Description
The Problem
The spec does not require support for negative playback rates. Some browsers support a negative playback rate, others do not.
| Browser | Support? |
|---|---|
| Safari | ✔ |
| Chrome | ✘ |
| Firefox | ✘ |
| Edge | ? |
Should I add other browsers to this table?
Proposed Changes
- an update to the spec to require support for negative playback rate
- browser willingness to implement the functionality
Perhaps it would make sense to require the same playback rates in both directions. So if a browser supports from +0.1 to +16, then it would also need to support -0.1 to -16.
Previous discussion
Firefox
@cpearce from the Mozilla team summarized the opinion of the Firefox team over in #2754 (comment) :
As a feature, it seems more of a gimmick, a usage pattern left over from the days of VCRs, rather than something which will have significant use in the modern web. We don't see a compelling use case for it.
Chrome
It has probably been discussed somewhere, but I do not where the discussion is at this time. I couldn't find an existing Chromium issue.
Usefulness
I originally described this example over in #2754 (comment)
Video editing in the browser is one area where negative playback rates would be useful. In Adobe Premiere, a popular video editing tool, there are 3 hotkeys that are used for "shuttling" (moving through the video): J, K, and L.
| Hotkey | Behavior |
|---|---|
| J | play the video in reverse. continually press it to increase the (negative) playback speed |
| K | pause the video, and set the playback speed to 1 |
| L | play the video in the forward direction. continued presses increase the (positive) playback speed |
Users of Premiere are constantly using this system to navigate videos, and anyone who is making a video editor in the browser will likely want to reproduce this same workflow.
A tutorial demonstrating shuttling in Premiere can be viewed on YouTube here.
Relevant links
I'll find and/or create links on the relevant browser issue trackers, but I haven't yet.
- Chromium issue
- Bugzilla issue
- Motivating comment: This is the comment from @annevk that motivated me to open this issue.