[mythtv-users] PCHDTV-5500 Sound and Contrast on ubuntu

[Brad Templeton]

On Mon, Jun 26, 2006 at 08:22:28PM -0400, mooshie wrote:
> On Mon, 2006-06-26 at 18:07 -0400, Daniel Kristjansson wrote:
> > On Mon, 2006-06-26 at 15:10 -0400, Nathan Smith wrote:
> > > On Mon, 26 Jun 2006, Brad Templeton wrote:
> > > > On Mon, Jun 26, 2006 at 10:26:28AM -0400, Nathan Smith wrote:
> > > > This makes no sense.  All HDTV "capture" cards are pretty much the same,
> > > > they just decode a raw bitstream out of the air, which is an mpeg-2/ts.
> > > Are you sure that the internals of the 5500 are the same as other HDTV
> > > capture cards? Even if it uses the same chipset, who's to know what other
> > > algorithms are run on the data before it is sent to the video device.
> > Brad is correct.
> > 
> > <snip>
> > > The "PCHDTV" option in mythtv-setup does not work at all, so I was forced
> > > to go with an analog capture card setting. That could be the problem, but
> > > I see no other option. I'm guessing the PCHDTV option is for the 3000 and
> > > previous cards, since the 5500 is running on a new chipset, AFAIK. Other
> > > than the settings problems, the playback looks superb.
> > You've configured the analog portion of the card, you should
> > use the DVB card settings for the HD-5500 for ATSC capture.
> > It is quite possible that the analog portion of the card has
> > the wrong default picture settings, I've yet to test the analog
> > portion of that card and most non-bttv frame capture card
> > require modified default picture settings.
> 
> Although, is what you're saying applicable to QAM streams as well?
> 

QAM and ATSC are just variant modulation schemes.  The end result is the
same, think of it like a file download over the air, not a capture.

Obviously a card like the pchdtv is primarily for that.  While they can
capture NTSC, they're not considered particularly good choices for
that.   Rather, people get the cards for digital TV and figure they might
as well have them as an extra analog card since they have the ability to
do it.  They have no compression hardware on them, so capture takes
CPU (of course any HD capable system has more than enough CPU.)

Even so many people find it better to get a card like the pvr-150 for
capture of NTSC, and perhaps use the NTSC part as an extra if the
pvr-150 is busy with a conflict.

Personally, I use my pchdtv for OTA rather than QAM.  There can be
some issues with occasional reception dropouts, but OTA you will
find more channels than the cable companies give you, including SD
versions of the HD channels (allowing much more compact recordings
of SD programs which are upscaled on the HD channels)   Some people
have reported cable companies reducing the data rate on their QAM
feeds, though QAM-256 does have 38 mb/s data rate and thus can
handle twice what an ATSC channel does, there are reports of people
seeing cable companies stuff in more channels.