Ok, thanks. By the way, when you mention the cx23883 chip, do you also mean its predecessors, the cx23882/1/0?
Sam --- Hans Verkuil <[EMAIL PROTECTED]> wrote: > It's inherent to the firmware. And even if it could > it wouldn't help you > since the cx23883 does not support sliced VBI which > is a prerequisite > to embedding VBI in the MPEG stream. > > In other words, it's a no go. > > Regards, > > Hans > > > Anyway, I'll pass along your thoughts to the > others > > in the mailing list. > > > > Thanks again, > > Sam > > > > --- Hans Verkuil <[EMAIL PROTECTED]> wrote: > > > On Thursday 29 November 2007 03:08:42 Sam Logen > > > > > > wrote: > > > > Hi everyone. I've been communicating through > the > > > > > > V4L > > > > > > > mailing lists about getting VBI support > through > > > > > > the > > > > > > > hardware encoder of cx88 blackbird devices. I > > > > > > learned > > > > > > > that there is no such support, and I'm > wondering > > > > > > what > > > > > > > the current status is for VBI support in the > IVTV > > > > drivers. > > > > > > > > I've read from posts dated back to 2005 that > there > > > > > > is > > > > > > > unreliable support for VBI in hardware cards > such > > > > > > as > > > > > > > the pvr 350. I'm wondering if the process > that > > > > > > you've > > > > > > > used to get support would work for cx88 > blackbird > > > > devices. > > > > > > > > I determined that support didn't exist for > > > > > > embedding > > > > > > > VBI in the stream of cx88-blackbird devices > with > > > > > > your > > > > > > > v4l2-ctl program. When I used the same steps > as > > > > > > was > > > > > > > described here: > > > > > http://www.gossamer-threads.com/lists/ivtv/devel/37060?page=last > > > > > > I learned that "stream_vbi_format" only > accepts a > > > > value of "0" > > > > > > Hi Sam, > > > > > > Basically the current state of VBI support is > 100% > > > for raw VBI and > > > partial success for sliced VBI (I intend to try > and > > > fix that, but I > > > need to finish other projects first before I can > > > continue with that. > > > It's not an easy job). > > > > > > The problem is that to get VBI support working > with > > > MPEG cards you need > > > to have a close interaction between the video > > > digitizer chip and the > > > MPEG encoding chip. And this is quite > complicated to > > > get right. > > > > > > In order to get sliced VBI to work you need a > > > digitizer that can decode > > > the VBI data from the input signal. I have > already > > > seen that the > > > cx23883 does not support that, so that means > that it > > > will never be > > > possible to embed VBI data into an MPEG stream > > > unless you do it on the > > > application side. But while doable that is still > a > > > major project (get > > > and decode the raw VBI data, parsing the MPEG > stream > > > and splicing the > > > decoded VBI data into the stream). > > > > > > Note that embedded VBI support is sort of a hack > in > > > ivtv as well. > > > Officially the cx23416 firmware is supposed to > be > > > able to handle that, > > > unfortunately the firmware delivers a corrupt > MPEG > > > stream if you try > > > that. It simply never worked. So instead I take > the > > > sliced VBI output > > > and splice it into the MPEG stream. It's in a > custom > > > format, so > > > standard MPEG playback devices will just ignore > it. > > > > > > Raw VBI is supported by the cx23883, but I > really do > > > not know if it is > > > possible to get out both a raw VBI stream and a > > > compressed MPEG stream. > > > You need to talk to a blackbird expert (Mike > Krufky > > > comes to mind) to > > > see whether this is possible. With ivtv it is > > > possible to get multiple > > > streams (e.g. MPEG, raw YUV, raw VBI) out of the > > > cx23416, but I'm not > > > sure whether that is possible as well with the > > > blackbird design. As an > > > alternative, raw VBI might come directly from > the > > > cx23883 and the raw > > > video is passed through the cx23416. Again, no > idea > > > what is feasible > > > without doing a lot more research. > > > > > > Hope this helps, > > > > > > Hans > > > > > > > I'll include past emails below for review. I > know > > > > it's a lot of reading. Sorry. > > > > > > > > Thank you very much, > > > > Sam Logen > > > > > > > > Sam Logen wrote: > > > > > I came across directions for querying all > > > > > > available > > > > > > > > info from PVR cards with the utility > 'v4l2-ctl' > > > > > > from > > > > > > > > the ivtv driver package. > > > > > > > > > > (By the way, this is all NTSC, USA) > === message truncated === ____________________________________________________________________________________ Be a better pen pal. Text or chat with friends inside Yahoo! Mail. See how. http://overview.mail.yahoo.com/ _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
