AVF and DirectShow and access to media tracks and raw data

Paul Dupuis paul at researchware.com
Thu Nov 21 12:29:06 EST 2019

The evolution of LiveCode from Quicktime (OSX/Win) to AVF (OSX) and 
DirectShow (Win), while necessary, lost some potentially useful features.

Under Quicktime you have several player properties to see what "tracks" 
the player file has and to turn those track on and off.

With the current Player object you have the mediaTypes property, which 
appears to provide the tracks and that's it.

What I am really looking for is library or code to extract the audio 
track from videos? And subsequently to that, get access to the raw audio 
data as a string of bytes.

I am aware of an older LC stack, AudioWaveForm, written i believe by 
Mark Smith, that parsed raw audio data via a live code script for a very 
limited set of audio formats ( I that was just uncompressed AIC or WAV 
audio files)

Has anyone built a library or L9 widget that converts audio to a wave 
form image for display? Or at least lets you get the uncompressed audio 
byte data from a variety of video and audio sources?

Baring that, does any one know of a set fo OS APIs or 3rd party open 
source library that could be wrapped by LC9's FFI interface into a 
widget or library?

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