2-pass h.265 transcoding with hardware acceleration (nVidia CUDA/NVENC)

alonsomosley

I am very happy to see that DVDFab got HW-acceleration feature for 2-pass transcoding! As I tested it I was not sure what I get.

DVDfab does not show "first pass of two passes / second pass of two passes", I see only a nearly constant CPU and GPU usage (at about halftime there should be some change) and if I abort the transcoding procedure at an early stage I get a playable segment of the video (which should be not possible)... All these suggest that there is no real 2-pass encoding going on.

I must assume that 2-pass HW-accelerated transcoding is applied as a single-pass with some "lookahead". Could you clarify this for us?

PS: some h.264 files fail to transcode too, I have to set all decoders to DXVA from CUDA to get it work, and DVDFab shows only a single-pass transcoding. But I guess the files were not correcty in some ways...

Mona

CUDA should be supported in 2-pass, please post dvdfab_internal.log file and fabcheck_internal.log file, which could be helpful to check the problem. Thanks.

Wilson.Wang

hi alonsomosley,

cuda two pass use NVENC HardWare two pass, will not like soft x264 two pass have two encode flow(pass 1 get some data, pass 2 use pass 1 data),
It will be run on Nvidia driver and Nvenc chips.
About error problem, please post log.

Yours,
Wilson