Blender Tool

Audio Analysis

The Audio Analysis tool converts an audio signal's strength into an Ipo Curve. This allows items in Blender to change their properties, synchronised to a sound file.

Download

Audio Analysis v1.1.0

Installation

Instructions are written for UNIX users. Windows users will have to limp along.

1. Unpack the archive to a known location:

   su -
   cd /usr/local/src
   unzip audio-analysis-1.1.0.zip
   

2. Copy the files into Blender's scripts directory. The location will vary, depending on where Blender is installed. For example, if Blender is installed in /opt/blender then do the following, as root:

   cd audio-analysis-1.1.0
   cp *.py /opt/blender/.blender/scripts
   

   MacOS users, copy the files into the following directory:

   /Applications/Blender/Blender.app/Contents/MacOS/.blender/scripts/

3. Restart Blender.

Audio Analysis is now installed.

Overview

Running the script (Script » Misc » Audio Analysis) causes the following buttons to appear:

As well, the following canvas appears next to the buttons:

The widgets and buttons have the following behaviours:

• Open. Click this button to select a .wav file to analyse.
• Filename. The name of the audio file to analyse; this must be in .wav format.
• Curve Name. The name of the Ipo curve to create.
• Ipo Type. The type of Ipo to create (default: Lamp).
• Curve Type. The type of attribute associated with an Ipo (default: Energ).
• Scale. Power values, by default, range from 0 to 32768. The Scale parameter reduces the Power Max value to this amount. For example, if there were three power values: 10, 10000, and 32768, then a Scale factor of 100 would reduce them to 0.03, 30.517, and 100, respectively.
• Interval. The number of frames that must pass between one sample that matches the power range and the next. Measured in seconds, the lowest reasonable value is 0.04 (which equals one frame at 25 frames per second). Increasing this value will provide fewer data points, resulting in a smoother curve.
• Attack. Plots a zero-amplitude point a number of seconds before the data point. Do not set this less than the sum of the interval and decay.
• Decay. Plots a zero-amplitude point a number of seconds after the data point. Do not set this less than the sum of the interval and attack.
• Power Min. The minimum volume value to record as a data point. For loud sounds, set this value high and leave Power Max alone.
• Power Max. The maximum volume value to record as a data point. For quiet sounds, set this value low and set Power Min to 0.
• Plot. Click this button to generate the Ipo curve based on the values present in the audio file.
• Exit. Closes the script.

Usage

For more information on how to use the tool, read the Thunder and Lightning tutorial.