MPEG Camcorders & Vegas

mcfallison2 wrote on 6/13/2007, 9:01 AM
Can someone who has edited mpeg video with Vegas explain the disadvantage of using Vegas for mpeg? It seems like more and more hard drive and DVD disk camcorders are being sold and everyone will have to deal with mpeg video.

I'm not sure I understand the problem and whether I should avoid an mepg camcorder.

Thanks!

Comments

blink3times wrote on 6/13/2007, 10:19 AM
Vegas doesn't SMART RENDER mpeg.

Smart render is a method that allows you to render ONLY the parts of the video that have been changed. The result is that as much quality is retained as possible with a smartrender system. Vegas instead does a COMPLETE render... and every time you render something, you lose a bit of quality.

IMO... this is a TREMENDOUS weakness in Vegas the desperately needs to be updated.
farss wrote on 6/13/2007, 2:58 PM
I can think of no compelling reason why Vegas should do this. Sure there's plenty of low cost editors that take a stab at cutting mpeg-2 natively however much of the mpeg-2 standards require a fixed length GOP and in that scenario there is no way to produce a compliant output without re-encoding the whole stream.
From my understanding of the losses in re-encoding they seem to be dependant on the initial quality of the material and how it's encoded. There's at least one broadcast grade mpeg recording systems that's decoded and re-encoded over many generations with as close to zero loss as it gets.

Bob.
Laurence wrote on 6/13/2007, 3:15 PM
If you're already doing HDV with Cineform Neo, working with an SD mpeg camera is really easy. Just batch convert the mpegs to standard definition Cineform AVI's with HDLink, then edit away. This is better than converting the to converting to DV codec in that the Cineform codec will preserve the higher quality mpeg color space.
blink3times wrote on 6/13/2007, 4:12 PM
"I can think of no compelling reason why Vegas should do this. "

What i can render (in mpeg) in 2 hours with vegas, will take me about 20 minutes in Liquid. If there is no need to render..... then it should NOT be happening!
mcfallison2 wrote on 6/14/2007, 7:36 AM
Not sure I'm following, Blink3Times. Are you saying use Liquid, or that there should not be a lot of rendering in the workflow with Vegas?
Laurence wrote on 6/14/2007, 10:22 AM
I did a project last year with a lot of mpeg video. My wife had hired a videographer in El Salvador on one of her backpack delivery trips and he gave her the footage on DVD and kept the tapes.

Anyway, I figured out a workflow that worked wonderfully well. I just changed all the .mpg extensions to .m2t then ran Gearshift. I edited the standard DV proxies and "switched gears" back to the SD mpegs for the final render. Editing was easy and the final render looked great.
blink3times wrote on 6/14/2007, 11:23 AM
"Not sure I'm following, Blink3Times. Are you saying use Liquid, or that there should not be a lot of rendering in the workflow with Vegas?"

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To be honest... I'm not sure. I'm really torn between liquid and Vegas.

I initially tuned into Vegas because Liquid needed a patch or 3 badly and they were taking their sweet time. Meanwhile, I needed to get some work done so I purchased Vegas. I just fell in love with the interface. I can peice together a nice timeline in Vegas in 1/2 the time that I can in Liquid... but Liquid is FAR more efficient in terms of mpeg/M2T/M2V rendering. What Vegas can render (in terms of mpeg based material) Liquid can do again, in 1/2 the time because Liquid contains a smart render system. Vegas renders everything regardless to whether or not it needs it. But with Liquid, if you're careful to set things up with precalculated bitrates and such so that the only things you change are the effects/transitions on the timeline, then rendering is fast like the wind and more quality is retained in the process.

I tend to use Vegas for all of my HDV work because of the higher bitrates... a little bit of quality loss won't be noticed at all, and i can get the work done twice as fast because of the slick Vegas interface.

