format_wav_gsm.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <[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 Save GSM in the proprietary Microsoft format.
 *
 * Microsoft WAV format (Proprietary GSM)
 * \arg File name extension: WAV,wav49  (Upper case WAV, lower case is another format)
 * This format can be played on Windows systems, used for
 * e-mail attachments mainly.
 * \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"

#include "msgsm.h"

/* Some Ideas for this code came from makewave.c by Jeffrey Chilton */

/* Portions of the conversion code are by [email protected] */

#define  GSM_FRAME_SIZE 33
#define  MSGSM_FRAME_SIZE  65
#define  MSGSM_DATA_OFFSET    60 /* offset of data bytes */
#define  GSM_SAMPLES    160   /* samples in a GSM block */
#define  MSGSM_SAMPLES     (2*GSM_SAMPLES)   /* samples in an MSGSM block */

/* begin binary data: */
static char msgsm_silence[] = /* 65 */
{0x48,0x17,0xD6,0x84,0x02,0x80,0x24,0x49,0x92,0x24,0x89,0x02,0x80,0x24,0x49
,0x92,0x24,0x89,0x02,0x80,0x24,0x49,0x92,0x24,0x89,0x02,0x80,0x24,0x49,0x92
,0x24,0x09,0x82,0x74,0x61,0x4D,0x28,0x00,0x48,0x92,0x24,0x49,0x92,0x28,0x00
,0x48,0x92,0x24,0x49,0x92,0x28,0x00,0x48,0x92,0x24,0x49,0x92,0x28,0x00,0x48
,0x92,0x24,0x49,0x92,0x00};
/* end binary data. size = 65 bytes */

struct wavg_desc {
   /* Believe it or not, we must decode/recode to account for the
      weird MS format */
   int secondhalf;                  /* Are we on the second half */
};

#if __BYTE_ORDER == __LITTLE_ENDIAN
#define htoll(b) (b)
#define htols(b) (b)
#define ltohl(b) (b)
#define ltohs(b) (b)
#else
#if __BYTE_ORDER == __BIG_ENDIAN
#define htoll(b) \
   (((((b)      ) & 0xFF) << 24) | \
   ((( (b) >>  8) & 0xFF) << 16) | \
   ((( (b) >> 16) & 0xFF) <<  8) | \
   ((( (b) >> 24) & 0xFF)      ))
#define htols(b) \
   (((((b)      ) & 0xFF) <<  8) | \
   ((( (b) >>  8) & 0xFF)      ))
#define ltohl(b) htoll(b)
#define ltohs(b) htols(b)
#else
#error "Endianess not defined"
#endif
#endif


static int check_header(FILE *f)
{
   int type, size, formtype;
   int fmt, hsize, fact;
   short format, chans;
   int freq;
   int data;
   if (fread(&type, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (type)\n");
      return -1;
   }
   if (fread(&size, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (size)\n");
      return -1;
   }
#if __BYTE_ORDER == __BIG_ENDIAN
   size = ltohl(size);
#endif
   if (fread(&formtype, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (formtype)\n");
      return -1;
   }
   if (memcmp(&type, "RIFF", 4)) {
      ast_log(LOG_WARNING, "Does not begin with RIFF\n");
      return -1;
   }
   if (memcmp(&formtype, "WAVE", 4)) {
      ast_log(LOG_WARNING, "Does not contain WAVE\n");
      return -1;
   }
   if (fread(&fmt, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (fmt)\n");
      return -1;
   }
   if (memcmp(&fmt, "fmt ", 4)) {
      ast_log(LOG_WARNING, "Does not say fmt\n");
      return -1;
   }
   if (fread(&hsize, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (formtype)\n");
      return -1;
   }
   if (ltohl(hsize) != 20) {
      ast_log(LOG_WARNING, "Unexpected header size %d\n", ltohl(hsize));
      return -1;
   }
   if (fread(&format, 1, 2, f) != 2) {
      ast_log(LOG_WARNING, "Read failed (format)\n");
      return -1;
   }
   if (ltohs(format) != 49) {
      ast_log(LOG_WARNING, "Not a GSM file %d\n", ltohs(format));
      return -1;
   }
   if (fread(&chans, 1, 2, f) != 2) {
      ast_log(LOG_WARNING, "Read failed (format)\n");
      return -1;
   }
   if (ltohs(chans) != 1) {
      ast_log(LOG_WARNING, "Not in mono %d\n", ltohs(chans));
      return -1;
   }
   if (fread(&freq, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (freq)\n");
      return -1;
   }
   if (ltohl(freq) != DEFAULT_SAMPLE_RATE) {
      ast_log(LOG_WARNING, "Unexpected frequency %d\n", ltohl(freq));
      return -1;
   }
   /* Ignore the byte frequency */
   if (fread(&freq, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (X_1)\n");
      return -1;
   }
   /* Ignore the two weird fields */
   if (fread(&freq, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (X_2/X_3)\n");
      return -1;
   }
   /* Ignore the byte frequency */
   if (fread(&freq, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (Y_1)\n");
      return -1;
   }
   /* Check for the word fact */
   if (fread(&fact, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (fact)\n");
      return -1;
   }
   if (memcmp(&fact, "fact", 4)) {
      ast_log(LOG_WARNING, "Does not say fact\n");
      return -1;
   }
   /* Ignore the "fact value" */
   if (fread(&fact, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (fact header)\n");
      return -1;
   }
   if (fread(&fact, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (fact value)\n");
      return -1;
   }
   /* Check for the word data */
   if (fread(&data, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (data)\n");
      return -1;
   }
   if (memcmp(&data, "data", 4)) {
      ast_log(LOG_WARNING, "Does not say data\n");
      return -1;
   }
   /* Ignore the data length */
   if (fread(&data, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Read failed (data)\n");
      return -1;
   }
   return 0;
}

