[mythtv-users] Is there a good guide on recording profiles somewhere?

Jay R. Ashworth jra at baylink.com
Tue Aug 31 13:16:25 EDT 2004

On Tue, Aug 31, 2004 at 07:10:51AM -0400, Cory Papenfuss wrote:
> > I've noticed a lot of people using high bitrates with the PVR-x50's,
> > but I'm using a pretty low bitrate and getting what I consider to be
> > excellent results. I will admit that I'm coming from about 5 years
> > of having only watched TV after recording everything to VHS in EP
> > mode, so I'm not the best judge of quality (anything beats an EP VHS
> > recording :). Also, I have a satellite signal piped to the PVR-350
> > via S-Video (but I'm using nVidia GF4MX440 for output for OpenGL and
> > Xv support), so signal noise/bad signal quality aren't a problem.
>   I've also noticed that a lot of people have seemingly ridiculously
> high bitrates/resolutions. Of course you can't argue with, "It
> looks better," but I don't trust myself to make such subjective
> observations. I've got a resolution test pattern thingy I cooked up
> to try to objectify at least the static resolution test... check the
> thread archives.I still have yet to hear back from anyone who's tried
> it out. I just bought another PVR-250 (slickwilly's CC $90 AR retail
> version)... maybe the rev2 retail won't be as soft as my OEM rev1.

As soon as I can get it burnt onto something the DVD player will
actually play... ;-)

> > Anyway, I was wondering what someone with a discriminating eye might
> > think of my settings. I'm using a bitrate of 2200 and max bitrate of
> > 9800 and it seems to give me the best of both worlds--small files
> > and good quality. I'm averaging about 1 1/4 GB/hr.
>   I think I use on the order of 640x480, 4000/6000 for what I archive.
> I get about 1.7 GB/hour, and then crunch (with denoising, 2-pass) down
> to 352x480 at 2500 for better than SP VHS quality on a DVD. I've never
> played around large ranges for the encoder, but it might be worth
> looking at. I have seen ghosting artifacts during high-motion scene
> changes so it could help. Anyone else comment on large ranges being a
> good tradeoff for filesize/motion capture?


> I've heard that having a large range of > bitrates tends to stress the
> encoder, but I got 50 episodes and 174 hours of > Olympics without
> problems. Also, I'm using 640x480, but I can't tell a > difference in
> quality between 480x480, 640x480, and 720x480. I might be > switching
> to 720x480 to make DVD authoring easier, but...
>   Check the archives on my static resolution test. My experience
> has been the same... indiscernable differences at anything above
> about 420x480. Unfortunately, the PVR-250 *does* lose quality when
> capturing directly at 352x480... thus my 2-step process for archiving.
> I *really* wish that 480x480 SVCD resolution was supported as a
> DVD-standard resolution.... what were they thinking? Maybe like
> CD-Audio... they didn't want to have a "low-quality" "high-quality"
> because people might not use the "high-quality" one?

Noted.  I've actually heard that some players will play it... but I
don't recall where. 

> > Also, I'm wondering if the poor quality people have mentioned is
> > actually noticeable on the TV or only when transcoding for/playing
> > back on a computer (or other progressive display).
>   "Poor quality" describes a multitude of sins. I suspect that a lot
> of quality problems people see are bad TVOUT on their vid cards. My
> old NVIDIA sucked mightily.


> > BTW, at the bottom is a nice little query that can summarize your
> > recording profile information in a compact cross-tab format.
> > I'm posting my data in the standard tabular format because the
> > long-lines of the cross-tab don't go well with text-based mail
> > readers... (Oh, and you should probably stretch your terminal window
> > when running the query.)
>   I still have yet to figure out recording profiles. I managed to make
> another table (localhost.localdomain), and now that's all it uses.
> Sooner or later I"ll get tired of the condition of the box and redo
> it from scratch... originally built in December '03 on RH9. Three
> different motherboards on the same install, but it's just never broken
> to where I needed to do anything with it!

Indeed.  Lucky bastard.  :-)

-- jra
Jay R. Ashworth                                                jra at baylink.com
Designer                          Baylink                             RFC 2100
Ashworth & Associates        The Things I Think                        '87 e24
St Petersburg FL USA      http://baylink.pitas.com             +1 727 647 1274

	"You know: I'm a fan of photosynthesis as much as the next guy,
	but if God merely wanted us to smell the flowers, he wouldn't 
	have invented a 3GHz microprocessor and a 3D graphics board."
					-- Luke Girardi

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