I've been experiencing some artifacting in random places with compressor. When I finish my current job, I'll upload some samples, but for now, I'll try to describe it. It seems like a steady pulse every second where the image goes from crisp to blocky. It does it random places for less than a minute.
My workflow is to edit in FC, export the timeline as a reference quicktime and then open it in compressor using the DVD 120 minute Best template. These artifacts can not be seen in FC or the reference movies, so Compressor has to be the culprit. I'm using an 8-core Mac Pro and have Qmaster running on 4 of them.
The only fix I have found is to export the timeline from FC using Compressor. I have not been able to duplicate the artifacting this way. While it does work, it means I can't do anything in FC until it finishes.

Any thoughts?

It seems like a steady pulse every second where the image goes from crisp to blocky. It does it random places for less than a minute.

Any thoughts?

Have you tried a different output codec, for example H264 to see if it still occurs? Does it only occur with this particular source or with any source submitted to compressor? When you said "every second", I instantly thought "keyframe", but I can't imagine what's wrong, except that somehow the settings of your 120min DVD template got screwed up.

Dino

These are the settings that were used in Compressor:

Name: MPEG-2 5.0 Mbps 2-pass
Description: Fits up to 120 minutes of video with Dolby Digital audio at 192 Kbps or 90 minutes with AIFF audio on a DVD-5
File Extension: m2v
Estimated file size: 4.42 GB
Type: MPEG-2 video elementary stream
Usage:SD DVD
Video Encoder
Format: M2V
Width and Height: Automatic
Selected: 720 x 480
Pixel aspect ratio: NTSC CCIR 601/DV (16:9)
Crop: None
Padding: None
Frame rate: (100% of source)
Selected: 29.97
Frame Controls On:
Retiming: (Good) Frame Blending
Resize Filter: Linear Filter
Deinterlace Filter: Better (Motion Adaptive)
Adaptive Details: On
Antialias: 0
Detail Level: 0
Field Output: Same as Source
Start timecode from source
Aspect ratio: Automatic
Selected 16:9
Field dominance: Automatic:
Selected Progressive
Average data rate: 5 (Mbps)
2 Pass VBR enabled
Maximum data rate: 6.3 (Mbps)
High quality
Better motion estimation
Closed GOP Size: 15, Structure: IBBP
DVD Studio Pro meta-data enabled

The problem seemed to have stopped, but not its back.
I am capturing HDV and converting it to ProRes 422, editing it in FCP, exporting a Quicktime reference file, opening it in Compressor and using the 120 minute Best setting. I've been doing the same thing for months with no issues. I noticed it would always happen when I would use the cluster to render. When I leave it to "This computer", the problem seemed to stop.
I pulled a piece of the video file out and rendered it as a quicktime file and posted it here:
www.chaddyleproductions.com/video/sample.mov (Right click and "Save As").

I would appreciate any help with this.

-Chad