iOS: Bluetooth audio drops out with higher playback speeds
This has been an issue for about a year (see attached iOS App Store review -- not mine, just to mark time), but I don't see any existing issues so thought I'd make one.
I live in an area with very poor internet (reliability and speeds), and I use VLC mostly to watch online educational content that I download overnight (or over the course of several days or weeks) while I walk to work or do chores. I have my default playback speed set to 1.5x, which suits my needs.
Unfortunately, my bluetooth headphones (Apple AirPods) lose audio any time I scrub playback position. When I started having this issue a year or so ago, I noted the attached app store review that noted that lowering the playback speed seems to bring the audio back, and indeed it does. Every time I scrub position (or even just jump 15 seconds forward or back), it almost always loses audio, so I bring up the clock button (bottom left corner), transiently drop playback speed down to <0.8x, which brings back the audio, then I can bring it back up to 1.5x and it continues.
If I leave the default speed at 1x, everything seems to work fine -- audio continues as expected in spite of scrubbing. However, if I put default at 1x but manually take the speed back to 1.5x the symptoms return.
I'm using an iPhone X on iOS12.1, but I believe noticed the behavior first on my iP7 / iOS11. It is the same with Apple Airpods, Anker Soundbuds Curve, and using my Amazon Echo as a bluetooth speaker. I have tried toggling settings regarding time stretching audio and hardware video decoding with no change in behavior. I've seen the behavior with a number of types of video files. I'm currently on VLC 3.1.3 and have noticed this for around a year (likely ~2.8.4 or so?), but I can't say exactly when it started.
I've attached a screen recording of this behavior, including the audio (which is coming through my bluetooth headset, that I positioned near my iPhone's microphone). It goes through the audio loss 3 times -- the first two to show the process, and the 3rd time I leave a longer lag time to show that the audio doesn't seem to fix itself spontaneously (IOW showing that changing the speed slower doesn't seem just coincident with the restoration of audio, but causative).
- Screen Recording: 11-05-2018_13-07-49
Thanks for your work on a great product. I've never done any iOS or Swift / ObjC development and would be in far over my head, but I'd be happy to try to help figure out the issue.
