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by coldtea 2455 days ago
>For the vast majority, soft real-time is fine, since an occasional deadline-miss results in minor inconvenience, not property damage, injury or death.

A "minor inconvenience" like a recording session going wrong, a live show with stuttering audio, skipped frames in a live TV show, and so on?

2 comments

Most professional recording studios are using consumer computer hardware that can't do hard realtime with software that doesn't support hard realtime.

People like deadmau5, Daft Punk, Lady Gaga all perform with Ableton Live and a laptop or desktop behind their rig. If it were anything more than a minor inconvenience, these people wouldn't use this.

It's very unlikely to have audio drop outs, a proper setup will basically never have them. But still if you have one audio dropout in your life, you're not dead, your audience isn't dead, a fire doesn't start, a medical device doesn't fail to pump, and so on.

And yes you can badly configure and system, but the point is you can't configure these to be 100% guaranteed, 99.99% is perfectly fine.

Edit: Sometimes people call these "firm" realtime systems. Implying the deadline cannot be missed for it to operate, but also that failure to meet deadlines doesn't result in something serious like death (e.g in a video game you can display frames slower than realtime and it kind of works but feels laggy, however you cannot also slow down the audio processing because you'll a lowered pitch, so you have to drop the audio.)

As long as the individual event happens seldom enough few of these actually are a big problem. Soft real-time being allowed to blow deadlines doesn't mean it can't be expected to have a very high rate of success (at least that's the definitions I've learned), and clearly a sufficiently low rate of failure is tolerated. There's a vast difference between "there's an audio stutter every day/week/month/..." and "noticeably stuttering audio". The production side is obviously a lot more sensitive about this than playback, but will still run parts e.g. on relatively normal desktop systems because the failure rate is low enough.
The production side usually renders the final audio mix off-line, so no real-time requirements there for getting optimum sound quality. I'd say the occasional rare pop or stutter is worse to have during a live performance than when mixing and producing music.