Sounds recorded in certain situations are glitchy

[ericrosenbaum]

Expected Behavior

The sound recorder should be able to record audio smoothly and continuously no matter what else Scratch is doing.

Actual Behavior

In some cases, recorded sounds have loud crackles and other glitches in them.

I have observed this:

• On a Chrome Book, while the video motion extension is running
• On my Macbook Pro, in Chrome, while the video motion extension is running
• On my Macbook Pro, in Safari, in a project that is not currently running but has 14 bitmap assets that are 480x360
• @kathymakes reports a similar problem when recording sound on an Android tablet

Steps to Reproduce

• Enable the "video sensing" extension
• Record a sound and play it back

OR

• Use Mac Safari
• Add a dozen full stage size bitmap assets
• Record a sound and play it back

Operating System and Browser

Mac OS 10.13.2 Chrome 65
Samsung Chrome Book
Android tablet

[kerrtravers]

I can definitely repro this. macOS 10.13.3, Chrome Latest.