# -*- coding: utf-8 -*-
#
# Copyright (c) 2007-2010 Guillaume Pellerin <yomguy@parisson.com>
# Copyright (c) 2010 Olivier Guilyardi <olivier@samalyse.com>
# This file is part of TimeSide.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program 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 Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from timeside.core import implements, interfacedoc
from timeside.core.api import IGrapher
from timeside.core.grapher import Grapher, Image
from timeside.plugins.grapher.color_schemes import default_color_schemes
from . utils import interpolate_colors
import math
[docs]class SpectrogramLog(Grapher):
"""Logarithmic scaled spectrogram (level vs. frequency vs. time).
Adds pixels iteratively thanks to the adapter providing
fixed size frame buffers."""
implements(IGrapher)
@interfacedoc
def __init__(self, width=4096, height=256, bg_color=(0, 0, 0),
color_scheme='default'):
super(SpectrogramLog, self).__init__(
width, height, bg_color, color_scheme)
self.lower_freq = 100
self.colors = default_color_schemes[color_scheme]['spectrogram']
self.pixels = []
self.y_to_bin = []
[docs] @staticmethod
@interfacedoc
def id():
return "spectrogram_log"
[docs] @staticmethod
@interfacedoc
def name():
return "Spectrogram Log"
[docs] @staticmethod
@interfacedoc
def version():
return "1.0"
[docs] @interfacedoc
def setup(self, channels=None, samplerate=None, blocksize=None,
totalframes=None):
super(SpectrogramLog, self).setup(
channels, samplerate, blocksize, totalframes)
self.image = self.image.convert("P")
self.image = self.image.transpose(Image.ROTATE_90)
self.image.putpalette(interpolate_colors(self.colors, True))
self.set_scale()
[docs] def set_scale(self):
"""generate the lookup which translates y-coordinate to fft-bin"""
f_min = float(self.lower_freq)
f_max = float(self.higher_freq)
y_min = math.log10(f_min)
y_max = math.log10(f_max)
for y in range(self.image_height):
freq = math.pow(
10.0, y_min + y / (self.image_height - 1.0) * (y_max - y_min))
fft_bin = freq / f_max * (self.fft_size / 2 + 1)
if fft_bin < self.fft_size / 2:
alpha = fft_bin - int(fft_bin)
self.y_to_bin.append((int(fft_bin), alpha * 255))
def draw_spectrum(self, x, spectrum):
for (index, alpha) in self.y_to_bin:
self.pixels.append(
int(((255.0 - alpha) * spectrum[index] + alpha * spectrum[index + 1])))
for y in range(len(self.y_to_bin), self.image_height):
self.pixels.append(0)
[docs] @interfacedoc
def process(self, frames, eod=False):
if len(frames) != 1:
chunk = frames[:, 0].copy()
chunk.shape = (len(chunk), 1)
for samples, end in self.pixels_adapter.process(chunk, eod):
if self.pixel_cursor < self.image_width:
(spectral_centroid, db_spectrum) = self.spectrum.process(
samples, True)
self.draw_spectrum(self.pixel_cursor, db_spectrum)
self.pixel_cursor += 1
return frames, eod
[docs] @interfacedoc
def post_process(self):
""" Apply last 2D transforms"""
self.image.putdata(self.pixels)
self.image = self.image.transpose(Image.ROTATE_90)