Number of hours on a dual layer DVD

[Reddwarf4ever]

According to my research 4 Hours is the max for a DVD9, But Convertxtodvd & TMPGENC Authoring BOTH happily accept a project of 6Hours of video ( 6 tracks) & report as within the Dual layer target....Dont understand, am i missing something ?
Thanks

[DB83]

Yes !


Depends on the bitrate of the video.


Single Layer >> 8000 kbps = 1 hour. 4000 kbps = 2 hours


Double Layer and you double the run time. When you look at a blank disk it typical states "2 hours" which is based on the above and to get reasonable quality 4000 kbps is adopted. But, depending also on your content you could squeeze more run time at 3000 kbps or even less.

[Reddwarf4ever]

Hello
Thanks, the run time is the ones I see in windows explorer....Tmpgenc authoring works, wouldn’t I assume compress to fit onto a DVD9, as if I add a further 1 hour of video it says it’s exceeded ......just don’t understand

[davexnet]

Hello
Thanks, the run time is the ones I see in windows explorer....Tmpgenc authoring works, wouldn’t I assume compress to fit onto a DVD9, as if I add a further 1 hour of video it says it’s exceeded ......just don’t understand

Perhaps Tmpgenc AW is maintaining a minimum bitrate and wont let you go lower,
or there is possibly something in the settings you missed

[Brainiac]

I have TMPGenc Authoring Works 5. The lowest bitrate it will let you set for video is 1550 and the highest is 7000.

[Reddwarf4ever]

Thanks

[SF01]

AVS2DVD has bitrates from 500 to 9000, i might just do the trick. I managed to squeeze 4,5 hours into DVD5.

[Hoser Rob]

I read on the doc page of one of those DVD authoring programs the other day that the recommended video bitrate for decent quality was >4500K/s. I think that's true (though by the standards of moden codecs it's insane).

[jagabo]

You can put as much video as you want on a DVD by using lower and lower bitrates. The problem is that the video quality decreases as the bitrate decreases. To keep the video from breaking up into blocky artifacts you can use smaller frame sizes. PAL DVD allows for 720x576, 704x576, 352x576, and 352x288 frame sizes. When you use smaller frames you are trading off resolution to get fewer blocky artifacts. And in the case of 352x288 you may be trading off temporal resolution (motion smoothness) as well.

At the other end of the spectrum, DVD supports a maximum bitrate of 10080 kbps for all streams, a max of 9600 kbps for the video stream. So a single layer DVD at the highest bitrate will give you about an hour. So you can't fill a DVD with 30 minutes of super high quality video -- the bitrate will be too high.

Exactly how low a bitrate you can use depends on the particular video (some compress better than others), your personal tolerance for loss of detail and blocky artifacts, how big a TV you'll be watching on, and how far away you'll be sitting from that TV.

[johnmeyer]

You can get quite a bit more quality out of lower bitrates if you use a professional encoder which supports 2-pass encoding. You won't notice much difference until you encode at rates below about 4,500,000 bps, but at low bitrates the intelligence the encoder gains during the inspection (1st) pass lets it be far more intelligent in allocating bits for frames where this is motion or noise, and using few bits where the video is clean and not much is moving. Single pass encoding only does these optimizations across a few frames, and has no way of knowing that the last half of your video needs very few bits compared to the first half.

You also have to take into account the nature of your video. If your video contains lots of noise (e.g., video taken in low light) or if it contains a lot of motion (e.g., a football game), then you will get more artifacts at a lower bitrate. On the other hand, if it is video taken on a tripod of someone speaking at an outdoor graduation, you could probably encode all the way down to 1,00,000 bps and still have something that looks pretty decent.

As always, do your own tests on short sections of video before you proceed on the entire project.