Proposal Play-at-Speed

Proposal pages help us get from feature requests into actual plans. This proposal page is about making the Play-at-Speed slider real-time and stretchy.

Proposal pages are used on an ongoing basis by the Audacity development team and are open to edits from visitors to the wiki. They are a good way to get community feedback on a proposal.

• Note: Proposals for Google Summer of Code projects are significantly different in structure, are submitted via Google's web app and may or may not have a corresponding proposal page.

bug 133 is an enhancement request for this and has more details.

Problem

• Play-at-Speed only plays at the speed set when Play-at-Speed was started.
• It is difficult to precisely set a play speed.

20-21 July 2018: These two problems are essentially addressed now.

Proposed Feature

• Integrate Play-at-Speed with the scrubbing code, so that the slider can control the play speed in real time.
• Also support looped Play-at-Speed with dynamic varying speed.
• Also support cut-preview at speed with dynamic varying speed.
• Make the Play-at-Speed control resizable (like meter toolbars) so that greater precision in setting the speed is easy/possible.
• Negative Play-at-Speed
• Remove the Play-at-Speed play button. This will close Bug 815. Instead:
  • All play is play-at-speed
  • The transcription toolbar gains presets for x1 and user chosen speeds.
  • New projects open with the preset set at x1.

A possible Play-At-Speed with presets

Checklist

1. What is the purpose of the feature? - More controllable play-at-speed
2. What is the relative importance of the different features in it? (this is used to justify having a large button, a small button or just a menu item, for example) - The feature uses the same real estate and/or gives the user the option of giving the slider more/less real estate that they previously could not do.
3. Does the feature have modes, and if so how easy are the modes to get out of? (stuck in a mode) - No.
4. Does the feature have invalid states that can be greyed out? - No change from previous Play-at-Speed.
5. What is the factorization of the feature? (e.g. pin/unpin can operate on its own, independent of scrub/seek). - Resizing and real time are separate factors.
6. What are the justifications for 'novelty' in the design? (e.g. RSI free operation, lack-of-precision in conventional sliders). - Resizability gives greater precision
7. Is VI use integral? (e.g. labels added a label editor dialog, essential for VI, useful for non ). - VI users will probably use the numerical controls.

Developer/QA Backing

• James Crook
• Peter Sampson

Details

• We should consider having an easy click-stop at x1, x2 and x3.