Date: Thu, 4 Apr 2002 14:32:15 -0500 From: The Anarcat <anarcat@anarcat.dyndns.org> To: John Utz <john@utzweb.net> Cc: Lars Eggert <larse@ISI.EDU>, multimedia@FreeBSD.ORG Subject: Re: Soundblaster Live rear channels? Message-ID: <20020404193214.GD279@lenny.anarcat.dyndns.org> In-Reply-To: <Pine.LNX.4.44.0204041147440.2292-100000@jupiter.linuxengine.net> References: <3CAC8E70.3040700@isi.edu> <Pine.LNX.4.44.0204041147440.2292-100000@jupiter.linuxengine.net>
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--YToU2i3Vx8H2dn7O Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu Apr 04, 2002 at 11:57:33AM -0600, John Utz wrote: > Totally OTTOMH, >=20 > On Thu, 4 Apr 2002, Lars Eggert wrote: >=20 > > Hi, > >=20 > > does the pcm driver support the rear channels of Soundblaster Live=20 > > cards? (Or any other sound cards, for that matter?) If so, how? pcm supports multiple channels. =46rom /dev/sndstat FreeBSD Audio Driver (newpcm) Mar 27 2002 12:56:06 Installed devices: pcm0: <Creative EMU10K1> at io 0x9000 irq 5 (4p/1r/0v channels duplex) So it has 4 play channels. newpcm supports multiple through the use of multiple channels, AFAIK. On -stable, newpcm supports this through hw.snd.pcm0.vchans. The default value is 0 which means there is only one virtual channel available. If you bump this to 1 or 2, you have more virtual channels available. These are accessible through /dev/dspX.Y where Y is the virtual channel. On -current, this is handled automatically with devfs, ie dsp devices are created as channels are required. Now what I'm wondering is how these channels are mapped. My guess is that the driver will blindly use all hardware channels as you require more virtual channels and mix down extra virtual channels to already existing channels. =20 > if the back channels are supported then the mixer would show up with extra > things to mix?=20 Maybe. Here I have this in my mixer(1) output: Mixer vol is currently set to 75:75 Mixer pcm is currently set to 57:57 Mixer speaker is currently set to 75:75 Mixer line is currently set to 75:75 Mixer mic is currently set to 0:0 Mixer cd is currently set to 75:75 Mixer rec is currently set to 0:0 Mixer line1 is currently set to 75:75 Mixer phin is currently set to 0:0 Mixer phout is currently set to 0:0 Mixer video is currently set to 75:75 Mixer monitor is currently set to 75:75 I don't know what video and monitor are, but they're probably related to our issue here. =20 > an interesting pre-question would be 'is the mixer hardcoded to > have the selection of items that it currently supports?' The mixer detects which what devices are available, that's for sure, since I don't have the same mixer(1) output from my SBlive that I had from my SB16. > probably is hardcoded. but one wold have to go src-spelunking to know for= =20 > sure. mixer code is actually in /usr/src/sys/dev/sound/pcm, I think. =46rom what I can tell from mixer.c there is a default snd_mixerdefaults[SOUND_MIXER_NRDEVICES] value. But this table doesn't seem to be changed. > so, an interesting extention to the mixer would be to query for=20 > capabilities and present the correct items. >=20 > it might actually do this already, i dunno. Here's what I think: the mixer has a closed set of supported mixer channels and unsupported ones are not accessible from the mixer ioctl. Cheers A. --=20 Thoughtcrime does not entail death: thoughtcrime IS death. --YToU2i3Vx8H2dn7O Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: For info see http://www.gnupg.org iEYEARECAAYFAjysqj4ACgkQttcWHAnWiGfiNQCfcIRMv1EinvKc0IheINEuRn9l ILQAmgPlAfRyiT87E9150JCqeoXVbP9t =5B2c -----END PGP SIGNATURE----- --YToU2i3Vx8H2dn7O-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message
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