spek/src/spek-spectrogram.vala
2011-02-20 14:44:44 +08:00

285 lines
8.5 KiB
Vala

/* spek-spectrogram.vala
*
* Copyright (C) 2010 Alexander Kojevnikov <alexander@kojevnikov.com>
*
* Spek is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Spek 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Spek. If not, see <http://www.gnu.org/licenses/>.
*/
using Cairo;
using Gdk;
using Gtk;
using Pango;
namespace Spek {
class Spectrogram : DrawingArea {
public string file_name { get; private set; }
private Pipeline pipeline;
private string info;
private const int THRESHOLD = -92;
private const int NFFT = 2048;
private const int BANDS = NFFT / 2 + 1;
private ImageSurface image;
private ImageSurface palette;
private const int LPAD = 60;
private const int TPAD = 60;
private const int RPAD = 60;
private const int BPAD = 40;
private const int GAP = 10;
private const int RULER = 10;
private double FONT_SCALE = 1.0;
public Spectrogram () {
// Pango/Quartz fonts are smaller than on X.
if (Config.HOST_OS.down ().has_prefix ("darwin")) {
FONT_SCALE = 1.4;
}
// Pre-draw the palette.
palette = new ImageSurface (Format.RGB24, RULER, BANDS);
for (int y = 0; y < BANDS; y++) {
var color = get_color (y / (double) BANDS);
for (int x = 0; x < RULER; x++) {
put_pixel (palette, x, y, color);
}
}
show_all ();
}
public void open (string file_name) {
this.file_name = file_name;
this.info = "";
start ();
}
public void save (string file_name) {
var surface = new ImageSurface (Format.RGB24, allocation.width, allocation.height);
draw (new Cairo.Context (surface));
surface.write_to_png (file_name);
}
private void start () {
if (pipeline != null) {
pipeline.stop ();
}
// The number of samples is the number of pixels available for the image.
// The number of bands is fixed, FFT results are very different for
// different values but we need some consistency.
int samples = allocation.width - LPAD - RPAD;
if (samples > 0) {
image = new ImageSurface (Format.RGB24, samples, BANDS);
pipeline = new Pipeline (file_name, BANDS, samples, THRESHOLD, data_cb);
pipeline.start ();
info = pipeline.description;
} else {
image = null;
pipeline = null;
}
queue_draw ();
}
private int prev_width = -1;
protected override void size_allocate (Gdk.Rectangle allocation) {
base.size_allocate (allocation);
bool width_changed = prev_width != allocation.width;
prev_width = allocation.width;
if (file_name != null && width_changed) {
start ();
}
}
private double log10_threshold = Math.log10 (-THRESHOLD);
private void data_cb (int sample, float[] values) {
for (int y = 0; y < BANDS; y++) {
var level = double.min (
1.0, Math.log10 (1.0 - THRESHOLD + values[y]) / log10_threshold);
put_pixel (image, sample, y, get_color (level));
}
Idle.add (() => { queue_draw (); return false; });
}
protected override bool expose_event (EventExpose event) {
var cr = cairo_create (this.window);
// Clip to the exposed area.
cr.rectangle (event.area.x, event.area.y, event.area.width, event.area.height);
cr.clip ();
draw (cr);
return true;
}
private void draw (Cairo.Context cr) {
double w = allocation.width;
double h = allocation.height;
int text_width, text_height;
// Clean the background.
cr.set_source_rgb (0, 0, 0);
cr.paint ();
// Spek version
cr.set_source_rgb (1, 1, 1);
var layout = cairo_create_layout (cr);
layout.set_font_description (FontDescription.from_string (
"Sans " + (9 * FONT_SCALE).to_string ()));
layout.set_width (RPAD * Pango.SCALE);
layout.set_text ("v" + Config.PACKAGE_VERSION, -1);
layout.get_pixel_size (out text_width, out text_height);
int line_height = text_height;
cr.move_to (w - (RPAD + text_width) / 2, TPAD - GAP);
cairo_show_layout_line (cr, layout.get_line (0));
layout.set_font_description (FontDescription.from_string (
"Sans Bold " + (10 * FONT_SCALE).to_string ()));
layout.set_text (Config.PACKAGE_NAME, -1);
layout.get_pixel_size (out text_width, out text_height);
cr.move_to (w - (RPAD + text_width) / 2, TPAD - 2 * GAP - line_height);
cairo_show_layout_line (cr, layout.get_line (0));
if (image != null) {
// Draw the spectrogram.
cr.translate (LPAD, h - BPAD);
cr.scale (1, -(h - TPAD - BPAD) / image.get_height ());
cr.set_source_surface (image, 0, 0);
cr.paint ();
cr.identity_matrix ();
// Prepare to draw the rulers.
