Heey there! I've been working a little to enable VDPAU on several applications, after I learned this would aid my AVCHD editing. I got it to work on mplayer, ffmpeg and mlt, however, not with kdenlive. Under "video drivers" it does not appear (is it would with smplayer). CPU usage is still far above for example playback with mplayer and vdpau.

A few checks (i'm using arch linux):
----------FFMPEG----------
[daan@arch build]$ ffmpeg -codecs | grep vdpau
FFmpeg version SVN-r23536, Copyright (c) 2000-2010 the FFmpeg developers
built on Jun 8 2010 13:35:46 with gcc 4.5.0 20100520 (prerelease)
configuration: --prefix=/usr --enable-gpl --enable-libmp3lame --enable-libvorbis --enable-libfaac --enable-libfaad --enable-libxvid --enable-libx264 --enable-libtheora --enable-postproc --enable-shared --enable-pthreads --enable-x11grab --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libschroedinger --enable-version3 --enable-nonfree --enable-runtime-cpudetect --disable-debug
libavutil 50.18. 0 / 50.18. 0
libavcodec 52.75. 1 / 52.75. 1
libavformat 52.68. 0 / 52.68. 0
libavdevice 52. 2. 0 / 52. 2. 0
libavfilter 1.20. 0 / 1.20. 0
libswscale 0.11. 0 / 0.11. 0
libpostproc 51. 2. 0 / 51. 2. 0
D V D h264_vdpau H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (VDPAU acceleration)
D V DT mpeg1video_vdpau MPEG-1 video (VDPAU acceleration)
D V DT mpeg4_vdpau MPEG-4 part 2 (VDPAU)
D V DT mpegvideo_vdpau MPEG-1/2 video (VDPAU acceleration)
D V D vc1_vdpau SMPTE VC-1 VDPAU
D V D wmv3_vdpau Windows Media Video 9 VDPAU

------------MeLT------------
[daan@arch Maassluis]$ [b]melt -debug 00001.MTS 2>&1 | grep -i vdpau[/b]
vdpau_init
vdpau_decoder_init
successfully created VDPAU surface 3
successfully created VDPAU surface 4
successfully created VDPAU surface 5
vdpau_get_buffer
vdpau_get_buffer
[h264_vdpau @ 0x24ab670]no picture
vdpau_release_buffer (4)
vdpau_get_buffer
vdpau_release_buffer (5)

I installed svn and git versions from both mlt and kdenlive. Anyone has an idea what i'm missing? Thanks!

I've done some more research, and I discovered that MeLT actually isn't using the VDPAU system. So I was wondering, Could some measure their CPU usage during melt playback? I did the same with smplayer and melt, to discover the difference. This is what I got:

I played a 1080p - AVCHD on my core2duo 2.4ghz macbook pro (early 2008)
-smplayer with xv video output: CPU to 2.4 ghz and usage around 60%
-smplayer with vdpau video output : CPU on 800MHz and usage around 30%

With MeLT you can't really select a video output
-melt CPU to 2.4ghz and usage around 60% (same as xv on smplayer)

So, despite the little melt-vdpau lines posted in my previous message, melt doesn't seem to actually use VDPAU...
Any ideas? thanks!

Wbdsgnr, your tests are flawed. You are testing a program that uses both the decode and presentation portions of VDPAU (smplayer) with a program (melt) that uses only the decode portion of VDPAU. This a huge difference. If you only want to view videos, then use smplayer, not melt, but good luck trying to edit video and apply arbitrary image filters in smplayer while also trying to leverage its VDPAU integration and all of its performance gains.