Render slow on certain videos

ericd2003 wrote on 12/27/2005, 8:50 AM
Hello, I have been transferring videos from VHS and notice that on some videos they take up to 8 hours to render and others take 90 minutes. All videos are about an hour long. I have not done any editing to them at all. Just capture and rendering. Please let me know if this is normal or if I need to make some changes.
Thanks, Eric

Comments

johnmeyer wrote on 12/27/2005, 9:25 AM
By "rendering" do you really mean "encoding?" Rendering is the process of creating new video from the merging of different tracks with fX, transitions, etc. Encoding is the creation of a new format, most typically going from DV AVI to MPEG-2 files prior to creating a DVD.

A "cuts-only" project will "render" very quickly to DV AVI (if your source is DV AVI) because very little new video is being created, and most bits are simply being copied from one file to another. This same project, however, can take several hours to encode to MPEG-2, depending on the speed of your computer and your MPEG-2 settings.

When you select MPEG-2 as the output format, you do BOTH the encoding and the rendering at the same time.

Things to check:

1. Have you accidentally "bumped" the track opacity or event opacity levels? If they are not set at 100%, then every frame must be re-rendered. There are scripts at VASST (which I wrote) that will check for this for you.

2. If you are encoding to MPEG-2, make sure you use the same template each time. The "default" template is quite fast, but the output quality stinks. This template should NEVER be used. Instead, use the appropriate "DVD Architect" template. If you use Default one time and DVD Architect the next, your encode times will be quite different. Also, if you check "2-pass" encoding, it will exactly double the encode time. This is usually not necessary if you are using average bitrates above 6,000,000 bps.
ericd2003 wrote on 12/27/2005, 12:42 PM
Correct I mean Encoding.
Here's what I have done.
Captured 10 tapes.
All 10 tapes are on one time line and they are spaced apart from each other so that I won't mix them up.
I then highlight the video I want to encode (MPEG-2)
without making any changes some videos take 8 hours and some take 90 minutes. They are all on the same track, yet some encode much slower then others.
Hope this helps and thank you,
Eric
johnmeyer wrote on 12/27/2005, 3:16 PM
Make sure "Render Loop Region" is checked, and that you have actually selected the region you want to encode. Otherwise you will render the entire timeline rather than just the one segment. Both of these are easy mistakes to make.