Just to clarify, there is no such thing as "uncompressed m2t."

M2T files are MPEG2 Transport files and are highly compressed; on the order of 53 to 1. The video is compressed in the camera and recorded to tape. Truly uncompressed 1920x1080 29.97 8-bit HD video has a data rate of about 186 megaBYTEs per second. Once it's compressed to MPEG2 and written to tape, it's around 3.5 megabytes per second. That's some serious compression! Fortunately, there is no further encoding or compression involved in transferring this data from the camcorder's tape to your hard drive as the capture process is just copying the data from one place to another.

Unfortunately, Vegas will recompress all video on the timeline when rendering back to an .M2T file, whether you've modified the video or not. Now, there are ways to cut, trim and join .M2T files without re-encoding using dedicated MPEG2 editors like Womble MPEG2 Wizard or VideoReDo. One thing to note is that in order to produce a file with NO loss whatsoever using these programs, you'll need to cut the files on "I" frame boundaries, which occur every 1/2 second. However, if you modify the video in any way, like adding titles, filters or even a simple fade, the video MUST be recompressed. There is a quality hit and there's no way around it. (The same is true of standard DV video, but it's much less compressed to begin with and can handle recompression much better than the massively compressed HDV video.)

The fact of the matter is that any sort of editing that involves anything more than simple trimming, cutting or joining HDV video on "I" frames using an MPEG2 editor will require recompressing. Editing video in an HDV project in Vegas, whether modified or not, gets recompressed. The video will never look as good as it did as "raw" M2T files captured from the camcorder. Whether or not the viewer can notice the image quality degradation is the subject of another discussion.

To answer you're original question, since you say that you're doing a "five camera switch" you should probably just do as MH_Stevens says, render to an HDV .M2T file. That will incur the least amount of degradation. Now, if you wanted to get really fancy and have a BUNCH of time, you could use Womble MPEG2 Wizard or VideoReDo to losslessly cut and trim all the pieces you need and string them together. Probably not worth the effort...

John

After reading your explanation on what occurs with editing HDV, does this loss of image quality also apply to using cineform AVI's as well? I am under the impression that when working with Cineform AVI's, there is mush less of a hit to the image quality when rendering back out. Is that a correct assessment?

Forgive my ignorance - all the various iterations of compressed HDV is confusing to me as I am still shooting standard Def.

On that topic - what is the best way to render back out from the timeline in SD and retain as much image quality as possible??? Uncompressed AVI? Quicktime Animation???

Yes, using a Cineform intermediate file results in much less of a quality hit. Although, if you source footage is HDV and your destination format is eventually HDV, then you don't gain anything except the speed of the codec. Basically, if you're using Vegas, then the HDV video will have been compressed once in the camera and will be compressed again when rendered out of Vegas to the final HDV file. Where the Cineform intermediate comes into play is it requires much less horsepower to decompress and display, so you will get a higher frame rate playback on machines with limited horsepower.

If you're working in standard-def DV, then rendering back to DV is perfectly acceptable. While there will be a hit, the Sony DV codec is the best there is and any image degradation will be unnoticable. If ultimate image quality is your goal for further processing in another program, then uncompressed .AVI is your best bet. The files will be REALLY large though.

John

Thanks for the info. At this point I am rendering to the Main Concept MP2 at best. Anywhoo, At that point, What is the best possible quality DVD settings using DVDA 4. I want it to look as close to hd as possible.

L.T.