Which gives better quality VBR or CBR?

[ChachiFace]

Sorry for such a simple question but after searching the forum, I didn't find a simple clear cut answer.

Is there a difference in quality if you encode the same footage with the same nominal bitrate using VBR-2 pass or CBR? If so, which gives better quality? (ex. 75 min. movie encoded with VBR-2 pass 6000/8000/2000 vs. CBR at 6000) Would the quality be any different?

[MOVIEGEEK]

CBR will give better results if the max.VBR is the same,CBR also encodes in about half the time as 2-pass VBR.If you're using TMPGEnc give CQ a try,it is a good compromise between CBR and 2-pass VBR.

[AarontheRipper]

CBR is faster, and I use it whenever I'm putting home movies onto dvd because I generally only put an hour of footage on and I can use a bitrate of about 8000. However, if I'm putting a 2 hour + movie on dvd I will use a VBR because it is generally a rule that 2 pass VBR with an avg bitrate of 5000 will look better than a CBR of 5000. This is simply because the program will use a higher bitrate on frame sequences with a lot of movement and less on those with less movement. This gives you a superior product.

To condense, if you want max quality, are in a hurry, or don't have much that you want to fit on a disc, use CBR. If you want to fit a full movie or about 2 hours of footage on a disc, use VBR and you'll get better quality.

[hakeemshabazz]

I'm looking to do my first bit of mpeg2 encoding, and I was curious about VBR & CBR too. I'm not burning a whole movie to DVD, so room isn't a concernt...but quality is. Should I use CBR at 9800 bitrate? Would that give me the best qualiyt achievable?

What else should I shoot for if I want to recapture as much of the DVD quality as possible when I encode?

Thanks for the tips!

[dbecker]

the only reason to use vbr over cbr is to save space. The logic behind vbr is to give scenes with a lot of action a high video stream and scenes with little action low video stream and have both scenes have the same quality. This saves disk space. Now if space is not a concern then cbr is the best. I dont think you need to go to 9800. I would settle between 6000 and 8000.

[sacajaweeda]

General rules of thumb:

1. Video > 60 minutes = VBR
2. Video < 60 minutes = VBR anyways
3. See rules 1 & 2

[ronnylov]

I would say:
1. Video < 60 minutes = CBR
2. Video > 60 minutes = VBR

But even CBR is not vompletely constant bitrate, there will be bitrate peaks, especially if encoding with TMPGEnc. You also need room for the audio. So I would use CBR 8000 kbit/s for video less than 60 minutes.

[MavDVDR]

1. Video > 60 minutes = CBR
2. Video < 60 minutes = VBR

ronnylov, don't you mean the other way round?

ie.
1. Video longer than 60 minutes = VBR (2-pass)
2. Video less than 60 minutes = CBR

[ronnylov]

1. Video > 60 minutes = CBR
2. Video < 60 minutes = VBR

ronnylov, don't you mean the other way round?

ie.
1. Video longer than 60 minutes = VBR (2-pass)
2. Video less than 60 minutes = CBR

Yes, I got it wrong... I'll edit my post now!

[duhmez]

If spce isn't an issue less than 1 hour, then use 9400 for video and 384 for audio. No reason to encode with less than the max DVD allows as long as there is room. this will guarentee the best results, everytime.