ref: 4e77d5b7e74f8538614f3da466292b1ec2faee3a
dir: /src/spectrogram.c/
/* libSoX effect: Spectrogram (c) 2008-9 robs@users.sourceforge.net
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef NDEBUG /* Enable assert always. */
#undef NDEBUG /* Must undef above assert.h or other that might include it. */
#endif
#include "sox_i.h"
#include "fft4g.h"
#include <assert.h>
#include <math.h>
#ifdef HAVE_LIBPNG_PNG_H
#include <libpng/png.h>
#else
#include <png.h>
#endif
#include <zlib.h>
#define MAX_FFT_SIZE 4096
#define is_p2(x) !(x & (x - 1))
typedef enum {Window_Hann, Window_Hamming, Window_Bartlett, Window_Rectangular, Window_Kaiser} win_type_t;
static lsx_enum_item const window_options[] = {
LSX_ENUM_ITEM(Window_,Hann)
LSX_ENUM_ITEM(Window_,Hamming)
LSX_ENUM_ITEM(Window_,Bartlett)
LSX_ENUM_ITEM(Window_,Rectangular)
LSX_ENUM_ITEM(Window_,Kaiser)
{0, 0}};
typedef struct {
/* Parameters */
double pixels_per_sec, duration, start_time, window_adjust;
int x_size0, y_size, Y_size, dB_range, gain, spectrum_points, perm;
sox_bool monochrome, light_background, high_colour, slack_overlap, no_axes;
sox_bool raw, alt_palette, truncate;
win_type_t win_type;
char const * out_name, * title, * comment;
/* Shared work area */
double * shared, * * shared_ptr;
/* Per-channel work area */
int WORK; /* Start of work area is marked by this dummy variable. */
size_t skip;
int dft_size, step_size, block_steps, block_num, rows, cols, read;
int x_size, end, end_min, last_end;
sox_bool truncated;
double buf[MAX_FFT_SIZE], dft_buf[MAX_FFT_SIZE], window[MAX_FFT_SIZE];
double block_norm, max, magnitudes[(MAX_FFT_SIZE>>1) + 1];
float * dBfs;
} priv_t;
#define secs(cols) \
((double)(cols) * p->step_size * p->block_steps / effp->in_signal.rate)
static unsigned char const alt_palette[] =
"\0\0\0\0\0\3\0\1\5\0\1\10\0\1\12\0\1\13\0\1\16\1\2\20\1\2\22\1\2\25\1\2\26"
"\1\2\30\1\3\33\1\3\35\1\3\37\1\3\40\1\3\"\1\3$\1\3%\1\3'\1\3(\1\3*\1\3,\1"
"\3.\1\3/\1\3""0\1\3""2\1\3""4\2\3""6\4\3""8\5\3""9\7\3;\11\3=\13\3?\16\3"
"A\17\2B\21\2D\23\2F\25\2H\27\2J\30\2K\32\2M\35\2O\40\2Q$\2S(\2U+\2W0\2Z3"
"\2\\7\2_;\2a>\2cB\2eE\2hI\2jM\2lQ\2nU\2pZ\2r_\2tc\2uh\2vl\2xp\3zu\3|z\3}"
"~\3~\203\3\200\207\3\202\214\3\204\220\3\205\223\3\203\226\3\200\230\3~\233"
"\3|\236\3z\240\3x\243\3u\246\3s\251\3q\253\3o\256\3m\261\3j\263\3h\266\3"
"f\272\3b\274\3^\300\3Z\303\3V\307\3R\312\3N\315\3J\321\3F\324\3C\327\3>\333"
"\3:\336\3""6\342\3""2\344\3/\346\7-\350\15,\352\21+\354\27*\355\33)\356\40"
"(\360&'\362*&\364/$\3654#\3669#\370>!\372C\40\374I\40\374O\"\374V&\374]*"
"\374d,\374k0\374r3\374z7\375\201;\375\210>\375\217B\375\226E\375\236I\375"
"\245M\375\254P\375\261T\375\267X\375\274\\\375\301a\375\306e\375\313i\375"
"\320m\376\325q\376\332v\376\337z\376\344~\376\351\202\376\356\206\376\363"
"\213\375\365\217\374\366\223\373\367\230\372\367\234\371\370\241\370\371"
