[mythtv-users] bt878, btaudio, 2.6.9-1.681_FC3 and sound cards

[Larry Silverman]

Greetings, all!
 
I've built a MythTV box following Jarrod's excellent instructions at Fedora
Myth(TV)ology http://www.wilsonet.com/mythtv/fcmyth.php.
I'm using the 2.6.9-1.681_FC3 kernel from Red Hat.
I've got a brand new Hauppauge 250 and an old STB (card=40) bt878 card
(presumably with audio capture).
# lspci -v

00:0a.0 Multimedia video controller: Brooktree Corporation Bt878 Video
Capture (rev 02)
        Subsystem: STB Systems Inc: Unknown device 2636
        Flags: bus master, medium devsel, latency 32, IRQ 10
        Memory at eb000000 (32-bit, prefetchable) [size=4K]
 
00:0a.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture
(rev 02)
        Subsystem: STB Systems Inc: Unknown device 2636
        Flags: bus master, medium devsel, latency 32, IRQ 10
        Memory at eb003000 (32-bit, prefetchable) [size=4K]
 
bttv recognizes this card as:
bttv0: Bt878 (rev 2) at 0000:00:0a.0, irq: 10, latency: 32, mmio: 0xeb000000
bttv0: detected: STB TV PCI FM, Gateway P/N 6000704 [card=40], PCI subsystem
ID is 10b4:2636
bttv0: using: STB TV PCI FM, Gateway P/N 6000704 (bt878), 3Dfx VoodooTV 100
[card=40,insmod option]
bttv0: gpio: en=00000000, out=00000000 in=00ffffff [init]

I got it with an old Dell Dimension XPS-500T in 1999, I think.  It's been on
a shelf for about 5 years!  Who'da thought it'd see the light of day again?
 
Things are going well with the 250 (after I rewrote modprobe.conf because
the STB kept getting loaded early into /dev/video0), but the STB?  Not so
good. As for many, audio with this card is a problem.
 
The onboard C-Media CM8738 on my Soyo Dragon KT333 Platinum didn't work out
- a minute after starting MythTV's frontend, the machine would sieze, hard,
every time.  Reboot only. Turned off the onboard audio, no thanks.
 
Installed a first-generation Sound Blaster Audigy MP3+ (emu10k1).  The ALSA
mixer for this one is very tricky, there's no real capture channel, just a
capture mix bus.  Everything was configured properly I'm sure, but for the
life of me, couldn't get a peep out of /dev/dsp.  No problems with
line-through using xawtv, but the capture just would not route to /dev/dsp.
Ditched that.  What a shame, I would have liked to use this card.
 
Stuck in a PCI CM8738 from AOpen.  aplay /dev/dsp returned an 8-bit stream
that sounded like garbage, and I could never get a clean audio stream.  Saw
some posts about some versions of this chipset not being able to do more
than 8-bit full duplex.  Out she goes.
 
Searching now, found an old PCI card with a Yamaha something-or-other
chipset.  Man, that was a waste of time.
 
So, in lieu of buying a new sound card, I started exploring btaudio.
Firstly, no OSS drivers were compiled into this 2.6.9-1.681_FC3 kernel
(argh), so the btaudio module simply doesn't exist.  I read that the
snd_bt87x module is the one to use under ALSA.  I followed every instruction
I could google for configuring this module, but no new devices would appear.
I tried mknod'ing some devices, but I couldn't get anything to come through
/dev/dsp1.  I'd love a solid pointer towards properly configuring snd_bt87x.
If a module isn't auto-recognized and loaded at boot, does that mean it
probably wouldn't work anyway?
 
Next, I tried rebuilding the kernel.  I downloaded the sources for
2.6.9-1.681_FC3 and followed the basic kernel HowTo (make dep, make clean,
make oldconfig, make prepare, make bzImage, make modules, make
modules_install, etc).  I first copied configs/kernel-2.6.9-i686.config to
my /usr/src/linux/.config.  Using make xconfig, I turned on everything under
OSS.  Following the build and copying the bzImage and initrd, I successfully
booted under the new kernel.
 
Well, btaudio can now be loaded, but other modules I downloaded via RPMs
following the Fedora MythTV guide just aren't working (like ivtv).  I
haven't even tried listening to btaudio yet.  Am I going to have to rebuild
all the other drivers, like ivtv?  I'm a little frustrated at this point, so
before I go investigating whether I have to rebuild a ton of stuff, thereby
negating the wonder that is apt-get/rpm, I thought I'd post to you guys for
some advice.
 
Here are my questions for the collective brain:
1. Anyone know for sure whether this STB card will work with btaudio?
Googling turned up very few other users of this particular card.
2. Do I really have to rebuild ivtv?  Why didn't everything else "just work"
after I rebuilt the kernel using the old config?  I really just wanted a
stock-681_FC3 plus OSS.
3. If this is going to be a hassle, I'd rather just go buy a soundcard that
is known to work well.  What would you recommend as the best-supported,
full-duplex sound card under ALSA?  Newegg has a Creative Labs Sound Blaster
Live! 7.1 24-bit pci card for $30.
4. Oh, and is there an easy way to get the Hauppauge to default to
/dev/video0?  I couldn't seem to control when bttv got loaded through
modprobe.conf.  I had to rmmod all the bttv stuff, then install my ivtv,
then re-install bttv to get the ordering the way I wanted it.
 
Thanks very much,
 
Larry
 
 
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