static int update_header(FILE *f)
{
   off_t cur,end,bytes;
   int datalen, filelen, samples;

   cur = ftello(f);
   fseek(f, 0, SEEK_END);
   end = ftello(f);
   /* in a gsm WAV, data starts 60 bytes in */
   bytes = end - MSGSM_DATA_OFFSET;
   samples = htoll(bytes / MSGSM_FRAME_SIZE * MSGSM_SAMPLES);
   datalen = htoll(bytes);
   filelen = htoll(MSGSM_DATA_OFFSET - 8 + bytes);
   if (cur < 0) {
      ast_log(LOG_WARNING, "Unable to find our position\n");
      return -1;
   }
   if (fseek(f, 4, SEEK_SET)) {
      ast_log(LOG_WARNING, "Unable to set our position\n");
      return -1;
   }
   if (fwrite(&filelen, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write file size\n");
      return -1;
   }
   if (fseek(f, 48, SEEK_SET)) {
      ast_log(LOG_WARNING, "Unable to set our position\n");
      return -1;
   }
   if (fwrite(&samples, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write samples\n");
      return -1;
   }
   if (fseek(f, 56, SEEK_SET)) {
      ast_log(LOG_WARNING, "Unable to set our position\n");
      return -1;
   }
   if (fwrite(&datalen, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write datalen\n");
      return -1;
   }
   if (fseeko(f, cur, SEEK_SET)) {
      ast_log(LOG_WARNING, "Unable to return to position\n");
      return -1;
   }
   return 0;
}

static int write_header(FILE *f)
{
   /* Samples per second (always 8000 for this format). */
   unsigned int sample_rate = htoll(8000);
   /* Bytes per second (always 1625 for this format). */
   unsigned int byte_sample_rate = htoll(1625);
   /* This is the size of the "fmt " subchunk */
   unsigned int fmtsize = htoll(20);
   /* WAV #49 */
   unsigned short fmt = htols(49);
   /* Mono = 1 channel */
   unsigned short chans = htols(1);
   /* Each block of data is exactly 65 bytes in size. */
   unsigned int block_align = htoll(MSGSM_FRAME_SIZE);
   /* Not actually 2, but rounded up to the nearest bit */
   unsigned short bits_per_sample = htols(2);
   /* Needed for compressed formats */
   unsigned short extra_format = htols(MSGSM_SAMPLES);
   /* This is the size of the "fact" subchunk */
   unsigned int factsize = htoll(4);
   /* Number of samples in the data chunk */
   unsigned int num_samples = htoll(0);
   /* Number of bytes in the data chunk */
   unsigned int size = htoll(0);
   /* Write a GSM header, ignoring sizes which will be filled in later */