"\245\367\371\252\366\372\256\365\372\263\364\373\267\363\374\274\361\375"
"\300\360\375\305\360\376\311\357\376\314\357\376\317\360\376\321\360\376"
"\324\360\376\326\360\376\330\360\376\332\361\377\335\361\377\337\361\377"
"\341\361\377\344\361\377\346\362\377\350\362\377\353";
#define alt_palette_len ((array_length(alt_palette) - 1) / 3)
static int getopts(sox_effect_t * effp, int argc, char **argv)
{
priv_t * p = (priv_t *)effp->priv;
size_t duration;
char const * next;
int c;
lsx_getopt_t optstate;
lsx_getopt_init(argc, argv, "+S:d:x:X:y:Y:z:Z:q:p:W:w:st:c:AarmlhTo:", NULL, lsx_getopt_flag_none, 1, &optstate);
p->dB_range = 120, p->spectrum_points = 249, p->perm = 1; /* Non-0 defaults */
p->out_name = "spectrogram.png", p->comment = "Created by SoX";
while ((c = lsx_getopt(&optstate)) != -1) switch (c) {
GETOPT_NUMERIC(optstate, 'x', x_size0 , 100, 5000)
GETOPT_NUMERIC(optstate, 'X', pixels_per_sec, 1 , 5000)
GETOPT_NUMERIC(optstate, 'y', y_size , 64 , 1200)
GETOPT_NUMERIC(optstate, 'Y', Y_size , 130, MAX_FFT_SIZE / 2 + 2)
GETOPT_NUMERIC(optstate, 'z', dB_range , 20 , 180)
GETOPT_NUMERIC(optstate, 'Z', gain ,-100, 100)
GETOPT_NUMERIC(optstate, 'q', spectrum_points, 0 , p->spectrum_points)
GETOPT_NUMERIC(optstate, 'p', perm , 1 , 6)
GETOPT_NUMERIC(optstate, 'W', window_adjust , -10, 10)
case 'w': p->win_type = lsx_enum_option(c, optstate.arg, window_options); break;
case 's': p->slack_overlap = sox_true; break;
case 'A': p->alt_palette = sox_true; break;
case 'a': p->no_axes = sox_true; break;
case 'r': p->raw = sox_true; break;
case 'm': p->monochrome = sox_true; break;
case 'l': p->light_background = sox_true; break;
case 'h': p->high_colour = sox_true; break;
case 'T': p->truncate = sox_true; break;
case 't': p->title = optstate.arg; break;
case 'c': p->comment = optstate.arg; break;
case 'o': p->out_name = optstate.arg; break;
case 'S': next = lsx_parsesamples(1e5, optstate.arg, &duration, 't');
if (next && !*next) {p->start_time = duration * 1e-5; break;}
return lsx_usage(effp);
case 'd': next = lsx_parsesamples(1e5, optstate.arg, &duration, 't');
if (next && !*next) {p->duration = duration * 1e-5; break;}
return lsx_usage(effp);
default: lsx_fail("invalid option `-%c'", optstate.opt); return lsx_usage(effp);
}
if (!!p->x_size0 + !!p->pixels_per_sec + !!p->duration > 2) {
lsx_fail("only two of -x, -X, -d may be given");
return SOX_EOF;
}
if (p->y_size && p->Y_size) {
lsx_fail("only one of -y, -Y may be given");
return SOX_EOF;
}
p->gain = -p->gain;
--p->perm;
p->spectrum_points += 2;
if (p->alt_palette)
p->spectrum_points = min(p->spectrum_points, (int)alt_palette_len);
p->shared_ptr = &p->shared;
return optstate.ind !=argc || p->win_type == INT_MAX? lsx_usage(effp) : SOX_SUCCESS;
}
static double make_window(priv_t * p, int end)
{
double sum = 0, * w = end < 0? p->window : p->window + end;
int i, n = p->dft_size - abs(end);
