MythTV

My MythTV box has an Albatron KM18GPro motherboard in it. Last week, the Ethernet port on it went dead. I can plug in a known good cable, and don't even get LED activity on the port. Plug the same cable into any number of other machines, and it works fine. (This is repeatable across different cables and switches, too.)

So I submitted an online RMA request to Albatron. Despite their claim of "instant confirmation" when an e-mail address is supplied, after submitting the form, it says to call them if there's no response after 48 hours. I also submitted the proof of purchase as they requested.

Since there wasn't, I called them and got a voice mail box. Left a voice mail. It was never returned. I also e-mailed their RMA team. No response. I'm sure this has nothing to do with the fact that my warranty expires in a few weeks.

It's now been days since I first contacted them. This is absolutely the worst hardware support I've ever received from any vendor -- taking days to even *respond* to a problem. I recently had a problem crop up with my Sipura SPA-841 phone, and got a replacement on its way to me within 12 hours. That's right, a *phone* got better service than this motherboard.

I'll never buy from Albatron again.

Their site says "Capturing the spirit of the albatross." I think they got it wrong. It should be "capturing the spirit of the weasel."

Finally, HDTV is completely working in my MythTV setup.

The pcHDTV 3000 card is working nicely with the DVB drivers.

My problem was playback performance. After switching to nVidia cards, this is fixed.

I got a nVidia Geforce 6800 card for my main workstation. Overkill for MythTV, yes, but it is a stellar performer with games. Absolutely great. I can run my games at 1600x1200 to take advantage of the native resolution of my flat panel, and they all work great -- no framerate problems at all.

Very nice.

Some time back, I bought a pcHDTV HD-3000 card to use with MythTV. For various reasons, I never got around to getting it set up. Until now.

First, a quick background. HDTV is a means to transmit television signals digitally. In the USA, a standard called ATSC is used for over-the-air transmissions. ATSC transmissions can come in several different resolutions, ranging from no better than a basic analog signal to 1080i (1920x1080, interlaced).

To get HDTV to work with MythTV, there are several components that must be working first: HDTV playback in the frontend, HDTV kernel driver support, and HDTV tuner setup in the MythTV backend. I'll talk about each of these in turn.

Click here to read more...

HDTV Playback

I was initially surprised at how much of an issue this is, when when you pause to think about it, it makes sense. HDTV pictures can be at up to 1920x1080 (1080i) or 1280x720 (720p) or 960x540 (540p). DVD pictures are typically 720x480. That means that a HDTV frame can have up to 6 times the number of pixels as a DVD frame. Bitrates for HDTV broadcasts are far higher than for DVD broadcasts as well.

This all combines to make a situation that can be extremely challenging even for systems with powerful CPUs and video cards.

In my own case, the frontend I was trying to configure is an Athlon64 system with a Radeon 9600 video card. Yet it still couldn't keep up with even a 720p HDTV signal. I tried both the standard XFree86 radeon drivers, as well as the ATI proprietary fglrx ones, and none worked.

However, X.org CVS (NOT the latest release, I tried it!) has an extension to the radeon driver that permits DMA transfers for Xv. I grabbed this release, and with Steve's intstructions and the wiki instructions, got it installed. (Note: I would advise against the lndir approach, and also make sure you put the #defines at the *TOP* of the file.) My custom lines were:


#define ProjectRoot /usr/local/X11R6.8
#define NothingOutsideProjectRoot YES
#define HasFreetype2 YES
#define HasFontconfig YES
#define DefaultGcc2i386Opt -O2 -march=athlon-xp -mmmx -mfpmath=sse -msse -msse2 -m3dnow


Restart kdm and test out a few things and... SUCCESS! HDTV playback works.

Now, on to:

HDTV Kernel Driver Support

For a pcHDTV card, there are two different kernel drivers you can use. One set uses the Video4Linux system for everything. The other uses the Linux Digital Video Broadcasting (DVB) infrastructure. This latter one is generally considered to be better and the way of the future, but it's not very well documented.

The support for the pcHDTV card is in the mainline kernel as of 2.6.12-rc2. I downloaded and built 2.6.12-rc4.

There are a few surprises. First, in the video4linux config area (NOT the DVB area!), you must enable CONFIG_VIDEO_CX88 and CONFIG_VIDEO_CX88_DVB. I also enabled CONFIG_VIDEO_BT848 because some online resources said to, but I believe that is for the HD-2000, not the HD-3000.

Then, in the DVB area, you must enable CONFIG_DVB and CONFIG_DVB_CORE. HD-2000 owners, I think you want CONFIG_DVB_BT8XX. For the HD-3000, I set CONFIG_DVB_OR51132. HD-2000 owners will want CONFIG_DVB_OR51211. If you're not using IVTV, you'll also want to enable CONFIG_VIDEO_{TUNER,TVEEPROM}.

Also, you'll want to follow the firmware download instructions. On a Debian system, you'll want to put this into /usr/lib/hotplug/firmware.

Boot into your kernel. Now, you're ready for:

HDTV Tuner Setup in MythTV Backend

This step configures MythTV to record from the HDTV tuner. I am using MythTV 0.18.

But before you begin, you'll need to recompile MythTV. I'm using Matt's debs, so it's a simple matter of rebuilding from source.

The problem is that the files in /usr/include/linux on a default Debian install don't include the latest DVB api. Workaround: move /usr/include/linux out of the way, symlink it to /include/linux, rebuild mythtv, restore /usr/include/linux, and install new mythtv and libmyth debs.

Next, go to labs.zap2it.com and make sure you have the digital channels selected and analog ones deselected.

Now, you are ready to run mythtv-setup. Make sure you kill the backend before you do this. You'll want to add a new input source, DVB type, card 0. In input connections, connect your zap2it broadcast setup to this card. Then do a channel scan in the channel setup. Exit, run mythtv-filldatabase, then go back in. You'll see duplicates for each channel. Note the XML id in the newly-created ones, copy it to the ones you created with the auto scan, then delete the new ones with mythweb. Finally, run mythtv-filldatabase again. The DVB setup HOWTO helped me with this.

Now you're ready to enjoy HDTV!

If you're not careful, you may find MythTV interferes with your thought patterns...

I've received two e-mails from people asking for an update on the MythTV project. So here goes.

First, concerning the issue with the Biostar motherboard: the Biostar motherboard was bad. The TV out on it was physicially inoperative. It did not include the TV out in the box, so I had to buy that and the SPDIF out from Biostar. The SPDIF out was coax only, no optical, and the TV out was broken. I returned the motherboard and purchased an Albatron KM18g Pro 2.0 motherboard instead. The Albatron is nice. The TV out adapter is included and works. The SPDIF adapter is still extra, but instead of one port, has three ports: coax in, coax out, and optical out. My only complaint is that the GPU has a cooling fan that sounds like its about to die.

On the digital video (DVI output) side, I purchased an ATI Radeon 9200 card for $64.50. Together with the Gefen cable, I get crystal-clear output to my TV. While the picture is sharper than anything else, the colors are just not quite right somehow. After doing some checking, I am led to believe that this is because the TV does not auto-correct digital sources the way it does analog. I'm still looking into it. The ATI card is nice, and has a TV out too, so I could always fall back to that if need be. I am using the Free Software DRI drivers for the ATI card.

I've had a few problems with the MythTV unit overheating. We put it in a new entertainment center, and occasionally it will do a thermal shutdown to prevent damage. I ordered a nice SilenX power supply to try to move more air through there, and at a quieter volume. I also ordered one of their fans to mount on the entertainment center itself for ventilation.

The high-definition TV has been nice overall, but has exhibited discoloration in one corner. A repairman should be out this week to check it out.

Now that we have a HDTV unit and MythTV, it occured to me that there had to be a better way to get video to the HDTV than the standard S-Video cable I'd been using. And sure enough, there is.

Our TV has a HDMI input, which is pin-compatible with a digital DVI output on standard PC video cards. Slick. So, with the aid of a Gefen DVI to HDMI cable and a Radeon 9600 card stolen from my main PC, I got a pure digital picture on the TV. Wow. It's nice. Beats S-Video cables handily.

Moreover, the TV supports EDID, the technology that lets PC monitors tell the PC what video modes they support. My TV reported 1920x540, 720x480, and 640x480 modes. Again, nice. And the ATI fglrx driver reports all the information you need to generate the appropriate ModeLine for it. Even slicker.

I'm going to buy a Radeon 9200 card for the MythTV unit so I can get the 9600 back for my desktop.

The only problem: the display is now so sharp that MPEG compression artifacts are more noticable and annoying than before. Guess I'll have to bump up my bitrates in MythTV. Sigh.

Here are some links I found useful:

• Modeline generation for HDTV (detailed)


• Google search for modeline info

I've been talking a lot about MythTV lately, and here's a tangential topic: we bought our first HDTV unit last weekend. It's a widescreen 30" CRT Philips 30PW8402 unit. We don't yet have hi-def video sources (save for DVD), but I've still gotta say: wow. The picture is so much better than our Sony TV (and not just because that Sony's picture tube was dying, either!). There's some stuff in 16:9 even in standard def, and that can be zoomed in upon. Very slick.

And DVDs are stunning on this thing. We're very happy with it all and are glad we opted for a HDTV instead of a standard def one.

One of my concerns was about traditional stuff -- would it all be "squashed" by the wide screen? Turns out no -- the remote has a picture size button, that alternates between 4:3, zoomed 14:9, zoomed 16:9, widescreen, and superwidescreen modes. The zoomed modes are used when the black letterboxing at the top and bottom of a standard screen are part of the signal (such as widescreen movies broadcast in standard definition). The widescreen modes are used with true widescreen signals, such as from a DVD player.

Our DVD player already had component video out, so a few cables, and a quick check of the setup menu to tell it we had a 16:9 unit, and wow -- stunning results. We're really enjoying it.

