Scrubbing and Seeking

Peter 01May15: Very rough draft notes copied from Notes for Testers in the Wiki.

• Peter 20May15: Updated with Paul's revised UI - notes taken from Paul's email.

Scrubbing is an interaction in which a user drags a cursor across a segment of a waveform to hear it. Scrubbing is a convenient way to quickly navigate an audio file. The term comes from the early days of the recording industry and refers to the process of physically moving tape reels to locate a specific point in the audio track, this gave the engineer the impression that the tape was being scrubbed, or cleaned.

Scrubbing

Finally the promised changes to scrubbing user interface:

• Scrubbing works only in Select tool mode.
• ctrl-click then drag to scrub.
  • Control wheel to vary the speed limit, while scrubbing (not seeking).
• ctrl-double-click then drag to scrub or while keeping the playhead at the midline of the track display.
  • Speed of play and direction of play is controlled by dragging left/right from the center of waveform display
• ctrl-click again to stop, or use space bar or > stop button, etc.
• The transcription toolbar setting determines the initial scrubbing speed limit each time you start scrubbing (under discussion, subject to change).
• The scrubbing position on completion can be marked with a left-click mouse gesture (moves the cursor to that position)

Between clicks, the scrub is governed by mouse movement, the shift key, and the (undepressed) mouse wheel.

Seeking

Like scrubbing but hold the SHIFT button down while in scrubbing mode to seek,

Also notice changes to status bar messages and the Mouse Preferences dialog.

James has changed the colors used for the speed numbers.

Are there any other strong opinions about other details?

1. Keep the transcription toolbar interaction or not
   • Peter 20May15: Definitely not. I still *really*don't like having the single click initial speed and the double click maximum speeds tied to the Transcription Toolbar. Imo scrubbing should work totally independent of Transcription Toolbar - the link is not intuitive and it's not discoverable. I would prefer the single click initial speed to be always 1.0 and I personally would prefer the double click max speed to always be x3. One of the issues is if the user chages the Transcription Toolbar speed and then hides the toolbar. The two pieces of functionality are independent and should remain so and unlinked.
2. Appearance of the speed numbers (font, size, ...)
   • Peter 20May15: I *like* James' new colorway for the speed numbers, much less in-your-face.
3. Range of speed limits (it goes to 32x now, maybe that is excessive)
   • Peter 20May15: The maximum scrubbing speed for single click scrubbing is set to x32.0, that to me seems a ridiculously high speed. Is anybody ever going to scrub at that speed. Anything much above 3.0 is pretty unintelligible to me.
4. Scrubbing backwards (Peter likes it, Gale does not)
   • Peter 20May15: yes I *do* want to keep the backwards scrubbing
5. Others?
6. Scrubbing only works in selection tool now, no longer in Multi-tool in which ctrl-click already had another meaning (time shift).
   • Peter 20May15: I think that's absolutely fine
7. Bug #961 Play cursor broken after double-click scrub play
8. Bug #962 Scrubbing gesture during recording places Audacity in scrubbing mode when recording stops