if (end) memset(p->window, 0, sizeof(p->window));
for (i = 0; i < n; ++i) w[i] = 1;
switch (p->win_type) {
case Window_Hann: lsx_apply_hann(w, n); break;
case Window_Hamming: lsx_apply_hamming(w, n); break;
case Window_Bartlett: lsx_apply_bartlett(w, n); break;
case Window_Rectangular: break;
default: lsx_apply_kaiser(w, n, lsx_kaiser_beta(
(p->dB_range + p->gain) * (1.1 + p->window_adjust / 50)));
}
for (i = 0; i < p->dft_size; ++i) sum += p->window[i];
for (i = 0; i < p->dft_size; ++i) p->window[i] *= 2 / sum
* sqr((double)n / p->dft_size); /* empirical small window adjustment */
return sum;
}
static double * rdft_init(int n)
{
double * q = lsx_malloc(2 * (n / 2 + 1) * n * sizeof(*q)), * p = q;
int i, j;
for (j = 0; j <= n / 2; ++j) for (i = 0; i < n; ++i)
*p++ = cos(2 * M_PI * j * i / n), *p++ = sin(2 * M_PI * j * i / n);
return q;
}
#define _ re += in[i] * *q++, im += in[i++] * *q++,
static void rdft_p(double const * q, double const * in, double * out, int n)
{
int i, j;
for (j = 0; j <= n / 2; ++j) {
double re = 0, im = 0;
for (i = 0; i < (n & ~7);) _ _ _ _ _ _ _ _ 0;
while (i < n) _ 0;
*out++ += re * re + im * im;
}
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
double actual, duration = p->duration, pixels_per_sec = p->pixels_per_sec;
memset(&p->WORK, 0, sizeof(*p) - field_offset(priv_t, WORK));
p->skip = p->start_time * effp->in_signal.rate + .5;
p->x_size = p->x_size0;
while (sox_true) {
if (!pixels_per_sec && p->x_size && duration)
pixels_per_sec = min(5000, p->x_size / duration);
else if (!p->x_size && pixels_per_sec && duration)
p->x_size = min(5000, (int)(pixels_per_sec * duration + .5));
if (!duration && effp->in_signal.length) {
duration = effp->in_signal.length / (effp->in_signal.rate * effp->in_signal.channels);
duration -= p->start_time;
if (duration <= 0)
duration = 1;
continue;
} else if (!p->x_size) {
p->x_size = 800;
continue;
} else if (!pixels_per_sec) {
pixels_per_sec = 100;
continue;
}
break;
}
if (p->y_size) {
p->dft_size = 2 * (p->y_size - 1);
if (!is_p2(p->dft_size) && !effp->flow)
p->shared = rdft_init(p->dft_size);
} else {
int y = max(32, (p->Y_size? p->Y_size : 550) / effp->in_signal.channels - 2);
for (p->dft_size = 128; p->dft_size <= y; p->dft_size <<= 1);
}
if (is_p2(p->dft_size) && !effp->flow)
lsx_safe_rdft(p->dft_size, 1, p->dft_buf);
lsx_debug("duration=%g x_size=%i pixels_per_sec=%g dft_size=%i", duration, p->x_size, pixels_per_sec, p->dft_size);
p->end = p->dft_size;
p->rows = (p->dft_size >> 1) + 1;
actual = make_window(p, p->last_end = 0);
lsx_debug("window_density=%g", actual / p->dft_size);
p->step_size = (p->slack_overlap? sqrt(actual * p->dft_size) : actual) + .5;
p->block_steps = effp->in_signal.rate / pixels_per_sec;
p->step_size = p->block_steps / ceil((double)p->block_steps / p->step_size) +.5;
p->block_steps = floor((double)p->block_steps / p->step_size +.5);
