how long is too long

[lakewud]

Very quick question

Using VS10+

Ive noticed in the past if I burn over 1hr 15min the dvd certainly seems to 'compress'? for want of a better word the picture...it seems a little...choppy..only slightly...occassionally says, when i come to burn, 'the video will be shortened to fit'.

Anyway, if i burn around 1hr 10min then the 'quality' seems better.

Basically what im asking is, regardless of time takes to burn / at what speed x2 ( i pefer ) and quality of disc used ( have bought more expensive ones and cheapo ones )....Whats the recommended length i can get away with on a video - to maximise quality...under an hour?

[DVDDoug]

If you use compressed audio (i.e. Dolby), you can use a video bitrate of about 6000kbps, and that will allow you about 90 minutes of good quality video on a single-layer DVD. With uncompressed LPCM audio, 60 minutes is probably a better target. A bitrate of 5000-6000kbps seems to be typical of commercial DVDs. (Keep in mind that most commercial DVDs are dual-layer, and the pros have high-quality originals and better MPEG encoders to squeeze better quality into a given bitrate.)

Higher bitrate = higher quality = bigger file size = lower compression = less playing time.

Lower bitrate = lower quality = smaller file size = higher compression = more playing time.

Using 2-pass encoding with a variable bitrate can help to squeeze the best quality into the smallest file size.

It helps if you start-out with a high-qualty, less compressed format (like AVI/DV) and compress once to your final format. All of the video compression methods use lossy compression, and you potentially loose quality when you transcode from one lossy format to another.

Here is a Bitrate Calculator and here is a chart showing bitrate vs. quality.
Or, you can estimate filesize with the following formula:
File Size in MB = (Bitrate in kbps x Playing Time in minutes) / 140
(Use the combined audio & video bitrate, and with variable bitrates use the average.)

...and quality of disc used ( have bought more expensive ones and cheapo ones )....

Assuming you don't get errors, a cheap disk will give you the same video quality as an expensive disc.

If you get errors (from a bad-burn or a bad disc), you'll usually get one or more places where the 'blocking' is very bad, or the picture might freeze-up for a few seconds (or permanently!). If you're getting compression artifacts (from over-compressing), you'll see 'blocks' wherever there is fast motion or during scene changes, throughout the movie.

...at what speed x2 ( i pefer )...

Slower burn speed can give you a "better burn", depending on the burner. But, 4X ior 6X s usually OK.

There is a program called Nero CD-DVD Speed that allows you to check the qualty of the burn. If you have Nero you might have it, but it seems to be no longer available for download.

[Ken Berry]

Frankly, VS 10 (and I think 9) were the only versions that had that squeeze to fit function, but it never worked well. The alternative was to produce a video that was (well) over 4.3 GB, and not burn a disc but choose 'DVD Folder' as the output target. Then you would use another program like DVD Shrink or Nero Recode to cut it down to size for burning to a single layer DVD. The end quality is much better that way.

However, otherwise your question is a bit like asking 'how long is a piece of string'... We have to read between the lines and make some assumptions before being able to provide an answer, given that you have not provided some essential information.

First, my basic assumption is that you are editing your project, and your project is over an hour long. Second assumption is that you then choose Share > Create Video File > DVD and accept the default settings inherent in that. Or do you jump straight to the burning module (Share > Create Disc > DVD)? In that case the more than one hour project file is inserted in the burning module, and conversion (and squeezing) occurs as part of the burning process.

Either way, the default DVD settings use a high quality bitrate of VBR max. 8000 kbps. Using that, you can fit about one hour of video on a single layer DVD. You can fit approximately another 10 minutes of video onto the disc if you also use either Dolby or mpeg layer 2 audio.

But rather than use the 'shorten to fit' feature, what you should be doing is to alter the bitrate used for the conversion. And to do that you either use Share > Create Video File > Custom in the Editing module, or else change the burning settings by clicking on the central cogwheel icon in the bottom left of the burning screen.

Many users here in any case feel that 8000 kbps may be too high as the default (I don't), and recommend using no more than 7000 kbps. You will certainly fit 1 hour 15 minutes using that (or more with compressed audio formats) and the quality will still be high.

After that, if you want to fit 90 minutes on a single layer disc, then the bitrate needs to be down around 6000 to 6500; and if you want 2 hours, then it will be around 4000 kbps -- though the quality then is only equivalent to VHS video tape.

Once you settle on a preferred option, you can use Make Movie Template Manager to make a permanent template which you can then select in Share > Create Video File> [the name you give the template]...