class SpectrogramWidget(QtGui.QWidget):
"""
Widget that visualize and interacts with a spectrogram graph
of an audio signal.
"""
# SIGNALS
# CONSTANTS
# Value of the axis lines opacity
AXIS_LINES_OPACITY = 255
# Max amount of columns to show on the visual widget.
MAX_SPECGRAM_COLUMNS = 800
def __init__(self, *args, **kwargs):
QtGui.QWidget.__init__(self)
# variable that handles the manipulation of the spectrogram
# create, recompute etc
self.specgramHandler = Spectrogram()
# create the histogram widget
self.imageItem = ImageItem()
self.__histogram = HorizontalHistogramWidget()
self.__histogram.item.setImageItem(self.imageItem)
# internal vieBox for image graph
self.viewBox = ViewBox()
self.viewBox.addItem(self.imageItem)
self.viewBox.setMouseEnabled(x=False, y=False)
self.viewBox.setMenuEnabled(False)
self.viewBox.setAspectLocked(False)
# set the X and Y axis for the graph
self.xAxis = OscXAxis(self, orientation='bottom')
self.yAxis = SpecYAxis(self, orientation='left')
self.xAxis.linkToView(self.viewBox)
self.yAxis.linkToView(self.viewBox)
self.xAxis.setGrid(self.AXIS_LINES_OPACITY)
self.yAxis.setGrid(self.AXIS_LINES_OPACITY)
# adjust the graph zone in the control
horizontal_histogram = kwargs[
"horizontal_histogram"] if "horizontal_histogram" in kwargs else True
visible_histogram = kwargs[
"visible_histogram"] if "visible_histogram" in kwargs else False
self.__updateLayout(histogramHorizontal=(
horizontal_histogram if visible_histogram else None))
def __updateLayout(self, histogramHorizontal=None):
"""
Updates the layout of the widget to change the histogram
position (horizontal-vertical) and visibility
:param histogramHorizontal: None if invisible, true if horizontal
false if vertical
:return:
"""
# graph_control_layout
self.graphics_view = pg.GraphicsView()
# set the layout of the graphics view internal
# that contains the axis and the view box to graph the spectrogram
graphics_view_grid_layout = QtGui.QGraphicsGridLayout()
graphics_view_grid_layout.setContentsMargins(0, 0, 0, 0)
graphics_view_grid_layout.setHorizontalSpacing(0)
graphics_view_grid_layout.setVerticalSpacing(0)
graphics_view_grid_layout.addItem(self.xAxis, 1, 1)
graphics_view_grid_layout.addItem(self.yAxis, 0, 0)
graphics_view_grid_layout.addItem(self.viewBox, 0, 1)
self.graphics_view.centralWidget.setLayout(graphics_view_grid_layout)
layout = QtGui.QGridLayout()
layout.setContentsMargins(0, 0, 0, 0)
layout.addWidget(self.graphics_view, 0, 0)
# add the elements in row,col
if histogramHorizontal is not None:
row = 1 if histogramHorizontal else 0
col = 1 - row
self.__histogram = HorizontalHistogramWidget() if histogramHorizontal else\
HistogramLUTWidget()
self.__histogram.item.gradient.loadPreset('thermal')
self.__histogram.item.setImageItem(self.imageItem)
layout.addWidget(self.histogram, row, col)
self.setLayout(layout)
# region Signal Property
@property
def signal(self):
return self.specgramHandler.signal
@signal.setter
def signal(self, signal):
if signal is None or not isinstance(signal, AudioSignal):
raise ValueError(
"Invalid assignation. Must be of type AudioSignal")
self.specgramHandler.signal = signal
max_columns = max(self.viewBox.width(), self.MAX_SPECGRAM_COLUMNS)
self.specgramHandler.recomputeSpectrogram(maxCol=max_columns)
# updating the axis scales
self.xAxis.scale = self.specgramHandler.signal.samplingRate
# updating the frequencies present in the signal
# samplingRate/2 by Nyquist theorem. After update the spectrogram handler
# there is an array in the specgramHandler with the freqs returned by the specgram
# freqs is an array with the values of the frequency of each row of the specgram matriz
self.yAxis.frequencies = self.specgramHandler.freqs
# endregion
# region Histogram Prop
@property
def histogram(self):
"""
Histogram widget with the values of the image.
interacts with the image graph to change its color,
threshold etc. Allow to visualize it outside the spectrogram widget
:return:
"""
return self.__histogram
# endregion
def getInfo(self, x, y):
"""
Gets the values at x, y in the spectrogram
:param x: the time position in rows of the spectrogram matriz
:param y: the freq position in columns of the spectrogram matriz
:return: a tuple with (time, freq, intensity)
"""
return self.specgramHandler.getInfo(x, y)
def graph(self, indexFrom=0, indexTo=-1, padding=0):
indexTo = indexTo if (indexTo >= 0
and indexTo > indexFrom) else self.signal.length
# avoid to set the max columns too high that the spectrogram cant be computed
# and do not consume more resources that necessary
# show at most as many columns as pixels in the widget's width
max_columns = max(self.viewBox.width(), self.MAX_SPECGRAM_COLUMNS)
self.specgramHandler.recomputeSpectrogram(indexFrom, indexTo,
max_columns)
self.yAxis.frequencies = self.specgramHandler.freqs
# set the new spectrogram image computed
self.imageItem.setImage(self.specgramHandler.matriz)
self.viewBox.setRange(
xRange=(self.specgramHandler.from_osc_to_spec(indexFrom),
self.specgramHandler.from_osc_to_spec(indexTo - 1)),
padding=padding)
# update the histogram colors of the spectrogram
self.histogram.item.region.lineMoved()
self.histogram.item.region.lineMoveFinished()
self.xAxis.setRange(indexFrom, indexTo)
self.update()