p->block_norm = 1. / p->block_steps;
actual = effp->in_signal.rate / p->step_size / p->block_steps;
if (!effp->flow && actual != pixels_per_sec)
lsx_report("actual pixels/s = %g", actual);
lsx_debug("step_size=%i block_steps=%i", p->step_size, p->block_steps);
p->max = -p->dB_range;
p->read = (p->step_size - p->dft_size) / 2;
return SOX_SUCCESS;
}
static int do_column(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
int i;
if (p->cols == p->x_size) {
p->truncated = sox_true;
if (!effp->flow)
lsx_report("PNG truncated at %g seconds", secs(p->cols));
return p->truncate? SOX_EOF : SOX_SUCCESS;
}
++p->cols;
p->dBfs = lsx_realloc(p->dBfs, p->cols * p->rows * sizeof(*p->dBfs));
for (i = 0; i < p->rows; ++i) {
double dBfs = 10 * log10(p->magnitudes[i] * p->block_norm);
p->dBfs[(p->cols - 1) * p->rows + i] = dBfs + p->gain;
p->max = max(dBfs, p->max);
}
memset(p->magnitudes, 0, p->rows * sizeof(*p->magnitudes));
p->block_num = 0;
return SOX_SUCCESS;
}
static int flow(sox_effect_t * effp,
const sox_sample_t * ibuf, sox_sample_t * obuf,
size_t * isamp, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
size_t len = *isamp = *osamp = min(*isamp, *osamp);
int i;
memcpy(obuf, ibuf, len * sizeof(*obuf)); /* Pass on audio unaffected */
if (p->skip) {
if (p->skip >= len) {
p->skip -= len;
return SOX_SUCCESS;
}
ibuf += p->skip;
len -= p->skip;
p->skip = 0;
}
while (!p->truncated) {
if (p->read == p->step_size) {
memmove(p->buf, p->buf + p->step_size,
(p->dft_size - p->step_size) * sizeof(*p->buf));
p->read = 0;
}
for (; len && p->read < p->step_size; --len, ++p->read, --p->end)
p->buf[p->dft_size - p->step_size + p->read] =
SOX_SAMPLE_TO_FLOAT_64BIT(*ibuf++,);
if (p->read != p->step_size)
break;
if ((p->end = max(p->end, p->end_min)) != p->last_end)
make_window(p, p->last_end = p->end);
for (i = 0; i < p->dft_size; ++i) p->dft_buf[i] = p->buf[i] * p->window[i];
if (is_p2(p->dft_size)) {
lsx_safe_rdft(p->dft_size, 1, p->dft_buf);
p->magnitudes[0] += sqr(p->dft_buf[0]);
for (i = 1; i < p->dft_size >> 1; ++i)
p->magnitudes[i] += sqr(p->dft_buf[2*i]) + sqr(p->dft_buf[2*i+1]);
p->magnitudes[p->dft_size >> 1] += sqr(p->dft_buf[1]);
}
else rdft_p(*p->shared_ptr, p->dft_buf, p->magnitudes, p->dft_size);
if (++p->block_num == p->block_steps && do_column(effp) == SOX_EOF)
return SOX_EOF;
}
return SOX_SUCCESS;
}
static int drain(sox_effect_t * effp, sox_sample_t * obuf_, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
if (!p->truncated) {
sox_sample_t * ibuf = lsx_calloc(p->dft_size, sizeof(*ibuf));
sox_sample_t * obuf = lsx_calloc(p->dft_size, sizeof(*obuf));
size_t isamp = (p->dft_size - p->step_size) / 2;
int left_over = (isamp + p->read) % p->step_size;
if (left_over >= p->step_size >> 1)
isamp += p->step_size - left_over;
lsx_debug("cols=%i left=%i end=%i", p->cols, p->read, p->end);
p->end = 0, p->end_min = -p->dft_size;
