format_mp3.c File Reference

MP3 Format Handler. More...

#include "asterisk.h"
#include "mp3/mpg123.h"
#include "mp3/mpglib.h"
#include "asterisk/module.h"
#include "asterisk/mod_format.h"
#include "asterisk/logger.h"
#include "asterisk/format_cache.h"

Include dependency graph for format_mp3.c:

Go to the source code of this file.

Data Structures
struct	mp3_private

Macros
#define	BLOCKSIZE   160
#define	GAIN   -4 /* 2^GAIN is the multiple to increase the volume by */
#define	MP3_BUFLEN   320
#define	MP3_DCACHE   8192
#define	MP3_SCACHE   16384
#define	OUTSCALE   4096

Functions
	AST_MODULE_INFO_STANDARD_EXTENDED (ASTERISK_GPL_KEY, "MP3 format [Any rate but 8000hz mono is optimal]")
static int	load_module (void)
static void	mp3_close (struct ast_filestream *s)
static int	mp3_dqueue (struct ast_filestream *s)
static char *	mp3_getcomment (struct ast_filestream *s)
static int	mp3_open (struct ast_filestream *s)
static int	mp3_queue (struct ast_filestream *s)
static struct ast_frame *	mp3_read (struct ast_filestream *s, int *whennext)
static int	mp3_rewrite (struct ast_filestream *s, const char *comment)
static int	mp3_seek (struct ast_filestream *s, off_t sample_offset, int whence)
static int	mp3_squeue (struct ast_filestream *s)
static off_t	mp3_tell (struct ast_filestream *s)
static int	mp3_trunc (struct ast_filestream *s)
static int	mp3_write (struct ast_filestream *fs, struct ast_frame *f)
static int	unload_module (void)

Variables
static struct ast_format_def	mp3_f
static const char	name [] = "mp3"

Detailed Description

MP3 Format Handler.

Definition in file format_mp3.c.

Macro Definition Documentation

BLOCKSIZE

#define BLOCKSIZE   160

Definition at line 70 of file format_mp3.c.

GAIN

#define GAIN   -4 /* 2^GAIN is the multiple to increase the volume by */

Definition at line 73 of file format_mp3.c.

MP3_BUFLEN

#define MP3_BUFLEN   320

Definition at line 45 of file format_mp3.c.

Referenced by mp3_read().

MP3_DCACHE

#define MP3_DCACHE   8192

Definition at line 47 of file format_mp3.c.

Referenced by mp3_dqueue(), and mp3_squeue().

MP3_SCACHE

#define MP3_SCACHE   16384

Definition at line 46 of file format_mp3.c.

Referenced by mp3_squeue().

OUTSCALE

#define OUTSCALE   4096

Definition at line 71 of file format_mp3.c.

Referenced by mp3_open(), and mp3_queue().

Function Documentation

AST_MODULE_INFO_STANDARD_EXTENDED()

AST_MODULE_INFO_STANDARD_EXTENDED	(	ASTERISK_GPL_KEY	,
		"MP3 format "	[Any rate but 8000hz mono is optimal]
	)

Referenced by unload_module().

load_module()

static int load_module ( void  )

static

Definition at line 317 of file format_mp3.c.

References ast_format_def_register, ast_format_slin, and ast_format_def::format.

{
   mp3_f.format = ast_format_slin;
   InitMP3Constants();
   return ast_format_def_register(&mp3_f);
}

mp3_close()

static void mp3_close ( struct ast_filestream *  s )

static

Definition at line 106 of file format_mp3.c.

References ast_filestream::_private, and mp3_private::mp.

{
   struct mp3_private *p = s->_private;

   ExitMP3(&p->mp);
   return;
}

mp3_dqueue()

static int mp3_dqueue ( struct ast_filestream *  s )

static

Definition at line 135 of file format_mp3.c.

References ast_filestream::_private, mp3_private::dbuf, mp3_private::dbuflen, mp3_private::dbufoffset, mp3_private::mp, MP3_DCACHE, NULL, and mp3_private::sbuflen.

Referenced by mp3_queue().

