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mirror of https://github.com/cookiengineer/audacity synced 2025-07-15 08:07:41 +02:00
2019-12-16 00:57:09 -06:00

70 lines
2.6 KiB
C

/* cmupvdbg.c -- debug support for cmupv
* Roger B. Dannenberg
* Nov 2015
*/
/* To see what data is going into the phase vocoder, write_pv_frame
* saves frames or buffers to disk as audio.
* If something is wrong with your applications delivery of analysis frames,
* probably most frames are wrong, so you should write, say, 10 initial
* files and look at them. Set MAX_FILES to 10 and MAX_SAVE to 10. Then,
* after running your program, use Audacity to open the 10 frames saved
* to disk: use the Files:Import:Audio command to load all 10 in one
* command as different tracks. You should see 10 tracks, each containing
* one frame, shifted to the correct source time location. (If not, then
* find and fix the bug.)
*
* This function is also useful for printing other data, e.g. synthesis frames
* or output buffers. To get the most out of this, you should set the first
* parameter, zeros, to the absolute sample offset, e.g. if you want to view
* synthesis frames that are spaced with a 64 sample hop size, you should set
* zeros to 0, 64, 128, 192, ... so that when you view the files in Audacity,
* the samples will line up in time with each other and with the output file.
*
* You can display multiple frame types and lengths, so the prefix parameter
* allows you to effectively label the data. This prefix is used to construct
* the file name.
*
* MAX_FILES tells how many files to write. Because of padding, file writing
* is an N-squared operation, so only write initial frames if possible, but
* use a large number if you need to see everything.
*
* MAX_SAVE tells how many file *names* to use. Files are numbered, so we'll
* simply take the number modulo MAX_SAVE so that file names are reused and
* old files are overwritten. Use a large value of MAX_SAVE to save everything.
* Use 1 to get only the last frame.
*/
#include "stdio.h"
#include "sndfile.h"
#define MAX_FILES 10
#define MAX_SAVE 10
static int file_no = 0;
void write_pv_frame(long zeros, float *frame, long fftsize, char *prefix)
{
float z = 0;
char path[128];
SF_INFO sfinfo;
SNDFILE *sf;
if (file_no >= MAX_FILES) return;
sprintf(path, "%s-%02d.wav", prefix, (file_no % MAX_SAVE) + 1);
sfinfo.frames = 0;
sfinfo.samplerate = 44100;
sfinfo.channels = 1;
sfinfo.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16;
sfinfo.sections = 0;
sfinfo.seekable = 0;
sf = sf_open(path, SFM_WRITE, &sfinfo);
for (long i = 0; i < zeros; i++) {
sf_writef_float(sf, &z, 1);
}
sf_writef_float(sf, frame, fftsize);
sf_close(sf);
printf("wrote %s, %ld zeros\n", path, zeros);
file_no++;
}