ref: 1e0a00d4e1d42f775a426519c97fbb2e7a648fe5
dir: /src/gsrt.c/
/* libSoX file format: Grandstream ring tone (c) 2009 robs@users.sourceforge.net
*
* See https://web.archive.org/web/20101128121923/http://grandstream.com/ringtone.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* This library 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 Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "sox_i.h"
#include <time.h>
#define VERSION_ 0x1000000
#define MAX_FILE_SIZE 0x10000
#define HEADER_SIZE (size_t)512
#define PADDING_SIZE (size_t)478
static char const id[16] = "ring.bin";
typedef struct {
char const * string;
int ft_encoding;
unsigned bits_per_sample;
sox_encoding_t sox_encoding;
} table_t;
static table_t const table[] = {
{NULL, 0, 8, SOX_ENCODING_ULAW},
{"G726", 2, 0, SOX_ENCODING_UNKNOWN},
{NULL, 3, 0, SOX_ENCODING_GSM},
{NULL, 4, 0, SOX_ENCODING_G723},
{NULL, 8, 8, SOX_ENCODING_ALAW},
{"G722", 9, 0, SOX_ENCODING_UNKNOWN},
{"G728", 15, 2, SOX_ENCODING_UNKNOWN},
{"iLBC", 98, 0, SOX_ENCODING_UNKNOWN},
};
static int ft_enc(unsigned bits_per_sample, sox_encoding_t encoding)
{
size_t i;
for (i = 0; i < array_length(table); ++i) {
table_t const * t = &table[i];
if (t->sox_encoding == encoding && t->bits_per_sample == bits_per_sample)
return t->ft_encoding;
}
return -1; /* Should never get here. */
}
static sox_encoding_t sox_enc(int ft_encoding, unsigned * bits_per_sample)
{
size_t i;
for (i = 0; i < array_length(table); ++i) {
table_t const * t = &table[i];
if (t->ft_encoding == ft_encoding) {
*bits_per_sample = t->bits_per_sample;
if (t->sox_encoding == SOX_ENCODING_UNKNOWN)
lsx_report("unsupported encoding: %s", t->string);
return t->sox_encoding;
}
}
*bits_per_sample = 0;
return SOX_ENCODING_UNKNOWN;
}
static int start_read(sox_format_t * ft)
{
off_t num_samples;
char read_id[array_length(id)];
uint32_t file_size;
int16_t ft_encoding;
sox_encoding_t encoding;
unsigned bits_per_sample;
lsx_readdw(ft, &file_size);
num_samples = file_size? file_size * 2 - HEADER_SIZE : SOX_UNSPEC;
if (file_size >= 2 && ft->seekable) {
int i, checksum = (file_size >> 16) + file_size;
for (i = file_size - 2; i; --i) {
int16_t int16;
lsx_readsw(ft, &int16);
checksum += int16;
}
if (lsx_seeki(ft, (off_t)sizeof(file_size), SEEK_SET) != 0)
return SOX_EOF;
if (checksum & 0xffff)
lsx_warn("invalid checksum in input file %s", ft->filename);
}
lsx_skipbytes(ft, (size_t)(2 + 4 + 6)); /* Checksum, version, time stamp. */
lsx_readchars(ft, read_id, sizeof(read_id));
if (memcmp(read_id, id, strlen(id))) {
lsx_fail_errno(ft, SOX_EHDR, "gsrt: invalid file name in header");
return SOX_EOF;
}
lsx_readsw(ft, &ft_encoding);
encoding = sox_enc(ft_encoding, &bits_per_sample);
if (encoding != SOX_ENCODING_ALAW &&
encoding != SOX_ENCODING_ULAW)
ft->handler.read = NULL;
lsx_skipbytes(ft, PADDING_SIZE);
return lsx_check_read_params(ft, 1, 8000., encoding,
bits_per_sample, (uint64_t)num_samples, sox_true);
}
static int start_write(sox_format_t * ft)
{
int i, encoding = ft_enc(ft->encoding.bits_per_sample, ft->encoding.encoding);
time_t now = sox_globals.repeatable? 0 : time(NULL);
struct tm const * t = sox_globals.repeatable? gmtime(&now) : localtime(&now);
int checksum = (VERSION_ >> 16) + VERSION_;
checksum += t->tm_year + 1900;
checksum += ((t->tm_mon + 1) << 8) + t->tm_mday;
checksum += (t->tm_hour << 8) + t->tm_min;
for (i = sizeof(id) - 2; i >= 0; i -= 2)
checksum += (id[i] << 8) + id[i + 1];
checksum += encoding;
return lsx_writedw(ft, 0)
|| lsx_writesw(ft, -checksum)
|| lsx_writedw(ft, VERSION_)
|| lsx_writesw(ft, t->tm_year + 1900)
|| lsx_writesb(ft, t->tm_mon + 1)
|| lsx_writesb(ft, t->tm_mday)
|| lsx_writesb(ft, t->tm_hour)
|| lsx_writesb(ft, t->tm_min)
|| lsx_writechars(ft, id, sizeof(id))
|| lsx_writesw(ft, encoding)
|| lsx_padbytes(ft, PADDING_SIZE) ? SOX_EOF : SOX_SUCCESS;
}
static size_t write_samples(
sox_format_t * ft, sox_sample_t const * buf, size_t nsamp)
{
size_t n = min(nsamp, MAX_FILE_SIZE - (size_t)ft->tell_off);
if (n != nsamp)
lsx_warn("audio truncated");
return lsx_rawwrite(ft, buf, n);
}
static int stop_write(sox_format_t * ft)
{
long num_samples = ft->tell_off - HEADER_SIZE;
if (num_samples & 1) {
sox_sample_t pad = 0;
lsx_rawwrite(ft, &pad, 1);
}
if (ft->seekable) {
unsigned i, file_size = ft->tell_off >> 1;
int16_t int16;
int checksum;
if (!lsx_seeki(ft, (off_t)sizeof(uint32_t), SEEK_SET)) {
lsx_readsw(ft, &int16);
checksum = (file_size >> 16) + file_size - int16;
if (!lsx_seeki(ft, (off_t)HEADER_SIZE, SEEK_SET)) {
for (i = (num_samples + 1) >> 1; i; --i) {
lsx_readsw(ft, &int16);
checksum += int16;
}
if (!lsx_seeki(ft, (off_t)0, SEEK_SET)) {
lsx_writedw(ft, file_size);
lsx_writesw(ft, -checksum);
return SOX_SUCCESS;
}
}
}
}
lsx_warn("can't seek in output file `%s'; "
"length in file header will be unspecified", ft->filename);
return SOX_SUCCESS;
}
LSX_FORMAT_HANDLER(gsrt)
{
static char const *const names[] = { "gsrt", NULL };
static sox_rate_t const write_rates[] = { 8000, 0 };
static unsigned const write_encodings[] = {
SOX_ENCODING_ALAW, 8, 0,
SOX_ENCODING_ULAW, 8, 0,
0
};
static sox_format_handler_t const handler = {
SOX_LIB_VERSION_CODE, "Grandstream ring tone",
names, SOX_FILE_BIG_END | SOX_FILE_MONO,
start_read, lsx_rawread, NULL,
start_write, write_samples, stop_write,
lsx_rawseek, write_encodings, write_rates, 0
};
return &handler;
}