Feature request: Removing the restriction on Playback rate to 0.5x, 0.75x, 1x, etc

[lkydev]

Currently the value of "TTS Playback rate" is limited to the values in the drop-down list (0.5x, 0.75x, 1x, 1.25x, etc).

I can't see why a playback rate of 0.75x or 1x (for example) is allowed whereas 0.85x or 0.9x is not.

My request is simply to remove the artificial restriction. I would like to use a rate of 0.9x or 0.85x.

[panaC]

This is not an issue, but rather an open discussion.

[danielweck]

what kind of GUI control would you prefer for selecting predefined values AND also enter abitrary values bounded by a minimum and a maximum (and of course corrected to correct syntax and decimal point roudning)?
would the current pull-down list and combined text input work? (currently the input is for searching/narrowing down an existing value in the hard-coded set, there is no allowance for a totally arbitrary user-entered value)

[lkydev]

If the text input is not bound to the pull-down list, the existing UI could work.

Either: pick a value in the pull-down list and it becomes the box value.
Or: type a value directly into the box.

Alternative GUI could be:

1. Slider

Value can be adjusted using the slider or typing in the box on the right.

2. Arrow buttons

Value can be entered in the middle box, or be controlled by the arrow buttons.

Double arrows increase/decrease value to the next 0.25 boundary - 0.5x, 0.75x, 1x, 1.25x, ... etc.
For example, if value = 1.05x, press >> multiple times will change it to 1.25x, 1.5x, 1.75x, ... etc.

Single arrows increase/decrease value to the next 0.05 boundary - 0.55, 0.60x, ... 1x, 1.05x, 1.10x ... etc.
For example, if value = 1.06x, press << multiple times will change to 1.05x, 1.00x, 0.95x, ... etc.

Just my thought.

[danielweck]

issue: #3589

[danielweck]

Fixed in #3622

The delta is now 0.1, the minimum is 0.2 (inclusive) and the maximum is 6.0 (inclusive). I tested this with TTS readaloud synthetic speech voices on my Mac computer, as well as with pre-recorded audio in EPUB3 Media Overlays publications.

Similarly to the zoom keyboard shortcut (ctrl + 0 to reset, ctrl + 8 to decrease, ctrl + 9 to increase), the audio speed keys are ctrl + 7 to reset, ctrl + 5 to decrease, ctrl + 6 to increase.