Re: [GnomeMeeting-list] Re: audio - fragment size mismatch

[Damien Sandras <dsandras seconix com>]

le sam 22-06-2002 à 21:58, Christian Lambert a écrit :
> 
> Hi,
> 
> I investigated more on this issue with the 4front OSS folks, and
> they found a programming error for OSS in the pwlib oss.cxx module:
>  

Hi,

Thanks for your feedback,

I will forward this mail to Equivalence, the company who created PWLib.
Thanks a lot.


> The Envy24 card uses fixed fragment size so applications cannot change it.
> This may cause problems with applications that try to do something stupid.
> 
> The message about "fragment size mismatch" is related with this. However
> the main reason is that the application doesn't make certain ioctl() calls
> in right order. As documented in our Programmer's Guide the application
> should set the number of channels, # of bits and sampling rate before
> calling SNDCTL_DSP_GETBLKSIZE or SNDCTL_DSP_GET[IO]SPACE.
> 
> The application has two errors (at least):
> 
> 1) It must in not call SNDCTL_DSP_RESET after opening the device.
> 
> 2) It calls SNDCTL_DSP_GETOSPACE and SNDCTL_DSP_GETISPACE before setting
> the sampling parameters.
> 
> Best regards,
> 
> Hannu
> -----
> Hannu Savolainen (hannu opensound com)
> http://www.opensound.com (Open Sound System (OSS))
> http://www.compusonic.fi (Finnish OSS pages)
> 
> 
> On Wed, 19 Jun 2002, Christian Lambert wrote:
> 
> | 
> | I use gnomemeeting 0.92.1 with the latest libs from mandrake cooker
> | RPMS packages.    I'm using Mandrake 8.2.
> | 
> | I can't get the sound to work on my Envy24 (audiophile 24/96) using
> | OSS commercial drivers.   When it tries to output audio, there is
> | only garbage coming out on the external DAC I use thru SDPIF and it can't
> | get a lock on a frequency.  Normally it works fine even for 8Khz.
> | 
> | I do get an error message in syslog that says the application is trying
> | to do a DMA of 1k which is too small for the hardware.  It needs a minimum
> | of 2k to work from what I understand.  This is not your typical soundcard tough,
> | it's in the category of pro soundcards used for digital recording and playback.
> | 
> | It also does not have an OSS mixer, it's got channels for input/output
> | and you need to use a mic pre-amp for the line-in.  But I'm planning on getting
> | the input from the usbaudio microphone and outputting thru the envy24 dsp0, so
> | I'm only interesting in getting the sound output to work, not recording.
> | 
> | I looked quickly at the pwlib file called oss.cxx, but I didn't find in it
> | that it forced a size of 1024, so I'm a bit confused.
> | 
> | Does anyone know which change I would need to make in order to make it
> | work with this soundcard?
> | 
> | Jun 17 22:14:16 onyx4 kernel: Envy24: Fragment size mismatch: hw=2048, sw=1024
> | Jun 17 22:14:16 onyx4 kernel: Envy24: Application bug detected. Fix ioctl()
> | calling order
> | 
> | Let me know
> | 
> | 
> 
> -- 
> Christian Lambert               Networking & Communications
> clambert csd sgi com            Global Product Support
> Mountain View, CA               SGI
> 
> 
> 
> 
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