One big advantage to VBR is that it's just flat more efficient than CBR. With CBR you're encoding many/most scenes at a much higher bitrate than is necessary, thus wasting a lot of disc space.
Properly done VBR eliminates this problem, but the encoder has to do its analysis properly to get things "right". The problem is some encoders do VBR, and especially 2-pass, better than others.
TMPGEnc does a decent job with straight VBR but has had a problem or two with 2-pass (which is why you see 2 versions of it in their menu). It's also rather slow compared to newer software like MC.
MC started out with a VBR quality problem in their core, but this went bye-bye quite a while ago and they keep getting better and better with every release. My only problem with their standalone now is that their video capture engine/TV tuner doesn't (yet) support Video for Windows devices and that it can't use externally encoded AC3 audio.
There are a few problems with home-burned discs and older (and some new) decks:
1. many older and even some new decks cannot read the full DVD spec bitrate, VBR or CBR, even on commercial discs.
I test decks for this using the Roy Orbison "Black & White Night" concert video. You'd be suprised how many decks choke on it.
2. many decks, even name brand ones, read DVD-R/+R using VBR but not at the full DVD spec rates. CBR makes it easier for the decoder to keep up, but sometimes it too is limited but not as much as VBR.
3. There is also an issue with the discs reflectivity (separate from the decoder issue) in that some older decks have trouble because recordable media, CD or DVD, are a bit less reflective than "real" discs.
4. while MPEG audio is supported it's not the spec in NTSC land and as such it can give older decks decoding trouble, especially when combined with the other issues noted above. As such when authoring for these decks you should stick to Dolby Digital audio (AC3).
Some have better luck with these issues when using CD/DVD-RW/+RW because they are often just a hair more reflective than their non-rewritable cousins, but this doesn't usually help the decoder issues.
IMO the best way around these problems is to up the Q, chop the video VBR bitrate to < 7000 kbps with and use AC3 whenever possible.
Dr. Mordrid
Properly done VBR eliminates this problem, but the encoder has to do its analysis properly to get things "right". The problem is some encoders do VBR, and especially 2-pass, better than others.
TMPGEnc does a decent job with straight VBR but has had a problem or two with 2-pass (which is why you see 2 versions of it in their menu). It's also rather slow compared to newer software like MC.
MC started out with a VBR quality problem in their core, but this went bye-bye quite a while ago and they keep getting better and better with every release. My only problem with their standalone now is that their video capture engine/TV tuner doesn't (yet) support Video for Windows devices and that it can't use externally encoded AC3 audio.
There are a few problems with home-burned discs and older (and some new) decks:
1. many older and even some new decks cannot read the full DVD spec bitrate, VBR or CBR, even on commercial discs.
I test decks for this using the Roy Orbison "Black & White Night" concert video. You'd be suprised how many decks choke on it.
2. many decks, even name brand ones, read DVD-R/+R using VBR but not at the full DVD spec rates. CBR makes it easier for the decoder to keep up, but sometimes it too is limited but not as much as VBR.
3. There is also an issue with the discs reflectivity (separate from the decoder issue) in that some older decks have trouble because recordable media, CD or DVD, are a bit less reflective than "real" discs.
4. while MPEG audio is supported it's not the spec in NTSC land and as such it can give older decks decoding trouble, especially when combined with the other issues noted above. As such when authoring for these decks you should stick to Dolby Digital audio (AC3).
Some have better luck with these issues when using CD/DVD-RW/+RW because they are often just a hair more reflective than their non-rewritable cousins, but this doesn't usually help the decoder issues.
IMO the best way around these problems is to up the Q, chop the video VBR bitrate to < 7000 kbps with and use AC3 whenever possible.
Dr. Mordrid
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