Why the difference

[Dave Davison]

"Not a problem, just puzzled". Today I downloaded 5 videos (discussions / Interviews) which totaled 284 minutes in length and 759 MB in size. After conversion with ConvertX the file showed the accumulative size to be 2.95 GB. Why the difference in details please? I was under the impression that ConvertX actually compressed files. Thank you Dave.

[HansV]

What was the file format of the downloaded file(s)?

[Rudi]

And what is the format of the converted files? .vob, .avi?

[Dave Davison]

Original format mp4 converted to (as shown below) Thanks Dave.

[Rudi]

MP4 is a highly compressed video format that effectively is being decompressed when converted into .VOB (This is as I understand it!)

[HansV]

Both .mp4 and .vob files are compressed, but they use different compression algorithms: .mp4 is based on MPEG-4, and .vob on MPEG-1 and MPEG-2. So it is quite possible that the .vob files take up more space than the original .mp4.

[Dave Davison]

thanks gentlemen, all very complex but slowly getting the hang of things, on this basis it seems a 4.7 GB disc should record 7.5 hours of video. Seeing that DVD's state the maximum recording time is 120 minutes what format is that assumption made on? Regards Dave.

[HansV]

It depends on the quality of the video. A 4.7 GB DVD can contain a bit more than 1 hour of high-quality, high-resolution video, or about 9 hours of VHS-quality video, or something in between...

[Rudi]

Is your questions based on a camcorder you have that records directly to DVD? Assuming so, the hand-guide for your camcorder will give you the specs regarding capacity, recording time and formats for various resolutions that it can deal with.

[Dave Davison]

Thanks again, sorry if this sounds patronizing but I thank the day I some how came across this lounge, No Rudi, I don't possess a cam corder the only videos I dabble with are those mostly on You Tube. As for quality, yes I appreciate very much good visual and sound reproduction but seeing the content matter appeals to me most -and the fact that the more I can cram on to one DVD means less cost - the more hours a disc will hold the better. Cheers Dave.

[Rudi]

I find it interesting that you chose to convert the videos you downloaded.
I'd keep them in the MP4 format since it has such a high compression ratio.

[HansV]

But conventional (stand-alone) DVD players won't play .mp4 files - the DVD standard supports MPEG-1 and MPEG-2, but not MPEG-4.

[Rudi]

Yes, you are correct. I never thought of that as i haven't use a DVD player in a long time... My laptop is on hand for all my entertainment needs.

[Dave Davison]

"Why convert them?" Simply because they can then be watched by friends or family through the TV. not enough room or comfort in the tiny box room where the computer resides. Then again, if I use DVD-RW they can be used repeatedly. Cheers Dave.

[Rudi]

"Why convert them?" Simply because they can then be watched by friends or family through the TV. not enough room or comfort in the tiny box room where the computer resides. Then again, if I use DVD-RW they can be used repeatedly. Cheers Dave.

Understood