Cablevision firewire channel changer and new Intel video drivers

Sometime last Saturday (September 28) my cable provider, Cablevision, must have updated the software on my cablebox (Scientific Atlanta 4200HD). I use the firewire port for channel changes with the sa3250ch channel changer in the current MythTV SVN contrib directory. The commands being sent to the box were being received, but something happened in the new software that expected a slightly different command to properly change the channels. Anyway, here's some updated code to make it work. Change line 195 with the following diff:

195c195
< cmd[1] = CTL_CMD1 | (dig[0] << 16) | (dig[1] << | dig[2];
---
> cmd[1] = cmd[1] = CTL_CMD1 | (chn << 8);

I've also been toying with getting HD working with the Intel G33 integrated chipset that came in my new Dell Vostro 200 mini tower that I bought a few months ago. The CPU (Intel(R) Core(TM)2 Duo CPU E7200 @ 2.53GHz) seems to be OK handling pre-recorded HD from the Silicon Dust HDHomerun as well as h.264 content, so long as the bitrate isn't up there in the Blu-Ray range. I'm currently connected to a LCD HDTV with VGA, which is sufficient for my needs.

The latest Intel driver is here:

http://xorg.freedesktop.org/archive/individual/driver/xf86-video-intel-2.4.97.0.tar.bz2

By the way, you'll need to have at least xserver 1.3.0 to compile against, so make sure your system is updated! They say in the README you only need to specify Driver "intel" in your Device section of xorg.conf, but I've got a mess of options I'm playing with to get HDTV working nicely:

Section "Device"
BoardName "G33"
BusID "0:2:0"
Driver "intel"
Identifier "Device[0]"
Option "monitor-VGA" "Monitor[0]"
Screen 0
VendorName "Intel"
Option "UseEvents" "true"
Option "XvPreferOverlay" "true"
Option "DRI" "true"
Option "UseFBDev" "true"
Option "PageFlip" "true"
Option "TripleBuffer" "true"
Option "XAANoOffscreenPixmaps" "true"
Option "FramebufferCompression" "false"
# Enable offload of Motion Compensation (XvMC)
Option "LinearAlloc" "16384"
Option "XvMCSurfaces" "7"
Option "XvMC" "true"
Option "AccelMethod" "XAA" # The default is "EXA"
Option "CacheLines" "2048" # Allows the user to change the amount of graphics
# memory used for 2D acceleration and video when
# XAA acceleration is enabled.
# Decreasing leaves more for 3D textures. Increasing
# can improve 2D performance at the expense of 3D.
# can improve 2D performance at the expense of 3D.
# xxxx=8192/16384/32768 etc.
# Note AccelMethod XAA does not appear to work with Xvmc enabled. Testing required.
EndSection

You'll notice some lines in there for XVMC. Unfortunately this driver doesn't support 720p or 1080i/p frame sizes with XVMC, so for my purposes it's a bit pointless. I don't use XVMC under MythTV, but I have it in there anyway just for reference.

Finally, if you do compile the Intel video driver from source for MythTV, you may or may not notice that the driver chooses textured video as its default choice for rendering. I didn't have good performance with this, presumably because of weak 3D processing on this chip. I don't know for sure, but I have (and had) better results with overlay video. Another key setting for MythTV is to enable "extra audio buffering".

There's a long diff patch for the Intel video driver source, so it's attached here thanks to this MythTV-Users thread.

intel-prefer-hardware-overlay.diff