Converting HD to SD to burn a DVD with iDVD

Question

Hello,
I bought myself an HD-camera with a Hard Disk (Sony HDR-XR500E). The native format is AVCHD.
When I transfer the video to my iMac (Intel Core Duo 2,16GHz) I can see the video in my Final Cut Express where the video is transcoded in Apple Intermediate Codec AIC format.
The editing works fine. The pictures are sharp and there are no visible artefacts.
I can export the timeline to Quicktime Movie, and the result is a rather big .mov file.
When I playback this file it appears automatically in a FCExpress window, and I have no problem playing the file.
When I use that .mov file to create a DVD with iDVD the there is a problem. When there is amore than a little bit of movement in the picture, the vertical transitions become distorted (jagged). It looks like I see an interlaced picture where both frames are displaced a little bit. This effect is very good visible when I stop the movie playing.
I see the same effect when I playback the same .mov file in the Quicktime player.
What am I doing wrong?
I see no place where I can manipulate settings in iDVD or Quicktime.
It is strange that I don’t see this problem when I export my timeline using Quicktime Conversion to create a file for the internet (eg Broadband high).
Who can give me a hint?
Thx

Answer 1

Hello Tom,
Sorry for the late reply but the last few days I had other things to my mind.
In the meantime I realise why I was confused, … and you gave me the understanding or the missing link to understand what was happening.
My original problem was burning a HD project I made in FCE on a DVD in SD.
I thought that:
1. FCE made an export in a HD format, … and this is right.
2. iDVD could only accept a movie file in SD, … and this was wrong.
That’s why I was looking for a method to convert my HD-movie in an SD-movie to feed iDVD.
So my problem is solved.
Bringing a HD movie from FCE to iDVD is very simple: It’s the same as bringing a SD movie to iDVD. iDVD recognizes an HD movie, and does the conversion to SD automatically. So my problem is solved. I produced a DVD starting from my HD movie and it looks as good as the movies I made in the past with my old DV-camera.
It’s a pity I couldn’t find the workflow, to turn a HD movie made by FCE into a SD movie on a DVD using iDVD, in the documentation of FCE or iDVD.
Why was I confused?
When I was looking at the playback in the canvas window I saw rather good pictures (no artefacts).
When I was looking at the exported movie with my QT player I saw a lot of interlacing artefacts. That’s why I thought there was something wrong with the coding of the exported video, … but it wasn’t.
Your explanation about looking at the canvas window in 100%, and the fact that viewing at any other than 100% was showing a reduced resolution (with interpolation, using only one field) made me understanding the problem.
I did a few tests to verify my thinking. In FCE I used de-interlacing on the video. In the canvas I saw a rather good picture nearly the same as the original (without de-interlacing). When I exported that de-interlaced video and viewed this file in QuickTime, the artefacts were gone.
So, my conclusion is: Don’t use QuickTime to control an exported movie from FCE, because QT is using an interpolating scheme with both fields. The result is absolutely bad especially when there are fast moving objects in the movie.
Tom, thanks again for your help.
I was just wondering what kind of education you have in video, because you seems to know what you are talking about.
MDW