cr.set_source_rgb (1, 1, 1);
cr.set_line_width (1);
cr.set_antialias (Antialias.NONE);
layout.set_font_description (FontDescription.from_string (
"Sans " + (8 * FONT_SCALE).to_string ()));
layout.set_width (-1);
// Time ruler.
var duration_seconds = (int) pipeline.duration;
var time_ruler = new Ruler (
"00:00",
{1, 2, 5, 10, 20, 30, 1*60, 2*60, 5*60, 10*60, 20*60, 30*60},
duration_seconds,
1.5,
unit => (w - LPAD - RPAD) * unit / duration_seconds,
unit => "%d:%02d".printf (unit / 60, unit % 60));
cr.translate (LPAD, h - BPAD);
time_ruler.draw (cr, layout, true);
cr.identity_matrix ();
// Frequency ruler.
var freq = pipeline.sample_rate / 2;
var rate_ruler = new Ruler (
"00 kHz",
{1000, 2000, 5000, 10000, 20000},
freq,
3.0,
unit => (h - TPAD - BPAD) * unit / freq,
unit => "%d kHz".printf (unit / 1000));
cr.translate (LPAD, TPAD);
rate_ruler.draw (cr, layout, false);
cr.identity_matrix ();
// File properties.
cr.move_to (LPAD, TPAD - GAP);
layout.set_font_description (FontDescription.from_string (
"Sans " + (9 * FONT_SCALE).to_string ()));
layout.set_width ((int) (w - LPAD - RPAD) * Pango.SCALE);
layout.set_ellipsize (EllipsizeMode.END);
layout.set_text (info, -1);
cairo_show_layout_line (cr, layout.get_line (0));
layout.get_pixel_size (out text_width, out text_height);
// File name.
cr.move_to (LPAD, TPAD - 2 * GAP - text_height);
layout.set_font_description (FontDescription.from_string (
"Sans Bold " + (10 * FONT_SCALE).to_string ()));
layout.set_width ((int) (w - LPAD - RPAD) * Pango.SCALE);
layout.set_ellipsize (EllipsizeMode.START);
layout.set_text (file_name, -1);
cairo_show_layout_line (cr, layout.get_line (0));
}
// Border around the spectrogram.
cr.set_source_rgb (1, 1, 1);
cr.set_line_width (1);
cr.set_antialias (Antialias.NONE);
cr.rectangle (LPAD, TPAD, w - LPAD - RPAD, h - TPAD - BPAD);
cr.stroke ();
// The palette.
cr.translate (w - RPAD + GAP, h - BPAD);
cr.scale (1, -(h - TPAD - BPAD) / palette.get_height ());
cr.set_source_surface (palette, 0, 0);
cr.paint ();
cr.identity_matrix ();
}
private void put_pixel (ImageSurface surface, int x, int y, uint32 color) {
var i = y * surface.get_stride () + x * 4;
unowned uchar[] data = surface.get_data ();
// Translate uchar* to uint32* to avoid dealing with endianness.
uint32 *p = (uint32 *) (&data[i]);
*p = color;
}
// Modified version of Dan Bruton's algorithm:
// http://www.physics.sfasu.edu/astro/color/spectra.html
private uint32 get_color (double level) {
level *= 0.6625;
double r = 0.0, g = 0.0, b = 0.0;
if (level >= 0 && level < 0.15) {
r = (0.15 - level) / (0.15 + 0.075);
g = 0.0;
b = 1.0;
} else if (level >= 0.15 && level < 0.275) {
r = 0.0;
g = (level - 0.15) / (0.275 - 0.15);
b = 1.0;
} else if (level >= 0.275 && level < 0.325) {
r = 0.0;
g = 1.0;
b = (0.325 - level) / (0.325 - 0.275);
} else if (level >= 0.325 && level < 0.5) {
r = (level - 0.325) / (0.5 - 0.325);
g = 1.0;
b = 0.0;
} else if (level >= 0.5 && level < 0.6625) {
r = 1.0;
g = (0.6625 - level) / (0.6625 - 0.5f);
b = 0.0;
}
// Intensity correction.
double cf = 1.0;
if (level >= 0.0 && level < 0.1) {
cf = level / 0.1;
}
cf *= 255.0;
// Pack RGB values into Cairo-happy format.
uint32 rr = (uint32) (r * cf + 0.5);
uint32 gg = (uint32) (g * cf + 0.5);
uint32 bb = (uint32) (b * cf + 0.5);
return (rr << 16) + (gg << 8) + bb;
}
}
}