DVD Quality

[L.Paton]

Hi ,
My friend asked me to copy some cam corder recording for him and asked me to do it in high qualiry dvd . I told him there is no high or low quality format for dvd .it is standard dvd , and uses a file system , vob , ifo .

Can some one who knows more explain if this is right or wong .

i told him nowdays avi has many differant formatts like divx , xvid etc and maybe this is what he was referring to but this isnt standard dvd format .

i also put a dvd and a divx (converted from the dvd ) , side by side and playing at the same time , on the same screen and could see no differance in picture quality . he said that isnt possible , ( i did it after he left )

[tinker]

You are right. DVD is mpeg2, DivX is mpeg4. They are both very good format, DivX is newer and has more efficient compression engine, so files created with it are about 4-6 times smaller. Not too many players can play that format, specially older once.
When you create DVD(mpeg2) it all depend on bitrate you use to compress your avi file.
Bitrate depend on length of the file in minutes. Maximum bitrate for video would be about 9000kbs, it depend on audio type with the video and also how many audio tracks are there as DVD5 can hold 4.7GB data.
With bitrate below 3000kbs, quality will start degrade, it will be more pronaunced on large screen TV
You can read more on this, if you check left side of this page "WHAT IS DVD".
This site also has Bitrate calculator to figure out Max bitrate for your particular file.
Bottom line is, either mpeg2 or mpeg4 will produce same quality file.

If you want to realy compare you should create DVD and DivX from the same avi file, not convert DVD to DivX.

[jagabo]

My friend asked me to copy some cam corder recording for him and asked me to do it in high qualiry dvd . I told him there is no high or low quality format for dvd .it is standard dvd , and uses a file system , vob , ifo .

Yes, DVD is a standard but there is a lot of room for variation which effects quality. PAL DVD supports several different resolutions: 720x576, 704x576, 352x576, and 352x288. You can encode with low bitrates or high bitrates. Higher bitrates give higher quality. For noisy handheld camcorder footage I would stick with high bitrates -- 8000+ kbps.

Standalone DVD recorders have settings for different running times. The more running time you want to put on a DVD the lower the bitrate has to be. To partially compensate these will reduce the resolution when you ask for longer running times. This trades off resolution in order to reduce macroblocking artifacts. Typically you will get 720x576 for 1 to 2 hours on a single layer DVD. Over 2 hours they may reduce that to 352x576. At 6 or 8 hours resolution may be reduced to 352x288.

[L.Paton]

Thanks for the replys .

MY next question is :
Does an actual dvd recorder( as connected to a tv) when recording use vob files or is it just makig a dvd compliant recording

[guns1inger]

There are a couple of different recording methods, but the differences amount only to how the video is packaged. The two main methods are Video mode and VR mode. Video mode creates a standard video_ts folder with VOB, IFO and BUP files. VR mode is designed for editing on the disc and has a different file structure.

[jagabo]

DVD recorders record in VOB format. When you finalize a disc they create the master table of contents with the rest of the standard movie DVD structure (IFO files etc).

[L.Paton]

hi , thanks .
so when i am recording using my dvdrecorder , and it asks what quality i would like , it is adjusting the bitrate and not changing the formatt it is using ( gives me low quality and high quality settings when durning t dvd )

[jagabo]

hi , thanks .
so when i am recording using my dvdrecorder , and it asks what quality i would like , it is adjusting the bitrate and not changing the formatt it is using ( gives me low quality and high quality settings when durning t dvd )

Are you sure? The lower resolution recordings will still fill the frame a 4:3 TV at playback. Examine one of your low quality VOB files with GSpot or MediaInfo to check the resolution.

As an example, the Panasonic ES15 records at 720x480 (NTSC) when set at the 1, 2, and 4 hour settings. At 6 and 8 hours it reduces the resolution to 352x240. Here's are some samples of 1 and 4 hour recordings of the same handheld camcorder footage. A small (160x120) portion of the frame was enlarged 4x so the difference in quality is very obvious: