AVI size on DVD

Hope this hasnt been asked before. If anyone got good links on this subject Id be greatefull for them. Ive only had the burner for three days and to be honest I know f-all about buring DVDs.

And now my Q.

With my DVD-recorder I got NeroVision Express so I though Id put some AVI files on a DVD to watch on a standalone player. Thing is that while these files are about 200MB on HDD they take about 800MB on the DVD as video. Why? My guess is that DVD-Video goes after playback time and not the file size.

Thanx!

DVD’s use MPEG-2 video compression and is probably not nearly as efficient as what your AVI’s used. Also, the choices of frame rate, frame size and audio quality/compression rate are severely limited on DVD, so there’s another difference. DVD specs were defined long before there was mp3 and mpeg-4, so there is a lot of regression in going from AVI to DVD. AVI is an ongoing, open ended sort of spec that pretty much allows anything.

But, the electronics required to play a DVD are far less complicated than for AVI, hence the low cost players.

Your avi files were more compressed than your DVD mpeg2 files. When transcoding to another format the video is first decompressed and also resized to match the destination format. Then it is compressed again to a bitrate that you set in the encoder (unless it’s done automatically).

DVD bitrates are typically from 1 mbit/s up to 10 mbit/s.

Avi bitrates depends on the codec that is used and what bitrate it’s set to. DV Avi from digital camcorders need 13 GB for one hour of video and divx may only need 400 MB for one hour. But when transferred to DVD both will be the same size if compressed with same bitrate. The maximum bitrate on a DVD will hold one hour on a DVD-R (with almost transparent quality) but it can be compressed at lower bitrates and resolutions and you may fit up to 8 hours at the lowest quality settings (with quality worse than VCD).

Alternatively you may want to find a standalone player that can play divx. Then you can burn your avi as a file and you will not degrade the quality or increase the filesize.

Originally posted by v2k
Hope this hasnt been asked before. If anyone got good links on this subject Id be greatefull for them. Ive only had the burner for three days and to be honest I know f-all about buring DVDs.

Check out the Tutorial http://club.cdfreaks.com/showthread.php?s=&threadid=61142

[b]And now my Q.

With my DVD-recorder I got NeroVision Express so I though Id put some AVI files on a DVD to watch on a standalone player. Thing is that while these files are about 200MB on HDD they take about 800MB on the DVD as video. Why? My guess is that DVD-Video goes after playback time and not the file size.

Thanx! [/B]

The original size of the AVI in mb has absolutely nothing to do with the size of an MPEG2 conversion as totally different compression techniques are used in both. The AVI(dixv/xvid) is almost always smaller than when its converted to dvd MPGE2.