The ongoing MythTV saga continues
I have good news, bad news, and worse news. The good news is that I managed to get MythTV working well enough that it now plays standard definition channels better than the cable box alone, even though it's getting its signal from the cable output of the cable box. I get this benefit because MythTV allows me to tweak various parameters that you can't change on the cable box.
The bad news is that high definition channels still look worse through MythTV than they do if I watch then directly from the cable box. I don't expect to solve this problem. The cable box may be able to handle HDTV itself, but it outputs a digital signal in 480p, which is basically standard definition. The fact that I have two HDTV-capable tuner cards does me little good.
Here's the worse news. I had to learn way too much to get this far.
I now know the difference between ATSC and NTSC, what vertical blanking is, how to use things like overscan percentages to adjust a picture, and much more. I still haven't tried to set up a remote and IR blaster, so there's a lot of research left to be done. Aside from a little more tweaking, this will be my final step -- to add a remote control that sends a signal to an IR blaster in order to change channels on the cable box.
I admit that I find everything I have learned interesting, and I will enjoy writing it up as a Linux Journal article when I'm done taking this project to a point where I'm satisfied with the results. But I don't think I should have had to become so familiar with everything from driver firmware to the way television signals are formatted in order to get satisfactory results. It was never my goal to learn any of this.
It's unrealistic to make a one-for-one comparison to buying a car. This is, after all, a PC, and it requires additional hardware like a tuner card just to get started. Even a Windows installation of similar software would require you to install a driver, reboot, and then step through a wizard setup program to get everything working. Of course, there is Windows Media Center Edition. I've heard that it is relatively trivial to install a tuner card and get Windows MCE to behave as a PVR, but I can't confirm or deny it from personal experience.
Regardless, I am tempted to compare it to buying and driving a car if only because I have absolutely no interest in learning how a piston engine works. I'd rather walk than learn about piston engine internals. It is pure coincidence that I found the technology interesting in the case of MythTV. There's no reason why anyone who isn't interested should have to know these things just to turn a Linux box into a decent PVR.
No way out
One cannot solve this problem by writing a good How-To, either. You need to know too many details about your own equipment in order to get optimal results. The MythTV software doesn't make any attempt to detect hardware, television signals, configuration details. It doesn't walk you through the process of discovering these details and it doesn't give you any advice on what to do with the information you glean on your own. It even puts some configuration options in unusually awkward places.
For example, you can't adjust the contrast or brightness from the MythTV front end software. You have to run the MythTV setup program to do that, and you have to do it channel-by-channel. Not only is this inconvenient, you can't view how your settings will affect the quality of the picture until you exit the setup program and start the front end again. Maybe you can run the two programs simultaneously, but it was more trouble than it was worth to find out. I only want MythTV to receive channel 3. That's the output of my cable box. But I pity the poor fool who needs to adjust things like contrast, brightness, color and hue for multiple channels.
MythTV is still excellent
Some of MythTV is simply brilliant. I love the fact that MythTV is a client/server application. You can connect a back-end server to the cable box and watch TV with the front-end software on any other computer on your network. There's a lot more to like, too, such as the variety of add-ons that make MythTV much more than a PVR. I'm not ready to talk about these plug-ins because I haven't tried them yet. But there's a music player, phone plug-in, browser, picture gallery, speech synthesis (via festival), and more.
I guess I'm simply disappointed that MythTV is like so much other free software. It is built under the assumption that people who use it know (and care) about the technical details that the authors know (and care) about. In short, it's by geeks, for geeks. I confess, I'm a geek, and many of you are geeks, too, so I hope you enjoy the How-To article when I get to it. But I still have compassion for the non-geek population, and I wish more developers had the same.
To be continued...