/* 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;}