17 Jul
2011
17 Jul
'11
6:58 p.m.
Does anyone know if USB DACs use any sort of internal buffer or if the
data they receive is converted the moment it is received? Does this
behavior change depending on whether the DAC operates in synchronous
or asynchronous mode?
- Grant
17 Jul
17 Jul
7:52 p.m.
On Sun, Jul 17, 2011 at 09:57:59AM -0700, Grant wrote:
Does anyone know if USB DACs use any sort of internal
buffer or if the
data they receive is converted the moment it is received? Does this
behavior change depending on whether the DAC operates in synchronous
or asynchronous mode?
Audio data is always buffered. You can't expect the USB system
to deliver 48000 (or whatever your sample rate is) packets
'just' in time. How much buffering depends on the USB mode and
on what the device requests.
--
FA
8:43 p.m.
Does anyone
know if USB DACs use any sort of internal buffer or if the
data they receive is converted the moment it is received? Does this
behavior change depending on whether the DAC operates in synchronous
or asynchronous mode?
Audio data is always buffered. You can't expect the USB system
to deliver 48000 (or whatever your sample rate is) packets
'just' in time. How much buffering depends on the USB mode and
on what the device requests. 
10:55 p.m.
On Sunday 17 July 2011 18:57:59 Grant wrote:
Does anyone know if USB DACs use any sort of internal
buffer or if the
data they receive is converted the moment it is received?
First, usb is a packet based transport where (additionally) multiple devices
have to share the transmission time. So there will be buffers.
Second, the dsp in the device will probably talk to the adc/dac via a serial
connection (probably i2s) so there have to be buffers again.
And the pc is not made for continous stream processing but also uses blocks of
audio. So there are buffers there as well.
Have fun,
Arnold
4865
days inactive
4865
days old
linux-audio-user@lists.linuxaudio.org
3 comments
3 participants
participants (3)
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Arnold Krille -
Fons Adriaensen -
Grant