   /*  0: Chunk ID */
   if (fwrite("RIFF", 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /*  4: Chunk Size */
   if (fwrite(&size, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /*  8: Chunk Format */
   if (fwrite("WAVE", 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 12: Subchunk 1: ID */
   if (fwrite("fmt ", 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 16: Subchunk 1: Size (minus 8) */
   if (fwrite(&fmtsize, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 20: Subchunk 1: Audio format (49) */
   if (fwrite(&fmt, 1, 2, f) != 2) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 22: Subchunk 1: Number of channels */
   if (fwrite(&chans, 1, 2, f) != 2) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 24: Subchunk 1: Sample rate */
   if (fwrite(&sample_rate, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 28: Subchunk 1: Byte rate */
   if (fwrite(&byte_sample_rate, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 32: Subchunk 1: Block align */
   if (fwrite(&block_align, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 36: Subchunk 1: Bits per sample */
   if (fwrite(&bits_per_sample, 1, 2, f) != 2) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 38: Subchunk 1: Extra format bytes */
   if (fwrite(&extra_format, 1, 2, f) != 2) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 40: Subchunk 2: ID */
   if (fwrite("fact", 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 44: Subchunk 2: Size (minus 8) */
   if (fwrite(&factsize, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 48: Subchunk 2: Number of samples */
   if (fwrite(&num_samples, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 52: Subchunk 3: ID */
   if (fwrite("data", 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   /* 56: Subchunk 3: Size */
   if (fwrite(&size, 1, 4, f) != 4) {
      ast_log(LOG_WARNING, "Unable to write header\n");
      return -1;
   }
   return 0;
}

static int wav_open(struct ast_filestream *s)
{
   /* We don't have any header to read or anything really, but
      if we did, it would go here.  We also might want to check
      and be sure it's a valid file.  */
   struct wavg_desc *fs = (struct wavg_desc *)s->_private;

   if (check_header(s->f))
      return -1;
   fs->secondhalf = 0;  /* not strictly necessary */
   return 0;
}

static int wav_rewrite(struct ast_filestream *s, const char *comment)
{
   /* We don't have any header to read or anything really, but
      if we did, it would go here.  We also might want to check
      and be sure it's a valid file.  */

   if (write_header(s->f))
      return -1;
   return 0;
}

static void wav_close(struct ast_filestream *s)
{
   if (s->mode == O_RDONLY) {
      return;
   }

   if (s->filename) {
      update_header(s->f);
   }
}

static struct ast_frame *wav_read(struct ast_filestream *s, int *whennext)
{
   /* Send a frame from the file to the appropriate channel */
   struct wavg_desc *fs = (struct wavg_desc *)s->_private;

   s->fr.samples = GSM_SAMPLES;
   AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, GSM_FRAME_SIZE);
   if (fs->secondhalf) {
      /* Just return a frame based on the second GSM frame */
      s->fr.data.ptr = (char *)s->fr.data.ptr + GSM_FRAME_SIZE;
      s->fr.offset += GSM_FRAME_SIZE;
   } else {
      /* read and convert */
      unsigned char msdata[MSGSM_FRAME_SIZE];
      size_t res;

      if ((res = fread(msdata, 1, MSGSM_FRAME_SIZE, s->f)) != MSGSM_FRAME_SIZE) {
         if (res && res != 1) {
            ast_log(LOG_WARNING, "Short read of %s data (expected %d bytes, read %zu): %s\n",
                  ast_format_get_name(s->fr.subclass.format), MSGSM_FRAME_SIZE, res,
                  strerror(errno));
         }
         return NULL;
      }
      /* Convert from MS format to two real GSM frames */
      conv65(msdata, s->fr.data.ptr);
   }
   fs->secondhalf = !fs->secondhalf;
   *whennext = GSM_SAMPLES;
   return &s->fr;
}

static int wav_write(struct ast_filestream *s, struct ast_frame *f)
{
   int len;
   int size;
   struct wavg_desc *fs = (struct wavg_desc *)s->_private;

