Stretch CHOP


The Stretch CHOP preserves the shape of channels and the sampling rate, but resamples the channels into a new interval. All data in the range is stretched or compressed to the new start and end positions.

A Reverse Interval parameter reverses the order of the samples of each channel.


Parameters - Stretch Page

Interpolation interp - - The interpolation method to use when resampling.

  • No Interpolation nointerp - Use the value of the nearest sample.
  • Linear linear - Use linear interpolation between samples when the interval is lengthened. Averages all samples near the new sample when the interval is shortened.
  • Cubic cubic - Cubically interpolates between samples, for smoother curves than Linear. This method is not recommended for channels with sharp changes.
  • Pulse Preserve edge - A linear interpolation that recognizes single sample pulses and preserves their height and one sample width. A pulse is a non-zero value preceded and followed by zero-value samples.

Constant Area constarea - If enabled, keeps the area under the channel constant by scaling the values of the channel.

Unit Values relative - - Determines how Start/End parameters are interpreted:

  • Absolute abs - The value is the new start/end position.
  • Relative to Start/End rel - The value is a shift from the old start/end position.
  • Relative to Current Frame cur -

Start start - The CHOP's new start position.

Start Unit startunit -

End end - The CHOP's new end position.

End Unit endunit -

Length Scale scale - Scales the length of the channel after determining the start/end interval. Good for doubling or halving the length.

Reverse Interval reverse - Reverses the channel so that it plays backwards.

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. See Pattern Matching.

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).

Operator Inputs

  • Input 0: -
  • Input 1: -

Info CHOP Channels

Extra Information for the Stretch CHOP can be accessed via an Info CHOP.

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.

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