EMU 0404USB: Odd sample rate shown during playback.

EMU 0404USB: Odd sample rate shown during playback.

[Klaus Schulz]

Hi there.

The EMU 0404 is running in async USB mode as you know. When looking at the
stream parameters  during playback the sample rate shown is always slightly
below 44100 -- something
like 44098 is shown.

As you write in the driver,  the 0404 is returning number of samples per
packet instead of the number of samples per microframes. Has this something
to do with
it?

Question: Are we looking at  a wrong output  or is the samplerate really
lower than 44100?

THX
Klaus

Re: EMU 0404USB: Odd sample rate shown during playback.

[Clemens Ladisch]

Klaus Schulz wrote:
> The EMU 0404 is running in async USB mode as you know. When looking at the
> stream parameters  during playback the sample rate shown is always slightly
> below 44100 -- something like 44098 is shown.

This is what "asynchronous" means: The computer's clock and the device's
clock run independently from each other, so they can have slightly
different speeds.


Best regards,
Clemens

Re: EMU 0404USB: Odd sample rate shown during playback.

[kls.schlz]

Hi Clemens.

THX for dropping in.

On my M-Audio Transit though it remains 44.1 even though it says "async" at  
16/44.1 in the stream0 file.

Cheers
\Klaus

On Jun 8, 2009 9:24am, Clemens Ladisch <clemens@ladisch.de> wrote:
> Klaus Schulz wrote:

> > The EMU 0404 is running in async USB mode as you know. When looking at  
> the

> > stream parameters during playback the sample rate shown is always  
> slightly

> > below 44100 -- something like 44098 is shown.



> This is what "asynchronous" means: The computer's clock and the device's

> clock run independently from each other, so they can have slightly

> different speeds.





> Best regards,

> Clemens

Re: EMU 0404USB: Odd sample rate shown during playback.

[Clemens Ladisch]

kls.schlz@googlemail.com wrote:
> On my M-Audio Transit though it remains 44.1 even though it says "async" at  
> 16/44.1 in the stream0 file.

It could have a clock that happens to run at the same speed as your
computer's.  Or it could be that it runs the ADC synchronously to the
computer but says "async" so that it can deliver recorded SPDIF data at
the source's speed.


Best regards,
Clemens

Re: EMU 0404USB: Odd sample rate shown during playback.

[Klaus Schulz]

Hi Clemens.

Reading you answer below. Does this mean the Transit is necessarily not
running in async mode during playback of 44.1 material
even though it says so in the stream0 file?

As far as I know I can slave the Transit to an external SPDIF clock. This
would mean that in this case the Transit would slave the PC, thus working
async.

The open question is still if even without external clock the Tranist works
in async as the log is saying.

How can I find that out?

Cheers


On Mon, Jun 8, 2009 at 1:39 PM, Clemens Ladisch <clemens@ladisch.de> wrote:

> kls.schlz@googlemail.com wrote:
> > On my M-Audio Transit though it remains 44.1 even though it says "async"
> at
> > 16/44.1 in the stream0 file.
>
> It could have a clock that happens to run at the same speed as your
> computer's.  Or it could be that it runs the ADC synchronously to the
> computer but says "async" so that it can deliver recorded SPDIF data at
> the source's speed.
>
>
> Best regards,
> Clemens
>