   /* XXX this might fail... if the input is a multiple of MSGSM_FRAME_SIZE
    * we assume it is already in the correct format.
    */
   if (!(f->datalen % MSGSM_FRAME_SIZE)) {
      size = MSGSM_FRAME_SIZE;
      fs->secondhalf = 0;
   } else {
      size = GSM_FRAME_SIZE;
   }
   for (len = 0; len < f->datalen ; len += size) {
      int res;
      unsigned char *src, msdata[MSGSM_FRAME_SIZE];
      if (fs->secondhalf) {   /* second half of raw gsm to be converted */
         memcpy(s->buf + GSM_FRAME_SIZE, f->data.ptr + len, GSM_FRAME_SIZE);
         conv66((unsigned char *) s->buf, msdata);
         src = msdata;
         fs->secondhalf = 0;
      } else if (size == GSM_FRAME_SIZE) {   /* first half of raw gsm */
         memcpy(s->buf, f->data.ptr + len, GSM_FRAME_SIZE);
         src = NULL; /* nothing to write */
         fs->secondhalf = 1;
      } else { /* raw msgsm data */
         src = f->data.ptr + len;
      }
      if (src && (res = fwrite(src, 1, MSGSM_FRAME_SIZE, s->f)) != MSGSM_FRAME_SIZE) {
         ast_log(LOG_WARNING, "Bad write (%d/65): %s\n", res, strerror(errno));
         return -1;
      }
   }
   return 0;
}

static int wav_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
   off_t offset = 0, min = MSGSM_DATA_OFFSET, distance, max, cur;
   struct wavg_desc *s = (struct wavg_desc *)fs->_private;

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

   /* XXX ideally, should round correctly */
   if ((max = ftello(fs->f)) < 0) {
      ast_log(AST_LOG_WARNING, "Unable to determine max position in WAV filestream %p: %s\n", fs, strerror(errno));
      return -1;
   }

   /* Compute the distance in bytes, rounded to the block size */
   distance = (sample_offset/MSGSM_SAMPLES) * MSGSM_FRAME_SIZE;
   if (whence == SEEK_SET)
      offset = distance + min;
   else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
      offset = distance + cur;
   else if (whence == SEEK_END)
      offset = max - distance;
   /* always protect against seeking past end of header */
   if (offset < min)
      offset = min;
   if (whence != SEEK_FORCECUR) {
      if (offset > max)
         offset = max;
   } else if (offset > max) {
      int i;
      fseek(fs->f, 0, SEEK_END);
      for (i=0; i< (offset - max) / MSGSM_FRAME_SIZE; i++) {
         if (fwrite(msgsm_silence, 1, MSGSM_FRAME_SIZE, fs->f) != MSGSM_FRAME_SIZE) {
            ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
         }
      }
   }
   s->secondhalf = 0;
   return fseeko(fs->f, offset, SEEK_SET);
}

static int wav_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 WAV 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 WAV filestream %p: %s\n", fs, strerror(errno));
      return -1;
   }
   /* Truncate file to current length */
   if (ftruncate(fd, cur)) {
      return -1;
   }
   return update_header(fs->f);
}

static off_t wav_tell(struct ast_filestream *fs)
{
   off_t offset;
   offset = ftello(fs->f);
   /* since this will most likely be used later in play or record, lets stick
    * to that level of resolution, just even frames boundaries */
   return (offset - MSGSM_DATA_OFFSET)/MSGSM_FRAME_SIZE*MSGSM_SAMPLES;
}

static struct ast_format_def wav49_f = {
   .name = "wav49",
   .exts = "WAV|wav49",
   .open =  wav_open,
   .rewrite = wav_rewrite,
   .write = wav_write,
   .seek = wav_seek,
   .trunc = wav_trunc,
   .tell = wav_tell,
   .read = wav_read,
   .close = wav_close,
   .buf_size = 2*GSM_FRAME_SIZE + AST_FRIENDLY_OFFSET,
   .desc_size = sizeof(struct wavg_desc),
};

static int load_module(void)
{
   wav49_f.format = ast_format_gsm;
   if (ast_format_def_register(&wav49_f))
      return AST_MODULE_LOAD_DECLINE;
   return AST_MODULE_LOAD_SUCCESS;
}

static int unload_module(void)
{
   return ast_format_def_unregister(wav49_f.name);
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Microsoft WAV format (Proprietary GSM)",
   .support_level = AST_MODULE_SUPPORT_CORE,
   .load = load_module,
   .unload = unload_module,
   .load_pri = AST_MODPRI_APP_DEPEND
);