banding in output file at DVinfo.net

Ho-Jong Wong · October 28th, 2007, 08:58 AM

When I render to a video file from Vegas 7, there is a sunset scene fading out to black that exhibits a lot of color banding. They are mainly around the glow of the sun into the sky. The weird thing is when the project is on the vegas timeline, and I scroll around, my external preview monitor (a regular computer CRT monitor) doesn't show this banding at all.

I have tried exporting the video out to many different formats including Cineform 2.5, xvid, wmv9, etc. Also I have tried using Debugmode Frameserver to serve to an avisynth file, and encoded the video into xvid in virtualdub... all with the same banding artifacts. I have also played around with the rendering settings in Vegas, setting all of them to "best" where I could.

My source files are m2t converted to cineform 2.5 (the one built into vegas 7).

Ho-Jong Wong · October 28th, 2007, 09:05 AM

Ok, I just realized most of the banding is visible only when playing the output video file on my lcd (which isn't a very good one). When I play it on my CRT, the banding is greatly reduced. However, there is still a little more banding than when playing back directly from the timeline. Is this just an unavoidable result from generational loss?

Mike Kujbida · October 28th, 2007, 09:16 AM

Is this just an unavoidable result from generational loss?

Unfortunately it is :-(
Extreme examples of this are when shows on satellite (maybe cable too) fade to/from black.
Depending on the transmission bandwidth, the blockiness can be extremely bad.

David Newman · October 28th, 2007, 10:54 AM

It is not generation loss so much, it is much more related to 8-bit banding -- there are just not enough levels in 8-bit data to smoothly present 8-bit gradients. In version 3.x CineForm codecs we bump the data to 10-bit before compression, then dither back to 8-bit for presentation for applications like Vegas, this helps a lot. For data that you already compressed, you have simulate dithering by injecting 0.05% noise (about one 1 bit of noise), but it will not work as well doing it after 8-bit compression. You can get some of higher quality using NEO Player which upgrade your Sony CineForm license to v3 for free, or even more benefits by purchasing NEO HDV/HD which gives you much more quality controls.

October 28th, 2007, 08:58 AM	#1
Ho-Jong Wong New Boot Join Date: Aug 2007 Location: Cedar Rapids, IA Posts: 6	banding in output file When I render to a video file from Vegas 7, there is a sunset scene fading out to black that exhibits a lot of color banding. They are mainly around the glow of the sun into the sky. The weird thing is when the project is on the vegas timeline, and I scroll around, my external preview monitor (a regular computer CRT monitor) doesn't show this banding at all. I have tried exporting the video out to many different formats including Cineform 2.5, xvid, wmv9, etc. Also I have tried using Debugmode Frameserver to serve to an avisynth file, and encoded the video into xvid in virtualdub... all with the same banding artifacts. I have also played around with the rendering settings in Vegas, setting all of them to "best" where I could. My source files are m2t converted to cineform 2.5 (the one built into vegas 7).

October 28th, 2007, 10:54 AM	#4
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	It is not generation loss so much, it is much more related to 8-bit banding -- there are just not enough levels in 8-bit data to smoothly present 8-bit gradients. In version 3.x CineForm codecs we bump the data to 10-bit before compression, then dither back to 8-bit for presentation for applications like Vegas, this helps a lot. For data that you already compressed, you have simulate dithering by injecting 0.05% noise (about one 1 bit of noise), but it will not work as well doing it after 8-bit compression. You can get some of higher quality using NEO Player which upgrade your Sony CineForm license to v3 for free, or even more benefits by purchasing NEO HDV/HD which gives you much more quality controls. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

October 28th, 2007, 09:05 AM	#2
Ho-Jong Wong New Boot Join Date: Aug 2007 Location: Cedar Rapids, IA Posts: 6	Ok, I just realized most of the banding is visible only when playing the output video file on my lcd (which isn't a very good one). When I play it on my CRT, the banding is greatly reduced. However, there is still a little more banding than when playing back directly from the timeline. Is this just an unavoidable result from generational loss?

October 28th, 2007, 09:16 AM	#3
Mike Kujbida Inner Circle Join Date: May 2005 Location: Windsor, ON Canada Posts: 2,770	Is this just an unavoidable result from generational loss? Unfortunately it is :-( Extreme examples of this are when shows on satellite (maybe cable too) fade to/from black. Depending on the transmission bandwidth, the blockiness can be extremely bad.