AVI - To Compress or Not

Nathan_Shane wrote on 5/5/2005, 12:10 PM
I was reading here in past posts that AVI basically works as a wrapper in which the video can be rendered as uncompressed or compressed by one of the many codecs available in Vegas. So I took a short project and started experimenting with using some of these different codecs to see how the output quality and actual file size compared with the uncompressed AVI. Wow, talk about being able to save some hard drive space using compression on an AVI render.

Which leads me to some questions...I've got some short videos to produce of which I've been asked to deliver the final renders as AVI files so that they can determine the final output media format.

So what should I do here...just stick with the raw uncompressed AVI format, or use some compression codec for the AVI? And if I use a codec, which one would be the best to use?

Comments

JohnnyRoy wrote on 5/5/2005, 12:36 PM
You realize there is no free lunch. More compression means less quality.

How did you capture the source media? What is the codec of the AVI files that you are starting with? I would render them using the same codec so that any video that hasn’t been edited becomes a straight copy with no re-encoding. This will give you the highest quality. Forget about raw uncompressed, unless you have captured uncompressed (which is not very likely), staying with the codec of the source media is the best plan.

~jr
Former user wrote on 5/5/2005, 12:36 PM
Are you capturing UNCOMPRESSED or are you capture COMPRESSED (such as DV AVI or MJPEG)?

Dave T2
Nathan_Shane wrote on 5/5/2005, 1:32 PM
Sorry...guess I should have given more details.

Well, for some short videos it would be DV AVI so you're right, it would be best to stay within the format.

But for other videos, it would be all just screen captured AVI (such as using Snag-it), plus still captured images as well from the pc screen...aren't screen video captures raw uncompressed AVI's?

And then some shorts will be video logo intros I create using Bluff Titler, which outputs as Uncompressed AVI...so I guess Bluff actually does create raw and purely uncompressed AVI output right?
cbrillow wrote on 5/6/2005, 8:00 AM
Hmmmmm.... Workbench video tutorials on the horizon, eh? ;^)
JohnnyRoy wrote on 5/6/2005, 9:37 AM
> ...aren't screen video captures raw uncompressed AVI's?

Not necessarily. The ones I’ve tried (CamStudio and HyperCam) allow you to use a codec to reduce the size of the file. Raw uncompressed AVI is huge and most hard drives will not stream it well without stuttering.

> I guess Bluff actually does create raw and purely uncompressed AVI output right?

Yep. You need to use uncompressed to maintain the alpha channel information because most codecs are 24 bit (and alpha requires 32 bit)

~jr
Nathan_Shane wrote on 5/6/2005, 8:49 PM
LOL!!!! Fellow Line 6 user huh...

As far as Workbench video tutorials...that may be the case. :o)
johnmeyer wrote on 5/6/2005, 9:14 PM
You're spending WAY too much time on this. Render as DV AVI files and get on with it. Uncompressed AVI files are a waste of time and space unless your source material is mostly very high quality, non-DV material, such as high-resolution stills, Beta SP, or HDV. The 4:1:1 DV colorspace issue is the only real practical "gotcha" for most people and the only real reason to avoid using the DV AVI codec. Try a test with uncompressed and with DV AVI and then render it all the way to the final delivery format (DVD, DV tape, VHS, etc.). I'll bet you can't tell any differnece. This isn't to say that a difference doesn't exist, only to say that unless your input is all 4:2:2 or higher colorspace and you are delivering in a format that preserves this, you won't see the difference. This is especially true because, even though the Sony DV codec does compress, there have been lots of tests that show virtually no detectable degradation, even after 5-10 generations. This is one of the truly remarkable things about Sony Vegas.
Cheesehole wrote on 5/7/2005, 11:19 AM
Render as DV AVI files and get on with it.

Except he mentioned screen captured material. DV resolution (720x480) is not ideal unless the material is very simple with large text / buttons. The Techsmith codec (TSCC) is good for this.

What is the final delivery format? (CDROM / DVDROM / WEB / DVD?)
Nathan_Shane wrote on 5/7/2005, 11:48 AM
" What is the final delivery format? (CDROM / DVDROM / WEB / DVD? )"

That hasn't been fully determined just yet. All I know at this point is they said they would prefer that I deliver them the AVI files and they would use those and create their own final formats.

So I guess I'll just be sending them the AVI files as data on a DVD.

I just found the info you mentioned about the Techsmith codec (TSCC) just last night, so that sounds like good news, but like you also said, the screen captures still looking good at DV resolution...I'll have to experiment with that one.
cbrillow wrote on 5/7/2005, 1:32 PM
" LOL!!!! Fellow Line 6 user huh..."

Yeah, longtime ION & Line 6 forum member, too. Spent a lot of time there after ordering Variax in August 2002, and waiting for its release. On those fora, I'm imaginatively known as "cbrillow." Must be a reason for that...

Interesting dilemma you're faced with here. There has to be a lot of detail in the screencaps, knowing what the screens look like. I'll be watching to see what you come up with.