diathelia / platypus

An audio tool using the Web Audio API to record, visualize and edit mp3 blobs

Platypus

An audio tool which uses the Web Audio API to record, visualize and edit mp3 blobs

Adapted from Zhuker's excellent LAME.js library https://github.com/zhuker/lamejs

The full 4.47mb Library can be found there but is omitted here to reduce app size

Platypus uses a callback polyfill for the Streams API getUserMedia promise

Platypus uses a monkey patch to alias Web Audio API syntax for WebKit browsers

Platypus uses FileSaver.js to give blob downloads semantic filenames instead of UID's

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This repo also contains a feature detection script for all core dependencies and also
run Platypus audio specific tests properties on the following two bugs:

• Sometimes the audio blob is properly encoded but the browser fails to display it;
  to counteract this a sample blob mp3 from Platypus is included to test blob URLs

• Sometimes the hardware and browser prefers sample rates and buffer sizes which
  can cause a sporadic mixture of sped-up playback and high-end artifacts; while this
  is currently fixed via a forced huge bufferSize of 16384 bytes, new devices and
  operating systems may have issues reoccur. To help debug them the preferred
  sample and buffer values are also saved.

When run, this script saves the level of support and preferred sample/buffer values;
these are all returned as an object to the IsMicSupported global module for access