Macros

Ed 7Feb13: I am going to top post this on this strawman as a ToDo – some of us have made wording changes on one or more of these strawman pages; before publishing one of them we need to go back with a fine tooth comb and make sure all the tweaks end up in the final published page.

• Peter 8Feb13: Until we decide otherwise THIS is the primary strawman and the following ones are kite-flying style suggestions, until we decide otherwise. So major changes should ideally be made here. But yes I have been striving to keep these 3 strawmen in step (not easy as you imply Ed) and I note that Gale has in the meantime made changes to Apply Chain thus rendering Strawman-3 out of date (but fixable). It would help me greatly if we could decided soonest which of the the 3 styles we prefer. I think Strawman-2 the fully consolidated has been ruled out but we still need to decide between #1 and #3. What we should remember is that either of these versions is vastly superior to the current inadequate Batch Processing page which kicked this particular project off.
• Peter 9Feb13:Following our discussions and voting (and in the Adacity spirit of "doer decides") I have changed the title of this page. For me this is the primary strawman, to the extent that I have stripped off the user page designation from this page, effectivley publishing it in the manual, it is not yet replacing the current Batch Processing in the manual and is not linked to to from anywhere apart from my user pages for now. But I would like to take this oppportunity to request greenlight for formal publication and linkage, removing the old Batch Processing page - @Gale: I think that that is down to you as you hold the veto rights.
  • This does not preclude us from still considering a two-page solution or even a consolidated solution as they can easily be constructed from this page and the material on Edit Chains and Apply Chain. For the time being I do propose to retain Strawmen #2 and #3 on my user pages for reference, see: User:PeterSampson/Chains - for batch processing and effects automation - Strawman-2 and User:PeterSampson/Chains - for batch processing and effects automation - Strawman-3

Gale 09Feb13: OK I'm reviewing this, at the moment for intro, workflow and examples.

1. I have moved the export stuff out of the intro into the workflow.
2. I think the examples are insufficiently explained (in the absence of a "tutorial") so I have expanded them into their own note div. This makes me wonder if the details of the examples should be completely separate underneath the workflow. ATM I am fairly sure this works better. See this way of doing it on the Talk page. Can we decide this fundamental first? Also if this is the better way, I am wondering if we can work a trimmed version of the Edit Chains and Apply Chains sections (possibly still with their images) into the workflow. Then we have Intro - Workflow - Examples (that's it).

• Peter 10Feb13: I still think it's fundamentally more importtant to tell the user waht the functionality is for before you get into the nitty gritty of how to use it. Ok, the re-titling is a good clue to the reader here - but it also means that I prefer to see the ordering on this page with the "example" note coming before the Workflow section. But I also agree with Ed that I don't like a note dive immediately following an intro div. Two solutions: a) consolidate the intro div and the note div making a longer intro div, or b) turn the "example" note into a suitable H2 headered plain text initial section.

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 can be added to a Chain.

The two uses of Chains can be seen as batch processing and effects automation as illustrated in the following 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).

Workflow

There are two related Chain commands in the File Menu called Edit Chains and Apply Chain. The workflow is as follows.

1. First, use File > Edit Chains... to create a new Chain or to edit an existing Chain (if required).
   • To save an audio file as part of the Chain process, you must either:
     • add an Export command for 16-bit WAV, MP3, FLAC or OGG (which use any currently set "Options" for that format in the File Export Dialog ) or
     • use one or both commands to save "MP3_56k" (a low quality MP3 at 56 kbps bit rate).
2. Second, 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 (this is essentially an unattended batch processing of many individual items).

Edit Chains

Enables you to either edit, remove or rename existing Chains, or add a new Chain. 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.

Accessed by: File > Edit Chains...

The left hand box in the dialog box (labeled Chains) 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

Enables you to select a Chain and apply it to either the entirety of the current project, to a single audio file or to a group of specifically selected audio files in a single directory.

Accessed by: File > Apply Chain...

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 (you must have a new, empty Audacity Project window open to use this option).

For more details see the Apply Chain page.