Ideal CBR for compatibility with DVD players?

[Mark Prebonich]

‘Top quality is nearly always VBR, not CBR. If you have no space constraints, you might go to CBR for encoding speed, but that’s about the only reason.’

Dave,
Many of us are after the highest quality regardless of the time element. If there are no space constraints and time is not a concern, what is the correct VBR settings to obtain the best quality render? Thanks

-Mark

[Dave Haynie]

VBR works by analyzing the video and varying the bitrate based on content. Of course, that’s implied in the name, “Variable Bit Rate”. Unless your encoder is broken, VBR always looks better than CBR at the same effective bitrate.

However, if space is no issue, you might as well encode in CBR. Far as I know, VBR can’t exceed the 9.8Mb/s peak defined by the DVD specs even momentarily… so clearly, it can’t be any better than “the best possible”. So for practical discs, save 192kb/s or 448kb/s for audio (unless you’re encoding PCM audio for higher quality), and you have about 9.3Mb/s-9.5Mb/s to work with. So you get roughly an hour’s worth of the best possible CBR on a DVD5.

There’s a risk it may not play in older players. No idea how much of a problem that is… I’ve sold 100’s of videos on DVD-R, but never anything that didn’t need VBR encoding in order to fit.

-Dave

[Mark Prebonich]

Thanks for the reply.
The default settings for VBR are:
Max 9,500,000
Ave 6,000,000
Min 192,000

Would you recommend leaving these as is or adjusting them in ‘custom’ to increase the quality of the VBR render?

Regards,

-Mark

[Mike Kujbida]

[Mark Prebonich] “ould you recommend leaving these as is”

Never!!

“or adjusting them in ‘custom’ to increase the quality of the VBR render?”

Always!!
My rule of thumb (and it’s never let me down) is to use a CBR of 8,000,000 for any program 70 min. or less.
Anything longer and I use VBR settings as determined by the bitrate calculator at https://www.johncline.com/bitcalc110.zip
The only change I make to it is to increase the Safety Margin to 5%.
This way, I’m guaranteed that the program will fit on a DVD with a bit of room to spare.
If the program is 90 min. or longer or is of marginal quality, than I do it as a 2-pass.
I shot a 2.5 hr. play last spring that, to my surprise, looked very acceptable on a single-layer DVD.
Shooting it with a pro camera on a professionally lit stage helped a lot in keeping the quality level high.
BTW, I never let the Max setting go over 8,000,000 to ensure maximum compatibility on older/cheaper players and media.