if (flow(effp, ibuf, obuf, &isamp, &isamp) == SOX_SUCCESS && p->block_num) {
p->block_norm *= (double)p->block_steps / p->block_num;
do_column(effp);
}
lsx_debug("flushed cols=%i left=%i end=%i", p->cols, p->read, p->end);
free(obuf);
free(ibuf);
}
(void)obuf_, *osamp = 0;
return SOX_SUCCESS;
}
enum {Background, Text, Labels, Grid, fixed_palette};
static unsigned colour(priv_t const * p, double x)
{
unsigned c = x < -p->dB_range? 0 : x >= 0? p->spectrum_points - 1 :
1 + (1 + x / p->dB_range) * (p->spectrum_points - 2);
return fixed_palette + c;
}
static void make_palette(priv_t const * p, png_color * palette)
{
int i;
if (p->light_background) {
memcpy(palette++, (p->monochrome)? "\337\337\337":"\335\330\320", (size_t)3);
memcpy(palette++, "\0\0\0" , (size_t)3);
memcpy(palette++, "\077\077\077", (size_t)3);
memcpy(palette++, "\077\077\077", (size_t)3);
} else {
memcpy(palette++, "\0\0\0" , (size_t)3);
memcpy(palette++, "\377\377\377", (size_t)3);
memcpy(palette++, "\277\277\277", (size_t)3);
memcpy(palette++, "\177\177\177", (size_t)3);
}
for (i = 0; i < p->spectrum_points; ++i) {
double c[3], x = (double)i / (p->spectrum_points - 1);
int at = p->light_background? p->spectrum_points - 1 - i : i;
if (p->monochrome) {
c[2] = c[1] = c[0] = x;
if (p->high_colour) {
c[(1 + p->perm) % 3] = x < .4? 0 : 5 / 3. * (x - .4);
if (p->perm < 3)
c[(2 + p->perm) % 3] = x < .4? 0 : 5 / 3. * (x - .4);
}
palette[at].red = .5 + 255 * c[0];
palette[at].green= .5 + 255 * c[1];
palette[at].blue = .5 + 255 * c[2];
continue;
}
if (p->high_colour) {
static const int states[3][7] = {
{4,5,0,0,2,1,1}, {0,0,2,1,1,3,2}, {4,1,1,3,0,0,2}};
int j, phase_num = min(7 * x, 6);
for (j = 0; j < 3; ++j) switch (states[j][phase_num]) {
case 0: c[j] = 0; break;
case 1: c[j] = 1; break;
case 2: c[j] = sin((7 * x - phase_num) * M_PI / 2); break;
case 3: c[j] = cos((7 * x - phase_num) * M_PI / 2); break;
case 4: c[j] = 7 * x - phase_num; break;
case 5: c[j] = 1 - (7 * x - phase_num); break;
}
} else if (p->alt_palette) {
int n = (double)i / (p->spectrum_points - 1) * (alt_palette_len - 1) + .5;
c[0] = alt_palette[3 * n + 0] / 255.;
c[1] = alt_palette[3 * n + 1] / 255.;
c[2] = alt_palette[3 * n + 2] / 255.;
} else {
if (x < .13) c[0] = 0;
else if (x < .73) c[0] = 1 * sin((x - .13) / .60 * M_PI / 2);
else c[0] = 1;
if (x < .60) c[1] = 0;
else if (x < .91) c[1] = 1 * sin((x - .60) / .31 * M_PI / 2);
else c[1] = 1;
if (x < .60) c[2] = .5 * sin((x - .00) / .60 * M_PI);
else if (x < .78) c[2] = 0;
else c[2] = (x - .78) / .22;
}
palette[at].red = .5 + 255 * c[p->perm % 3];
palette[at].green= .5 + 255 * c[(1 + p->perm + (p->perm % 2)) % 3];
palette[at].blue = .5 + 255 * c[(2 + p->perm - (p->perm % 2)) % 3];
}
}
static const Bytef fixed[] =
"x\332eT\241\266\2450\fDVV>Y\371$re%2\237\200|2\22YY\211D\"+\337'<y\345\312"