{
   struct mp3_private *p = s->_private;
   int res=0;

   if((res = decodeMP3(&p->mp,NULL,0,p->dbuf,MP3_DCACHE,&p->dbuflen)) == MP3_OK) {
      p->sbuflen -= p->dbuflen;
      p->dbufoffset = 0;
   }
   return res;
}

mp3_getcomment()

static char* mp3_getcomment ( struct ast_filestream *  s )

static

Definition at line 295 of file format_mp3.c.

References NULL.

{
   return NULL;
}

mp3_open()

static int mp3_open ( struct ast_filestream *  s )

static

Definition at line 98 of file format_mp3.c.

References ast_filestream::_private, mp3_private::mp, and OUTSCALE.

{
   struct mp3_private *p = s->_private;
   InitMP3(&p->mp, OUTSCALE);
   return 0;
}

mp3_queue()

static int mp3_queue ( struct ast_filestream *  s )

static

Definition at line 147 of file format_mp3.c.

References ast_filestream::_private, mp3_private::dbuflen, mp3_private::dbufoffset, ast_filestream::f, mp3_private::mp, mp3_dqueue(), mp3_squeue(), mp3_private::offset, OUTSCALE, mp3_private::sbuflen, and mp3_private::seek.

Referenced by mp3_read().

{
   struct mp3_private *p = s->_private;
   int res = 0, bytes = 0;

   if(p->seek) {
      ExitMP3(&p->mp);
      InitMP3(&p->mp, OUTSCALE);
      fseek(s->f, 0, SEEK_SET);
      p->sbuflen = p->dbuflen = p->offset = 0;
      while(p->offset < p->seek) {
         if(mp3_squeue(s))
            return -1;
         while(p->offset < p->seek && ((res = mp3_dqueue(s))) == MP3_OK) {
            for(bytes = 0 ; bytes < p->dbuflen ; bytes++) {
               p->dbufoffset++;
               p->offset++;
               if(p->offset >= p->seek)
                  break;
            }
         }
         if(res == MP3_ERR)
            return -1;
      }

      p->seek = 0;
      return 0;
   }
   if(p->dbuflen == 0) {
      if(p->sbuflen) {
         res = mp3_dqueue(s);
         if(res == MP3_ERR)
            return -1;
      }
      if(! p->sbuflen || res != MP3_OK) {
         if(mp3_squeue(s))
            return -1;
      }

   }

   return 0;
}

mp3_read()

static struct ast_frame* mp3_read ( struct ast_filestream *  s, int *  whennext  )

static

Definition at line 191 of file format_mp3.c.

References ast_filestream::_private, AST_FRAME_SET_BUFFER, AST_FRIENDLY_OFFSET, ast_filestream::buf, mp3_private::buflen, mp3_private::dbuf, mp3_private::dbuflen, mp3_private::dbufoffset, ast_filestream::fr, MP3_BUFLEN, mp3_queue(), NULL, mp3_private::offset, and ast_frame::samples.

{

   struct mp3_private *p = s->_private;
   int delay =0;
   int save=0;

   /* Pre-populate the buffer that holds audio to be returned (dbuf) */
   if (mp3_queue(s)) {
      return NULL;
   }

   if (p->dbuflen) {
      /* Read out what's waiting in dbuf */
      for (p->buflen = 0; p->buflen < MP3_BUFLEN && p->buflen < p->dbuflen; p->buflen++) {
         s->buf[p->buflen + AST_FRIENDLY_OFFSET] = p->dbuf[p->buflen + p->dbufoffset];
      }
      p->dbufoffset += p->buflen;
      p->dbuflen -= p->buflen;
   }

   if (p->buflen < MP3_BUFLEN) {
      /* dbuf didn't have enough, so reset dbuf, fill it back up and continue */
      p->dbuflen = p->dbufoffset = 0;

      if (mp3_queue(s)) {
         return NULL;
      }

      /* Make sure dbuf has enough to complete this read attempt */
      if (p->dbuflen >= (MP3_BUFLEN - p->buflen)) {
         for (save = p->buflen; p->buflen < MP3_BUFLEN; p->buflen++) {
            s->buf[p->buflen + AST_FRIENDLY_OFFSET] = p->dbuf[(p->buflen - save) + p->dbufoffset];
         }
         p->dbufoffset += (MP3_BUFLEN - save);
         p->dbuflen -= (MP3_BUFLEN - save);
      }

   }

   p->offset += p->buflen;
   delay = p->buflen / 2;
   AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, p->buflen);
   s->fr.samples = delay;
   *whennext = delay;
   return &s->fr;
}

mp3_rewrite()

static int mp3_rewrite ( struct ast_filestream *  s, const char *  comment  )

static

Definition at line 275 of file format_mp3.c.

