DVD to H264 bitrate percentage

[mwbridges]

I am attempting to automate the DVD to H264 bitrate quantity setting. Using the average bitrate of a MPEG2 video, I believe the desired H264 average bitrate may be calculated using a set value for all coversions (i.e. not longer needing to set bit rate each time). Using 30% as the converted bitrate%: if the MPEG2 bitrate is 5.04, then the bitrate for the H264 coversion is automatically set to 1.5.

Consistently using 40% of orginal as the conversion amount, the resulting video looks great. A rate that is 30% of the original MPEG2 bit rate also looks good. I notice though, that movies that are LB/ Widescreen tend to look better than those that are full/ Widescreen. Should my conversion consider the size of the picture? Doesn't the original bitrate reflect the original size of the picture?

[jagabo]

Use target quantizer encoding. It's faster and you'll get exactly the right bitrate for the quality you specify, regardless of the frame size, frame rate, etc.

[mwbridges]

When converting using Nero, I have to first specify a target average bit rate. Since I am doing two-pass encoding, no quantizer is specified.