Constant Quality levels - Why 65?

[Trenton_Net]

Hi,

I was wondering why tmpgenc for SVCD has a QC level of 65? Do they just pick a level? Or is 65 some optimum level or fair size/quality trade off? I'd rather have it at SVCD specs.

[adam]

The quality level has no effect on whether your svcd complies to the Svcd specifications, thats handled by your max bitrate setting.

There have been numerous tests done on how TMPGenc's CQ mode distributes bitrate. The general consenus is that with anything over %60-65 the quality doesnt increase that much while the filesize gets dramatically larger. So yes you are correct, a quality level of ~65 is probably the best balance between quality and compression but no matter what your settings you will never achieve as good a quality per size as multipass vbr.

[poopyhead]

yep..like wut adam said.

for example, if you're using CQ_VBR and set max bitrate of 2100. if you set your CQ to 100, then it is basically the same thing as if you use CBR with a bitrate of 2100.

basically, the closer you set the CQ to 100, the closer to the max bitrate your dvd rips will be. as adam said, anything much higher than 65 for CQ is waste because the filesize gets bigger but little increase in quality.