The HD-PVR and MythTV

For years now, we have run a MythTV DVR. It is a Linux-based software package that turns a computer into a digital video-recorder, complete with scheduling of programs.

We started with a single cable box with an active firewire connection to change the channel and a PVR-250 card we got cheap. That encoded the composite output from the box to MPEG2.

Eventually, we got the hang of firewire, discovered a bunch of tricks to get it to cooperate without crashing, and we’re working almost entirely off of cable with firewire, using a digital tuner to add redundancy on broadcast stations.

Then one day, the cable company shut down every firewire connection. The channel changing still works, but not streaming directly from the box. So we ordered the HD-PVR 1212.

The HD-PVR turns high definition component video and analog or digital audio into H264-encoded files. Ultra-compressed, and requiring a good CPU to decode. It exploits the so-called “analog loophole“, allowing one to record HD video off of an HD source.

And MythTV will support it in Version 0.22. Some have backported the device support to 0.21, the current stable version. So, we upgraded our installation(after a backup) to the 0.22 ‘bleeding’ version. You use development versions at your own risk. Unless you are contributing to the process with information, complaints about things not working will be ignored, mostly.

The HD-PVR seemed very buggy under Version 0.22, capturing at all resolutions, 480i, 720p, 1080i, with AC3 audio. And all of the files were filled with corruption, making it hard to play them back. So, the other night, despite the notation that the ability of the HD-PVR to handle multiple resolutions at a time had been stabilized, we reverted to 720p and AAC analog audio. So far, it has made everything rock solid. We’re doing tests of this over this weekend, after which we’ll try bringing back AC3 audio and/or 1080i, to see how high a quality we can get with complete stability.

The HD-PVR is a decent device that is developing better Linux-based support.  It is unfortunately the best option for recording HD video from other sources, as any digital options are shut down by the content providers.

More on our efforts in this area when all tests are complete.