The waveform operation creates an image showing the temporal audio activity within the recording like this:


The implementation uses an ffmpeg filter that produces a waveform PNG image file from an audio/video file with at least one audio channel.

Parameter Table

configuration example description default
source-flavors */audio Flavor specifying tracks for which a waveform should be created n/a
source-tags edit Tags specifying tracks for which a waveform should be created n/a
target-flavor */waveform Flavor used for the generated waveform n/a
target-tags preview Comma-separated list of tags to be added to the waveform n/a
pixels-per-minute 400 Width of waveform image in pixels per minute 200
min-width 10000 Minimum width of waveform image in pixels 5000
max-width 30000 Maximum width of waveform image in pixels 20000
height 60 Height of waveform image in pixels 500
color black Color of waveform image, see ffmpeg.org/ffmpeg-all.html#Color black
Additional notes:
  • All media, that match either source-flavors or source tags will be processed.
  • Using a wildcard in the target-flavor will cause the main flavor of the input being used.

Operation Example

  description="Generating waveform">
    <configuration key="source-flavor">*/audio</configuration>
    <configuration key="target-flavor">*/waveform</configuration>
    <configuration key="target-tags">preview</configuration>
    <configuration key="pixels-per-minute">200</configuration>
    <configuration key="min-width">5000</configuration>
    <configuration key="max-width">20000</configuration>
    <configuration key="height">60</configuration>
    <configuration key="color">black</configuration>