Ok, I have been able to re-run my tests using one of the latest nightly builds and I have to say that my results were much different this time. I have to assume that the encoding of HB has improved since the last time I ran this kind of test (probably about a year ago) as my results are much different this time.
I did a direct comparison primarily using the aTV3 preset and modifying the RF setting. Unlike the last time, I am unable to see much difference between the RF i am currently using (16.5) and RF 20. (dynaflash now saying "see, I told you so"). I can see a slight sharpness increase at 16.5 but to be honest I have to look for this on paused images side-by-side.
I also went back and re-tested my Fifth Element encode where I was seeing a definite brightness difference between RF20 and RF 16.5 and this time I did not get the same result and the image brightness remained consistent between the encodes.
So I guess I will be rethinking my RF setting. I am now thinking that I may go up to at least an RF of 18 at a 720p resolution. For me, I am looking at saving file space while retaining an acceptable picture quality (like I've said, if I want the best I'll put in the original Blu-ray). I looked at both the 720p and 1080p image in full screen mode on my 27" iMac screen and found that I could see very little difference in quality. I would have suspected that I would have seen more artifacts in the 720p image. I have not yet compared these two files on my 60" Kuro yet.
DYNAFLASH - I still have a couple lingering questions that hopefully you can answer.
1) From all that I have read, Blu-ray being fixed pixel count, they are not anamorphically encoded. Therefore, does using the Anamorphic setting (either strict or loose) really do anything? Is using the None option really the correct thing to do?
2) When using the cropping option, as long as you leave the width the same (i.e 1920 or 1280) you do not affect the overall image quality; however, if you have a 4x3 image in HD and you allow HB to crop the image and the output width increases from the original then technically you are adding more information than is really there in the original and compromising quality? For example, say you have a 640x480 image but have cropped 20 pixels off each side but the resulting output size is still 640x480 are you now stretching the image and (further) compromising quality?
Just for info, my results are tabulated below. I am using an 2011 iMac with a 3.4Ghz i7 processor.
HB Version 4728svn x86_64 (2012061401)
RF Resolution File Size (MB) Time to Encode (min)
16.5 1080p 776.1 10
20 1080p 487.8 7
16.5 720p 423.6 5
18 720p 362.1 4
20 720p 307.6 4
The above test was performed using the Avatar Blu-ray and chapter 31 which is 5:19 long. The base setting was the AppleTV2 preset and only changing the RF value.
HB Version 5170svn x86_64 (2013101501)
RF Resolution File Size (MB) Time to Encode (min)
16.5 1080p 750.5 11
18 1080p 611.7 9
20 1080p 475 8
16.5 720p 415.2 4
18 720p 356.1 4
20 720p 303.5 4
The above test was performed using the Avatar Blu-ray and chapter 31 which is 5:19 long. The base setting was the AppleTV3 preset and only changing the RF value.