Audio Play CHOP

From TouchDesigner 099 Wiki


The Audio Play CHOP plays back a sound file through any attached audio output device using DirectSound. It supports .aif, .mp3, .mid, .wav and .m4a files up to 48.000 kHz, which can have mono, stereo or even up to 5.1 channels in them. The audio channels can then be routed to any speaker location that DirectSound uses. See Outputs section below.

NOTE: With the Audio Play CHOP, audio samples do not enter or pass through TouchDesigner, so you will not see them in CHOPs, and you cannot process them in CHOPs. The Audio Play CHOP starts an external process that opens the file and sends it directly to the the audio outputs of your computer. If you want to process the audio within TouchDesigner or output them into a Movie File Out TOP or Audio Device Out CHOP, use the Audio File In CHOP.

The Audio Play CHOP contains a channel called state. This channel is 1 whenever any file is being played, 0 otherwise.

The first input (Input 0:Triggers) is used to trigger the audio file to play. The second input (Input 1: Volume) can be used to control volume, if no input is connected the Volume parameter will be used. The third input (Input 2: Pan) is for panning, no input assumes it is centered. When using the DAT List parameter, the inputs can contain mulitiple channels to manipulate each file individually. Multiple Audio Play CHOPs can output to different devices simutaneously.

It can also be triggered by the Trigger parameter below, but in this case if multiple files are specified via the DAT List, then all files will be played at the same time when triggered.

Sound files can also be triggered through the play() method audioplayCHOP_Class. Some advanced options are only available through the audioplayCHOP_Class.

The file can be read in from disk or from the web. Use http:// when specifying a URL.

PythonIcon.png audioplayCHOP_Class

Parameters - Audioplay Page

Device /device - A menu of available audio devices to output to. Selecting default sets the audio device to that which is selected in Windows Control Panel>Sound>Playback.

Sound File /file - .aif, .mp3, .mid, .wav or .m4a audio file. The file can be mono or stereo.

DAT List /datlist - Links to a Table DAT which can be used as list of audio files to choose from. When using the DAT List, the first input (Input 0: Triggers) on the CHOP can contain mulitiple channels to fire the files in the list individually. Using the audioplay command the index can be specified directly.

Volume /volume - 0 = mute, 1 = full volume. Using the second input (Input 1: Volume) or the python .play(volume=val) method, will override the value of this parameter.

Mode /mode - Determines how the audio is triggered when using the first input to trigger.

  • Play While On - Plays while input is 1.
  • Trigger - Triggers once when input goes to 1.
  • Loop - Plays and loops when input goes to 1.

Trigger /trigger - Triggers the audio to play.

Cook Every Frame /cookalways - Forces CHOP to cook every frame.

Parameters - Output 1 Page

Stereo Mode /stereo - Sets output to just 2 channels, front left and front right.

Outputs - The outputs on this page and the following Output 2 page are for routing to an audio device's different speaker outputs. Not all devices will support all outputs. For each speaker output, you can route any of the file's channels to play through it. For example, you can easily output the front left channel of the file to the all the front left speaker outputs, or you could output the front left channel to both front and rear speaker outputs. The value of each output parameter determines which channel from the file it plays, see below.

  • -1 - no audio plays through this output
  • 0 - front left channel will play
  • 1 - front right channel will play
  • 2 - rear left channel will play
  • 3 - rear right channel will play
  • 4 - center channel will play
  • 5 - sub or low frequency channel will play

The following speaker outputs are found on this parameter page.

Front Left
Front Right
Front Center
Low Frequency
Back Left
Back Right
Front Left of Center
Front Right of Center
Back Center

Parameters - Output 2 Page

The following speaker outputs are found on this parameter page.

Side Left
Side Right
Top Center
Top Front Left
Top Front Center
Top Front Right
Top Back Left
Top Back Center
Top Back Right


ASIO not supported.

See also File Types