From owner-freebsd-multimedia Mon Dec 9 18:04:37 1996 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.4/8.8.4) id SAA24568 for multimedia-outgoing; Mon, 9 Dec 1996 18:04:37 -0800 (PST) Received: from MVS.OAC.UCLA.EDU (mvs.oac.ucla.edu [164.67.200.200]) by freefall.freebsd.org (8.8.4/8.8.4) with SMTP id SAA24559 for ; Mon, 9 Dec 1996 18:04:33 -0800 (PST) Message-Id: <199612100204.SAA24559@freefall.freebsd.org> Received: from UCLAMVS.BITNET by MVS.OAC.UCLA.EDU (IBM MVS SMTP V2R2.1) with BSMTP id 9259; Mon, 09 Dec 96 18:04:33 PST Date: Mon, 09 Dec 96 18:03 PST To: dwhite@RESNET.UOREGON.EDU From: Denis DeLaRoca (310) 825-4580 Subject: Re: GUS & Mbone: more updates CC: multimedia@FREEBSD.ORG Sender: owner-multimedia@FREEBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Mon, 9 Dec 1996 16:41:37 -0800 PST, Doug White said: > Hello again... > > After I replaced my VAT with a full duplex version from rah, the looping > and popping and whatnot has stopped. I've been watching the IETF stuff > for several hours now and it works like a charm. The only annoying thing > is that the audio cuts out every so often, but I think this is from > problems at the gateway or transmitter at ietf2.bbnplanet.com so I'm not > worried about it. Yes that gateway was dropping packets. Here at UCLA I was seeing a loss not exceeding 8% -- not enough for significant audio cuts/dropouts, only tiny dropouts here and there. > I've noticed that the volume bars lag quite a bit behind the audio, such > that I've just turned them off. Any ideas behind that? Humm? I'll check that tomorrow. > The thing that does worry me is the excessive debugging output from the > kernel. I get lots of these: > > isa_dmastart: channel 1 busy > isa_dmastart: channel 3 busy It's in /sys/i386/isa/isa.c, I am not sure it these messages are legacy diagnostic messages or legitimate error output... > I know this is a silly stupid thing, but I can't remeber where this is at. > Someone have the patch? (BTW: these pop up whenever I jump between vats > (I'm watching both IETF channels currently), and just every so often. Any > guesses why both the play and record DMAs bounce? > > Secondly, when I was using the half-duplex vat, I got a lot of these > lines: > > Dec 8 23:55:26 gdi /kernel: write select 1 > Dec 8 23:55:27 gdi last message repeated 672 times > Dec 8 23:55:27 gdi /kernel: isa_dmastart: channel 3 busy > Dec 8 23:55:29 gdi /kernel: write select 0 > Dec 8 23:55:29 gdi last message repeated 4 times > Dec 8 23:55:29 gdi /kernel: write select 1 > Dec 8 23:55:31 gdi /kernel: write select 0 > Dec 8 23:55:31 gdi last message repeated 4 times I've never seen these with my PAS16 card. What I keep seeing very freuqntly is aud write: resource temporarily busy which is a result of a pwrite("aud write") in vat's audio-voxware.cc when its write() to the audio device fails. I haven't figured out what activity on the system interferes with /dev/audio to trigger the above failures. > Here is the interesting part. The audio was clear until the 'channel 3 > busy' message came up. Then I got the write select 0's interspersing > thoughout the write select 1 messages. (I got these write select's > regularly.) At the same time, the looping, popping, and general poor > audio started up. > > I'm guessing that these status messages may be related to the poor audio > output from the half duplex vat (which must be used on SoundBlasters). > Note that i got the exact same poor output until I bumped my vat to the > full duplex version. I still have the half-duplex, so I'd be glad to do > some testing. I'll only have my net until midday tomorrow or so, so get > back to me soon if you want to deal with this before January. > > I'm not experienced enough programming to track down this stuff. I'm > hoping someone will pick this up (bill?) and work with this. I'd really > like to see the half-duplex vat's audio quality improve, as many of us are > stuck with them and don't want to spend the $xxx on a gus when (IMHO) the > awe32 has nicer MIDI audio :), and paid $200-300 for the AWE originally. The sound quality I am getting in half-duplex mode with a ProAudio Spectrum 16 card is quite good, not as splendid as with the GUS card mind you, but quite acceptable -- the only minor problem is that vat's clocking of audio output is slightly amiss and every so often a couple of audio samples overlap on output as the playback buffer is reset. -- Denis