It is a simple but fairly powerful program for interactive display of sound pressure waveforms, spectral sections, spectrograms, pitch tracks and transcriptions. Without understanding what the heightFactor is for, I wonder if it can be removed. WaveSurfer is an audio editor widely used for studies of acoustic phonetics. In an ideal world the spectrogram plugin could determine the original sampling rate and so something with that information (such as create an audioContext with the same sampling rate) so that it doesn't resample and create that empty space, but I guess in the case of compressed audio this might be trickier. Does anybody know why it was originally set to something other than 1? ![]() The issue appears not to be with the FFT/spectrogram but with that heightFactor. Notice that the original demo.wav file has a sample rate of 22050hz and yet the demo implies there is frequency content above nyquist. This proved important when displaying waveforms with more frequency content if their sampleRate was low since the default audioContext seems to resample things pretty high (44.1 or 48kHz) and this results in a lot of black space at the top of the spectrogram. 0.0.8 Published 3 months ago spectroplot. (spectrogram settings in PRAAT: window length 70ms, view range 5 kHz). react wavesurfer waveform typescript spectrogram microphone canvas pan zoom timeline. I also specified an audioContext with "audioContext: new AudioContext()". Two spectrograms created for the phrase bioacoustics ebook spoken by a male. Changing the heightFactor = 1 fixed things. To start using a plugin, you need to insert the plugin library into your HTML page, alongside wavesurfer. Figure 3: The Spectrogram display, seen at the top of this screen capture, showshow the spectrum changes over time. ![]() In order to get the desired time/frequency resolution of the spectrogram, you can change several parameters in the Propertiesof Spectrogram (Right-click on the spectrogram and select properties). Spectrograms may be viewed in either two or three dimensions and in monochrome or color gradients. Notice that the fundamental frequency is incorrectly labeled at 8kHz. Short description of changes: Change display style property on spectrogram labels from 'fixed' to 'absolute' to correct their position when scrolling, to prevent the spectrogram from scrolling away. Open the file with the spectrogram cofiguration. To demonstrate what I was seeing, we replaced the demo.wav file with a file that contains a 4kHz square wav (wav file with 16kHz sampling rate) and this is what I saw: My coworker came across this bug report when he searched around after we discovered that the spectrogram frequency content was mislabeled and half of what we expected it to be. wavesurfer/CHANGES.md 17, - Add a getFilters method (982) 18, - New feature for spectrogram plugin to display frequency labels 19 20, 1.3.1 ().
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