Date: Wed, 9 Jul 1997 22:24:44 -0400 From: Randall Hopper <rhh@ct.picker.com> To: Amancio Hasty <hasty@rah.star-gate.com>, Charles Henrich <henrich@crh.cl.msu.edu>, Tony Kimball <Anthony.Kimball@East.Sun.COM> Cc: freebsd-multimedia@FreeBSD.ORG Subject: Re: vat on sb16? Message-ID: <19970709222444.41185@ct.picker.com> In-Reply-To: <199707091621.JAA16772@rah.star-gate.com>; from Amancio Hasty on Wed, Jul 09, 1997 at 09:21:21AM -0700 References: <19970709105848.60794@crh.cl.msu.edu> <199707091621.JAA16772@rah.star-gate.com>
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(...catching up on this thread:) Agree that SB cards aren't good for audio conferencing, but if you're not into that in a big way, a soundcard buyer is hard pressed to find a class of cards with better all-around support in most OSs. With a SB32/AWE32 getting you SB16's 16-bit 44Khz Stereo play/record + 32 chan wavetable synth for under $100 at a computer show, they're worth it. To the sounds bad comment, some do, some don't. Like all products with multiple models, you research them all and then pick-n-choose. It's well known that the original SB16 chipset has DSP noise problems. However its also well known that the Vibra16 replacement for this chipset has no such problems. The latter's what's on my SB32 non-PnP, and I have no complaints about its play or record quality up to and including 44KHz 16-bit Stereo. Regarding the SB16 full-duplex issue, (yes I'm an e-mail pack-rat :-), attached is a thread bite from Dec 1995 where Hannu mentioned it can be done with 8-bit one direction and 16-bit in the other, or with DMA one way and programmed I/O in the other. He might not have known what he was talking about--I don't know him personally. But if he did, the Windoze drivers could be using one of these two techniques. Would one or the other of these two be practical to implement in our sound drivers? The latter sounds like it might be completely transparent to the client. Randall Amancio Hasty: |Charles Henrich: | |Amancio Hasty: | | | |> You really don't want a SB thingie for audio conferencing. | |... | |> The SB thingies have two main problems lack of full duplex dma and | |> a decent clock. | | | |Yea its crap, but its most widely available. :) And the SB16 works great | |under windows | |They just simply sound bad . Ask John Dyson he just recently got a | |Mine sounds just peachy playing back mpeg audio streams. | |Tony Kimball: | |There are full-duplex windows drivers for the SB16. Do they fake it? | |There was once some talk of a Linux full-duplex driver but (to my | |knowledge) it got nowhere because supposedly Hannu was doing it. | |(This was before the commercialization of OSS.) Does anyone know: | |Did full-duplex SB support make it into OSS? | |As far as I know the SB thingies don't have fully functionable |full duplex dma. The Windows driver fake it. To: Stephen Hocking <sysseh@devetir.qld.gov.au> Cc: multimedia@rah.star-gate.com, hannu@voxware.pp.fi Subject: Re: Conceptual difficulties with new sound driver Date: Sat, 30 Dec 1995 00:51:16 -0800 From: "Amancio Hasty Jr." <hasty@rah.star-gate.com> >>> Stephen Hocking said: > I'm having a bit of a problem trying to reconcile some new ways of doing > things that the new driver introduces. To wit, the idea of full duplex > audio being done off the same device file. This is a bit of problem, as > a number of cards capable of full duplex audio do so by having their own > wonderful device, plus a sound blaster emulation (usually of dubious > quality) on the same card. > > One then can use one for input & one for output. > > The problem with hanging these off the one device file is that they > usually have vastly differing capabilities. Take for example the > PAS16. Its native chipset can do stereo 16bit 44KHz, but the > Thunderboard SB emulation chipset also on the card can only reliably do > mono 8bit 12KHz. Things get worse for the full duplex changes I intend > introducing for the SB16. In this mode, one channel has to stay at > 16bits and the other has to stay at 8 bits. With device semantics like > this we either have to restructure to ioctl calls or use different > device files for input & output. Okay, I admit that there are problems with the new sound driver with respect to supporting legacy sound cards . Having two devices to do input and output confuses the hell out of people not to say the little changes that he have to do to software when we are porting from other systems such as Sun or Sgi --- yes there are other changes that one usually has to do ... I am forwarding this mail to Hannu cause he is going to be bumping against the same sort problems and who knows maybe someone on the linux camp has it sorted out. At any rate , is worth asking. We should be grateful that there is at least a way of doing full duplex to the SB16! Okay let me get off my soap box cause I think that we are making good progress in this arena. Hannu's email: Hannu Savolainen <hannu@voxware.pp.fi> Date: Sat, 30 Dec 1995 19:24:52 +0200 (EET) From: Hannu Savolainen <hannu@voxware.pp.fi> X-Sender: hannu@voxware To: "Amancio Hasty Jr." <hasty@rah.star-gate.com> Cc: Stephen Hocking <sysseh@devetir.qld.gov.au>, multimedia@rah.star-gate.com Subject: Re: Conceptual difficulties with new sound driver On Sat, 30 Dec 1995, Amancio Hasty Jr. wrote: > I am forwarding this mail to Hannu cause he is going to be bumping > against the same sort problems and who knows maybe someone on the linux > camp has it sorted out. At any rate , is worth asking. We should be > grateful that there is at least a way of doing full duplex to the SB16! There are actually two ways to do full duplex with SB16. The first one uses 8 bit to one direction and 16 bits to another. The second method uses DMA to one direction and programmed I/O to the other. Both methods are completely brain dead and will never be supported by VoxWare. The only way to do full duplex audio with VoxWare is to use a card that has full duplex capability. Currently just some CS4231 based cards such as GUS MAX and AudioTriX Pro have this capability. The plain old GUS has full duplex capability too. Hannu ----------------------------- Hannu Savolainen <hannu@voxware.pp.fi> http://personal.eunet.fi/pp/voxware/hannu.html (my home page) http://personal.eunet.fi/pp/voxware (VoxWare's home page)
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