format_sln.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Anthony Minessale
 * Anthony Minessale ([email protected])
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief RAW SLINEAR Formats
 * \ingroup formats
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/mod_format.h"
#include "asterisk/module.h"
#include "asterisk/endian.h"
#include "asterisk/format_cache.h"

static struct ast_frame *generic_read(struct ast_filestream *s, int *whennext, unsigned int buf_size)
{
   size_t res;

   /* Send a frame from the file to the appropriate channel */
   AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, buf_size);
   if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) < 1) {
      if (res) {
         ast_log(LOG_WARNING, "Short read of %s data (expected %d bytes, read %zu): %s\n",
               ast_format_get_name(s->fr.subclass.format), s->fr.datalen, res,
               strerror(errno));
      }
      return NULL;
   }
   *whennext = s->fr.samples = res/2;
   s->fr.datalen = res;
   return &s->fr;
}

static int slinear_write(struct ast_filestream *fs, struct ast_frame *f)
{
   int res;

   /* Don't try to write an interpolated frame */
   if (f->datalen == 0) {
      return 0;
   }

   if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
         ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
         return -1;
   }
   return 0;
}

static int slinear_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
   off_t offset=0, min = 0, cur, max;

   sample_offset <<= 1;

   if ((cur = ftello(fs->f)) < 0) {
      ast_log(AST_LOG_WARNING, "Unable to determine current position in sln filestream %p: %s\n", fs, strerror(errno));
      return -1;
   }

   if (fseeko(fs->f, 0, SEEK_END) < 0) {
      ast_log(AST_LOG_WARNING, "Unable to seek to end of sln filestream %p: %s\n", fs, strerror(errno));
      return -1;
   }

   if ((max = ftello(fs->f)) < 0) {
      ast_log(AST_LOG_WARNING, "Unable to determine max position in sln filestream %p: %s\n", fs, strerror(errno));
      return -1;
   }

   if (whence == SEEK_SET)
      offset = sample_offset;
   else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
      offset = sample_offset + cur;
   else if (whence == SEEK_END)
      offset = max - sample_offset;
   if (whence != SEEK_FORCECUR) {
      offset = (offset > max)?max:offset;
   }
   /* always protect against seeking past begining. */
   offset = (offset < min)?min:offset;
   return fseeko(fs->f, offset, SEEK_SET);
}

static int slinear_trunc(struct ast_filestream *fs)
{
   int fd;
   off_t cur;

   if ((fd = fileno(fs->f)) < 0) {
      ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for sln filestream %p: %s\n", fs, strerror(errno));
      return -1;
   }
   if ((cur = ftello(fs->f)) < 0) {
      ast_log(AST_LOG_WARNING, "Unable to determine current position in sln filestream %p: %s\n", fs, strerror(errno));
      return -1;
   }
   /* Truncate file to current length */
   return ftruncate(fd, cur);
}

static off_t slinear_tell(struct ast_filestream *fs)
{
   return ftello(fs->f) / 2;
}

static struct ast_frame *slinear_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 320);}
static struct ast_format_def slin_f = {
   .name = "sln",
   .exts = "sln|raw",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear_read,
   .buf_size = 320 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear12_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 480);}
static struct ast_format_def slin12_f = {
   .name = "sln12",
   .exts = "sln12",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear12_read,
   .buf_size = 480 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear16_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 640);}
static struct ast_format_def slin16_f = {
   .name = "sln16",
   .exts = "sln16",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear16_read,
   .buf_size = 640 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear24_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 960);}
static struct ast_format_def slin24_f = {
   .name = "sln24",
   .exts = "sln24",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear24_read,
   .buf_size = 960 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear32_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 1280);}
static struct ast_format_def slin32_f = {
   .name = "sln32",
   .exts = "sln32",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear32_read,
   .buf_size = 1280 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear44_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 1764);}
static struct ast_format_def slin44_f = {
   .name = "sln44",
   .exts = "sln44",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear44_read,
   .buf_size = 1764 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear48_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 1920);}
static struct ast_format_def slin48_f = {
   .name = "sln48",
   .exts = "sln48",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear48_read,
   .buf_size = 1920 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear96_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 3840);}
static struct ast_format_def slin96_f = {
   .name = "sln96",
   .exts = "sln96",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear96_read,
   .buf_size = 3840 + AST_FRIENDLY_OFFSET,
};

static struct ast_frame *slinear192_read(struct ast_filestream *s, int *whennext){return generic_read(s, whennext, 7680);}
static struct ast_format_def slin192_f = {
   .name = "sln192",
   .exts = "sln192",
   .write = slinear_write,
   .seek = slinear_seek,
   .trunc = slinear_trunc,
   .tell = slinear_tell,
   .read = slinear192_read,
   .buf_size = 7680 + AST_FRIENDLY_OFFSET,
};

static struct ast_format_def *slin_list[] = {
   &slin_f,
   &slin12_f,
   &slin16_f,
   &slin24_f,
   &slin32_f,
   &slin44_f,
   &slin48_f,
   &slin96_f,
   &slin192_f,
};

static int unload_module(void)
{
   int res = 0;
   int i = 0;

   for (i = 0; i < ARRAY_LEN(slin_list); i++) {
      if (ast_format_def_unregister(slin_list[i]->name)) {
         res = -1;
      }
   }
   return res;
}

static int load_module(void)
{
   int i;

   slin_f.format = ast_format_slin;
   slin12_f.format = ast_format_slin12;
   slin16_f.format = ast_format_slin16;
   slin24_f.format = ast_format_slin24;
   slin32_f.format = ast_format_slin32;
   slin44_f.format = ast_format_slin44;
   slin48_f.format = ast_format_slin48;
   slin96_f.format = ast_format_slin96;
   slin192_f.format = ast_format_slin192;

   for (i = 0; i < ARRAY_LEN(slin_list); i++) {
      if (ast_format_def_register(slin_list[i])) {
         unload_module();
         return AST_MODULE_LOAD_DECLINE;
      }
   }

   return AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Raw Signed Linear Audio support (SLN) 8khz-192khz",
   .support_level = AST_MODULE_SUPPORT_CORE,
   .load = load_module,
   .unload = unload_module,
   .load_pri = AST_MODPRI_APP_DEPEND
);