Wanting Mpeg encode to Higher BitRate

[grannyGeek]

I used AviSynth script to use DeComb /Telecide~ Decimate and Convolution3d on a 105-minute avi capture (captured in VirtualDubMPEG2 with Huffyuv in YUY2)
Loaded the avs script into TMPGenc free, and now discover it won't encode at higher than 8000 k. I used VBR and end up with a file of only 3.5 gb, and so sad that I can't get a higher bitrate out of TMPGenc.

QUenc will do it, but encodes to mpg, and I planned to use DVDAuthorGui to author the dvd files, and it must have elementary streams.

Will de-muxing the mpg to m2v and mp2 degrade the quality noticably, or is this just something I will have to test with my own eyeballs?

Or, alternatively, should I just stick with what I got out of TMPGenc? It looks pretty good, no screaming artifacts or pixelization.

Yes, I'm soliciting opinions here, and hoping for your input -

Thanks in advance.
gG

[RoopeT]

Demuxing is a lossless process.

However, you must have something wrong with your TMPGEnc Settings, as 105 min @ 8000 kbps should result roughly 6 Gb filesize. What is your capture resolution? If you have captured in 1/2D TMPGEnc may have decided that increasing the bitrate won't increase the quality and hence the smaller than expected filesize.

[grannyGeek]

Well, I'm confused about some of this myself.

I captured at 720x480.
I'm not at my home computer right now, so can't remember exact numbers, but I think the cap was about 32 gb.

I'm quite positive I set it in TMPGenc for 720x480 encoding.
I used VBR, and not too sure just how much that saved

I would have expected to use between 5000 and 5500 for CBR, but haven't used VBR before.


any thoughts????

EDIT ADDED ---
Maybe I had my minimum set too low in the VBR settings, and since this movie is low-action, it just never used the max rate of 8000 all that much ??????????

any thoughts on that thought ????

[jagabo]

Load the Unlock template in TMPGEnc and you can bump the bitrate up. But that isn't your real problem.

Using VBR encoding the output file size should be based on the average bitrate times the running time of the video. The codec juggles the bitrate between the min and max (depending on the complexity of each frame and scene) to achieve the requested average over the entire video.

[grannyGeek]

Hi jagabo
You said it clearer, that's kind of what I meant when I babbled about having my Minimim setting too low. Maybe what I mean is that I had the AVERAGE set too low ????
Like I said, I haven't used VBR before, so not too familiar with working out the settings yet.
But I'll get there.....

I'm using TMPGenc v 2.5 (2.52? the last free one they have on their site), and I'm pretty sure right-click Unlock on the bitrate only showed me a max of 8000. But then too, my eyes are getting older, maybe I mis-read.

edit added ---
like I said, old eyes ---
You are referring to some sort of patch, yes?
I'll hunt down the information.....

[guns1inger]

Single or 2-pass VBR ? Single pass vbr isn't accurate as it allocates on the fly, and can either leave too much in reserve, or may starve itself before the end. 2-pass goes through an analysis pass that looks at the allocation of the video data based on your numbers, the second pass refines this as it encodes, resulting is accurate file size and better fit.

You might hit a low upper limit if you have PCM audio, as this will require 1536 kbps on it's own. If the encoder is conservative, this could reduce your upper video limit into the 8000 range.

[grannyGeek]

Hey guns1inger, up at all hours again, hmmmm?

Source audio was ac3.
I used 2-pass, migod, it took ten hours !!!!

I think this will just be a mystery forever.

no, probably, I had the minimum and average settings much too low.

(being an escaped Pinnacle Studio user, with that one, you don't set min-max-avg, you just click on VBR and pray. A LOT.)

[jagabo]

Min and Max generally make no difference in the file size. It's the average that matters.

To unlock all the fields (you can't just unlock the bitrate field because it is constrained by other settings) press the Load button down at the bottom between Setting and Save. Navigate to TMPGEnc's Template\Extra folder (usually c:\program files\tmpgenc\template\extra) and select the Unlock template.

[guns1inger]

When you are finished with the demo version and looking to buy an encoder, consider ProCoder Express or CCE Basic. Both are relativelt cheap, and substantially faster than tmpgenc. As you are becoming a dab hand at avisynth scripting, you really don't need the (often slow) built in filters.

BTW - it's only 11:15pm here. The night is still young.

[grannyGeek]

jagabo, thank you so much for your help!
And tnanks to all who responded, I'm back on the road to better video.

TMPGenc is a fooler, isn't it? All the dialogs and settings look so straight-forward, and then they throw this tiny monkey-wrench into the works.


Now I'm off to read up on establishing good VBR settings.


Regards -
granny

[grannyGeek]

guns1inger, its 22:15 here, I'm only an hour behind you, how can this be?

I'll check into those suggestions, hopefully they have demo versions so I don't have to commit sight-unseen.

Thanks much.

[kschang]

I thought max for DVD is 8000?

[jagabo]

Max total bitrate for DVD is about 10,000. If you use 192 kbps for audio that leaves about 9800 kbps for video.

http://www.dvddemystified.com/dvdfaq.html

Maximum video bit rate is 9.8 Mbps... the maximum rate of combined elementary streams (audio + video + subpicture) is 10.08