mencoder error using vdpau

mobrien · 01-13-10, 07:37 PM

Hi!

I just got a GT 220 a couple of days ago and discovered this *great* feature called VDPAU! So, I thought I would give it a spin at backing up a DVD I own to my media server and, actually, since my roommate has the same movie and it is a dual core processor, run a double encode simultaneously, one using VDPAU and the other using software decoders and see what the delta is in time!

Anyway, I am getting this freaky error that I can't get past.

I can run "mplayer -dvd-device /dev/sr0 dvd:// -vo vdpau -vc ffmpeg12vdpau" and the video pops up using about 3% CPU. Omitting the last two parameters, it uses about 7% CPU.

Also, using mencoder to software decode and rip the video works no problem by running "mencoder -dvd-device /dev/sr0 dvd:// -ovc xvid -xvidencopts pass=1 -alang en -oac mp3lame -lameopts vol=6 -o AmGang2.XviD.avi".

However, when I try to add "-vc ffmpeg12vdpau" as a parameter, I get a very cryptic error

Code:

[mpegvideo_vdpau @ 0x7f9f5e789880]get_buffer() failed (-1 0 0 (nil))
Error while decoding frame!

I have attached my STDOUT, STDERR and nvidia-bug-report.log for reference. Please let me know if you have any suggestions!

Thanks!!!

--mobrien118

**AaronP** · 01-13-10, 08:33 PM

I don't think mencoder supports using VDPAU at this time.

mobrien · 01-13-10, 08:58 PM

Quote:

Originally Posted by AaronP

I don't think mencoder supports using VDPAU at this time.

Oh! That is one thing I forgot to mention...

I am using the version of mencoder provided by the nvidia-vdpau ppa for Karmic. It is supposed to be compiled with VDPAU support. Also, I experienced the same results with both the 190 drivers and the 195 beta drivers (both provided through the same ppa).

Whether it works or not, you would know better than me. Has anyone gotten this to work? Or have I just wasted 4 hours trying to find some solution (well, I guess I would have just wasted the time on something else anyway :-))

Thanks again!!

--mobrien118

**Stephen Warren** · 01-13-10, 11:06 PM

Compiling the MPlayer source tree creates both the mplayer and mencoder binary. The nvidia-vdpau PPA includes both binaries from the build simply because that's how MPlayer is typically packaged. However, only MPlayer actually supports VDPAU, mencoder doesn't.

cehoyos · 01-14-10, 06:14 AM

Quote:

Originally Posted by mobrien

I just got a GT 220 a couple of days ago and discovered this *great* feature called VDPAU! So, I thought I would give it a spin at backing up a DVD I own to my media server and, actually, since my roommate has the same movie and it is a dual core processor, run a double encode simultaneously, one using VDPAU and the other using software decoders and see what the delta is in time!

As said, mencoder does not support VDPAU.
Note that mencoder is mostly unmaintained, so the application you would normally want to use is ffmpeg (which also does not support VDPAU yet and does not support decrypting DVD's). Additionally, is is unlikely that you could beat a fast dual-core processor at decoding MPEG-2 using VDPAU (at least not significantly).

Carl Eugen

mobrien · 01-14-10, 09:10 AM

Quote:

Originally Posted by cehoyos

As said, mencoder does not support VDPAU.
Note that mencoder is mostly unmaintained, so the application you would normally want to use is ffmpeg (which also does not support VDPAU yet and does not support decrypting DVD's). Additionally, is is unlikely that you could beat a fast dual-core processor at decoding MPEG-2 using VDPAU (at least not significantly).

Well, I can't say that I'm not a little sad to hear this. I only have a 1.86 GHz Core2 Duo processor, and as I indicated with my test using MPlayer, there was a CPU savings. I mostly was interrested in actually finding out what the difference would be. I find the possibility of offloading video processing to the GPU to be fascinating and just want to learn about how it works and of the potential.

Also, you probably know better than me, but I thought MEncoder pretty much used the same "code" as MPlayer, only instead of directing the output to a video frame, it sends it to an encoder library to create a file. That said, how can it be that mencoder is unmaintained?

Anyway, I hope that some day (soon) mencoder will be able to grab the vdpau output. Not necessarily for a huge cost savings, but just "for fun" maybe.

Thanks, all, for the info. Very interesting topic!

--mobrien118

01-13-10, 08:33 PM	#2
AaronP NVIDIA Corporation Join Date: Mar 2005 Posts: 2,487	Re: mencoder error using vdpau I don't think mencoder supports using VDPAU at this time.

01-13-10, 11:06 PM	#4
Stephen Warren Moderator Join Date: Aug 2005 Posts: 1,327	Re: mencoder error using vdpau Compiling the MPlayer source tree creates both the mplayer and mencoder binary. The nvidia-vdpau PPA includes both binaries from the build simply because that's how MPlayer is typically packaged. However, only MPlayer actually supports VDPAU, mencoder doesn't.