Channels DVR on Ubuntu, HDHomeRun tuner. For 80% of recordings this works just fine. We've had a few recordings that have broken video/audio on playback, and sometimes simply freeze.
The active HDTV antenna plugged into the HDHR seems adequate--typical signal quality is 80-90% for local stations. The DVR hardware is an older Celeron with 2TB disk. All are directly connected via a local gigabit Ethernet network.
Where else can I look for problems? The hardware seems okay, as does the signal quality. Thanks