Very nice :-)). Thanks. ----- Original Message ----- From: "David A. Hoatson" <dhoatson@xxxxxxx> To: <wdmaudiodev@xxxxxxxxxxxxx> Sent: Thursday, September 16, 2004 4:19 PM Subject: [wdmaudiodev] Re: Record Buffer Issue > 192kHz PCI audio card with a 16-channel scatter-gather engine. See > http://www.lynxstudio.com/aes16.html. I support up to 8 cards per system > for a total of 128 input channels and 128 output channels. US$695/each. > You can get a demo in London at HHB ;-). > > Thank you, > > David > > ----- Original Message ----- > From: "Jerry Evans" <jerry@xxxxxxxxxx> > To: <wdmaudiodev@xxxxxxxxxxxxx> > Sent: Thursday, September 16, 2004 8:07 AM > Subject: [wdmaudiodev] Re: Record Buffer Issue > > > > Hi David > > > > Sorry, this is peripheral to your question: can you tell me what audio > > hardware you are using here ? > > > > Thx > > > > Jerry > > ----- Original Message ----- > > From: "David A. Hoatson" <dhoatson@xxxxxxx> > > To: <wdmaudiodev@xxxxxxxxxxxxx> > > Sent: Thursday, September 16, 2004 3:30 PM > > Subject: [wdmaudiodev] Record Buffer Issue > > > > > >> Hello, > >> > >> I have noticed some specific behaviour for recording that is causing > >> major > >> grief for my audio driver (IMiniportWavePci/IMiniportWavePciStream). > >> > >> For playback, the buffers are chopped up into 10ms increments and it > >> seems > >> that a maximum of about 3 buffers are sent down to my driver from the > >> WDM > >> port class driver. If the sample rate scales up, so does the buffer > >> size > >> so each buffer is still 10ms in length. Playback at any sample rate > >> works > >> as expected. > >> > >> For recording, eight 64-byte buffers are passed in regardless of sample > >> rate. At 48kHz stereo, this means each buffer represents ~0.66ms, which > > is > >> just at the limit of what gives acceptable performance from faster > >> machines. At 192kHz, the port driver still only gives eight 64-byte > >> buffers, so now that same buffer only represents 0.166ms for stereo, or > >> only 1 sample period for 16 channel interleaved 32-bit (which my device > > can > >> do)! This means the PC is not able to respond to each interrupt fast > >> enough and audio breakup will occur in only 1.3ms (192kHz/Stereo). This > >> essentially means that recording through the port class driver is not > >> possible at higher sample rates/higher channel counts. I should mention > >> that I am using Windows XP SP2. > >> > >> So far I have found nothing that allows my driver to control the size or > >> number of buffers that are passed in from the upper level driver. Does > >> anyone have a solution to this problem? I'm sure there is something > >> very > >> basic that I am missing... > >> > >> Thank you, > >> > >> David > >> > >> ****************** > >> > >> WDMAUDIODEV addresses: > >> Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx > >> Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe > >> Unsubscribe: > >> mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe > >> Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx > >> > >> URL to WDMAUDIODEV page: > >> http://www.wdmaudiodev.de/ > >> > > > > ****************** > > > > WDMAUDIODEV addresses: > > Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx > > Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe > > Unsubscribe: > > mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe > > Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx > > > > URL to WDMAUDIODEV page: > > http://www.wdmaudiodev.de/ > > > > ****************** > > WDMAUDIODEV addresses: > Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx > Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe > Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe > Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx > > URL to WDMAUDIODEV page: > http://www.wdmaudiodev.de/ > > ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.de/