Rendering times

Clark5080 wrote on 10/13/2009, 11:39 AM

I have a few family movies that were shot on VHS, I have captured them and edited them. I am going to reedit them down to 80 mins of video. I used contrast, saturation and sharpening on them and the rendering times were huge.

Is there any one of the three effects I have used that is way more intensive than the others? It took me nearly all day to render one 2 hour video.

Jim

Comments

musicvid10 wrote on 10/13/2009, 12:50 PM

Any video effect you have means a significant impact on your rendering times. The reason is because the CPU will have to reprocess every single pixel in every frame. That is a lot of work to do!

Use the fastest CPU you can, close down other background apps, and don't multitask when rendering. That is the common advice.

Chienworks wrote on 10/13/2009, 6:33 PM

In this particular case sharpening is the major culprit. It's much more CPU intensive than the other two. While saturation and contrast have to work on every pixel, sharpen has to compare every pixel to many of it's neighbors, multiplying the effort by a huge amount.

I'll also add that sharpening probably isn't as useful as you might think. It really doesn't sharpen the image; it merely exaggerates the edges. Try it with and without and show it to a few folks, without telling them which is which. Chances are about half will say one looks better and the rest will say the other one looks better.

In fact, most folks smooth/soften VHS captures instead of sharpening. Why, you might ask? VHS images tend to be very noisy with lots of static and interference. These things are hard to compress, deteriorating the image and causing lots of artifacts. Smoothing them out allows the finished image to look substantially better when compressed to formats like MPEG for DVD or WMV/mp4/etc for web posting.

On the other hand, soften/smooth filters can be slower than sharpen.

musicvid10 wrote on 10/13/2009, 6:54 PM

While probably equally CPU intensive, I have gotten used to using Unsharp Mask (a misnomer) because of extensive experience setting the radius and intensity in Photoshop.

That being said, my preferred method of transferring VHS to computer is via a Panasonic set-top combo. The DVDs are of equal or more often superior quality than I could accomplish in a NLE, and the .vro files are easily transferred using VideoReDo.

Eigentor wrote on 10/14/2009, 5:39 AM

My only project so far renders to about 12 minutes, using about 30 mpegs as source. It takes about 45 minutes on my Pentium 4 W-XP. I have very few special affects. so you're numbers don't surprise me. I shut down every app. I can, including my virus protection. I think a Core 2 Quad is in my future.