"\375\fd\345f\222\224\313\236\235{\270\344L\247a\232\4\246\351\201d\230\222"
"\304D\364^ \352\362S\"m\347\311\237\237\27\64K\243\2302\265\35\v\371<\363y"
"\354_\226g\354\214)e \2458\341\17\20J4\215[z<\271\277\367\0\63\64@\177\330c"
"\227\204 Ir.\5$U\200\260\224\326S\17\200=\\k\20QA\334%\342\20*\303P\234\211"
"\366\36#\370R\276_\316s-\345\222Dlz\363my*;\217\373\346z\267\343\236\364\246"
"\236\365\2419\305p\333\267\23(\207\265\333\233\325Y\342\243\265\357\262\215"
"\263t\271$\276\226ea\271.\367&\320\347\202_\234\27\377\345\222\253?\3422\364"
"\207y\256\236\229\331\33\f\376\227\266\"\356\253j\366\363\347\334US\34]\371?"
"\255\371\336\372z\265v\34\226\247\32\324\217\334\337\317U4\16\316{N\370\31"
"\365\357iL\231y\33y\264\211D7\337\4\244\261\220D\346\1\261\357\355>\3\342"
"\223\363\0\303\277\f[\214A,p\34`\255\355\364\37\372\224\342\277\f\207\255\36"
"_V\7\34\241^\316W\257\177\b\242\300\34\f\276\33?/9_\331f\346\36\25Y)\2301"
"\257\2414|\35\365\237\3424k\3\244\3\242\261\6\b\275>z$\370\215:\270\363w\36/"
"\265kF\v\20o6\242\301\364\336\27\325\257\321\364fs\231\215G\32=\257\305Di"
"\304^\177\304R\364Q=\225\373\33\320\375\375\372\200\337\37\374}\334\337\20"
"\364\310(]\304\267b\177\326Yrj\312\277\373\233\37\340";
static unsigned char * font;
#define font_x 5
#define font_y 12
#define font_X (font_x + 1)
#define pixel(x,y) pixels[(y) * cols + (x)]
#define print_at(x,y,c,t) print_at_(pixels,cols,x,y,c,t,0)
#define print_up(x,y,c,t) print_at_(pixels,cols,x,y,c,t,1)
static void print_at_(png_byte * pixels, int cols, int x, int y, int c, char const * text, int orientation)
{
for (;*text; ++text) {
int pos = ((*text < ' ' || *text > '~'? '~' + 1 : *text) - ' ') * font_y;
int i, j;
for (i = 0; i < font_y; ++i) {
unsigned line = font[pos++];
for (j = 0; j < font_x; ++j, line <<= 1)
if (line & 0x80) switch (orientation) {
case 0: pixel(x + j, y - i) = c; break;
case 1: pixel(x + i, y + j) = c; break;
}
}
switch (orientation) {
case 0: x += font_X; break;
case 1: y += font_X; break;
}
}
}
static int axis(double to, int max_steps, double * limit, char * * prefix)
{
double scale = 1, step = max(1, 10 * to);
int i, prefix_num = 0;
if (max_steps) {
double try, log_10 = HUGE_VAL, min_step = (to *= 10) / max_steps;
for (i = 5; i; i >>= 1) if ((try = ceil(log10(min_step * i))) <= log_10)
step = pow(10., log_10 = try) / i, log_10 -= i > 1;
prefix_num = floor(log_10 / 3);
scale = pow(10., -3. * prefix_num);
}
*prefix = "pnum-kMGTPE" + prefix_num + (prefix_num? 4 : 11);
*limit = to * scale;
return step * scale + .5;
}
#define below 48
#define left 58
#define between 37
#define spectrum_width 14
#define right 35
static int stop(sox_effect_t * effp)
{
priv_t * p = (priv_t *) effp->priv;
FILE * file = fopen(p->out_name, "wb");
uLong font_len = 96 * font_y;
int chans = effp->in_signal.channels;
int c_rows = p->rows * chans + chans - 1;
int rows = p->raw? c_rows : below + c_rows + 30 + 20 * !!p->title;
