Mpeg 4 vs Mpeg 2 - File size

[Akaz1976]

As far as i know, DVD quality Video has file size of roughly 10MB per minute.

How much does Mpeg 4 shrink this by?

Akaz

 

[Traire]

Dependson a couple different things

1. which version of mp4, there are several different variations of mp4 codecs. Divx, xvid, wmv9, Nero Recode, etc... Different codecs are better than others, and will be able to encode a smaller file with less loss of quality.

2. Resolution and bit rate. Obviously a file with a bit rate of 5000 b/s will be larger than one with a 1000 b/s. Also whether or not you use variable bit rate or constant bit rate. And if you use a high resolution and low bit rate, the quality of the video will suffer. shrinking the resolution will let you get a smaller bit rate with fewer artifacts.

The short answer:

I have my PVR set up to record tv shows at a high 10,000 constant bit rate into mp2 files. A half hours worth is about 3 gigabytes. Using Xvid or WMV9 I can encode the file with very minimal loss of quality down to files sizes of 175-200 mb for xvid and around 220-250 mb for WMV for a 30 minute video. So thats around 5-6 mb per minute of video.

Also DVD quality video is a bit higher than 10mb per minute. More like 3-4 mb/second

 

[Traire]

If you want to play around with encoding some files, I highly reccomend Auto Gordian Knott for Xvid encoding. Its just about the easiest encoder to use. Also Windows Media Encoder, which you can download from microsofts web site, has a easy to use wizard for setting up files to encode, but is not the speediest program.

 

[Akaz1976]

Thanks. That helps a lot!