Video file too small??

sparkash · Post by **sparkash** » Fri Sep 23, 2005 3:10 pm

Hi All,

I have rendered a 60 minute project as mpeg2. The quality bar was set to 100 and was 8000kbs. Rendering took about 2.5 hours. However, the finished file is only 2.5 gig in size.

If one can only fit sixty minutes of DVD Quality footage on to a dvd (4.7 gig) deos this mean that the quality of my video file has been compromised.

My main factor when creating a DVD is Playback Picture Quality, so how can i improve this.

I used the guidlines set out at the top of this webboard.

I am using VS 9 and captured from my Camcorder using firewire.

THoff · Post by **THoff** » Fri Sep 23, 2005 6:29 pm

Something is not right.

Even with low-bitrate audio (like 128Kbps AC3), you cannot get a file that small at 8Mbps for the video. Did you have a Preview range selected and accidentally instruct Videostudio to only render the Preview range?

On a side note, the Quality setting has absolutely no impact on the file size -- the file size is determined solely by the bitrate and the duration of the video. The Quality setting only determines how exhaustive the MPEG encoder's search for motion vectors is -- the more time it spends on examining each frame, the smoother the video and the better the overall quality.

Trevor Andrew · Post by **Trevor Andrew** » Fri Sep 23, 2005 8:44 pm

Hi
Are you sure about the render properties.!!!!!
After you Share-Create Video File a thumbnail of your file is placed in the library.

Right click the thumbnail and select properties, What are they?

Trevor

Trevor Andrew · Post by **Trevor Andrew** » Fri Sep 23, 2005 8:46 pm

Hi
Are you sure about the render properties.!!!!!
After you Share-Create Video File a thumbnail of your file is placed in the library.

Right click the thumbnail and select properties, What are they?

Trevor

sparkash · Post by **sparkash** » Sat Sep 24, 2005 12:18 am

HI Trevor, Thoff

These are my file settings

File Format:PAL DVD
File size :2,590,530 KB
Duration:3614.08 seconds

These are my video properties

Video type: Mpeg-2 video
Total frames: 90,352 (frames)
Attributes 24 bits, 720x576 , 4.3
Frame rate : 25.0000frames/sec
Data rate: Variable bit rate (max 6000kbps

Any ideas?

gordon_fan_24 · Post by **gordon_fan_24** » Sat Sep 24, 2005 4:02 am

"Variable bit rate (max 6000kbps "

I'm pretty sure that would be the problem, the max is only 6000kbps, not 8000kbps, try rendering again with the bitrate set to 8000 in the options box.

sparkash · Post by **sparkash** » Sat Sep 24, 2005 9:03 am

thanks gordon.

Would this improve the quality of the dvd?

thanks

sparkash · Post by **sparkash** » Sat Sep 24, 2005 11:23 am

I've just finished re- renderfing at 8000kbs, and the size is now 3.3gb.

Is this as OK size for a 60 minute project?

Trevor Andrew · Post by **Trevor Andrew** » Sat Sep 24, 2005 11:37 am

Hi

In theory yes.
But quality is not just associated with bit rate.

As a guide:-
8000 kbps is dvd quality
6000 kbps is very good quality
4000 kbps is Vhs quality.(which is good)

I have been using 6000 kbps at constant rate for a while and find the quality acceptable.
I tend to use the highest bit rate that will fit to a dvd, so for 1 hour I would use 8000.

If you have a dvd-rw disc you could try several settings without wasting discs.

For more reading try :-
http://dvd-hq.info/Calculator.html

Trevor

8000 is a guide to fit 1 hour of video to one dvd.
The audio rate does influence the Gb used, ntsc uses a lot, mpeg and Digital Dolby not so much.

Variable bit rate is smaller in size than Constant.

I managed to fit 74 minutes on to a dvd at 8000 constant, mpeg audio.

There are quite a few factors when determining size and bit rate.
So if you are variable and mpeg audio 3.3Gb may be ok.

Check out the bitrate calculator, throw in a few settings to compare.

I do not think you have a problem.
Except i would use Constant bit rate

sparkash · Post by **sparkash** » Sat Sep 24, 2005 11:58 am

Thanks Trevor,

I appreciate your help mate.