I have a Thinkpad T42 with an ATI Radeon Mobility 7500 graphics chip (RV200 chipset), which is supported by the open radeon driver.
Under 11.04 vlc is happy to play back HD video at an excellent framerate using the xvideo extension (hardware accelerated overlay):
vlc --vout xvideo MYVIDEO.mp4
VLC media player 1.1.9 The Luggage (revision exported)
Blocked: call to unsetenv("DBUS_ACTIVATION_ADDRESS")
Blocked: call to unsetenv("DBUS_ACTIVATION_BUS_TYPE")
[0x903e914] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
Blocked: call to setlocale(6, "")
Warning: call to srand(1323805494)
Warning: call to rand()
Blocked: call to setlocale(6, "")
(process:4926): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
brainfart cropping not supported, this could look slightly wrong .
..
Under 11.10, vlc will not use the xvideo extension. When overlay is enabled (hardware acceleration), video becomes choppy. With it disabled, performance is better, but not smooth.
vlc --vout xvideo MYVIDEO.mp4
VLC media player 1.1.12 The Luggage (revision exported)
Blocked: call to unsetenv("DBUS_ACTIVATION_ADDRESS")
Blocked: call to unsetenv("DBUS_ACTIVATION_BUS_TYPE")
[0x8a4292c] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
Blocked: call to setlocale(6, "")
Blocked: call to setlocale(6, "")
(process:1817): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
(vlc:1817): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap",
libva: VA-API version 0.32.0
libva: va_getDriverName() returns 0
libva: Trying to open /usr/lib/dri/radeon_drv_video.so
libva: va_openDriver() returns -1
[0x9905e84] main video output error: video output creation failed
[0x8cb8a64] main decoder error: failed to create video output
