Tempgnc

[Dow]

what is the best encoding quality that is in TEMPGnc??????
Constant bitrate, 2pass varible, manual VBR, etc, etc...????

[Vejita-sama]

CBR - constant bitrate. The same (video) bitrate is used for the whole encode.

VBR - variable bitrate. The bitrate is raised or lowered. For high motion scences the bitrate is raised, for low motion scences it's lowered.

CQ_VBR - constant quaility VBR. Tries to do the above. But no one really knows what the 0-100 setting means, and you can't predict file size (ie. lots of high motion scences and the file could be huge).

2pass VBR - first TMPGenc makes a CBR pass. Then using that file as a template it makes a 2nd VBR pass to allocate the bitrate as needed. You set a min/max bitrate and a desired ave. Then the bitrate will be raised/lowered as TMPGenc feels is necessary, but the ave will be what you entered. This means that you can predict the final file size using a bitrate calculator.

As for the best. The best is to use the highest bitrate you standalone will support (normall ~2880kbit/s total). But that only holds ~40min of video. If you want to hold more movie per CDR you have to lower the bitrate, then it's more a personal choice.

You'll hear a lot of debate about this, but for DVD rip source I normally do CBR if the video bitrate > 2000, and multiple pass VBR if < 2000 (I normally use CCE which can do up to 9pass VBR, but normally just do 3pass).

[kinneera]

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CQ_VBR - constant quaility VBR. Tries to do the above. But no one really knows what the 0-100 setting means, and you can't predict file size (ie. lots of high motion scences and the file could be huge).
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The definition I found of CQ is that it keeps the quantize value for the video the same no matter what. This means that it will allocate as many bits as necessary to keep the quality of a scene equivalent, even if its a huge amount, such as in a high motion scene.

I don't know for sure that this is actually what TMPGEnc odes, but using CQ, I've never had it produce a file that caused an mux-rate error in bbMPEG, so I presume that it doesn't actually allow the bitrate to exceed the specified max. In that sense, it is at best a partial true CQ encoding method.