Web Video at 320x240, why? at DVinfo.net

Go Back   DV Info Net > Cross-Platform Post Production Solutions > Distribution Center > Flash / Web Video


Reply
 
Thread Tools Search this Thread
Old May 24th, 2005, 01:19 PM   #1
Regular Crew
 
Join Date: Mar 2003
Location: Surprise, AZ
Posts: 144
Web Video at 320x240, why?

We are looking at streaming video on the net and of course the first size that came to mind was the standard 320x240. Question is if I render it at a constant bit rate of 300k at 320x240, will it run smoother than a 640x480 version if they are both set at 300k? My thought was you are giving the movie a pipeline big enough to run at 300k but because there is more data for a 640 version it will chug along trying to play it. Am I right on this? Is that why every movie on the net is almost all 320x240?? Or does it not matter what the movie res is because I set it at 320? Thanks
__________________
Vlog On!
http://youtube.com/clintus
Clint Comer is offline   Reply With Quote
Old May 24th, 2005, 03:42 PM   #2
Trustee
 
Join Date: Mar 2004
Location: Carlsbad CA
Posts: 1,132
if you set both frame sizes at the same 300kbps, they will both be pushing the same amount of data, one is just more compressed than the other... so it's a question of how your footage looks, do a bunch of test encodes for both frame sizes... full frame size may be pushing it at 300kbps, dropping the frame rate way down is how it's typically done... so talking heads at 7.5 fps will look a lot better than high-action stuff at 7.5 fps.
Dan Euritt is offline   Reply With Quote
Old May 25th, 2005, 09:51 AM   #3
Major Player
 
Join Date: Jun 2002
Location: Venice, CA
Posts: 346
300 kbps means your video has 300 kilobytes of data per second. Whatever your screen resolution, that is how much data is being pushed through.

300 kilobytes is then divided among the number of frames you set per second.

So 2 things affect the "look" of your video when you set a data rate of 300 kbps. The pixel dimensions and the framerate. 320x240 at 15 fps will "look" better than 320x240 at 30 fps because that 300 kbps is "stretched" out over twice as many frames. Meaning there is less data per frame. Similarly, 320x240 at 15fps will "look" better than 640x480 at 15 fps because the 320x240 is able to use more bytes per pixel for clarity.

Setting 300 kbps affects the file size. Framerate and pixel dimensions affect the "quality" of the video.
Mark Sloan is offline   Reply With Quote
Old May 25th, 2005, 12:02 PM   #4
Major Player
 
Join Date: Jan 2005
Location: Cardiff, UK
Posts: 221
Quote:
Originally Posted by Mark Sloan
300 kbps means your video has 300 kilobytes of data
kilobits not kilobytes, big big difference.
James Connors is offline   Reply With Quote
Old May 25th, 2005, 12:31 PM   #5
Major Player
 
Join Date: Jun 2002
Location: Venice, CA
Posts: 346
Whoops. :-) yes, big difference if you are trying to calculate what your file size will be in the end, but not for the basic concept.

8 bits = 1 byte. So 300kbps = 37.5 kBps or kilobytes per second. Which is then 2,250 KB per minute of video. Or to round it off, a little under 2.5 MB per minute of video.

But basically, if you are streaming 300kbps it will mean users need DSL or Cable to view it without much buffering.
Mark Sloan is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Cross-Platform Post Production Solutions > Distribution Center > Flash / Web Video

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 12:39 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network