ref: fb0d5415f4388223a510a342ccae0264d93f07d1
dir: /src/spectrogram.c/
/* libSoX effect: Spectrogram (c) 2008 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
*/
/* TODO
* o Two-channel support.
* o Option for a larger font (for use with image down-scaling).
*/
#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>
#include <png.h>
/* we are playing games with getopt aliases so this needs to be included
* after system header files to prevent aliasing OS's version of getopt.
*/
#include "getopt.h"
#define malloc lsx_malloc
#define calloc lsx_calloc
#define realloc lsx_realloc
#define FROM_SOX SOX_SAMPLE_TO_FLOAT_64BIT
#define DFT_BASE_SIZE 512
#define MAX_DFT_SIZE_SHIFT 3
#define MAX_DFT_SIZE (DFT_BASE_SIZE << MAX_DFT_SIZE_SHIFT)
#define MAX_COLS 999 /* Also max seconds */
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;
int y_size, dB_range, gain, spectrum_points, perm;
sox_bool monochrome, light_background, high_colour, slack_overlap, no_axes;
win_type_t win_type;
char const * out_name, * title, * comment;
/* Work area */
int WORK; /* Start of work area is marked by this dummy variable. */
int dft_size, step_size, block_steps, block_num, rows, cols, read;
int end, end_min, last_end;
sox_bool truncated;
double buf[MAX_DFT_SIZE], dft_buf[MAX_DFT_SIZE], window[MAX_DFT_SIZE];
double block_norm, max, magnitudes[(MAX_DFT_SIZE>>1) + 1];
int bit_rev_table[100]; /* For Ooura fft */
double sin_cos_table[dft_sc_len(MAX_DFT_SIZE)]; /* ditto */
float * dBfs;
} priv_t;
#define secs(cols) \
((double)(cols) * p->step_size * p->block_steps / effp->in_signal.rate)
static int getopts(sox_effect_t * effp, int argc, char **argv)
{
priv_t * p = (priv_t *)effp->priv;
int c;
assert(array_length(p->bit_rev_table) >= (size_t)dft_br_len(MAX_DFT_SIZE));
p->pixels_per_sec = 100, p->y_size = 2, p->dB_range = 120;/* non-0 defaults */
p->spectrum_points = 249, p->perm = 1;
p->out_name = "spectrogram.png", p->comment = "Created by SoX";
while ((c = getopt(argc, argv, "+x:y:z:Z:q:p:w:st:c:amlho:")) != -1) switch (c) {
GETOPT_NUMERIC('x', pixels_per_sec, 1 , 5000)
GETOPT_NUMERIC('y', y_size , 1 , 1 + MAX_DFT_SIZE_SHIFT)
GETOPT_NUMERIC('z', dB_range , 20 , 180)
GETOPT_NUMERIC('Z', gain ,-100, 100)
GETOPT_NUMERIC('q', spectrum_points, 0 , p->spectrum_points)
GETOPT_NUMERIC('p', perm , 1 , 6)
case 'w': p->win_type = lsx_enum_option(c, window_options); break;
case 's': p->slack_overlap = sox_true; break;
case 't': p->title = optarg; break;
case 'c': p->comment = optarg; break;
case 'a': p->no_axes = 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 'o': p->out_name = optarg; break;
default: lsx_fail("invalid option `-%c'", optopt); return lsx_usage(effp);
}
p->gain = -p->gain;
--p->y_size, --p->perm;
p->spectrum_points += 2;
return optind !=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 + 20.));
}
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 int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
double actual;
if (effp->in_signal.channels != 1) {
lsx_fail("only 1 channel is supported");
return SOX_EOF;
}
memset(&p->WORK, 0, sizeof(*p) - field_offset(priv_t, WORK));
p->end = p->dft_size = DFT_BASE_SIZE << p->y_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 / p->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 (actual != p->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 == MAX_COLS) {
lsx_warn("PNG truncated at %g seconds", secs(p->cols));
p->truncated = sox_true;
return SOX_EOF;
}
++p->cols;
p->dBfs = 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 = min(*isamp, *osamp);
int i;
memcpy(obuf, ibuf, len * sizeof(*obuf)); /* Pass on audio unaffected */
*isamp = *osamp = len;
