audacia/lib-src/libscorealign/audiofilereader.cpp

103 lines
2.8 KiB
C++

/* audiofilereader.cpp -- implements a class to read samples
*
* 14-Jun-08 RBD
* 16-Jun-08 RBD revised to use libsndfile
*/
#include "assert.h"
#include "stdlib.h"
#include "stdio.h"
#include "string.h"
#include "sndfile.h"
#include "audioreader.h"
#include "audiofilereader.h"
#ifdef WIN32
#include <malloc.h>
#include <windows.h>
#define bzero(addr, siz) memset(addr, 0, siz)
#define alloca _alloca
#endif
double Audio_file_reader::get_sample_rate()
{
return sf_info.samplerate;
}
long Audio_file_reader::get_frames()
{
return total_frames;
}
long Audio_file_reader::read(float *data, long n)
{
// note that "samples_per_frame" is really "frames_per_window" in this
// context, so we're computing bytes per window
float *input_data = (float *) alloca(bytes_per_frame * samples_per_frame);
assert(input_data != NULL) ;
long frames_read = (long) sf_readf_float(sf, input_data, n);
long chans = sf_info.channels;
// now convert to mono and move to data
for (int frame = 0; frame < frames_read; frame++) {
float sum = 0;
for (int chan = 0; chan < sf_info.channels; chan++) {
// sum over channels within a frame
sum += input_data[frame * chans + chan];
}
// write the frame sum to result array
data[frame] = sum;
}
return frames_read;
}
bool Audio_file_reader::open(const char *filename, Scorealign &sa, bool verbose)
{
bytes_per_frame = 0; // initialize now in case an error occurs
name[0] = 0;
bzero(&sf_info, sizeof(sf_info));
sf = sf_open(filename, SFM_READ, &sf_info);
if (!sf) {
#ifdef WIN32
/* windows-specific code to report error opening file */
char *msg;
DWORD code = GetLastError();
DWORD code2 = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM,
0, code, 0, (LPSTR) &msg, 0, 0);
printf("Error string: %s\n", msg);
LocalFree(msg);
#endif
return false;
}
strncpy(name, filename, MAX_NAME_LEN);
name[MAX_NAME_LEN] = 0; // just in case
total_frames = (long) sf_seek(sf, 0, SEEK_END);
sf_seek(sf, 0, SEEK_SET);
// we're going to read floats, but they might be multi-channel...
bytes_per_frame = sf_info.channels * sizeof(float);
calculate_parameters(sa, verbose);
return true;
}
void Audio_file_reader::close()
{
sf_close(sf);
}
void Audio_file_reader::print_info()
{
printf(" file name = %s\n", name);
double sample_rate = sf_info.samplerate;
printf(" sample rate = %g\n", sample_rate);
printf(" channels = %d\n", sf_info.channels);
/*=============================================================*/
printf(" total frames number is = %ld\n", total_frames);
printf(" audio duration = %g seconds\n", total_frames / sample_rate);
/*=============================================================*/
}