CUDA GPU Acceleration

[Boston Joe]

It just does not work yet. Can't recognize my GeForce 8800GTX CUDA card. If it does recognize your card DvdFab is not getting the performance increase of other GPU acceleration applications. I am sure the guys will figure it out with a little research at nVidia and ATI.

What driver are you using?

[Johan]

The driver is in my sig beside I thinl its fab that doesn't support mpeg2

[drobo]

@Boston Joe

Currently using 196.21_desktop_win7_winvista_64bit_english_whql. I've pretty much tried all the 19....... series drivers and never got DvdFab to recognize my 8800 GTX card.

[Boston Joe]

I just installed the latest drivers and it is not recognizing my GTX as Cuda either,

[Complication]

I have done a little research and I think I may have found out why there is such a difference in in compression speed. Now anyone can correct me if I am wrong cause I am still trying to wrap my head around this. Video encoding is not my specialty.

If I understand things correctly the powers that be have established a standard for Bluray movies and hardware. All Bluray discs shall include VC1 format, MPEG-4(H.264/AVCHD) and MPEG-2 part 2(H.262).
When compressing to BDDVD9 only the AVCHD stream is re-encoded which my GPU's support. Bluray format on DVD's is not supported by Bluray players. So these are more like HDDVDs.
When compressing to BD25 all Bluray content is compressed to the disc.
.m2ts stands for MPEG-2 transport stream. MPEG-2(H.262) is not supported by my video cards therefore GPU acceleration only works with the other streams.
Like I said I may be way off here but this makes sense to me.
I'm fairly certain that MPEG 2 encoding is possible with my cards so this may be something for the Developers to add to DVDFab compression

I suggest you open up the compressed M2TS files in MediaInfo to see what encoding DVDFab is doing. Last I checked, DVDFab was maintaining the same encoding (VC-1 or H264) as the original when making a BD9. Only Blu-Ray players understand BD format on DVDR (a.k.a. AVCHD). Although MPEG2 is supported in the Blu-Ray specification, I haven't seen a title use it for the main movie yet.

As for the CUDA support being available or not per title, this is probably a function of the title authoring rather than whether you are selecting BD25 vs BD9. It is up to the BD author to choose VC-1 or H264 and I personally don't know how many titles are each. I believe DVDFab only uses the GPU for the decode process (when available) and the CPU is being used for the encode. It makes sense then that if your GPU does not support VC-1 then your CPU cannot offload the decode task and must do all the work when the source video is VC-1. Even if DVDFab was converting VC-1 to H264, it would not be able to use the your GPU for help.

As for DB9 being faster than DB25, this is actually not uncommon. You can demonstrate something similar by doing DVD to Mobile at 100 vs 1000 bitrate. Maximizing the use of a higher bitrate may be more calculation intensive then at a lower bitrate where detail is going to be lost regardless. It depends on how close the source and destination bitrates are as well as other characteristics of the video.

[Johan]

Complication,
Thanks for your insight. If I understand you correctly it is the increase in bitrate that slows my processing speed. I think I get it now.

[Complication]

Complication,
Thanks for your insight. If I understand you correctly it is the increase in bitrate that slows my processing speed. I think I get it now.

Just to be clear. This is not always true but is very common when the difference in bitrate is drastic and where neither bitrate is close to the original bitrate.