Bitrate calculator for VBR in TMPGEnc Plus?

[stantheman1976]

The bitrate calculator here is good, but I think it only does CBR. Or am I looking at it wrong? Is there a bitrate calculator that will take into account a 2 pass VBR setting in TMPGEnc Plus? Or when I use the VideoHelp Bitrate Calculator should I use the bitrate I get from it as the average, then use 0 as minimum and 8000 as maximum, or something like that?

[Baldrick]

please post encoding in the conversion forums. moving you.

yes, use it as the average if you are using 2-pass.

[stantheman1976]

Does it matter what I use as the max setting then?

[jimmalenko]

Yep, the bitrate calculator here gives you the value you need to use as your average if doing 2-pass VBR. As for your Maximum and Minimum, there's quite a debate going. You need to keep in mind that the Max Video bitrate is 9800 kbps for MPEG2 video and 1856 for MPEG1 video for DVDs. Also, the total combined bitrate (all audio streams and video combined) should be under 10,080 kbps.

Personally, I like using 9000 for the Max and 1000 for the Min, but there are schools of thought that say that you don't need to go above 8000 kbps, or that some players will choke on excessively high bitrates, or that a Min of 0 is fine ... etc etc.

As an alternative, you might like to try this Bitrate Calculator.

[DRP]

From my experience TMPGEnc really doesn't vary its bitrate all that much anyway. It doesn't seem to stray too far from what you request the average to be, so having your min/avg/max to be something like 1000/4000/8000 would actually be no different to say 2500/4000/5500 because TMPGEnc won't go above 5500 if you're asking for a 4000 average anyway.

Also from what I've read in here and from my own experience as well, there isn't any point in going above a bitrate of 4000 if your source is MPEG-4 (DivX/XviD etc.) because there will be no gain in quality whatsoever.

I tend to use the max bitrates of the lower format as the min bitrate for the higher format. So for example if VCD is 1150kbps, SVCD is 2500kbps and DVD is nominally ~5000kbps and knowing that the line where SVCD quality = VCD quality is generally regarded as being 1600kbps you can arrive at the following 'rules of thumb' as a guide of what to do:

VCD = CBR 1150 or anything else up to 1856, that being the max for DVD. No point going higher even if using CD because quality won't improve unless you just wanna fill disc space. Absolute max is 2500 though for CD only. If need to go below 1150 then make it VBR with min at 300 (TMPGEnc default) and max at 1150 (or 1856 if burning to DVD).

SVCD = CBR @ 2500 or VBR with min 1600 and max 2500

DVD = min at 2500, max at 4000 (if MPEG-4 conversion) or whatever you need to fill the disc space with ultimate max at 9800.

Another option is CVD. With CVD being a hybrid of VCD and SVCD the bitrate rules should follow suit, so for CVD make the min 1150 and the max 2500.

As a general rule 2000kbps is another point at which CVD quality roughly equals SVCD quality like the 1600 line between VCD and SVCD. So you can use this to decide whether it would be best to encode as CVD or SVCD based on running length. If the length of the video means that your bitrate needs to be < 2000 but > 1600 then encode as VBR CVD. If < 2500 but > 2000 then encode as VBR SVCD. If < 1600 then you're firmly in VCD territory.

HTH