1 /* cmupvdbg.c -- debug support for cmupv
2 * Roger B. Dannenberg
3 * Nov 2015
4 */
5
6 /* To see what data is going into the phase vocoder, write_pv_frame
7 * saves frames or buffers to disk as audio.
8 * If something is wrong with your applications delivery of analysis frames,
9 * probably most frames are wrong, so you should write, say, 10 initial
10 * files and look at them. Set MAX_FILES to 10 and MAX_SAVE to 10. Then,
11 * after running your program, use Audacity to open the 10 frames saved
12 * to disk: use the Files:Import:Audio command to load all 10 in one
13 * command as different tracks. You should see 10 tracks, each containing
14 * one frame, shifted to the correct source time location. (If not, then
15 * find and fix the bug.)
16 *
17 * This function is also useful for printing other data, e.g. synthesis frames
18 * or output buffers. To get the most out of this, you should set the first
19 * parameter, zeros, to the absolute sample offset, e.g. if you want to view
20 * synthesis frames that are spaced with a 64 sample hop size, you should set
21 * zeros to 0, 64, 128, 192, ... so that when you view the files in Audacity,
22 * the samples will line up in time with each other and with the output file.
23 *
24 * You can display multiple frame types and lengths, so the prefix parameter
25 * allows you to effectively label the data. This prefix is used to construct
26 * the file name.
27 *
28 * MAX_FILES tells how many files to write. Because of padding, file writing
29 * is an N-squared operation, so only write initial frames if possible, but
30 * use a large number if you need to see everything.
31 *
32 * MAX_SAVE tells how many file *names* to use. Files are numbered, so we'll
33 * simply take the number modulo MAX_SAVE so that file names are reused and
34 * old files are overwritten. Use a large value of MAX_SAVE to save everything.
35 * Use 1 to get only the last frame.
36 */
37
38 #include "stdio.h"
39 #include "sndfile.h"
40
41
42 #define MAX_FILES 10
43 #define MAX_SAVE 10
44 static int file_no = 0;
45
46
write_pv_frame(long zeros,float * frame,long fftsize,char * prefix)47 void write_pv_frame(long zeros, float *frame, long fftsize, char *prefix)
48 {
49 float z = 0;
50 char path[128];
51 SF_INFO sfinfo;
52 SNDFILE *sf;
53 if (file_no >= MAX_FILES) return;
54 sprintf(path, "%s-%02d.wav", prefix, (file_no % MAX_SAVE) + 1);
55 sfinfo.frames = 0;
56 sfinfo.samplerate = 44100;
57 sfinfo.channels = 1;
58 sfinfo.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16;
59 sfinfo.sections = 0;
60 sfinfo.seekable = 0;
61 sf = sf_open(path, SFM_WRITE, &sfinfo);
62 for (long i = 0; i < zeros; i++) {
63 sf_writef_float(sf, &z, 1);
64 }
65 sf_writef_float(sf, frame, fftsize);
66 sf_close(sf);
67 printf("wrote %s, %ld zeros\n", path, zeros);
68 file_no++;
69 }
70