Conexant CX2388x

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Revision as of 23:07, 11 March 2007 by Indulis (Talk | contribs)

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Big brother to the BT878 produced by Conexant Systems, Inc.. Has specialised DVB support in a new PCI function, instead of using the digital audio input for it. (Yay!). In fact it has stacks of functions, like 6 or something, but fortunately they all share the same (huge 16MB!) memory mapping. Has the same (identical?) RISC programs as the BT878 and the same kind of i2c bus control controller.

Note that according to the product brief, the maximum video signal that this chip can capture is "up to 768 x 576 (square pixel PAL/SECAM)", that is 576p. No true HD signals (720i, 720p, 1080i) can be captured with cards using this chipset. Some countries, such as Australia, have defined HD to be 576p or above, but 576p is not generally considered HD.

But really for DVB I don't think it gives you anything that the BT878 doesn't. If however you want to put analogue video on the same card (like DViCO do) then it seems to have a few improvements in that department.

Analog audio inputs

The cx2388x family of ICs are capable of providing demodulation of all major global broadcast audio standards. In other words, they can directly accept S-IF from a TV tuner pll. These signals will in turn be decoded and are output either to the PC's sound card directly via a patch cable (invokes a DAC step), to a digital audio output interface (eg. SPDIF), or to the host via a DMA channel.

The cx2388x IC's do not process other analog audio sources. They do, however, provide the ability to connect directly, via an i2s input port, to a 3rd party audio ADC.

Also see v4l's cx88 page

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