Ever since I upgraded to an HD capture card in my MythTV backend, I’ve noticed a wide variation in the playback speeds of the recordings it makes. Some play back at normal speed while others play back far too slowly or quickly. It’s frustrating.
I was going to blame MythTV for this craziness until I remembered the dvb-utils application azap. This little app tunes the HD card and dumps the output to a pipe, thus it provides a way of testing the card (and driver) outside of Myth. I’ve never used it before but it seems to be the perfect test tool. It turns out the streams produced by the driver and card exhibit the same synchronization issues I’ve seen in Myth itself. That means Myth isn’t to blame.
But what is? My card or its driver? I suppose the next step is to somehow get Windows running on my server long enough to test the card using the Windows driver. If that works, I know Linux or the Linux driver is to blame.
The investigation continues…