Yeah, I take the rendered MPEG and play it in Vegas and it shows the artifacts as well, so I know it has something to do with the rendering process. I've tried contstant bit rate and I've tried multipass.

Any ideas?

What FX filters are you using on the timeline?
If you have a lot of editing you might try rendering to uncompressed .avi first. The load the rendered .avi onto the timeline and re-render to Mpeg 2 using the DVDA NTSC video only stream (as you did before) with an average bitrate of 6 mbps and the DC Coefficient set to 10. Then render the AC3 template that goes with it (as you did before).

John

John, I'll try those settings and report back. I did experiment with rendering the timeline as a single .AVI, but using the DV template not the uncompressed. I'll give the uncompressed a spin and let you know.

Thanks.

(edited note: this is a video that came in from a client already edited, so no FX got applied to events, or tracks. I only cut the movie up and added some markers. I also noticed that the original tapes show a slight line that flickers 1/3 down the screen, those lines seem to translate to dropouts in the rendered MPEG. You can also hear a slight digital "chirp" at the same time.)

Are you 100% is not a issue with the captured source media? These one-frame dropouts are very hard to spot unless you do a very thorough scub of the timeline. Unless your getting full frame rate playback through your preview window, you'll never spot them....

QUOTE "small multi colored digital blocks appearing in the rendered MPEG2 "

bad encoding - pure and simple .. macroblocks (or a block) ..

what settings are you using to render mpeg2 ?

Ussually most often caused by to low a bit rate with some encoders ..


Definition:


A block is an 8 x 8 array of pixels. Four luma blocks plus a number of chroma blocks that depends on the chroma pixel structure indicated in the sequence header comprise a macroblock.

A block is the fundamental unit for the DCT (discrete cosine transform).

Each macroblock consists of a 16 x 16 array of luma (Y) pixels (4 blocks). The number of chroma pixels (Cr, Cb) will vary depending upon the chroma pixel structure indicated in the sequence header.

The macroblock is the fundamental unit for motion compensation and will have motion vector(s) associated with it if is predictively coded.

A macroblock is also classified as field coded or frame coded depending on how the four blocks are extracted from it.

Mark, I'm 100% sure. I compared the same frames.

B_JM, I used the default settings for both NTSC DVD and the DVDA video stream settings.

yes - well those default settings are only a starting point -- you should set up the settings based on the type and lenth of your material ..

Please allow me to thicken the plot.

I'm now working with a 30 second clip from the 50 minute problem project to speed up my trouble shooting efforts, and I figured a few things out. The :30 original clip does NOT have any major dropouts. I say major becuase there is still this odd line (almost like an analog video in need of a TBC) - but only visible if you go frame-by-frame. Anyway, if I render this :30 clip as an uncompressed AVI, or MPEG, then the dropouts i described above start happening. However, if I export that :30 clip as an AVI using the DV NTSC template, no dropouts. To make it even more odd, if I render the original 30 second clip as an AVI DV NTSC, but add any Video FX,... BAM, there is a dropouts again. If the frame gets re-compressed I get dropouts.

What I suspect is that the original tape is just shy of full blown dropouts. Somehow it made it into my computer intact. But the file is so error ridden that any sort of process that requires the frames to be re-compressed, does it in. The encoder is willing to allow a straight copy of the damaged frames, but enough information must be destroyed that any sort of modification to those frames results in dropouts in the final rendered video file.

I'm going to try and run it through some other apps, to see if any of those play better with these mischievous frames.

Arghh!!!

Everyone can rest easy now, my problem has been solved... no really, everyone, it's okay now. :-P Vegas 6 saved my @ss!!!!

I took my :20 test AVI clip into the Vegas 6 demo and exported it to MPEG without dropouts. I ended up rendering to DVD Architect 24p Video Stream, btw.

If I open the project in Vegas 5, and render my :20 clip to MPEG, I get dropouts.
The same project, opened in Vegas 6, SAME part rendered out to MPEG, NO dropouts. No kidding.

Should I mention that Vegas 6 rendered something that Vegas 5 couldn't to Sony tech support?

Even better, Vegas 6 is about 20% faster rendering.

Vegas 5 took about 60 seconds to render a 20 second clip to 24p MPEG.
Vegas 6 took about 39 seconds to render the same :20 clip to 24p MPEG.

I know I'm preaching to the choir here, but Vegas 6 rocks.

as i stated - the default settings are only a starting point -- and the default settings are not the same between the two versions , so it's not a correct assumption you are making ..


I thought the demo version would not render MPEG2 ?

B_JM - as far as I can tell, the only different default settings between versions 5 and 6 are found under the Advanced Video tab in the render as dialoged box. The box next to "Allow field-based motion compensation" is unchecked in Vegas 6 (default is checked in 5). During my many hours of testing last night; I tried un-checking it in Version 5 and I still had the same problem. Version 6 also has a "Use closed GOPs", I left that unchecked since that was its default and I assume that is how it must be set up in Vegas 5 even though I didn't see a box for it. All of the other settings are the same. In fact, I tested many combinations last night, some made big changes in picture quality, some didn't. But all of them introduced artifacts on this particular video. I even had the same digital artifacts when I rendered the video to a 75 GB uncompressed AVI. Even adding an effect and rendering this video back to the native DV codec... STILL introduced dropouts. But, two minutes after installing the demo of version of Vegas 6, I had a working MPEG of this screwed up video I have. So I doubt the defaults have anything to do with it. I've encoded lot's of mini-DV to MPEG, this is the first time I've seen anything like this.

Perhaps the render engine's upgrade changed something???

Oh, the trial version I was handed at NAB does render MPEG2.

Thanks for taking the time to help.

Jeff

WIth all of the negative postings its great to see positive things about 6 and DVDA 3

once you install vegas 6 , your mpeg encoder dll's and plug-in is upgraded to to the version in 6 , even using sony vegas 5 .. (ac3, mp3 also) ..so its the same encoder, but the same file rendered at the default settings in each version will produce different results -- so the interface default settings are different (probably also the way the material is fed into the encoder also) ...

i'm sure i can make them match , but i havent really looked into it as there is no point really ..


even installing the demo version of 6 will upgrade version 4 , im not sure if this by design or an oversight ..