Vegas and swf banding

vitalforce wrote on 4/8/2008, 11:00 AM
I have a flash intro to a DV movie (moving smoke on a black background from Particle Illusion 2.0) which renders from the Vegas timeline to MPEG-2 for DVD, and shows noticeable artifacts when the DVD is played on a big-screen TV. Would rendering first to a deeper color space or applying another Vegas FX over the clip, help reduce the banding artifacts?

I considered trying to point Vegas' "use third-party codec" feature to an Avid DNxHD codec, for the deeper color space, but don't know if this works?

Comments

busterkeaton wrote on 4/8/2008, 11:53 AM
If you have Vegas Pro 8, I believe that is the situation that 32 bit rendering is intended for. You have to make sure it's set up correctly (see posts by GlennChan on the subject). Are the artifacts just banding? I bet smoke is one those things that really stresses the encoder.
GlennChan wrote on 4/8/2008, 12:03 PM
It could also be the compression... one compression technique is that the DCT coefficients are quantized more heavily... essentially the bit depth is reduced... so banding is sometimes an artifact of the compression.

To check if Vegas is at fault, try flipping into 32-bit mode (and 2.222 compositing gamma) and see if the banding is there. Ignore any color shifts for now.

To check if it's the compression, you could look at the video preview window to see if there are issues there. Or try higher-quality compression (e.g. higher bitrate, more efficient encoding like 2-pass VBR, etc.)
Laurence wrote on 4/8/2008, 3:48 PM
8 bit vs 32 bit renders might cause the kind of subtle banding you'd see on a 60" HDTV if you look really hard, but not the kind of banding you are going to notice on a small flash encoded video.

Are you using odd dimensions. Usually compression works best if you use multiples of 16 or at least 8. That is why dimensions like 320 x 240 or 640 x 480 are used so commonly. All those numbers are divisable by 16. Sometimes odd dimensions can cause some very weird artifacts.
vitalforce wrote on 4/8/2008, 11:32 PM
I had set Vegas 8 for 32-bit and actually re-corrected my entire 93-minute film because the color depth seemed to be sightly better. Will try this at the 2.222etc. setting on just the output Particle Illusion file alone.

No, using standard dimensions and will follow Glenn's advice in a few days. I live a double life and have to get an appeal brief finished.

Thanks to all for your helpful thoughts.