Another "Render Format" question.

dsanders wrote on 11/14/2001, 2:55 PM
What is the best render format if my goal is to further process the video through a third party MPEG encoder (TMPG for instance)? If I use just a straight uncompressed .avi file, the file size is huge! Is there a loss less compression that I could use? If I choose .avi, there are several "Video" options. Should I be choosing one of these instead of "Uncompressed"? If I compress the file, is the file still truly considered a .avi file?

Sorry for all for of the rambling questions!

Thanks,
Don Sanders

Comments

CDM wrote on 11/14/2001, 3:36 PM
I would think the best would be the NTSC DV template (or whatever size your video is). That's straight DV. Yes, it's a codec so is technically compressed but is as close as you can get to uncompressed. There's really no reason to ever use uncompressed. No DV file is uncompressed. Typical is 3.71 megs per second of video (NTSC DV).

Hope that helps. Vegas 3 has a MUCH better codec developed by Sonic Foundry which is light years better than the MS one that Vegas 2 uses. It allows for tons or re-rendering with no degredation.
suni wrote on 11/15/2001, 5:19 AM
Loss less compression? YES, no problem with Huffyuv loss less codec. See http://www.math.berkeley.edu/~benrg/huffyuv.html.
dsanders wrote on 11/15/2001, 8:16 AM
When I take a short (30 second) video with a title and render it to uncompressed .avi the picture looks great. But more importantly, the text on the titles looks very clean and crisp. Whenever I use any type of compression the titles come out looking like crap. Why is this? They are just static, none moving, solid graphics. It should be very easy to compress this, but instead the edges get all smeared and the color changes through the width of each character! Will this problem be solved with the VV3 DV codec? What am I doing wrong?

Thanks,
Don Sanders
Cheesehole wrote on 11/17/2001, 2:31 AM
this is not a suggestion for an intermediate codec for going to MPEG files, but since we're on the topic of lossless compression...

i often use Indeo RAW. you are limited as to what framerates/max resolution you can use, but it works for me.

i usually capture DV and them recompress to Indeo RAW at something like 320x240x15fps. this makes the files nice and small and i can store/edit them easily. then i go to Windows Media (ASF).

download the Indeo codec pack (from intel i believe) and install it with the 'developer' option to get the Indeo RAW codec.

- ben
SonyEPM wrote on 11/17/2001, 7:51 PM
"lossless compression"- I keep hearing this, and I don't buy into it. If you are compressing, you are getting rid of information, so by definition it cannot be lossless.

Don't refer me to the Huffy link again- I've read that. Still not convinced.
Chienworks wrote on 11/17/2001, 8:33 PM
Very true. Even the new wavelet compression schemes that are starting
to come out recently only work because they group together pixels of
such similar color that you won't notice the difference if they all become
the same color.

I guess the thing to keep in mind is the difference between physical loss
and perceptual loss. If you can't tell the difference between the original
image and the compressed image, then there is no perceptual loss. MPEG
at high bit rates suffers from very little perceptual loss. This is what
makes DVDs such a popular format. VHS has it's own compression, even
if it is analog instead of digital, and electronic rather than computational.
Yet even with all it's scumminess, VHS is still enjoyed by many.

Where it really matters is when there are multiple generations involved.
Compression does involve a physical loss of information, which must be
restored when using or playing the file. Simply playing back the file isn't
too bad; the missing information is recreated by the decompression
process. However, when using a compressed file as source data, the
compression/decompression/recompression process keeps adding more
new errors with each step. This is why you'll see the SF techs and other
users in here always telling people NOT to use MPEG for source files.
Always stay with .avi or some other much less compressed format until
you have a finished project to deliver.
SonyEPM wrote on 11/17/2001, 8:51 PM
Exactly. Perceptibly lossless is not lossless.
Cheesehole wrote on 11/18/2001, 3:27 AM
i stand corrected. i had always assumed it was utilizing lossless zip-like compression, but now that i think about it, that wouldn't give me the 3:1 compression.

this is describing the lossy compression used in Indeo RAW:
--------------------------------
* YVU9 is the format in which video is captured by the Intel Smart Video Recorder. In YVU space, a pixel is represented by one luminance (Y) value and two chrominance (U and V) values. In YVU9 format, the chrominance values are sub sampled: a single UV pair is used to represent the chrominance of an entire 4x4 block of pixels. Since Y, U, and V components are each stored as 8-bit numbers, the color sub sampling results in an average 9 bits per pixel. Because the human eye is more sensitive to luminance than to chrominance, the perceived loss of information due to sub sampling is minimal.