Re: [Openpvr-devel] On-going development; ideas, etc.
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Re: [Openpvr-devel] On-going development; ideas, etc.
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From: Brian J. M. <fd7...@in...> - 2002-03-14 10:55:35
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On Wed, Mar 13, 2002 at 10:00:26AM -0500, Kulagowski, Robert wrote:
> It's good to see that progress is being made.
Indeed.
> I read your description
> of your idea of a brute-force versus optimized scheduler. Good
> reading.
And the result is very pleasing. I have been able to include much
more conflicting programming in the new version of the scheduler than
I could in the old version.
> If you have the time, can you detail what parts and pieces you are
> considering at this point? Which encoder and encoder technology are
> you going with?
Encoding: definately MPEG(1 for the moment). AVI files are unseekable
unseekable until they are closed (i.e. the capture is
finished). I don't know if there are any good MPEG2
encoders yet -- any that compare to MPEG1 with mp1e, which
brings me to the encoder software I am using.
I am using mp1e, but a recent cvs version from RTE, not the
1.9.2 release. Unfortunately, recent cvs versions are not
working. I have an older CVS version that I am quite
pleased with. mp1e used to have A/V sync problems for me
but it seems to have cleared up.
I would probably perfer to use RTErec from the NVrec package
because Justin's A/V sync is excellent, but RTE is very much
in flux right now and the API has changed and Justin won't
update NVrec until an official RTE release.
Ooooo! Just checked and looks like mp1e is back in order
again. I will build it and test it later today.
mp1e is by far and away the most CPU friendly encoder.
Perhaps the quality of the MPEG file is worse than other
encoders at the same bitrate, but I find mp1e at 5Mb/s is
quite nice. I can even re-encode that to Divx using a 2
pass encoder (I use mencoder) at 1250Mb/s and only see the
difference with very fast moving scenes. I don't watch auto
racing so it's not a big deal for me. :-)
=20
> For the scheduling algorithm, have you considered the case where they
> may be multiple encoders available?
It has occurred to me. It's not coded for right now but adding it
should not be difficult.
> Have you made any consideration of obtaining guide data?
XMLTV.
> Right now
> I'm aware of at least three ways of obtaining guide data:
>=20
> 1) xmltv from sourceforge
> 2) tvlisting at cherrynebula.net
Haven't seen that one. Just checked out the site. Somebody ought to
get that guy over to XMLTV and then get_tv_na could have options on
where to get data from.
> 3) vbi - there are at least some TVs and VCRs that can obtain guide
> data encoded in the video signal
Do you mean Guide+? My mom's TV has an OSD TV guide which is
downloaded over the cable connection. That would be sweet because I
can see the web-based outfits shutting down the "scrapers" due to them
bypassing the ad revenue. But my guess is that the Guide+ data is
proprietary.
Is it really transferred over vbi or some other means? I know some
versions of ATI capture cards come with some Guide+ software, but some
googling seems to indicate in that case, the data is downloaded over
the Internet.
I also wonder if enough data is available with Guide+. The more data
you can feed to the scheduler (I use a running two week window) the
better it will be at resolving conflicts with repated programming.
> o Rock-solid A/V sync. If it can't maintain sync over a long period
> of time it's going to be too annoying to use.
Right. Recent versions of mp1e seem to be good. I don't usually
watch stuff longer than an hour though so if there is drift beyond
hour long programs, I wouldn't know.
> o Set-top / black-box functionality. The wife doesn't want to know
> anything about linux. Needs to connect to a standard TV and look
> decent.
Yup. Got that/working on that. I am using a G400 with a TV hooked to
the 2nd head. I am working on a GUI program "chooser". My first
rough cut at it (a GTK clist with filenames in it) is functional,
although with a mouse, not an IR remote yet.
> o Tivo and Replay-like "trick play". Pausing live TV, FF, RW, etc.
> The PowerVCR II program from CyberLink can do this already using
> MPEG-1 on Windows.
I do that. I use mplayer to play. As long as you are playing MPEG
files, you can FF/REW/Pause the same file you are encoding to.
> o Picking programs through the guide instead of manually. Manual
> should still be available though.
Picking for play or recording?
> o Sorting saved programs into categories. Tivo doesn't do this very
> well, so everything ends up in one long "What's playing". I don't
> have a replay, but I understand that it does this better.
Yeah, I have one long list right now. One problem is who catagorizes?
What if you don't agree that a program is a drama and think of it more
as a sitcom? Maybe when you choose to record it, you pick what
catagory it should be filed in?
> o Multiple tuner support, as long as there's sufficient CPU.
Yes.
> Things that I consider in the future:
> o Seperating capture and display functionality, so that a "super
> server" can sit in a basement near all the coax and a display box can
> be lightweight, diskless/fanless (quiet) in the family room.
I have separate boxes for my recording and playing. I have the PVR
box with TV out and will have the remote, etc. for playback and my
desktop workstation does the recording, just because that's the box
with the most CPU in it. :-)
> o Sharing of programs internally. If you have a bunch of boxes /
> tuners as opposed to a super-server, they should be able to share
> programs that they've saved either through direct streaming or through
> file sharing.
Yes. Replay 4000 like.
> o Conflict resolution amongst numerous boxes. If I need to record
> multiple programs, and there's no tuner available on the box that I'm
> on, then hand off the job to another recorder.
Well, that's just an abstraction of the "multiple tuner" paradigm, but
instead of a second job on the same machine, it's a job on a second
machine.
> o Adding hard drive space through the LVS.
LVS? Do you mean LVM? All my boxes run with LVM. Using PeeCee
partitions is just arcane. :-)
> Far future:
> o Recommendations based on what others watch. "I see that you like
> watching The Simpsons. 88% of viewers that watch The Simpsons also
> watch "Farscape". Do you want to add Farscape to your recording
> queue?
Yeah, that would be neat. There are privacy issues with that. You
need to "volunteer" what you watch to a body to coallate the data. I
am not sure I want someobdy knowing all of my viewing habits. But I
am a bit of a privacy zealot.
> o Sharing video over the internet.
Like what Replay (Sonic Blue actually) are being sued over by the
major networks?
> Of course, being an "Idea guy" is easy. The hard part is
> implementing!
Yes. And finding the time to implement. Testing and evaluating has
chewed up a huge chunk of my time. I am at the integrating stage now.
I need IR. Once I get that and have a basic functioning system that
everybody can use, I will look at more useful features.
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Is there any way for you to get rid of this disclaimer? It gives me
the heebie-jeebies with all that "distribution or copying of this
communication is strictly prohibited" garbage. You are participating
on a mailing list which by it's very nature, copies and distributes
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Thanx,
b.
--=20
Brian J. Murrell
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