472 static int load_module(void)
 473 {
 474         int index;
 475
 476         /* XXX better init ? */
 477         for (index = 0; index < (sizeof(ulaw_silence) / sizeof(ulaw_silence[0])); index++)
 478                 ulaw_silence[index] = AST_LIN2MU(0);
 479         for (index = 0; index < (sizeof(alaw_silence) / sizeof(alaw_silence[0])); index++)
 480                 alaw_silence[index] = AST_LIN2A(0);
 481
 482         return ast_format_register(&pcm_f)
 483                 || ast_format_register(&alaw_f)
 484                 || ast_format_register(&au_f)
 485                 || ast_format_register(&g722_f);
 486 }
 487
 488 static int unload_module(void)
 489 {
 490         return ast_format_unregister(pcm_f.name)
 491                 || ast_format_unregister(alaw_f.name)
 492                 || ast_format_unregister(au_f.name)
 493                 || ast_format_unregister(g722_f.name);
 494 }
 495
 496 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Raw/Sun uLaw/ALaw 8KHz (PCM,PCMA,AU), G.722 16Khz");