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"Use GPU accelerated decoding" option is greyed out

Posted: 29 Apr 2012 16:01
by 98Guy
I swapped an MX440 (64 mb) video card for an Evga GeForce 6200 (256 mb) video card because VLC can't really play large h.264 video files smoothly on my system.

I updated VLC to the latest version (2.0.1 I think) but I was still seeing this issue with version 2.0.0.

This chart:

http://www.nvidia.com/docs/CP/11036/Pur ... arison.pdf

indicates that the AGP version of GeForce 6200 has H.264 decode acceleration for both Hi-def and standard-def content (but it doesn't have H.264 decode with IDCT and CAVLC/CABAC - what ever the hell those are). It also has MPEG-2 decode acceleration, but not Mpeg-2 inverse telecine (what-ever that is).

VLC has a check-box to enable "Accelerated video output (overlay)" - and I have that checked.

VLC also has (in the Input & Codecs settings section) a check-box for "Use GPU accelerated decoding" - but that option is greyed out. Any idea why?

I was trying to play a video file with these specifications:

Codec ID : V_MPEG4/ISO/AVC
Bit rate : 3550 Kbps
Width : 1280 pixels
Height : 720 pixels
Frame rate : 29.970 fps
Writing library : x264 core 120 r2164 da19765

VLC did a poor job playing that file. I was getting about one or two second's worth of frames that played ok before it stuttered and pixelized for a second or two before playing again. The audio was AC3 stereo, and it played just fine.

However, when I play the same file using MediaPlayer Classic, the file plays really well. The system is based on a Soyo motherboard with Intel 845 chipset and it has Pentium 4 CPU running 2.53 Ghz (533 mhz FSB) with 512 kb L2 cache.

Ideas? Comments?

Re: "Use GPU accelerated decoding" option is greyed out

Posted: 29 Apr 2012 17:58
by 98Guy
Ok, after messing around with a bunch of settings, I've got this particular video file playing pretty well.

Here are some of the settings I've either experimented with (and left as default) or have changed.

In the "simple" menu under Input & Codecs settings, the "Use GPU accelerated decoding" is still greyed out, but there is a checkmark in the box. Also on that page I have "Skip h.264 in-loop deblocking filter" set to ALL, X264 preset and tuning set to faster / film, and x264 profile and level selection set to high444 / 0.

====================
Show settings (All)

Under Advanced
- CPU features -> I see no options (why?)

Under Video section (all these are enabled)
- drop late frames (try disabling this one)
- skip frames (try also disabling this one)
- quiet syncro
- keypress events
- mouse events
- overlay video output
- disable screensaver
- fix HDTV height
- window decorations

Under Filters
- no filters are selected

Under Output modules
- OpenGL video output
(this was the best setting for me. Several of the settings gave no video at all - such as Direct2D and 3D).

Under Subtitles/OSD
- enable sub-pictures (disable)
(I'm not sure disabling sub-pictures does anything for performance)

Under Input/Output codecs
- File caching (ms) set to 2000

Under Demuxers / H.264
- frames per second
(was 25, I set to 29.9 but I don't think it helped)

Under Video Codecs
Under FFmpeg
- direct rendering
- hurry up
- hardware decoding

Under x264
- h.264 profile set to high444

Re: "Use GPU accelerated decoding" option is greyed out

Posted: 30 Apr 2012 01:08
by Jean-Baptiste Kempf
Are you on XP?

Re: "Use GPU accelerated decoding" option is greyed out

Posted: 30 Apr 2012 02:30
by 98Guy
Windows 98. Using forceware 81.98 drivers (which I think is giving me the "system hangs during windows shutdown" problem).

Re: "Use GPU accelerated decoding" option is greyed out

Posted: 30 Apr 2012 09:41
by Lotesdelere
VLC hardware acceleration requires Vista or better.

Re: "Use GPU accelerated decoding" option is greyed out

Posted: 30 Apr 2012 22:45
by 98Guy
> VLC hardware acceleration requires Vista or better.

Where exactly can I find that listed as a requirement?

Re: "Use GPU accelerated decoding" option is greyed out

Posted: 30 Apr 2012 23:40
by Jean-Baptiste Kempf
> VLC hardware acceleration requires Vista or better.

Where exactly can I find that listed as a requirement?
On our wiki.

Re: "Use GPU accelerated decoding" option is greyed out

Posted: 01 May 2012 03:54
by 98Guy
I've turned on and off the hardware acceleration (as listed under FFmpeg / Hardware decoding check-box). I've done this while playing the same video and watching my kernel processor usage (win-98 system monitor utility). Putting a check in that box does indeed result in a 20% reduction in CPU usage.