View Single Post
Old 20th March 2016, 13:26   #2922  |  Link
manolito
Registered User
 
manolito's Avatar
 
Join Date: Sep 2003
Location: Berlin, Germany
Posts: 3,078
Hi SuLyMaN,

as always this is mostly a compromise between speed and quality. As a rule of thumb you can say that the higher the encoding bitrate the less you will notice differences in quality between the different encoding modes.

This already is the philosophy of AVStoDVD. If you have activated "Smart Selection" for the encoding modes (this is the default), FFMpeg CBR will be used for high bitrates above 6500 kbps, HCenc 1-pass VBR for medium bitrates between 4500 kbps and 6500 kbps, and HCEnc 2-pass VBR for lower bitrates below 4500 kbps. Generally these thresholds do make sense, but they can probably be optimized depending on the source characteristics.

And of course there are folks who put quality above anything else, and they will use 2-pass VBR all the time regardless of the bitrate.

For the difference between FFMpeg and HCenc the answer is not so easy. A lot depends on the command line parameters for FFMpeg, and they can get quite complicated. Using only FFMpegs default parameters the output quality will mostly be inferior compared to HCenc.

My plugin uses Fishman0919s extreme high quality parameters by default for bitrates below 3500 kbps (the threshold can be edited), and according to Fishman using these parameters gives FFMpeg an edge over HCenc - at least at lower bitrates.

The latest version of my plugin has added some versatility in using different FFMpeg encoding modes. Now it is possible to force 2-pass VBR regardless of the bitrate, and the 2-pass mode can now be combined with parameters for normal quality, regular HQ and extreme HQ. And you also can combine it with any Custom Quant Matrix you like (with the exception of the Extreme HQ Mode where the MPEG Adapted Matrix is forced).

I know that this versatility is only important for power users, most users will be happy with the default automatic mode. Still it is nice to have this versatility, and it can be quite useful for users who cannot get HCenc working (there were reports that HCenc can crash under Win10).


Cheers
manolito

Last edited by manolito; 20th March 2016 at 13:55.
manolito is offline   Reply With Quote