int cols = p->raw? p->cols : left + p->cols + between + spectrum_width + right;
png_byte * pixels = lsx_malloc(cols * rows * sizeof(*pixels));
png_bytepp png_rows = lsx_malloc(rows * sizeof(*png_rows));
png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0,0);
png_infop png_info = png_create_info_struct(png);
png_color palette[256];
int i, j, k, base, step, tick_len = 3 - p->no_axes;
char text[200], * prefix;
double limit;
free(p->shared);
if (!file) {
lsx_fail("failed to create `%s': %s", p->out_name, strerror(errno));
goto error;
}
lsx_debug("signal-max=%g", p->max);
font = lsx_malloc(font_len);
assert(uncompress(font, &font_len, fixed, sizeof(fixed)-1) == Z_OK);
make_palette(p, palette);
memset(pixels, Background, cols * rows * sizeof(*pixels));
png_init_io(png, file);
png_set_PLTE(png, png_info, palette, fixed_palette + p->spectrum_points);
png_set_IHDR(png, png_info, (size_t)cols, (size_t)rows, 8,
PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
for (j = 0; j < rows; ++j) /* Put (0,0) at bottom-left of PNG */
png_rows[rows - 1 - j] = (png_bytep)(pixels + j * cols);
/* Spectrogram */
for (k = 0; k < chans; ++k) {
priv_t * q = (priv_t *)(effp - effp->flow + k)->priv;
base = !p->raw * below + (chans - 1 - k) * (p->rows + 1);
for (j = 0; j < p->rows; ++j) {
for (i = 0; i < p->cols; ++i)
pixel(!p->raw * left + i, base + j) = colour(p, q->dBfs[i*p->rows + j]);
if (!p->raw && !p->no_axes) /* Y-axis lines */
pixel(left - 1, base + j) = pixel(left + p->cols, base + j) = Grid;
}
if (!p->raw && !p->no_axes) for (i = -1; i <= p->cols; ++i) /* X-axis lines */
pixel(left + i, base - 1) = pixel(left + i, base + p->rows) = Grid;
}
if (!p->raw) {
if (p->title && (i = (int)strlen(p->title) * font_X) < cols + 1) /* Title */
print_at((cols - i) / 2, rows - font_y, Text, p->title);
if ((int)strlen(p->comment) * font_X < cols + 1) /* Footer comment */
print_at(1, font_y, Text, p->comment);
/* X-axis */
step = axis(secs(p->cols), p->cols / (font_X * 9 / 2), &limit, &prefix);
sprintf(text, "Time (%.1ss)", prefix); /* Axis label */
print_at(left + (p->cols - font_X * (int)strlen(text)) / 2, 24, Text, text);
for (i = 0; i <= limit; i += step) {
int y, x = limit? (double)i / limit * p->cols + .5 : 0;
for (y = 0; y < tick_len; ++y) /* Ticks */
pixel(left-1+x, below-1-y) = pixel(left-1+x, below+c_rows+y) = Grid;
if (step == 5 && (i%10))
continue;
sprintf(text, "%g", .1 * i); /* Tick labels */
x = left + x - 3 * strlen(text);
print_at(x, below - 6, Labels, text);
print_at(x, below + c_rows + 14, Labels, text);
}
/* Y-axis */
step = axis(effp->in_signal.rate / 2,
(p->rows - 1) / ((font_y * 3 + 1) >> 1), &limit, &prefix);
sprintf(text, "Frequency (%.1sHz)", prefix); /* Axis label */
print_up(10, below + (c_rows - font_X * (int)strlen(text)) / 2, Text, text);
for (k = 0; k < chans; ++k) {
base = below + k * (p->rows + 1);
