On Sat, 2009-04-11 at 17:17 -0400, Ben Gelb wrote: > Perhaps this isn't the perfect forum for this question since its not > really a software question, but I can't really think of any other. So > sorry in advance if people find this to be "off topic." > > I'm interested in accessing the "encoded stream output interface" on > the CX23416 (not the MCU/PCI interface!) and using it to drive some > other digital logic (homebrew DVB-S transmitter). > > >From the CX23416 datasheet, it looks like I can just stream a TS out > of this output port.
AFAIK, the CX23416 firmware does not produce a TS; just a PS, an MPEG 1 Stream, or PES's of various types. I'm unsure about the CX23417's ability to produce a TS (I doubt it), but it certainly has an output port of some sort, as it doesn't have a PCI interface. I know that the CX23418 firmware can produce a TS; the Linux cx18 driver can tell the chip to do just that. The publicly available datasheet also says that MPEG output can be supported on a 1-bit serial peripheral interface. (Note, the linux cx18 driver doesn't configure that output port; the driver only sets up MPEG streams to come the PCI bus.) > Does anybody know if this port is physically accessible on any of the > common capture cards? I have no idea. The ones you'd have the best shot at are cards with a CX23417. That chip doesn't have a PCI interface. It has to clock the MPEG stream out to a PCI bridge chip, so the MPEG stream should be accessable. Of course, I have no idea if the CX23417 produces an MPEG TS. You'll have to check the linux drivers that actually support boards with that chip to try and get an idea. > It's a bit unfortunate that the CX23416 is a BGA > package, since it makes it hard (not really possible) to tack on > wires. Also the pinouts aren't publicly available. > Any helpful suggestions appreciated. 1. If this is a one-off project, I'd just use a CX23418 based card to capture an MPEG TS. Then I'd use a homebrew piece of hardware to shift it out a serial or parallel interface. You're going to have to stuff the TS with NULL packets to get proper DVB-S rate adaptation correct anyway (right?). (BTW who's transponder are you going to use? ;) ) With that, I think you'll spend less time on guessing at software commands to get the output port configured and started, and also less time guessing at pins and frying boards. 2. If this is a serious project into which you'd like to invest a non-trivial amount of $, then contact your regional Conexant sales rep. Unless you get lucky figuring out the pins on a board with a CX23417, anything other than 1 or 2 above is likely to be frustrating, and may consume a lot of time and effort in the process. Regards, Andy > Thanks, > Ben _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