References ast_log, and LOG_ERROR.

{
   ast_log(LOG_ERROR,"I Can't write MP3 only read them.\n");
   return -1;
}

mp3_seek()

static int mp3_seek ( struct ast_filestream *  s, off_t  sample_offset, int  whence  )

static

Definition at line 248 of file format_mp3.c.

References ast_filestream::_private, ast_filestream::f, max, min, mp3_private::offset, mp3_private::seek, and SEEK_FORCECUR.

{
   struct mp3_private *p = s->_private;
   off_t min,max,cur;
   long offset=0,samples;
   samples = sample_offset * 2;

   min = 0;
   fseek(s->f, 0, SEEK_END);
   max = ftell(s->f) * 100;
   cur = p->offset;

   if (whence == SEEK_SET)
      offset = samples + min;
   else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
      offset = samples + cur;
   else if (whence == SEEK_END)
      offset = max - samples;
   if (whence != SEEK_FORCECUR) {
      offset = (offset > max)?max:offset;
   }

   p->seek = offset;
   return fseek(s->f, offset, SEEK_SET);

}

mp3_squeue()

static int mp3_squeue ( struct ast_filestream *  s )

static

Definition at line 114 of file format_mp3.c.

References ast_filestream::_private, ast_log, mp3_private::dbuf, mp3_private::dbuflen, mp3_private::dbufoffset, errno, ast_filestream::f, LOG_WARNING, mp3_private::mp, MP3_DCACHE, MP3_SCACHE, mp3_private::sbuf, and mp3_private::sbuflen.

Referenced by mp3_queue().

{
   struct mp3_private *p = s->_private;
   int res=0;

   res = ftell(s->f);
   p->sbuflen = fread(p->sbuf, 1, MP3_SCACHE, s->f);
   if (p->sbuflen < MP3_SCACHE) {
      if (ferror(s->f)) {
         ast_log(LOG_WARNING, "Error while reading MP3 file: %s\n", strerror(errno));
         return -1;
      }
   }
   res = decodeMP3(&p->mp,p->sbuf,p->sbuflen,p->dbuf,MP3_DCACHE,&p->dbuflen);
   if(res != MP3_OK)
      return -1;
   p->sbuflen -= p->dbuflen;
   p->dbufoffset = 0;
   return 0;
}

mp3_tell()

static off_t mp3_tell ( struct ast_filestream *  s )

static

Definition at line 288 of file format_mp3.c.

References ast_filestream::_private, and mp3_private::offset.

{
   struct mp3_private *p = s->_private;

   return p->offset/2;
}

mp3_trunc()

static int mp3_trunc ( struct ast_filestream *  s )

static

Definition at line 281 of file format_mp3.c.

References ast_log, and LOG_ERROR.

{

   ast_log(LOG_ERROR,"I Can't write MP3 only read them.\n");
   return -1;
}

mp3_write()

static int mp3_write ( struct ast_filestream *  fs, struct ast_frame *  f  )

static

Definition at line 240 of file format_mp3.c.

References ast_log, and LOG_ERROR.

{
   ast_log(LOG_ERROR,"I Can't write MP3 only read them.\n");
   return -1;

}

unload_module()

static int unload_module ( void  )

static

Definition at line 324 of file format_mp3.c.

References ast_format_def_unregister(), AST_MODULE_INFO_STANDARD_EXTENDED(), ASTERISK_GPL_KEY, and name.

{
   return ast_format_def_unregister(name);
}

Variable Documentation

mp3_f

struct ast_format_def mp3_f

static

Definition at line 300 of file format_mp3.c.

name

const char name[] = "mp3"

static

Definition at line 68 of file format_mp3.c.

Referenced by unload_module().