Reading raw data from a .wav audio file

[helen....@gmail.com]

We want to record short periods (1-10 seconds) of microphone input in an uncompressed format (a .wav file would be ideal), and then access the raw data to plot it within the app.  At the moment, we can only see how to record .mp4 format files... is there a way to record a .wav file in App Inventor?  And once we've got that, do we have to read it as a text file, or is there a more efficient way to display the waveforms directly?   Thanks!

[Taifun]

unfortunately you can't record wav files with App Inventor

but probably there is an API available, which can convert a mp4 file into wav?

you can do a search here: programmableweb.com

Taifun

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Trying to push the limits of App Inventor! Snippets and Tutorials from Pura Vida Apps by Taifun.         

[Scott Ferguson]

Are you using the Camcorder component to record a video with the camera to get the mp4 file?

On my tablet, recording audio with the SoundRecorder component saves the audio file with a 3gp extension.

There appear to be at least three javascript libraries that support display of waveform data.

Here is one.

It is not clear what audio formats are supported, but if recording with the Camcorder component you may need to spit the audio out before the waveform can be displayed.

But regardless of which library is used, I can envisionn the process as record the audio or video (if recording video a javascript library must be found to split out the audio) and send the link to the audio or video file with WebViewString to an html document that uses a javascript library to display the waveform in the WebViewer.

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sf