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Re: Max sample rate and resolution for audio devices

At 2:48 PM -0700 4/20/05, david tay wrote:

Is there an easy way to figure out the maximum sample rate and resolution (32 bits /24 bits / 16 bits) for a USB bus?

Would a USB 2.0 bus enable audio devices to reach a max of 192khz at 24 bits?

There's notes about this chapter 5 of the spec, but its not difficult. First you need to work out what packet size is needed, then you need to work out if you can sustain that packet size.

You need 192*24/8 bytes per channel per frame. That's 576 bytes per channel per frame.

If you're talking full speed, I wouldn't bet on more that 1023 bytes a frame, you'd be able to do mono full speed at that rate/resolution. If you were really lucky you might do 2 channels, you might find a system which can support 1152 bytes a frame. You'd have to use 2 endpoints to do that though, as one endpoint can only do 1023 bytes.

If you're talking high speed, 3*1024 bytes per micro frame, 24k/frame should be possible. You could manage upto 42 channels at that rate/resolution.

Also when you say "USB 2.0" you should specify if you mean full speed or high speed, USB 2.0 defines both full and high speeds (and low speed).
--
Barry Twycross
email@hidden
---
USB, it's not a Dyslexic BUS. (Thanks to TC.)
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 >Max sample rate and resolution for audio devices (From: david tay <email@hidden>)



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