format_sln.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Anthony Minessale
 * Anthony Minessale (anthmct@yahoo.com)
 *
 * 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|slin|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
);