MPg2 & DVD Capacity question

Maverick wrote on 7/28/2005, 7:08 PM
Hi

My fiancee wants a copy on DVD of the entire 8 hours we filmed while on holiday. I will later condense this to around 40-50 minutes.

It was shot on a Sony E30 PAL in UK.

I have just transferred the first hour's MiniDV to PC via Firewire and rendered this as MPG-2 and AC-3 using the PAL DVD Widescreen Stream settings which I thought would be optimum for what I require.

The resultant mpg-2 file is 2.8Gb.

I expected to be able to put 2 hours on each standard 4.7Gb DVD but, obviously, this is not possible with these settings. Can anyone offer some advice as to what settings I should be using to get what I require without compromising quality too much?

My second question is this; It's well documented that pushing the capacity of a HDD to it's limits can cause serious problems. Is there a similar situation with DVDs. i.e., if the total size of all files and menus, etc are 4.9 Gb could I end up with a disc that will become more easliy corrupted?

I would appreciate any help on these matters.

Cheers

Mav

Comments

Spot|DSE wrote on 7/28/2005, 8:13 PM
Go dual layer, use DVDA 3.0, and you'll be able to put it all on at approx 2.0Mbps. Quality will stink, but you'll get it all on one disk. Or, do 2 DVD9's (dual layer) and go approx 4.5 Mbps, quality will be decent.
If there isn't a lot of motion and good lighting, you'll be able to maintain a lower bitrate. Squish the blacks a little, that'll help maintain image quality.
Maverick wrote on 7/29/2005, 3:28 AM
Dual layer isn't an option for me at this time - any other suggestions, please.

Mav
Serena wrote on 7/29/2005, 4:30 AM
Well, you can render to avi and then let DVDA work out the bitrate for rendering to MPEG-2. There's no way you're going to get 8 hours into 4.7GB at anything I would consider acceptable quality. You can readily get 2 hours on a 4.7 GB so it will spread over 4 disks. Probably good to divide it up this way, in any case. This question of bitrate was discussed a few weeks ago with a link given to a very useful bitrate calculator. For example read the postings under: Batch Render and 2-pass VBR
Maverick wrote on 7/29/2005, 5:50 AM
Thanks

I think I didn't make myself clear enough in my original post. I wanted to put two hours on each DVD but found that each hour's worth was being rendered by Vegas 5 as MPEG-2 at around 2.8Gb.

I will now try putting the orginal 13GB of AVI captured files directly into DVDA and let it work out bitrates, etc. as you suggested.

Cheers

Mav
JJKizak wrote on 7/29/2005, 5:51 AM
Cut, cut, cut, cut, or burn, burn, burn, burn. You can't violate the physical laws and constants that exist in our galaxy. There is always VHS 8 hr tape.

JJK
Serena wrote on 7/29/2005, 6:09 AM
Hey Maverick, don't do that!!
Really you can't put 8 hrs on a single-layer DVD. But you can put 2 hours on one. What you need to do is work out the bitrate required, which will be something of the order of 5 Mbs (1 hr at 8 Mbs is about 4.7 GB).
This is a commonly addressed issue. See also the topic: Just an idea for Vegas 7--calculator. Therein you'll find reference to the calculator I mentioned. http://www.videohelp.com/calc.htm
-- others also.

Serena
Maverick wrote on 7/29/2005, 7:23 AM
Serena

What I have done is rendered each hour's of captured video to an AVI file (I suppose I could have simply joined all the separate captured files but it only took about 16 minutes for each hour's worth).

I then put two of these AVI files into DVDA and selected Fit to Disc with the reultant bit-rate showing as 4.546. Not too sure how good the quality will be but I will now render in DVDA. I expect it will take around 7 hours on my system.

I'll let you know how it develops later.

Cheers

Mav
johnmeyer wrote on 7/29/2005, 9:57 AM
You just change the AVERAGE bitrate for the MPEG-2 encode. A lower bitrate lets you fit more minutes of video into the same space. For two hours, assuming you use 192 kbps AC-3 for your audio, the required bitrate is 4,400,280,312.

You can use the bitrate calculator here:

Bitrate Calculator

to calculate bitrates for other durations.

The quality will look pretty good until you get to about 90 minutes on one DVD. By the time you reach two hours, it will definitely start looking worse than the original.

You should definitely use two-pass VBR encoding when trying to fit lots of stuff on one DVD.

Finally, even if dual-layer DVD becomes an option, you should be aware that these discs fail to play on a huge number of existing players.
ScottW wrote on 7/29/2005, 2:21 PM
You can significantly increase the playability for +R DL media by selecting a burner that burns a booktype of DVD-ROM rather than the new booktype that was assigned for DL media. I've a player that won't play anything other than DVD-ROM and it happily plays my DL burn since it was burnt with a DVD-ROM booktype (likewise it will happily play any +R media that I burn with a DVD-ROM booktype).

--Scott