import VOB, render MP4, output flickers once/secon

Jasper Bluto wrote on 1/10/2009, 10:44 PM
I have to encode video for a client to these specs, to be posted on the website iAmplify:

VIDEO:
File Format: Mp4 (Basic - NOT Mp4 ISMA)
Video Format: H.264
Data Rate: 1372 kbps/sec (Single Pass/CBR)
Image Size: 640x480 VGA
Frame Rate: 29.97 (this may change to 15)
Key Frame: Automatic

AUDIO:
Audio Format: AAC-LC (Music)
Data Rate: 128 kbps
Channels: Stereo
Output Sample Rate: 44.100 kHz
Encoding Quality: Best

I used the MainConcept AVC/AAC MP4 codec to encode, using as many of the specs above as I could discern. I have a hunch the "data rate" may be an issue, as none of the template rates were anything like it. When playing back the file the entire frame will "flicker" or "flash" roughly once per second. I really appreciate any help you folks can toss my way. It's really generous of you experts to browse these forums and help noobs like me! Thanks! Jake

Comments

erikd wrote on 1/11/2009, 10:40 PM
I'm not an expert but since no experts replied... did you try rendering this with a template that comes in Vegas without altering it? Do you get the same flicker problem then ? My guess is that you may be changing something in the preset parameters that is causing the problem. If you can get a basic template render for MPEG4 to render without the flicker, make one change at a time until you find out which alteration is causing the flicker effect. Just a guess and hope it helps.

Erik
srode wrote on 1/12/2009, 3:33 AM
Had a similar problem with a file - had to go frame by frame to see what was going on and there were 2 odd frames with random pixels out of every 10 - had to change formats. See if you can take the rendered file to Vegas time line and check if there are odd frames in there. If not burn to RW disc and play it in a standalone player to see if it goes away. Comuters induce flickers in otherwise smooth videos sometimes.
Jasper Bluto wrote on 1/13/2009, 10:40 PM
Erik,
Thanks for the reply. That's a sensible way to start - with the factory presets.
I'll give it a shot.
Thanks!
JB
AtomicGreymon wrote on 1/14/2009, 12:44 AM
I've found that Vegas' handling of MPEG-2 off DVDs like that isn't always perfect. You can get weird green frames, bits repeating, pixellation, etc. I've seen it all, when trying to import video off a DVD.

They've got specialized MPEG Editing software for that. TMPGEnc MPEG Editor 3, Womble, etc.
Jasper Bluto wrote on 1/14/2009, 1:26 AM
Also a good idea! I would not have thought to use Vegas as a diagnostic tool.
I'll try putting the rendered stuff on the timeline and see if anything looks wrong with it.

Thanks to both of you!

JB
Jasper Bluto wrote on 1/14/2009, 1:35 AM
"I've found that Vegas' handling of MPEG-2 off DVDs like that isn't always perfect. You can get weird green frames, bits repeating, pixellation, etc. I've seen it all, when trying to import video off a DVD."

Greymon -
Everything seems to play ok while editing and I can render in other formats with no artifacts or flickering. I barely know how to get by in Vegas... I would be lost (and broke!) trying to add another NLE to my overworked brain.

I guess the next response will be someone from Sony...
"Oh yeah, 6.0 sucks. We fixed all that in 8.02b ! That will be $600, please."

I spent all this money on their software, then a year and a half later, it's "legacy" software and they refuse to provide any tech support for it. WTF? I have Adobe Premier, I just can't stand the UI.

I'm ranting...
Thanks for all your help, guys.
JB
farss wrote on 1/15/2009, 1:30 PM
"I spent all this money on their software, then a year and a half later, it's "legacy" software and they refuse to provide any tech support for it. "

1) It isn't $600 to upgrade V6 to V8 as far as I know.
2) It's a LOT more than a year and a half between V6 and V8.

As for providing tech support. I doubt it's anything wrong in the software anyways.
Some more details would be helpfull. It seems like in the midst of all this you're doing a frame rate conversion but I don't know what your source material is other than it's in a VOB on a DVD.

Also what are the keyframe settings for the H.264 encode?

Bob.