Why no Mpeg smart Render??

blink3times wrote on 7/16/2007, 5:08 AM
If you do a lot of mpeg work then sooner or later you find that It's a pretty important feature...... and most every body else has it.

Liquid and Pinnacle studio have their own unique mpeg encoder, with smart render (pretty dam good encoder at that). But we use Main Concept encoder and it just dawned on me that all Ulead products use Main Concept as well. Yet they have smart render in all their products and we don't.

So how come we're being short changed???

Comments

bsuratt wrote on 7/16/2007, 6:27 AM
I question that too.

But take a look at the thread below on Ulead's VS forum. Most other editing packages are having problems with mpeg smartrendering.

Apparently has to do with cutting on other than a I-frame. This results in a sometimes visible "blip" in the video before and after a transistion or title. Womble DVD is the only editor so far to master this.

I was hoping for an update from Vegas to add the smartrendering for mpeg but as late as it is we will probably have to wait and pay for the upgrade later this year.

http://phpbb.ulead.com.tw/EN/viewtopic.php?t=15084
farss wrote on 7/16/2007, 7:15 AM
Given that HDV has a fixed 15 frame GOP I'd hate to be only able to make cuts at 15 frame boundaries. With smart rendering you're always facing a risk. You might be able to get away with a shortened GOP that's been healed or not.
mpeg-2 for DVDs seems to be pretty tolerant, I've used Womble without problems, that I know of. And that to me is the worry. If a spec says something must be a certain way I feel safer sticking to it, especially if 100s or 1000s of copies of the DVD are being pressed.

Bob
PeterWright wrote on 7/16/2007, 7:34 AM
I've questioned this before and still am not clear about the importance of smart rendering in an HDV context.

With DV, this was the capture format and also the format we would generally output, back to tape, so only having to render the bits we'd changed (transitions, FX etc) and being able to put the whole lot straight out to tape was beneficial, BUT....

With HDV, we are capturing HDV resolution m2t and, more often than not, outputting to SD MPEG2 DVD, so every part has to be rendered anyway, and with modern PC's this doesn't take as long as it used to ..... so can someone please explain what this issue is about?
blink3times wrote on 7/16/2007, 8:30 AM
"With HDV, we are capturing HDV resolution m2t"
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Well that may be a big mistake right there.

Liquid captures as M2V/WAV so smart render DOES work on everything that has not been changed. It even works with large bit rate changes (albeit not as fast). But I work with HDV and I don't go to dvd... I go to HD DVD so smart render has a BIG effect in my world. It's VERY fast too. Liquid renders much faster than Vegas and smart render has a lot to do with it. There is ALWAYS a quality loss when rendering so the less rendering, the better and IF you can set your project up to include the smart render feature (and in my position I can) then there is the much LESS loss to worry about.

The liquid/Pinnacle encoder by the way does not suffer from the same problems that are being encountered by the Ulead products. It does however tend to be a bit more finicky on what it wants to see as a smart render project.
bsuratt wrote on 7/16/2007, 8:35 AM
The issue arises mostly from individuals who are creating "red laser" HD-DVD and Blu Ray DVDs on standard "red" media. But, if you are creating HD files for any method of burning this problem exists.

A smartrendered HD file will be markedly sharper, hands down, if you avoid all re-render possible. (Remember in HDV we are starting out with a compressed mpeg file to begin with!). The difference on a 1080p HDTV is clearly seen. Smartrendered files look indistinguishable from camera footage viewed directly. Re-rendered files have a very noticeable softness in comparison.

This is probably due to the fact that we do not have available at this price point a super quality HD encoder.

For SD downconversion you can afford to lose some resolution and it will not be readily noticed.
blink3times wrote on 7/16/2007, 8:50 AM
". Smartrendered files look indistinguishable from camera footage viewed directly. Re-rendered files have a very noticeable softness in comparison."
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Exactly! It's about as close to lossless as one can get when dealing with mpeg and disks.
TheHappyFriar wrote on 7/16/2007, 10:03 AM
i'd assume we don't have it is because other programs do it so well. Why have a half-assed feature everyone will complain about & say "get this program" when you can not have the feature & a very very small fraction of people say "we need this feature, use program X to do it"?

But I'd say with HD becoming the norm all over the US we'll see this feature in another two years, max. once most people abandon DV they'll have no choice (unless computers get so fast & HD space so huge HD is acquired uncompressed or very little compression, then this won't be an issue).
blink3times wrote on 7/16/2007, 12:06 PM
"But I'd say with HD becoming the norm all over the US we'll see this feature in another two years,"
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Well to be honest, I use it right now not just for HD DVD, but for SD DVD too.

