DVD-R 120 min.? or less...whats up?

[Thwiipp]

Hi all, i was wondering, DVD-R's say 120 min. on the package, so why do people keep saying you can only fit 60 min. on one, whats the deal, you can fit more on a CD if thats the case, can someone explain this?

[colebert]

The audio files on an audio cd (.WAV) are a standard and constant bitrate, so you can accurately say 80 Minutes. Video bitrates are not constant. If you have a video that is very high quality pushing the threshold of 9800kb/s you will only fit about 60 minutes onto a DVD, whereas if you get one that averages only 3000kb/s you can fit much longer than 2h on the DVD.

Frankly I don't understand why media companies say 120m because its misleading. They are probably assuming some Contant Bitrate video file. But most people here use VBR (variable bit rate) for their files.

-Cole

[Navellint]

i think a standalone dvd-recorder can record up to 4 different resolutions (x2 for PAL/NTSC =8) but at constant bitrate. So they probably record 120 at a certain common resolution (svcd?) on a single dvd-r. The indication is for people (like most) who don't know ANYTHING about videostreams and still need an indication. On the other hand, i wouldn't record more than 120 min of video (720x480/576) on a single-layer disk myself (especially with CBR or anamorphic) as the bitrate would have to become too low for fairly good quality. Anyone seen the pathetic disk of 'The Sting' by Universal ? It's 129 min of poor quality on a single layer... not even widescreen

Of course then you have the videostreams with lots of noise which need a drastically higher bitrate and vice versa. But the latter is of importance only to people like us, who practice desktop authoring. Correct me if i'm wrong =)

[atreides93]

Typically you can store about 2 hours of video on a DVD-R...so that's why they say 120minutes.
but in reality, that can vary somewhat...
but if someone says he can only fit 60 minutes on a dvd-r then he's really doing something wrong or something because I can typically fit 2 hours of regular DVD movies using VBR and high bit rates.

[padre]

atreides93

I own Studio v8, and when you create a DVD in it, it limits you to about 60 minutes. Why? They use a CBR encoder that max's the output at 60 minutes. If you were to use VBR, you could easily exceed 60 minutes, but they don't offer that option.

So, I just use Studio to import my DV from the camcorder to .AVI, then TMPenc to create the VBR MPEG2 file. I want to use more than 60 minutes!! :)

[atreides93]

Padre,

You should check out Premiere 6.5. It has a built in Mpeg-2 encoder which settings for DVD low/medium/high bitrate. The resulting quality isn't bad and it creates DVD compliant video files. It saves me the step of having to use Tmpgenc