In Firefox 32, the Web Audio Editor joins the Shader Editor and Canvas Debugger in Firefox Developer Tools for debugging media-rich content on the web. When developing HTML5 games or fun synthesizers using web audio, the Web Audio Editor assists in visualizing and modifying all of the audio nodes within the web audio AudioContext.

Visualizing the Audio Context

When working with the Web Audio API‘s modular routing, it can be difficult to translate how all of the audio nodes are connected just by listening to the audio output. Often, it is challenging to debug our AudioContext just by listening to the output and looking at the imperative code that creates audio nodes. With the Web Audio Editor, all of the AudioNodes are rendered in a directed graph, illustrating the hierarchy and connections of all audio nodes. With the rendered graph, a developer can ensure that all of the nodes are connected in a way that they expect. This can be especially useful when the context becomes complex, with a network of nodes dedicated to manipulating audio and another for analyzing the data, and we’ve seen some pretty impressive uses of Web Audio resulting in such graphs!

To enable the Web Audio Editor, open up the options in the Developer Tools, and check the “Web Audio Editor” option. Once enabled, open up the tool and reload the page so that all web audio activity can be monitored by the tool. When new audio nodes are created, or when nodes are connected and disconnected from one another, the graph will update with the latest representation of the context.

Modifying AudioNode Properties

Once the graph is rendered, individual audio nodes can be inspected. Clicking on an AudioNode in the graph opens up the audio node inspector where AudioParam‘s and specific properties on the node can be viewed and modified.

Future Work

This is just our first shippable release of the Web Audio Editor, and we are looking forward to making this tool more powerful for all of our audio developers.

• Visual feedback for nodes that are playing, and time/frequency domain visualizations.
• Ability to create, connect and disconnect audio nodes from the editor.
• Tools for debugging onaudioprocess events and audio glitches.
• Display additional AudioContext information and support multiple contexts.
• Modify more than just primitives in the node inspector, like adding an AudioBuffer.

We have many dream features and ideas that we’re excited about, and you can view all open bugs for the Web Audio Editor or submit new bugs. Be sure to check out the MDN documentation on the Web Audio Editor and we would also love feedback and thoughts at our UserVoice feedback channel and on Twitter @firefoxdevtools.