audio/waveform.mp3 must be an existed file?

[AsashioB]

If I want to handle an generated file, what should I do?

[ryanheise]

Even if you generate a file, it still has a file path, doesn't it?

[hey-nicolasklein]

I think OP is referring to the generation of waveforms e.g. during an audio recording. In this case there is no path for the file. But you could provide a stream of amplitude values.

OP should probably use the AudioWaveformWidget and Painter from the example. The just waveform packet is for extracting the amplitude values, not for visualizing them directly. In addition, most recording packages provide the amplitude values during recording. So there is no need for just waveforms.

[ryanheise]

You could be right that that is what @AsashioB means (in which case your answer is correct), although to me the question is still not clear. Since @AsashioB hasn't responded, I'll close this issue.