Audio File In CHOP


The Audio File In CHOP reads audio from files on disk or at http:// addresses. File types .mp3, .aif, .aiff, .au, and .wav files are supported. It always outputs time sliced audio data. If you want to record the data, use a Record CHOP or Movie File Out TOP.

See Audio Movie CHOP for reading from movie files. See OSC In CHOP for receiving audio streams via OSC.

For large files the Audio File In CHOP streams the file from disk so loading the entire file into memory is not needed.

  • It streams files from disk and from http: locations (latter copies to local disk first) - It only keeps a few seconds in memory at a time.
  • The supported audio files are .mp3 .aif .aiff .wav and other audio formats.
  • It also plays audio-only from any movie files that TouchDesigner supports, like .mov, .mpg .mp4. See also the Audio Movie CHOP for playing audio from movie files in sync with their video.
  • Audio files can be dragged/dropped onto TouchDesigner, double-clicked (if preferred), and RMB Open With... TouchDesigner.


Parameters - Audio File In Page

File file - Path of source.

Reload reloadpulse - Instantly reload the file from disk.

Play play - Audio will playback when this is set to 1 and stop when set to 0.

Play Mode playmode - - Specifies the method used to playback the audio, there are 3 options.

  • Locked to Timeline locked - This mode locks the playback position to the timeline. Scrubbing or jumping in the timeline will change the song position accordingly. The parameters Play, Reset, Speed, and Index are disabled in this mode since the timeline is directly tied to playback position.
  • Specify Index specify - This mode allows the user to specify a particular position in the song using the Index parameter below. Use this mode for random access to any location in the audio stream.
  • Sequential sequential - This mode continually plays regardless of the timeline position (the Index parameter is disabled). Reset and Speed parameters below are enabled to allow some control.
  • Timecode Object/CHOP/DAT timecodeop - This mode allows the user to set the movie index by reference to a timecode in the form of either a CHOP, DAT, or Timecode Class object.

Speed speed - This is a speed multiplier which only works when Play Mode is Sequential. A value of 1 is the default playback speed. A value of 2 is double speed, 0.5 is half speed and so on. This node can not play audio backwards so negative values will not work well.

Cue cue - Jumps to Cue Point when set to 1. Only available when Play Mode is Sequential.

Cue Pulse cuepulse - Instantly jumps to the Cue Point.

Cue Point cuepoint - Set any index in the song as a point to jump to.

Cue Point Unit cuepointunit - Units used when setting the Cue Point parameter.

Index index - This parameter explicitly sets the song position when Play Mode is set to Specify Index. The units menu on the right lets you specify the index in the following units: Index, Frames, or Seconds.

Index Unit indexunit - Units used for the Index parameter.

Timecode Object/CHOP/DAT timecodeop - Set the audio file index with a reference to a timecode. Should be a reference to either a CHOP with channels 'hour', 'second', 'minute', 'frame', a DAT with a timecode string in its first cell, or a Timecode Class object.

Repeat repeat - - Repeats the audio stream when the end is reached.

  • Off off -
  • On on -

Trim trim - Enables the Trim parameters below.

Trim Start trimstart - Sets an In point from the beginning of the audio, allowing you to trim the starting position of the audio stream. The units menu on the right let you specify this position by index, frames, or seconds.

Trim Start Unit trimstartunit - Units used for the Trim Start parameter.

Trim End trimend - Sets an Out point from the end of the audio, allowing you to trim the ending position of the audio stream. The units menu on the right let you specify this position by index, frames, or seconds.

Trim End Unit trimendunit - Units used for the Trim End parameter.

Pre-Read Length prereadlength - The amount of audio to buffer to maintain smooth playback.

Pre-Read Length Unit prereadlengthunit - Units used for the Pre-Read Length parameter.

Open Timeout opentimeout - The time (in milliseconds) TouchDesigner will wait for the audio file to open. If the Open Timeout time is reached, the Audio File In CHOP will stop waiting, and play silence. If the file still isn't opened the next time the CHOP cooks, it'll wait again, and do the same. It'll keep doing this until the file is opened, or the open fails.

Mono mono - Output mono channel only even if file has multiple channels.

Volume volume - Set the level the file is read in at. A setting of 1 is full signal while 0 is muted.

Parameters - Common Page

Time Slice timeslice - Turning this on forces the channels to be "Time Sliced". A Time Slice is the time between the last cook frame and the current cook frame.

Scope scope - To determine which channels get affected, some CHOPs use a Scope string on the Common page.

Sample Rate Match srselect - - Handle cases where multiple input CHOPs' sample rates are different. When Resampling occurs, the curves are interpolated according to the Interpolation Method Option, or "Linear" if the Interpolate Options are not available.

  • Resample At First Input's Rate first - Use rate of first input to resample others.
  • Resample At Maximum Rate max - Resample to the highest sample rate.
  • Resample At Minimum Rate min - Resample to the lowest sample rate.
  • Error If Rates Differ err - Doesn't accept conflicting sample rates.

Export Method exportmethod - - This will determine how to connect the CHOP channel to the parameter. Refer to the Export article for more information.

  • DAT Table by Index datindex - Uses the docked DAT table and references the channel via the index of the channel in the CHOP.
  • DAT Table by Name datname - Uses the docked DAT table and references the channel via the name of the channel in the CHOP.
  • Channel Name is Path:Parameter autoname - The channel is the full destination of where to export to, such has geo1/transform1:tx.

Export Root autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is Path:Parameter are relative to.

Export Table exporttable - The DAT used to hold the export information when using the DAT Table Export Methods (See above).

Info CHOP Channels

Extra Information for the Audio File In CHOP can be accessed via an Info CHOP.

Specific Audio File In CHOP Info Channels

  • sample -
  • true_sample -
  • fraction -
  • file_length -
  • file_length_frames -
  • true_file_length -
  • true_file_length_frames -
  • open -
  • opening -
  • open_failed -

Common CHOP Info Channels

  • start - Start of the CHOP interval in samples.
  • length - Number of samples in the CHOP.
  • sample_rate - The samplerate of the channels in frames per second.
  • num_channels - Number of channels in the CHOP.
  • time_slice - 1 if CHOP is Time Slice enabled, 0 otherwise.
  • export_sernum - A count of how often the export connections have been updated.

Common Operator Info Channels

  • total_cooks - Number of times the operator has cooked since the process started.
  • cook_time - Duration of the last cook in milliseconds.
  • cook_frame - Frame number when this operator was last cooked relative to the component timeline.
  • cook_abs_frame - Frame number when this operator was last cooked relative to the absolute time.
  • cook_start_time - Time in milliseconds at which the operator started cooking in the frame it was cooked.
  • cook_end_time - Time in milliseconds at which the operator finished cooking in the frame it was cooked.
  • cooked_this_frame - 1 if operator was cooked this frame.
  • warnings - Number of warnings in this operator if any.
  • errors - Number of errors in this operator if any.

TouchDesigner Build: