Why is DVD Size twice the MPEG size?

vbimport
#1

Hi,

I’m trying to create a DVD using Sony DVD Architect 4.0.
I have an MPEG2 file in DVD format, which is 2.8GB.
But when I insert it into an empty DVD-project, DVD Architect says that the DVD will become 5.8GB.

I don’t understand why the DVD will be more than twice the size of the MPEG source file.
Could you please tell why this is, and how to fix it?

Thanks!
Ramon.

These are the specs of this file (according to GSpot):

Size: 2.73 GB (2,800 MB / 2,867,486 KB / 2,936,305,668 bytes)
Container: MPEG-2 Program Stream << { 1 vid, 1 aud } Sys Bitrate: 6315 kb/s VBR
Avg Bitrate: 3996 kbps
Storage Frame: 720 x 576
Storage Aspect Ratio: 1.250 (5:4)
Pixel Aspect Ratio: 1.422 (~10:7)
Display Aspect Ratio: 1.778 (16:9)
Audio: MPEG-1 Layer 2 (CBR) / 0xc0:44100Hz 224 kb/s tot , Stereo

#2

Don’t know what is going on, unless DVDArchitect is reencoding the mpeg2 files at a much higher bitrate.

The audio will have to be reencoded, since the original is at 44khz and dvds need 48khz, but the size on that shouldn’t change much unless it is going to pcm instead of mp2. Even with pcm audio, it won’t add 3gb.

There should be some way to designate output as a DVD-5 (~4.3gb).

#3

Audio has to be re-encoded for sure, and probably the tool sets the bitrate for the video also to the max allowed for VideoDVD >>> bigger size.

#4

Not familiar with that tool, but they sometimes allow you to create your own template. When you create your own template, you simply set the audio/video specs to match your input files (assuming your input files meet DVD specs), in which case no encoding will then take place. This is helpful to reduce production time (ie: no encoding is needed) and it will help preserve the quality of your original files (each encoding reduces quality).