another slightly noobish question (I'm sorry )

when recording live TV, it makes .nuv files. my question is, how do I get those to .mpg? (i.e something playable in more than just mythTV

I went into the recording profile, and set the recording codec for liveTV, default, and high quality to mpeg, and set the bit rates and options the way I wanted, but it's still putting out HUGE (1 hour = 4.2gb ) .nuv files

if I'm missing something that I could have found in a forum search, please point me in the right direction? I've tried searching for a number of different patterns of words for this problem, with no luck ...

thanks again

My ".nuv" files are mpeg files. I can play them directly on windows without doing any transcoding.

4.2GB/hour would corresponding to a bit rate of ~8,800kbps. What bit rate did you use for video encoding? I am using a resolution of 352x480 at 2,200kbps and getting acceptable results.

in that case, what codec pack(s) do you have loaded?


and the 4.2gb for 1 hour encodings ... I'm not sure WHERE it's getting a bitrate from, I've got it set to use mpeg4 to encode at 3200kbps but it seems to be ignoring that ...

What hardware are you using to do your video capture? If it's a PVR-x50, then your recordings are MPEG2: changing your MPEG4 settings will only matter if you are transcoding from MPEG2 to MPEG4 (and then, only if you have changed the default, which is to transcode from MPEG2 to RTJPEG).

You can adjust bitrates in your Recording Profiles. 4GB/hr is around an 8Mbps bitrate which is pretty high.

Ceenvee703 makes a good point -- what card are you using? I am using the Hauppauge 250, whick does hardware mpeg2 encoding. I set my bitrate by doing the following:

Utilities/setup->setup->TVsettings->Recording Profiles->MPEG-2 Encoders->default.

At this point myth will step you through a set of screens. The bitrates are selected in the 3rd screen. There are two bitrate settings:

* bitrate: This is the average bitrate. I set to 2200.
* Max bitrate: This is the max bitrate for VBR encoding. I also set this to 2200.

My experience is that the H250 doesn't do a very good job of VBR encoding. It does do an excellant job a CBR (constant bit rate) encoding, which is why I set the average and max to the same values.


marc

I'm actually using Hauppage WinTV cards ... nothing special, just tuner functionality AFAIK.

I know, 8mps is high, considering I've got it set to 3200kbps ...

I'm going to try reinstalling the backend tonight, I messed up some settings in the database anyway, and now the frontends I have can't connect, and I can't get into the database locally anymore either ...
go me

It would be nice if there were some docs that were more specific about various captures cards, resolutions, bitrates, and transcoding.

I don't really know what's different between these codecs, and things like CBR encoding is better for PVR series cards.

Nimby:

If I'm not mistaken the Hauppauge winTV cards are software-based encoders. I'm guessing you probably paid $20 - $30 for that card. The hardware based cards from Hauppauge are in the range of $65 - $150 and the models are called, for example, PVR-150, PVR-250, etc. I am using the PVR-250.

I guess I still come back to, where exactly are you setting the bit rate? I am setting mine in:

Utilities/setup->setup->TVsettings->Recording Profiles->MPEG-2 Encoders->default.

Your card is different and I don't know which codec it is choosing. What choices do you get when you go to the following menu:


Utilities/setup->setup->TVsettings->Recording Profiles

Uh, guys... When you record with a YUV frame grabber card which requires software encoder like he's doing, it first encodes to RTJPEG. I believe the RT stands for "Real Time" i.e. the codec is fast enough to keep up with encoding in real time at the expense of compression efficiency. It then transcodes (decodes-translates-reencodes) to whatever the final format you chose is.

For live TV there is never any reason to transcode because it's supposed to be a transient (vs. persistant) recording.

I agree that liveTV is fine like that, but I'm talking about when I record a show ... either by hitting "R" while watching it, or by scheduling it. I'd like for it to end up in something NOT huge like RTjpg (.nuv? )

is there an transcoder to go from .nuv to .mpg? or is ther a setting inside of mythTV to change it's transcoder?

Yes, I believe there's a transcoding profile setting in the recording profiles section.

-brendan

I suspect it won't start transcoding until the recording is done.... I can think of a couple reasons for doing things this way, mostly just a matter of not adding extra complications... You do have transcoding set up with an appropriate profile and the rest, right? The MythTV docs have more detail... http://www.mythtv.org/docs/mythtv-HOWTO-22.html#ss22.14

tjc: actually hadn't seen that page. Will try that tonight. thanks

Sigh... I wonder if Cecil can do something to make that required reading... Like making you answer 3 randomly selected questions based on it before your user id is activated...

Don't people at least check out the documentation even just to get a feel for the difficulties before they plunge into this project? I read everything I could get my hands on before starting, and still ran into some interesting issues. I know teaching people reasoning skills and "critical thinking" are currently out of fashion in this country and the touchy-feely "use the force" mysticism(1) and irrationality is in vogue, but seriously folks... If you're starting in on what is essentially an engineering prject if pays to approach it like an engineer.

(1) - BTW, this demonstrates a fundamental misunderstanding of the real "trained intuition" techniques which are essentially ways to move rational recognition and response patterns down to a reflexive level. Not some mystical mumbo-jumbo as Lucas would have it. Of course "magic" obviously sells more movie tickets than good science...

Nimby, just thought I'd check in to see if you were you able to get the transcoding to work properly...

Marc