for (i = 0; i <= limit; i += step) {
int x, y = limit? (double)i / limit * (p->rows - 1) + .5 : 0;
for (x = 0; x < tick_len; ++x) /* Ticks */
pixel(left-1-x, base+y) = pixel(left+p->cols+x, base+y) = Grid;
if ((step == 5 && (i%10)) || (!i && k && chans > 1))
continue;
sprintf(text, i?"%5g":" DC", .1 * i); /* Tick labels */
print_at(left - 4 - font_X * 5, base + y + 5, Labels, text);
sprintf(text, i?"%g":"DC", .1 * i);
print_at(left + p->cols + 6, base + y + 5, Labels, text);
}
}
/* Z-axis */
k = min(400, c_rows);
base = below + (c_rows - k) / 2;
print_at(cols - right - 2 - font_X, base - 13, Text, "dBFS");/* Axis label */
for (j = 0; j < k; ++j) { /* Spectrum */
png_byte b = colour(p, p->dB_range * (j / (k - 1.) - 1));
for (i = 0; i < spectrum_width; ++i)
pixel(cols - right - 1 - i, base + j) = b;
}
step = 10 * ceil(p->dB_range / 10. * (font_y + 2) / (k - 1));
for (i = 0; i <= p->dB_range; i += step) { /* (Tick) labels */
int y = (double)i / p->dB_range * (k - 1) + .5;
sprintf(text, "%+i", i - p->gain - p->dB_range);
print_at(cols - right + 1, base + y + 5, Labels, text);
}
}
free(font);
png_set_rows(png, png_info, png_rows);
png_write_png(png, png_info, PNG_TRANSFORM_IDENTITY, NULL);
fclose(file);
error: png_destroy_write_struct(&png, &png_info);
free(png_rows);
free(pixels);
free(p->dBfs);
return SOX_SUCCESS;
}
static int end(sox_effect_t * effp) {return effp->flow? SOX_SUCCESS:stop(effp);}
sox_effect_handler_t const * lsx_spectrogram_effect_fn(void)
{
static sox_effect_handler_t handler = {"spectrogram", 0, SOX_EFF_MODIFY,
getopts, start, flow, drain, end, 0, sizeof(priv_t)};
static char const * lines[] = {
"[options]",
"\t-x num\tX-axis size in pixels; default derived or 800",
"\t-X num\tX-axis pixels/second; default derived or 100",
"\t-y num\tY-axis size in pixels (per channel); slow if not 1 + 2^n",
"\t-Y num\tY-height total (i.e. not per channel); default 550",
"\t-z num\tZ-axis range in dB; default 120",
"\t-Z num\tZ-axis maximum in dBFS; default 0",
"\t-q num\tZ-axis quantisation (0 - 249); default 249",
"\t-w name\tWindow: Hann (default), Hamming, Bartlett, Rectangular, Kaiser",
"\t-W num\tWindow adjust parameter (-10 - 10); applies only to Kaiser",
"\t-s\tSlack overlap of windows",
"\t-a\tSuppress axis lines",
"\t-r\tRaw spectrogram; no axes or legends",
"\t-l\tLight background",
"\t-m\tMonochrome",
"\t-h\tHigh colour",
"\t-p num\tPermute colours (1 - 6); default 1",
"\t-A\tAlternative, inferior, fixed colour-set (for compatibility only)",
"\t-t text\tTitle text",
"\t-c text\tComment text",
"\t-o text\tOutput file name; default `spectrogram.png'",
"\t-d time\tAudio duration to fit to X-axis; e.g. 1:00, 48",
"\t-S time\tStart the spectrogram at the given time through the input",
};
static char * usage;
handler.usage = lsx_usage_lines(&usage, lines, array_length(lines));
return &handler;
}