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> Yes. Facebook uses a trick to keep running in the background on your phone. At least on iOS, most apps aren't able to run background processes constantly. One

by avenoir 10y ago

> Yes. Facebook uses a trick to keep running in the background on your phone. At least on iOS, most apps aren't able to run background processes constantly. One of the exceptions is apps that play music, so Facebook plays a silent audio clip in the background so it can stay running. Interesting, according to this [1] article, Facebook claimed that running silent audio on a phone was a bug. That's one heck of an interesting bug. [1] https://techcrunch.com/2015/10/22/facebook-says-it-fixed-a-bug-that-caused-silent-audio-to-vampire-your-iphone-battery/ https://techcrunch.com/2015/10/22/facebook-says-it-fixed-a-b...

haikuginger 10y ago
I don't think it's that interesting. My guess is it was a glitch with the logic that autoplays videos silently while you scroll through the feed.
- alphabettsy 10y ago
  A glitch? I'm pretty sure they use location changes to notify the app just like Dropbox does for Auto Photo backup, but either way it's no glitch, audio doesn't even play unless you tap the video unless I'm mistaken.
  - haikuginger 10y ago
    Sure. But the audio has to be ready to play from one of any number of videos immediately that are already playing silently. My guess at architecture is that Facebook grabs audio device priority ahead of time and starts playing silent audio so that they can use their own logic to splice in the audio stream of any tapped video immediately when tapped, rather than first needing to acquire audio device priority. Twitter had something similar for a while; if you were listening to music, then if you scrolled through your timeline and came across an autoplay video (which would play silently at first), your music would stop. They were preemptively grabbing exclusive audio mode in anticipation of needing it for the video, and then playing silence through it until you tapped on the video itself.

by avenoir 10y ago

haikuginger 10y ago

I don't think it's that interesting. My guess is it was a glitch with the logic that autoplays videos silently while you scroll through the feed.

alphabettsy 10y ago
A glitch? I'm pretty sure they use location changes to notify the app just like Dropbox does for Auto Photo backup, but either way it's no glitch, audio doesn't even play unless you tap the video unless I'm mistaken.
- haikuginger 10y ago
  Sure. But the audio has to be ready to play from one of any number of videos immediately that are already playing silently. My guess at architecture is that Facebook grabs audio device priority ahead of time and starts playing silent audio so that they can use their own logic to splice in the audio stream of any tapped video immediately when tapped, rather than first needing to acquire audio device priority. Twitter had something similar for a while; if you were listening to music, then if you scrolled through your timeline and came across an autoplay video (which would play silently at first), your music would stop. They were preemptively grabbing exclusive audio mode in anticipation of needing it for the video, and then playing silence through it until you tapped on the video itself.