artifacts generated from compressor

I just produced a mpeg 2 file from compressor to use in a DVD. I noticed that in the last half of the program some pulsating artifacts around certain images in the picture. I don't see any artifacts in the video from the timeline on the canvas in FCP. Anybody ever experience this? Of course when you go ahead and use the file in DVDSP it shows up on the dvd. I cut a small piece from the end of the timeline and compressed that and no artifacts. Seems like it has to do with the length of the project.
Jim Ellis
Inspired Images Co

If you have a lot of motion in a particular area of a video sometimes you get that. I would use a compression marker in fcp to give compressor a little notice of the heavier motion.

secondly are the regular questions.

what sequence setting is used in the fcp TL?
what setting was used in dvdsp?
Did you compress strait from the TL or did you create a qt self-contained movie to compress?

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

Oh by the way

Your computer monitor can not allow you to see what you really have you will need an external monitor to truly see what you have in the TL.

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

I had some similar results recently with Compressor. Version 2.3 with Final Cut Studio 5.

I was using DV50 with my HVX-200, and found square pixels on some shots with mixed sunlight and shadows on two people walking. Noticed something similar once before with DV50 also. Never saw any artifacts in FCP 5.1.4 timeline, only after Compressor.

What codec were you using? Compressor version?

Compressor settings were DVD Best Setting 90 min 4:3, Mpeg2, then changed bitrate to 6.8.

Still have not solved it, but wondering if others have noticed it.

Good luck!

Marcus

Hi Guys,
No motion in the area affected. Did view the timeline on an external monitor - Clean.
Seq. settings
960x720
Pix aspect HD 960x720
Field Dom none
Timebase 29.97
Comp DVCPRO HD 720p60
Yes I did compress straight from the time line
and the compressor version is 3.0.2
NOW GET THIS. And I really am completely sober.
I just viewed it again and its gone.
I am looking at the preview monitor of compressor in order to view the completed file. Its clean!!!!
Got me.
Maybe someone in the next office turned on a big microwave dish or something. Or an alien presence was detected. Thanks for your input.
Jim
Inspired Images Co

Hi Jim, apologies for taking a while to get back to you. Was posting my reply yesterday, but the internet connection fizzed out for a bit and lost the post... Glad you got it fixed.

A side note if you're exporting off the timeline. I used to do it quite a lot, but now not so, as exporting a SCQT movie is faster, especially on multiple cores. And check the positioning and aspect ratio of your titles, especially if you have them done up in Boris Title 3D. Happened to me a while ago on an ad in DvcproHD 720p50- aspect of the titles were stretched and the position seemed slightly off. I suspect Compressor messed up the render. No issues encoding off the SCQT.

Marcus, need a bit more details on "square pixels" and whether you are exporting direct off the timeline or off a SCQT.



www.strypesinpost.com

Hi Gerard,
No problem,
I have a dual core 3ghz mac pro with 3gb memory. Do you think
exporting as a scqt and bringing that into compressor will still be quicker?

I'll have to give it a go and time it. Well sounds like it solves a few different problems going that route anyway.

What about nesting the timeline, does that shorten the encode process?

I have been doing 30 min clips for the internet and the more I hear about multiple core processors the more they sound worth the upgrade. I have been leaving the timeline unrendered just to save a step before making an ON2 flash file, it takes about 3 hours to encode. Looks great but jeez.
thanks,
Jim

I don't think it's a dual core mac pro. There should be least 4 cores that you can tap into in Qmaster (unless you are on a 'Tosh). And even on 2 instances (a dual G5 on 1 gig of RAM) it speeds things up dramatically (I had an 24 min ep encode in around 14 minutes yesterday with Qmaster and the usual time it takes is around half an hour).

To do that, go to Qmaster in System Preferences, select Quick Cluster with Services, deselect share, select managed, change number of instances to the max value, give the cluster a name and click start sharing. In Compressor, render with the cluster when you hit submit. And time that.

Encoding off the timeline is supposed to produce the highest quality, since it bypasses codec compression and renders everything off the source file.

Also, when you export a SCQT, make sure you include Compression Markers.

>What about nesting the timeline

That usually doesn't do anything useful, besides bloat up your project size.



www.strypesinpost.com

Thanks Gerard,
I will give it a go on Monday.
Jim
Inspired Images Co