Does Rendering/Encoding Happen Twice?

[yardbird]

I'm capturing analog video from an old Beta VCR through a breakout box which converts it to MPG on my PC. (There's no option to capture AVI.) When I import the clip into VS, I follow the sticky instructions and after editing the clip, I saveit to the PC, apparently initiating a render/encode step. Once I have several clips converted to MPG files, I re-import them into a new project and burn a DVD. Prior to burning, it looks like the files are being re-rendered. Is that so? If so, am I losing quality?
-- yardbird

[Ken Berry]

If indeed they are re-rendering, then notionally, yes, you are losing quality. The jury is out on how much quality you lose, but since you are starting with relatively low quality VHS, then I guess any amount might become noticeable.

When you capture, you should be setting the capture properties to as close to DVD-compatible mpeg-2 as the capture box may permit. If they cannot be set to those, then when you actually 'save' them to your computer after editing, you should be doing so with DVD-compatible properties (Share > Create Video File > DVD). This is the first render. But if indeed you have a DVD-compatible mpeg-2 file then you close your current project, and click Share > Create Disc > DVD. This will open the burning module. Insert your DVD-compatible file(s). Make sure you click on 'Do not convert compliant mpeg-2 files' in the little cog-wheel icon in the bottom left of the burning module screen. This should prevent a second render taking place.

[2Dogs]

Hi Yardbird,

if it's taking a long time it may well be re-rendering. You need to ensure that you have the "Perform Smart Render" box checked in the "Options..." button of the "Create Video File" dialogue box when saving your project as a single MPEG-2 file.

As an indication that Smart Rendering is actually happening, the preview screen should stay black whilst the file is being saved, rather than showing the video content.

Re-read the Recommended Procedure and make sure you follow it exactly. Trevor Andrew amongst others has posted concisely many times on how to ensure you get Smart Render to work, so you might chase up on some of his posts.

You'll know when you get it to work, 'cos it'll speed things up several times. And yes, every time the program re-encodes MPEG-2 footage, you'll get a loss in quality.

Good luck!

[yardbird]

Thanks for the replies, and for the info, it's helpful. But I guess my main question is, at what point(s) in jchunter_2's Recommended Procedure sticky is an actual encoding being done? MPG being a lossy format, I want to minimize the number of times my files get encoded. There's one initial encoding done by my brealout box converting the original analog feed into MPG. When I edit that file and save it from VS via "Share/Create Video File," is another encoding process taking place? Later, when I load several clips into VS and burn a DVD, is yet another encoding taking place? I'm not as concerned with processing time as I am final quality.

[Ken Berry]

I have already supplied the answers. The first process -- converting the analogue source material to a digital format (your original mpeg) is, of course, unavoidable as you have to get the signal into your computer somehow. But once you do the edits and go to Share > Create Video File, yes, another render is done (although using Smart Render should reduce the amount that is affected as it then just reprocesses those parts which have been edited or added. However, Smart Render has also been known to introduce other problems, including the dreaded out of sync audio and video.) But once you have created all the DVD-compliant mpeg-2s you want for your eventual DVD, then if you go to Share > Create Disc, then you AVOID a further render if you click 'do not convert compliant mpeg files' as I suggested. The burning process still involves multiplexing (muxing) of the files, but this is different from rendering them again.

[yardbird]

OK, I think I got it. I was a little unsure if "rendering" was the same as "encoding." Your suggestion seems like the cleanest way to create my DVDs so I'll follow those steps. Thanks again.