cx88

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cx88 is a kernel driver module meant to support devices that use a CX2388x A/V decoder chip, which, taken collectively, are known as cx88 devices (cx2388x).

Associated cx88 driver modules

  • cx88-alsa
  • cx88-blackbird
  • cx88-dvb
  • ...

See: http://git.linuxtv.org/media_tree.git/tree/HEAD:/drivers/media/video/cx88

Status

There are areas of the CX2388x chip's feature set that the Linux drivers currently lack support for or either need improvement upon. Nonetheless, most users will likely find the current rendition quite sufficient.

Video

  • Basically works.
  • Some minor image quality glitches
  • See cx88 Color problem patch
  • For now only capture; overlay support isn't completed yet.
  • Note: There had been a problem in the cx88 code that resulted in the need to set hue to either 0% or 100% in order to avoid seeing green and blue men on the screen. This problem has been corrected as of the CVS commit on Wed Jun 29 16:28:17 2005 UTC. We have collected information regarding this on this page.
  • There is also support in the kernel for a cx23416 mpeg encoder via the cx2388x host port though the blackbird driver, cx88-blackbird.c, which includes parts from the ivtv driver.

Audio

  • The chip specs for the on-chip TV sound decoder are next to useless :-/
  • Nevertheless, the built-in TV sound decoder starts working now, at least for PAL-BG. Other TV norms need other code ...
FOR ANY REPORTS ON THIS PLEASE MENTION THE TV NORM YOU ARE USING.
  • Most tuner chips do provide mono sound, which may or may not be useable depending on the board design. With the Hauppauge cards it works, so there is mono sound available as fallback.
  • audio data dma (i.e. recording without loopback cable to the sound card) is supported since 2.6.16 (CONFIG_VIDEO_CX88_ALSA). It only works with boards with function 01 enabled. To check if your board supports it, issue lspci -n. If supported, you should see a 14f1:8801 or 14f1:8811 PCI device.

vbi (cf. text capture)

  • Undocumented, but likely works in recent kernels (at least 2.6.19 and likely earlier).

TV audio (aka "broadcast audio) types

For an up-to-date list of TV audio types, see the latest version of the kernel sources. The list looked like this as of Nov 2008:

WW_NONE         1
WW_BTSC         2
WW_BG           3
WW_DK           4
WW_I            5
WW_L            6
WW_EIAJ         7
WW_I2SPT        8
WW_FM           9
WW_I2SADC	 10