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FFmpeg.wasm

Process audio and video files using FFmpeg.wasm

Actions21

Speed Adjustment

AI-generated

Summary

Adjusts video/audio playback speed using FFmpeg setpts and atempo filters.

Inputs

  • binaryPropertyName — Name of the binary property containing the input file. Default: 'data'.
  • outputBinaryPropertyName — Name of the binary property to store the output file. Default: 'data'. Hidden for 'metadata' operation.
  • speedValue (required) — Playback speed multiplier. Options: 0.25x (Very Slow), 0.5x (Slow), 0.75x (Slightly Slow), 1.25x (Slightly Fast), 1.5x (Fast), 2x (Double Speed), 4x (Quadruple Speed). Default: '2'.
  • adjustAudioPitch — Whether to adjust audio speed to match video. Recommended default: true. Displayed only for 'speed' operation.
  • speedOutputFormat — Output file format extension. Default: 'mp4'. Displayed only for 'speed' operation.
  • additionalOptions — Additional FFmpeg execution options. Collection with: timeout (number, default 300s), enableLogging (boolean, default false), encodingPreset (options, default 'ultrafast' with choices: ultrafast, superfast, veryfast, faster, fast, medium).

Output shape

Binary data property named by outputBinaryPropertyName containing the speed-adjusted media file, plus JSON metadata with ffmpeg operation, inputFilename, outputFilename, and size.

If adjustAudioPitch is false, audio is stripped via '-an'. Video is re-encoded with libx264 for x264 formats (mp4, mkv, mov, ts, avi, flv, wmv, 3gp) using the selected preset; otherwise the video stream is copied. Output format defaults to mp4.

Examples

Example 1: Double the playback speed of a video, keeping audio pitch intact.

Set speedValue to '2', leave adjustAudioPitch at default true, set speedOutputFormat to 'mp4'.

Example 2: Halve the speed of a video without modifying audio.

Set speedValue to '0.5', set adjustAudioPitch to false, set speedOutputFormat to 'mp4'. Audio will be stripped from the output.

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