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2. The BTTV Hardware

2.1. Bttv Basics

If you haven't figured it out by now, this document deals with the Linux-specific configuration of frame grabber cards that include the Conexant Bt848 and related family of video decoder chips, collectively referred to as the "Bt8x8" chipset. You can probably see the Bt8x8 chip (it's usually labelled as such) embedded on your TV card upon inspection, in addition to other chips which you should probably make note of before installation in case there are problems later. The "Bt" stands for Brooktree, after the original manufacturer of the chipset, now a part of Conexant. The Bt8x8 family has enjoyed remarkable longevity in a world where Moore's Law is the rule, the first ISA boards manufactured in the mid-1990s. There are several chips in this family, including the Bt848, Bt848A, Bt849, Bt878 and Bt879, and as a rule are all supported by the BTTV driver for which this document is named.

In addition to the Bt8x8 decoder chip, these cards vary by accompanying components such as the tuner and sound decoder, and may include an optional videotext decoder, radio tuner, and/or hardware mpeg encoder.

Note that the next generation of bt8x8, the Conexant 2388x, is now supported by a driver in the Linux 2.6 kernel. The configuration of hardware with that chipset is beyond the scope of this document (but similar).

In general, any PCI card with a Bt8x8 chipset should work with the Linux Bttv driver. TV cards known NOT to work include the following:

  • Cards with a Zoran 36057/36067 PCI controller chipset, which are instead supported by this driver, and includes the following models:

    • Iomega Buz

    • Pinnacle DC10+

    • Linux Media Labs LML33

  • Cards with a Philips SAA7130/7134 controller

  • Multimedia eXtension Board cards, manufactured by Siemens-Nixdorf

  • Hexium HV-PCI6, Orion or Gemini framegrabber cards

  • Any ISA-based TV card

If you are uncertain which chipset your TV card has, use the lspci command. An example of such output for a Bt8x8 card might look similar to the following:

   0000:02:0a.0 Multimedia video controller: Brooktree Corporation Bt878 Video 
      Capture (rev 02)
   0000:02:0a.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture
      (rev 02)

A list of hardware (mostly PCI cards) compatible with the Bttv driver is found in Appendix B

2.2. The Sound Output

Your card may have come with a short external audio connector with two male ends. This is for connecting your Bttv audio out to your sound card's input jack so you won't require an extra set of speakers. Some cards may also have a 4-pin socket for output of your Bt8x8 audio signals directly to your sound card within your computer case. You can connect this to your "CDROM" input with reasonable certainty that you will be able to control the input with your mixer from your primary sound card as well as record (see Appendix D for more information on recording). Alternatively you can use external speakers connected to the line out of your Bt8x8 card.