Macros

Gale 13Feb13: ToDo-2 Although clearly this is much better than before, equally clearly there are still debates about the manner of presentation of this landing page and how much complexity it should have. So it is hardly finished.

• Peter 12Feb13:I really do prefer the top version on the Talk page where the "Examples" note div is positioned at the foot of the page.

Peter 13Feb13:Strawman-4 - does this consolidated version flow better and avoid repetition?

• Ed 13Feb13 : I really like this! Again, I would point out that this is a good place for non-standard images - add more chains and shrink down the window to its bare minimum.
  • ToDo-2 Edit Chains image needs redoing anyway - should not have had access key underlines. I am not sure about non-standard images on this page (meaning whatever the final version of this is). Wouldn't non-standard images be better on the split pages? Or are we still trying to make this page a tutorial?
• Gale 14Feb13: Thanks, Peter. Perhaps it is your best yet, but I still don't like it very much. The intro has become a sea of text again, and the sections give the same impression. You cannot see by skim read what the workflow is, and the direct comparison with mine (Apply Chain) shows that yours has twice the text, repeats itself, and doesn't highlight what matters (you have to close the project first if you are applying to files). We mention trivia that doesn't belong here like going up and down on the keyboard in Apply Chain, but say nothing about having to set export parameters outside the Chain.

  So I suppose I've still got to see if I can produce something "better", or tweak this, or accept everyone else likes this. It's not bad, I just think it should include the GOTCHAS that people trip over, and could be so much easier to follow (yes, like a workflow). If they are not good, why do we have them?

A Chain is a sequence of preconfigured commands in a set order (mainly effects) that can be applied automatically to projects or audio files. Any built-in or Nyquist effect shown in the Effect Menu and export commands can be added to a Chain. There are two related Chain commands in the File Menu called Edit Chains and Apply Chain.

The two uses of Chains are for:

• Batch processing (where many audio files are processed unattended with one or more effects then saved to a new file),
• Effects automation (where the track or tracks in the current project are subjected to the same prescribed sequence of effects, and optionally, a file exported).

See the examples below.

Edit Chains

Use File > Edit Chains... if you need to create a new Chain or to edit an existing Chain. To create an audio file as part of the Chain process you must include a command that exports an audio file such as ExportWav. The Chain can include a number of common Audacity functions and effects to be executed in any order you specify. In many cases the parameters for each command in the Chain can be specified within the Edit Chains window.

The left hand box in the dialog box (labeled Chains) contains a list of already defined Chains. You can define the name of a new Chain and select which Chain is active by using the Add, Remove and Rename buttons.

The right hand box (labeled Chain) lists the ordered sequence of commands for the Chain selected in the "Chains" box on the left. Here you can add or remove commands for the selected Chain, change the order in which the commands execute in the Chain, or edit the parameters for some effects in the Chain.

For further details see the Edit Chains page.

Apply Chain

Use File > Apply Chain... to select one of the existing chains and apply it to either:

• The project in the current window (this is essentially a method of effects automation)
  

or

• A selected list of external audio files in a single directory (this is essentially an unattended batch processing of many individual items)

The dialog window contains the list of all your current chains. Use left-click (or use the Up or Down arrow on the keyboard) to select the Chain you want to apply. Then use the Apply to Current Project button for effects automation or the Apply to Files button to apply the selected chain to a set of files which you select (the current Audacity Project window must be empty to use this option).

For more details see the Apply Chain page.

Examples:

• A batch processing Chain might use Compressor to reduce the dynamic range of multiple WAV files (also normalizing them to maximum amplitude of 0 dB), then convert them to MP3 format.
• An effects automation Chain for the current project might run:
  1. Normalize with settings of:
     • Remove any DC offset
     • -10 dB (to allow for boosting frequencies later in the Chain without clipping)
  2. Noise Removal
  3. Equalization (to perform the frequency adjustment)
  4. Normalize again at different settings (without offset removal, setting a final amplitude of -1 dB).