Video Quality problems

Kunkel · #1 (**permalink**) 08-23-2006, 08:58 PM

Basically the company I work for is 3Vista.
What we do is take 2D Floorplans and construct them in 3D Max to scale and launch them in our fancy OSG engine enabling the users to walk around and interactve with the models/siteplans.

Recently companies have approached us stating they would like two things

Avi's for the web and DVD.

For the web we are aiming at 320x240 in size.

The DVD part is easy enough, however our competition is Aareas
By click on that link it takes you to a page where you can view there
product demo.

Basically they have a 4minute movie that is 6 meg in size. Now I know
the quality is pretty good and they are using .wmv with Windows Media
9 as their codec.

I want to be able to match that quality with our video's. I have experimented
using targa sequences, video at 720x486, 320 x 240 as the source and doing
final exports in premiere.

I took Interactive Multimedia in college and know when to use Premiere/After Effects. I have testing using an assortment of different techniques. Just wondering which techniques could be best used for this problem.

Easystream · #2 (**permalink**) 09-26-2006, 01:20 PM

The quality all starts with the master. I would follow these tips.

1) If you are using basic blueprints, etc I would adjust the contrast up to accent the details. Be careful you do not wash out the picture out and that the scenes match.

2) Create the master as large as possible - 720x486 will work
Export at 29.97 or 30 FPS depending on master.

3) Do not add any compression on the master before it goes to the windows media encoder.

4) If the content is slow moving try 15 FPS on the WM encoder. Experiment with keyframes as well

Hope this helps

Sean Fleck
Easystream Networks
Your Streaming Media Partner since 1997
http://www.easystream.com

Mark W · #3 (**permalink**) 09-26-2006, 02:44 PM

After much experimantation i use the following settings when encoding .wmv direct from vegas. I assume a similar set up can be configured in wme.

I compress my DV avi movies for my web site. I keep the res at dv level, I use a bit rate of 700 kbitsec, this gives acceptable quality and is streamable for most people. I encode using vbr set to that bit rate target.

If you only need a lower res then you can drop as low as 500kbit/sec.

I have found little advantage in practice in dropping the frame rate untill bit rates are very low <200kb/s

If you insist on dvd quality then keep the res high and use a vbr bit rate of 1.5 to 2.0 mbit/sec.

This is still viewable for people who cannot stream at this speed but the film will buffer for much longer, up to nearly the length of the film.

Examples.

320 x 240, bit rate 250kb/s CBR- http://www.zaskarfilms.com/Films/tonyblair250.wmv

same film but 640 x480 750 kb/s VBR - http://www.zaskarfilms.com/filmPages.../tonyblair.wmv

The above had a poor source, a d loaded mpeg and i post them for comparative purposes.

This is 780 VBR from a good source - http://www.zaskarfilms.com/filmPages...saesidefun.wmv

And this is 1.8 mbit/sec and gives dvd (better I think) quality - http://www.zaskarfilms.com/Films/huntzas.wmv

It's a rather random selection of films but it should give you an idea of what to expect. VBR films also seem to buffer for longer thna CBR encoding.

Easystream · #4 (**permalink**) 09-27-2006, 06:48 AM

Mark

Yes the videos look good. Unless you really have the need, I would keep the bitrate anywhere from 300-500K to be on the safe side for users with slower dsl/cable on the longer videos if you are not using a streaming server. You know how people hate buffering. You could also use a MultiBit rate to ensure all users can view with little buffering. (autoconfigues to users bandwidth) But yes the quality looks good. I have not had the chance to use Vegas. I mostly use FCP and Premiere. Perhaps I should try this Vegas. I hear lots of good reviews about it.

Thank you

Sean Fleck
Easystream Networks
Your Streaming Media Partner
http://www.easystream.com