Bitrate question

[eclipse95]

I am preparing to convert DV-AVI files of home videos to MPEG-2 using CCE Basic. To ensure best quality, I plan not to have more than one hour of video on each DVD. The question is whether to use CBR or VBR. Either way, I presume that I should go with 2 passes. The audio will ultimately be converted to MP2 or AC3 (probably at 256) for DVD authoring. With those parameters in mind, should I use CBR or VBR? And what bitrates would be best? If VBR is the answer, what should the average, min and max video bitrates be? I've looked at a lot of info on this, but there does not seems to be a consensus.

[MOVIEGEEK]

To ensure best quality just use CBR @ 9MB/s and AC3(or LPCM).
2 pass VBR is best when trying to get over an hour on a SL DVD, a bitrate calculator is useful.

[edDV]

At ~1hr/DVD (9up Mb/s average), VBR abd CBR merge into the same thing.

VBR benefits from low motion, well lit scenes which implies stable pro shooting technique. Hand held consumer video is never stable, and lighing is usually suboptimal. This demands higher average bit rate.

[eclipse95]

Thanks. But if I use 9 mbps with PCM audio (1536, I think), doesn't this add up to beyond the DVD spec of 10.08 max total?

[MOVIEGEEK]

Yes it goes beyond so you will have to set bitrate to 8264kbps, if you use 192kbps AC3 then you can go as high as 9600kbps.
I recommend using VideoCalc.

[eclipse95]

So if it's stereo audio does 192 count as 192 or as 384 for calculation purposes?

[edDV]

So if it's stereo audio does 192 count as 192 or as 384 for calculation purposes?

Stereo mp2 or AC3 audio audio can be up to 384Kbps. Check your encoder settings.

I wouldn't max out video bit rate. 9500Kbps CBR is plenty. 9000Kbps is enough.

[jagabo]

kbps is the same whether the audio is stereo, joint stereo, or mono. Ie, 192 kbps stereo means 96 kbps for each channel.