I have Win tv pvr usb2 that records TV through hardware mpeg capture. I set up the captures with the pre calculated bitrate (so it fits on a disk) and the proper audio and all the rest. So all I have to do is cut commercials and smart render to disk. Right now I use Pinnacle because of the smart render. It takes me about 15 to 20 minutes to cut the commercials and put my movie on a disk.... mostly because of smart render. And those who aren't using Pinnacle are using womble or something similar for these kinds of little tasks.

If smart render was included in Vegas... then who would need pinnacle... or womble....or....

There are those that question the need for mpeg smart render.... me.... I'm quite the opposite... I'm having a tough time with the idea that there are still NLE's around without it!
farss wrote on 7/16/2007, 3:07 PM
It seems like a lot of R&D when mpeg-2 is already kind of sunset technology.

Bob.
John_Cline wrote on 7/16/2007, 4:20 PM
I'm not so sure we'll be getting rid of MPEG2 anytime soon. It's a mature technology with a lot of development behind it. When implemented properly, it's capable of looking really good. Unfortunately, most of the focus of H.264 is to have the same quality of MPEG2 at lower bitrates. My focus would be to have higher quality at the same bitrates of MPEG2. 25 megabits/sec is a perfectly reasonable bitrate, let's concentrate on making it look better than MPEG2 at that rate.

John
DJPadre wrote on 7/16/2007, 7:18 PM
Agreed, re h.264
however MPG is not without its vices, in addition to the nuances of HDV MPG2 with sacrificed sound quality, GOP structure, CCD size, ccd pixel count vs In cam scaling (95% of cams are scaling) the sacrifices made to achive this resolution are rather intense.
HDV has inherited XDCam MPG2 nuances, and i dont see it ever improving until we see a new codec
farss wrote on 7/17/2007, 5:11 AM
Not all mpeg-2 is not HDV, mpeg-2 is speced upto 100Mbits/sec at 4:2:2 (studio profile) although I've never seen anything that used it, or maybe I have as DigiBetacam is mpeg-2.

Bob.
bsuratt wrote on 8/6/2007, 11:51 AM
My observation through weeks of trying to identify the source and find a work around for the "SmartRender bug" in other packages is that the current crop of encoders used in $500 or less packages is simply not capable of really good rendered HD output. And I am speaking of the 1080i level here.

If you view footage on a top-of- the-line 1080p HDTV the difference between direct playback and rendered quality is readily apparent even to the untrained eye. It might not be as noticeable on a 720p set; in fact the viewed output quality of the current encoders looks more like 720 on all output, good, but not nearly as good as the original. There is a much smaller viewed difference between SD camera footage and rendered SD footage.

MainConcept, on their website, describes their new HDV plug in for Premier as being "entirely rebuilt from the ground up". This would seem to imply that for HDV they realized that the current level of encoders were somewhat marginal. I do not know how good the new encoder is, (at $400. one would hope it is great!) But, it seems to me that we are going to have to wait for an improved level of (bug free) encoders in our editing products before we can enjoy all that HD has to offer.

The quality knocks your socks off if you can smart render!
Laurence wrote on 8/6/2007, 12:07 PM
Well although I would love to see smart-rendering of HDV in Vegas, I don't expect it would change my life that much. I find I'm using the Deshaker script on almost every shot and that the improvement in steadiness is well worth whatever slight hit in clarity I might be incurring.

I am also rendering at a slightly reduced bit rate for more reliability and playback time on my 3x DVD (HD DVD on DVD-R) discs. I can't see the difference on my 1080i HD TV, but it's an older 37" CRT model which probably doesn't imperfections that you could see on a 50" or 60" set.

Also, I find I do a bit of minor color correction pretty regularly. Nothing much, just brightening detail lost in shadows and matching scenes a little.

I also use Cineform for anything that involves re-rendering. I always use the smart-rendering VFW rather than directshow flavor of Cineform, so in reality, my Cineform master is as much as it can be, just a single generation away from the original m2t source footage.

Now to my eyes, my Cineform masters look EXACTLY like the source m2t files quality wise. The only place I lose a little quality slightly is when I render back to mpeg2 with Vegas.

This brings me to another point: I know that several people have talked about the superior quality of third party mpeg2 codecs and rendering programs like Procorder. At this point, I am more interested in that than I am in smart-rendering mpeg2.

None-the-less, smart rendering mpeg2 from within Vegas would be quite useful for me in archiving projects since that would let me crop my source footage and throw away the junk when I was archiving projects.