Uncompressed - Is this true?

EW wrote on 6/7/2002, 3:39 PM

"If you incorporate any graphics or animation in your projects, your graphic clips will greatly benefit if you edit in an uncompressed [FCP] timeline as opposed to taking your graphics to a DV-based timeline edit."

This (slightly edited) statement was taken from an article on reasons to work on not work with uncompressed video in Final Cut Pro. Found at:
http://www.2-pop.com/article/mainv/0,7220,34478|2,00.html

In another part of the article...

"There are only two advantages to this entire DV/uncompressed process (with graphics and/or rendering included in the mix):

1. Going to a master tape format better or equal to 4:2:2.

2. Mastering to a tape/format different than the 4:1:1 DV source you captured from. This includes formats like MPEG-2 for DVD. Even though MPEG-2 for DVD is 4:2:0 (which is the same color space value for DV PAL users), the MPEG-2 codec is entirely different than the DV codec even though they might encompass the same or similar color space value. Whenever you change codec formats, transfer from the best resolution possible!"

1) Is all of this true for Vegas Video?
2) How would one create an uncompressed timeline in Vegas when starting with miniDV video information?

Comments

HeeHee wrote on 6/7/2002, 3:45 PM

I think they mean that you should not work with compressed(lossy) media like Mpeg, wmv, etc... The media you would be working with is DV AVI, which is a lossless compression. You should be fine with that.

SonyDennis wrote on 6/8/2002, 9:34 AM

HeeHee:

DV is not a lossless compression format. You lose information with every compress cycle. The loss is primarily due to the DCT quantization, which accounts for "mosquito noise" in busy areas. The Sonic Foundry DV codec tries to minimize the extent of the loss, and is particularly good at multi-generation recompression, but you still lose something due to the fact that DV is lossy, not lossless.

Part of the confusion about DV being lossless is because there is no loss during tranfers, captures, and print to tape between the DV tape and the hard disk. This is because DV is a digital format, and the digital transport (Firewire) just moves the bits verbatim with no further compression. Hence, some people think it's an "uncompressed" format because their PC does no further compression, but at it's heart, DV is a compressed format (as is M-JPEG, and all forms of MPEG).

But don't assume compressed = bad. Even high-end Digital Betacam decks do a similar kind of DCT compression inside the deck. It's just a matter of how much, and how much it affects your image. I consider DV a somewhat light level of compression. You have to really look to find artifacts.

///d@

DVedit wrote on 6/14/2002, 8:17 AM

OK..
So what's the final word on making a high quality DVD from DV.
Should I stay in DV compressed or decompress (maybe using HuffyYUV).
I am using CCE for my MPEGS-2s. Are there any web resources that explain
how to make the best DVD quality from a DV source?

SonyEPM wrote on 6/14/2002, 8:41 AM

If you are doing cuts only DV edits and want to export to a standalone MPEG encoder, rendering to DV will be fine. Cuts only DV does no recompression as long as the source/output paramters match, so that will be a bit for bit copy.

If you have DV source material and mix in graphics, transitions, motion fx, composites etc and want to export to a standalone MPEG encoder, rendering an intermediate uncompressed avi will result in the best quality.

Also, please be aware that Vegas doesn't have to convert source media to DV or anything else prior to putting it on the timeline (like AVID MC, Media 100 and some others do). Vegas decompresses the source files and does ALL calculations in uncompressed until you render it to the destination format. For instance, we are feeding the built in MC MPEG encoder (and all of the built in encoders) uncompressed frames, not compressing to DV first.

jgourd wrote on 6/14/2002, 11:53 AM

While DV may be good, and it is easy to work with, I do have a problem with it.

When I use blue text in a project and render to DV the blue smears to the left a little bit. MPEG-2 does NOT do this. It doesn't seem to matter who's edit program I use or who's codec I use so it must be part of the DV spec that allows this to happen.