Btaudio (bt878)

The btaudio kernel module allows you to get the audio from your tuner card directly over the PCI bus without using a patch cable to your sound card. This is useful if you would like to reserve your sound card for other functions, if you want to have multiple tuner cards in one computer, or if your sound card does not handle full-duplex.

Instructions

• Gerd Knorr's instructions (copied from the 2.6.12-rc2 kernel and lightly updated)
• MythTV wiki: setting up btaudio on an ATI TV Wonder card
• Failed attempt at getting the sound directly off a LifeView FlyVideo3000 bttv card
• Note that saa7133 cards unproblematically let you get the audio directly

Supported cards

For btaudio to work, you need a bttv tuner device with an MSP34xx chip. The chip also needs to be connected to the board in a certain way to work.

These cards are known to work with btaudio (thanks in part to MythTV HowTo):

   * ATI TV Wonder
   * Hauppauge WinTV-radio with dbx-TV stereo, model 401
   * Hauppauge WinTV-Theater, model 495, 498 (Europe)
   * Hauppauge WinTV Express, models 751, 753 (but see note)

Note: Hauppauge model labels are often uninformative. For example, the box labeled model 753 may contain one of these:

* board #44804 rev #D183, auto card=10; tuner TCL2002MB-3 (hidden sticker), but has to be forced to tuner=41 (Phillips PAL-MK(FI1216MK)
* board #44804 rev #D108, auto card=10; tuner FI1215MK5 (hidden sticker), autodetected as tuner=5.

The following cards do not work:

   * Pinnacle Studio PCTV Pro - note: this has a MSP34xx, but it's not wired correctly to the BT878 chip.
   * ATI TV Wonder VE
   * Leadtek Winfast 2000 XP (PAL, UK and NTSC)
   * I/O Magic PC-PVR. No MSP34xx chip.

The following cards have been reported to work, but have issues:

   * Avermedia AVerTV Studio (no digital DSP output, "whiney noise" on analog)

Once btaudio loads, it should register additional /dev/dsp and /dev/mixer devices. Typing $ dmesg will let you know what's going on.