while (sox_true) {
SOX_SAMPLE_LOCALS;
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] = FROM_SOX(*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];
lsx_rdft(p->dft_size, 1, p->dft_buf, p->bit_rev_table, p->sin_cos_table);
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]);
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 = calloc(p->dft_size, sizeof(*ibuf));
sox_sample_t * obuf = 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 (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 = 1;
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, "w");
uLong font_len = 96 * font_y;
int rows = below + p->rows + 30 + 20 * !!p->title;
int cols = left + p->cols + between + spectrum_width + right;
png_byte * pixels = malloc(cols * rows * sizeof(*pixels));
png_bytepp png_rows = 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, step, tick_len = 3 - p->no_axes;
char text[200], * prefix;
double limit;
if (!file) {
lsx_fail("failed to create `%s' :(", p->out_name);
png_destroy_write_struct(&png, &png_info);
free(png_rows);
free(pixels);
free(p->dBfs);
return SOX_EOF;
}
lsx_debug("signal-max=%g", p->max);
font = 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);
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);
/* Spectrogram */
for (j = 0; j < p->rows; ++j) {
for (i = 0; i < p->cols; ++i)
pixel(left + i, below + j) = colour(p, p->dBfs[i*p->rows + j]);
if (!p->no_axes) /* Y-axis lines */
pixel(left - 1, below + j) = pixel(left + p->cols,below + j) = Grid;
}
if (!p->no_axes) for (i = -1; i <= p->cols; ++i) /* X-axis lines */
pixel(left + i, below - 1) = pixel(left + i, below + p->rows) = Grid;
/* 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+p->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 + p->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 + (p->rows - font_X * (int)strlen(text)) / 2, Text, text);
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, below+y) = pixel(left+p->cols+x, below+y) = Grid;
if (step == 5 && (i%10))
continue;
sprintf(text, i?"%5g":" DC", .1 * i); /* Tick labels */
print_at(left - 4 - font_X * 5, below + y + 5, Labels, text);
sprintf(text, i?"%g":"DC", .1 * i);
print_at(left + p->cols + 6, below + y + 5, Labels, text);
}
/* Z-axis */
print_at(cols - right - 2 - font_X, below - 13, Text, "dBFS");/* Axis label */
for (j = 0; j < p->rows; ++j) { /* Spectrum */
png_byte b = colour(p, p->dB_range * (j / (p->rows - 1.) - 1));
for (i = 0; i < spectrum_width; ++i)
pixel(cols - right - 1 - i, below + j) = b;
}
for (i = 0; i <= p->dB_range; i += 10) { /* (Tick) labels */
int y = (double)i / p->dB_range * (p->rows - 1) + .5;
sprintf(text, "%+i", i - p->gain - p->dB_range);
print_at(cols - right + 1, below + y + 5, Labels, text);
}
free(font);
png_set_rows(png, png_info, png_rows);
png_write_png(png, png_info, PNG_TRANSFORM_IDENTITY, NULL);
png_destroy_write_struct(&png, &png_info);
free(png_rows);
free(pixels);
fclose(file);
free(p->dBfs);
return SOX_SUCCESS;
}
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, stop, 0, sizeof(priv_t)};
static char const * lines[] = {
"[options]",
"\t-x num\tX-axis pixels/second, default 100",
"\t-y num\tY-axis resolution (1 - 4), default 2",
"\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-s\tSlack overlap of windows",
"\t-a\tSuppress axis lines",
"\t-l\tLight background",
"\t-m\tMonochrome",
"\t-h\tHigh colour",
"\t-p num\tPermute colours (1 - 6)",
"\t-t text\tTitle text",
"\t-c text\tComment text",
"\t-o text\tOutput file name, default `spectrogram.png'",
};
static char * usage;
handler.usage = lsx_usage_lines(&usage, lines, array_length(lines));
return &handler;
}