To a first approximation you can think of Cineform HD as generating an uncompressed copy of the m2t clips (people using actual uncompressed 4:4:4 will object that the codec is good but not uncompressed!). To understand the advantage of this you should check out how mpeg (m2t 4:2:0 ) compression works, and in particular understand that most frames recorded to tape are abbreviated representations of a scene. Cineform decodes the m2t data and writes new files in which every frame is a full digital 4:2:2 representation of the scene at that frame time. Now when you copy and manipulate the data it is a "simple" process that maintains resolution that is a good as your original m2t through many copies. If you maintain m2t through post production, your computer is having to decode and encode at every generation, which leads to a much more rapid loss of information.

I've been kind of doing a "best of both worlds" approach lately. I put m2t's directly on the timeline, but any time I rerender or generate anything I use the Cineform codec.

This months DV mag editorial has some interesting comments on just what "uncompressed" means.

Michael

Another important benefit of using the Cineform codec in versions of Vegas prior to V7 is the improved playback performance from the timeline. Trying to get smooth playback from the original m2t files or other full resolution formats (uncompressed, Huffy UV, Sony YUV, etc.) was virtually impossible. With Cineform, you had all of the benefits of of using a vitually lossless format with full frame rate playback. Also, prior to Vegas 6, using Connect HD was the only way to print HDV back to tape.

Now that Vegas 7 plays the original m2t files with full or nearly full rates from the timeline, Cineform has lost some of its early benefits. The general consensus here seems to be with Vegas 7 that if you are doing cuts-only editing with minimal color correction or compositing, using the original m2t file is acceptable or even preferred. If you will be doing moderate to heavy color correction, compositing or multiple renderings, using Cineform is the way to go.

I have Connect HD which is a stand alone Cineform encoding application with a few additional benefits. First, it installs the Cineform codec to all video applications like After Effects, CG programs, etc. so you can render to Cineform from other programs besides Vegas. It can also capture and encode m2t files in near real time from HDV cameras to the Cineform codec. It can now also deinterlace, change frame rates (like 24p and 30p,) and frame sizes during the capture process. It can split files at scene changes and keep the original m2t file in addition to the Cineform encoded file, if you want it to. It can also take other video files and upconvert them to the Cineform. I'm not sure how well it converts compared to Vegas but it does do it much faster.

As far as I know, the Cineform events show a less superior preview performance in Vegas 7b, comparded even with m2t 1080i files. Hope that will be recovered in future versions of both Vegas and the codec.

The recent v3.22 is running at correct speed for me in V7b, including levels correction. However this was just a quick test to check this particular point. Cineform update notes say nothing about improved preview speed in V7, so you'd need to evaluate for yourself.

For me, on my 3.2gHz, Old Cinefor v2.2 that ran at full speed in 6 manages only 9fps in 7

Yes, that's what I'd expect. You have to use the new release of Cineform in Vegas 7.

So, essentially, you need to re-encode all Cineform avi's to the new format to have full speed playback in V7? Anybody measure any loss in the conversion?

Well, you could go back to the m2t tapes and recapture, or stay with Vegas 6d until that project is finished. I haven't tried re-encoding old CF v2.xx IDs and that might be a good question to put to Cineform.