[mythtv-users] Recording problems with PVR-350 and MythTV 0.24.3

David Parker parker.david.a at gmail.com
Thu Sep 27 03:47:12 UTC 2012


On Wed, Sep 26, 2012 at 1:58 AM,  <f-myth-users at media.mit.edu> wrote:
>     > Date: Wed, 26 Sep 2012 01:19:36 -0400
>     > From: "Michael T. Dean" <mtdean at thirdcontact.com>
>
>     > You're likely to get better quality output using an nvidia video card
>     > with CPU decoding than you'd get with PVR-350 decoder output or PVR-350
>     > Xv output.
>
> Why?  Particularly, if you've got interlaced SD content recorded from
> a PVR-x50, and you're displaying on an interlaced SD CRT, what makes
> you say that an nvidia card will be superior?  Especially since it's
> difficult to find modern cards that support (say) S-Video output,
> which is typically what an SD CRT accepts, so you might have to do
> something unpleasant like use a VGA-to-S-video converter.  [I know you
> personally regretted buying a PVR-x50 long long ago, but I'd like to
> know if there is some objectively-better result using an nvidia card
> instead in this particular case.  I'm talking straight video quality
> here, not all the other stuff that Myth might want to overlay when
> using its menus.]
>
> [I'm ignoring wss or direct line-21 CC support here, which I suspect
> no nvidia card can give you, but the 350's decoder can.]
>
> Yes, I'm guessing that the OP has an SD CRT and not something else,
> but if he was actively using the PVR-350's decoder, that seems likely.
>
>     > The biggest problem you'll have, though, is if you still need TV out
>     > (i.e. Composite/S-Video/SCART or whatever) versus a "real" output (VGA,
>     > DVI, HDMI, ...), you may find it hard to come by an nvidia card these
>     > days that supports it.
>
> Yes, precisely.
>
> Though I'll point out that I bought a $25 VGA-to-S-video converter
> from monoprice.com a few months ago which was surprisingly good,
> considering that such things used to be in the hundreds.  Just the
> cables alone that it comes with would cost you more than $25 from
> elsewhere.  I wouldn't willingly use it instead of a direct connection
> from an S-Video output to an S-Video input (there are always going
> to be conversion losses, and this unit is no exception), but it's a
> reasonable choice for hooking a laptop up to an SD CRT.  I can look up
> the monoprice part number if someone needs it and can't figure it out
> from their site.  [It's USB-powered, so you get a VGA cable, an S-Video
> cable, a USB cable, a stereo RCA pair cable, and a little converter box
> that's about the size of a pack of playing cards.  It'll also do VGA
> passthrough, IIRC.  One gotcha---its little DIP switches come preset
> for PAL (!) output, and you have to look in the little booklet and
> flip one to get NTSC.]

Wow, this is a great discussion!  To clear up some of the mystery, I
do have a CRT TV, and it's not likely I'll be getting a new TV anytime
soon.  Thanks for all of the information about video cards and
converters.  A VGA to S-Video converter would certainly be an option
if I got another video card, but I'm still holding onto the (fading)
hope that I won't need a new card.

The output to the TV isn't the problem, though.  The errors occur
during recording, not playback.  I did some more troubleshooting, and
I think the problem is strictly an issue with the PVR-350.  I took
deleted the PVR-350 as a capture card in mythtv-setup and left the
PVR-150 as the only available input, then scheduled another program to
record, and the recording worked fine.  No hardware lockups, crashes,
or mythbackend errors.  So, using the PVR-150 as the only tuner might
be a workaround for now.  I can't record two programs simultaneously
like I used to, but at least I can still record.

It might be feasible for me to get another tuner/encoder card for
input and a video card for output.  Then I would be back to having two
tuners and one output, and if the tuner card has a hardware encoder
then I should be able to record two programs and watch another one at
the same time.  The PVR-150 has a hardware encoder, but they stopped
making it long ago.  Any suggestions for tuner cards (analog) with
hardware encoders?

As always, thanks for the responses!

    - Dave


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