legacy/trunk/libburn/libdax_audioxtr.c

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/* libdax_audioxtr
Audio track data extraction facility of libdax and libburn.
Copyright (C) 2006 Thomas Schmitt <scdbackup@gmx.net>, provided under GPL
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include "libdax_msgs.h"
extern struct libdax_msgs *libdax_messenger;
/* Only this single source module is entitled to do this */
#define LIBDAX_AUDIOXTR_H_INTERNAL 1
/* All clients of the extraction facility must do this */
#include "libdax_audioxtr.h"
int libdax_audioxtr_new(struct libdax_audioxtr **xtr, char *path, int flag)
{
int ret;
struct libdax_audioxtr *o;
o= *xtr= (struct libdax_audioxtr *) malloc(sizeof(struct libdax_audioxtr));
if(o==NULL)
return(-1);
strncpy(o->path,path,LIBDAX_AUDIOXTR_STRLEN-1);
o->path[LIBDAX_AUDIOXTR_STRLEN]= 0;
o->fd= -1;
strcpy(o->fmt,"unidentified");
o->fmt_info[0]= 0;
o->wav_num_channels= 0;
o->wav_sample_rate= 0;
o->wav_bits_per_sample= 0;
ret= libdax_audioxtr_open(o,0);
if(ret<=0)
goto failure;
return(1);
failure:
libdax_audioxtr_destroy(xtr,0);
return(-1);
}
int libdax_audioxtr_destroy(struct libdax_audioxtr **xtr, int flag)
{
struct libdax_audioxtr *o;
o= *xtr;
if(o==NULL)
return(0);
if(o->fd>=0 && strcmp(o->path,"-")!=0)
close(o->fd);
free((char *) o);
*xtr= NULL;
return(1);
}
static int libdax_audioxtr_open(struct libdax_audioxtr *o, int flag)
{
int ret;
char msg[LIBDAX_AUDIOXTR_STRLEN+80];
if(strcmp(o->path,"-")==0)
o->fd= 0;
else
o->fd= open(o->path, O_RDONLY);
if(o->fd<0) {
sprintf(msg,"Cannot open audio source file : %s",o->path);
libdax_msgs_submit(libdax_messenger,-1,0x00020200,
LIBDAX_MSGS_SEV_SORRY, LIBDAX_MSGS_PRIO_HIGH,
msg, errno, 0);
return(-1);
}
ret= libdax_audioxtr_identify(o,0);
if(ret<=0) {
sprintf(msg,"Audio source file has unsuitable format : %s",o->path);
libdax_msgs_submit(libdax_messenger,-1,0x00020201,
LIBDAX_MSGS_SEV_SORRY, LIBDAX_MSGS_PRIO_HIGH,
msg, 0, 0);
return(0);
}
ret= libdax_audioxtr_init_reading(o,0);
if(ret<=0) {
sprintf(msg,"Failed to prepare reading of audio data : %s",o->path);
libdax_msgs_submit(libdax_messenger,-1,0x00020202,
LIBDAX_MSGS_SEV_SORRY, LIBDAX_MSGS_PRIO_HIGH,
msg, 0, 0);
return(0);
}
return(1);
}
static int libdax_audioxtr_identify(struct libdax_audioxtr *o, int flag)
{
int ret;
char buf[45];
/* currently this only works for MS WAVE files .wav */
/* info used: http://ccrma.stanford.edu/courses/422/projects/WaveFormat/ */
ret= read(o->fd, buf, 44);
if(ret<44)
return(0);
buf[44]= 0; /* as stopper for any string operations */
if(strncmp(buf,"RIFF",4)!=0) /* ChunkID */
return(0);
if(strncmp(buf+8,"WAVE",4)!=0) /* Format */
return(0);
if(strncmp(buf+12,"fmt ",4)!=0) /* Subchunk1ID */
return(0);
if(buf[16]!=16 || buf[17]!=0 || buf[18]!=0 || buf[19]!=0) /* Subchunk1Size */
return(0);
if(buf[20]!=1 || buf[21]!=0) /* AudioFormat must be 1 (Linear quantization) */
return(0);
strcpy(o->fmt,".wav");
o->wav_num_channels= libdax_audioxtr_to_int(o,(unsigned char *) buf+22,2,0);
o->wav_sample_rate= libdax_audioxtr_to_int(o,(unsigned char *) buf+24,4,0);
o->wav_bits_per_sample= libdax_audioxtr_to_int(o,(unsigned char *)buf+34,2,0);
sprintf(o->fmt_info,
".wav , num_channels=%d , sample_rate=%d , bits_per_sample=%d",
o->wav_num_channels,o->wav_sample_rate,o->wav_bits_per_sample);
return(1);
}
static unsigned libdax_audioxtr_to_int(struct libdax_audioxtr *o,
unsigned char *bytes, int len, int flag)
{
unsigned int ret= 0;
int i;
for(i= len-1; i>=0; i--)
ret= ret*256+bytes[i];
return(ret);
}
static int libdax_audioxtr_init_reading(struct libdax_audioxtr *o, int flag)
{
int ret;
/* currently this only works for MS WAVE files .wav */;
ret= lseek(o->fd,44,SEEK_SET);
if(ret==-1)
return(0);
return(1);
}
int libdax_audioxtr_get_id(struct libdax_audioxtr *o,
char **fmt, char **fmt_info,
int *num_channels, int *sample_rate, int *bits_per_sample,
int flag)
{
*fmt= o->fmt;
*fmt_info= o->fmt_info;
if(strcmp(o->fmt,".wav")==0) {
*num_channels= o->wav_num_channels;
*sample_rate= o->wav_sample_rate;
*bits_per_sample= o->wav_bits_per_sample;
} else
*num_channels= *sample_rate= *bits_per_sample= 0;
return(1);
}
int libdax_audioxtr_read(struct libdax_audioxtr *o,
char buffer[], int buffer_size, int flag)
{
int ret;
if(buffer_size<=0 || o->fd<0)
return(-2);
ret= read(o->fd,buffer,buffer_size);
return(ret);
}