But with SD mpeg at the lower bitrates, one can't afford to sacrifice too much quality without being noticed, so I tend to bend towards liquid for this kind of thing Please don't get the wrong idea.... Vegas puts out a pretty high quality end result. But if one had to render and re-render a mpeg over and over again for example, the vegas result would show signs of weakness sooner than the liquid result...... because of smart render..... it's an extremely valuable tool that even the cheaper NLE's are supplied with. IMO... it's really time for Vegas to jump on this bandwagon.
t-keats wrote on 6/14/2007, 11:40 AM
Laurence:
You wrote:
"I just changed all the .mpg extensions to .m2t then ran Gearshift. I edited the standard DV proxies and "switched gears" back to the SD mpegs for the final render."

Can you please spell this out a in a little more detail?

I am used to shooting straight mini-DV SD camcorder footage and feeding into Vegas 6 as avi files. I render the finished output to MPEG2 to burn to DVDV.

What is "m2t" extension?
What is "gearshift".
What are DV proxies?

Don't hesitate to "talk down" to me - make it real simple.
I want to get into HD and I need to learn this stuff.

Thanks a bunch.
farss wrote on 6/15/2007, 2:02 AM
But if one had to render and re-render a mpeg over and over again for example, the vegas result would show signs of weakness sooner than the liquid result

Well yes it would but in what scenario would this occur?

My only acquisition formats are DV, DigiBetacam and HDV. For DVD all of them get encoded to mpeg-2 once only, a lot of it two pass with CC.

Maybe you have some unique requirements but so far I can't deduce what they are.

Bob.
blink3times wrote on 6/15/2007, 3:01 AM
"Well yes it would but in what scenario would this occur?"
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I use this merely as an example of the power and plus of a Smart render system.

HDV IS mpeg so smart render works on it.... Not withstanding, the heading on this thread is MPEG camcorders, not DV or Betacam

Bob... if you are suggesting that Vegas would not benefit from a Smartrender system, then I would have to suggest that you are dead wrong
PeterWright wrote on 6/15/2007, 3:08 AM
Could you ,please clarify what this brand of smart render does.

HDV is M2t 1440 x 1080, so to create an MPEG2 for DVD, I would have thought that any system would have to render a new, single mpeg2 file at 720 x 576 (or 480 NTSC) from beginning to end.

I dare say that Liquid does this faster than Vegas, but I'd like to understand where smart render comes into this.
blink3times wrote on 6/15/2007, 3:44 AM
"Could you ,please clarify what this brand of smart render does."
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I'll give you 2 real life examples that I face all the time.

First, I shoot HDV, and I DON"T go to dvd... I go to hybrid HD DVD. I capture and edit in Vegas then I export as M2V/WAV where I import to Pinnacle Studio 10 and burn to hybrid HD DVD.

.

Vegas has already done a COMPLETE render once so I would rather not see it rendered again. FORTUNATELY Pinnacle has a smartrender system. With SR turned on a 50 minute HD timeline takes about 10 to 15 minutes to render (it's not being rendered but more or less copied). With SR turned off the render takes closer to 2 hours. It's not just the time increase that's a pain... it's also the fact that you're re-render and therefor losing quality.

In August the HD DVD burners will be out and I will most likely be burning to real HD DVD's by then. Vegas's lack of smart render will be a REAL hard pill to swallow at that point

I don't have a mpeg camcorder but I do record a lot of tv movies (mpeg hardware encoded)... I need to remove commercials and put them on disk. Simple job, but I wouldn't consider using Vegas because it COMPLETELY renders the timeline. Pinnacle studio does the job in a fraction of the time and retains as much quality as possible because almost none of it is actually being rendered. A 2 hour movie at 5700K minus the commercials is about 90 minutes. With studio (or liquid) and smartRender, I can import, edit commercials, render, and burn to disk (at 16x) in about 25 minutes. Never tried it in Vegas but my guess is.... closer to 2 hours.
murphy wrote on 6/20/2007, 10:07 AM
If anyone could answer the original question that mcfallison2 asked I sure would like to get their experience.
How good are the results when editing footage from a camcorder that uses a Hard Drive or a DVD as it's media?
Assuming it is rendered only once.

Appreciate your input.

Murph