My next project is to get a DVI to HDMI cable so I can hook it up to the MythTV unit digitally. This will get us the best possible quality, and I can use a Linux-based DVD player to send a pure digital signal to the TV.

My MythTV system is now mostly complete. My Biostar motherboard had a defective TV out, so it was sent in and now the TV out is working. I'll post a more complete update in the next few days. In short, Biostar = bad, Albatron = good.

Also, had a fun adventure stringing some cat5 cable to the part of our house where our TV is. After sawing through the floor to get to the previously-inaccessible crawlspace, we found, among other things, a working wire stripper, pipes connected to nothing, and lots and lots of spider webs.

And my latest book project is just about complete. I'll have some news there too in a day or two.

Here are some hints that I have gleaned so far:

• Enabling anti-aliased fonts (font smoothing)


• Thread on Running multiple frontends/backends (and how they all work together)


• Explanation of auto-expire behavior


• MythTV bug tracker


• Kernel 2.6 drivers for ivtv


• Kernel 2.6 drivers for lirc (have worked for me.)


• Alternative 2.6 lirc drivers (untested.)


• Debian repository


• Building LIRC transmitter to control Dish Network receiver (or mirror). Includes exact RadioShack part numbers you'll need to build this for under $10.

DVD stuff:

• Script to convert to DVD


• Initial hints on codec settings appropriate for DVDs (and a program to burn a DVD from an MPEG-2 source)


• An even better howto

And some MythTV-related sites:

• MythTV home


• MythTV wiki


• Fedora Myth(TV)ology Howto (useful even if you don't use Fedora)


• KnoppMyth bootable MythTV implementation

Well, I've had my MythTV setup up and running for a few days now and thought I'd write an initial review.

The bottom line is: MythTV is awesome. It is so much nicer than anything I've seen before, including both ReplayTV and Tivo. Read on for the full first look.

Let's start with the good things about MythTV. First of all, here's the biggest benefit: MythTV has an incredible amount of power, but it doesn't make the interface confusing. The interface is very simple and easy to use for basics for anyone already accustomed to a PVR. My wife and I both were able to navigate just about immediately.

Recording Features

The greatest MythTV asset over competitors lies in the recording setup. MythTV gives you all the options for recording that others do, such as record the program once, record it daily or weekly, anytime on this channel, anytime on any channel, etc. It also offers you a choice of "recording profiles", which generally are analogous to recording quality settings on other devices.

But MythTV also has a notion of priorities. If there is a conflict -- two recordings scheduled for the same time, so only one can be recorded -- it uses the recording priority to decide which one to record. The higher priority wins. The default priority is zero, and you can assign positive or negative priorities to any given program. So, using this feature alone, you can already set it up very nicely. I found myself not setting up some shows to record on the ReplayTV because I sorta liked them, but never knew if they would overwrite others. With MythTV, I can add them with a very low priority, so they'll get recorded -- but only if nothing else is being recorded at the same time.

You can also assign priority modifiers based on various criteria. For instance, you could automatically add 10 points to any "one time only" recording, so your special events override most things. Priority modifiers can also be added based on channels.

It goes farther than that, though. MythTV keeps track of episodes of programs, and can automatically adjust its schedule to record a program earlier or later if the original preference would conflict with something else.

Another nice feature is that you can set an upper bound on the numer of recordings of any particular show. You can also define what MythTV does when that limit is reached. It could either just delete the oldest episode to make room for a newer one (useful for, say, news programs). Or, it can simply stop recording until you watch and delete an episode (more sensible for sitcoms).

MythTV also has a great conflict finder and resolution system. You can see a list of all the recordings scheduled in order starting from the present time, which ones will be recorded, and which ones won't. For any particular recording, you can also see *why* it won't record, and adjust it.

It also has some pretty powerful program finding features.

TV Features
MythTV does all you'd expect for live TV viewing: pausing, replays, program guide, etc. For watching recorded programs, it has an awesome commercial skip feature. Turn it on, and you can just sit back and watch a program -- no need to press any button on your remote at all. It just skips right past the commercials. I found it didn't detect all commercials, but it has some options to tweak that I haven't tried yet.

LAN features
We have our TV in our family room on the main floor of our house. The office, where all the other computer stuff is, is in the basement on the other end of the house. There's no satellite connection there, and reception with an indoor antenna down there is very poor.

MythTV has a nice client/server setup. You run the MythTV backend on any machine that has a video capture card. You run the frontend on any machine that has a display device. In many cases, this would be the same machine. But it can also be distributed. In my case, I put a frontend on my laptop. With that frontend, I can watch any recorded programs or live TV as if I were sitting at the "MythTV box" itself. It is a very useful and powerful capabilitiy.

You can also have video capture cards on multiple machines (or in a single machine), and MythTV will then be able to record multiple programs at once. It will integrate nicely into the schedule, and it will know the capabilities of each unit, and use it to record multiple things simultaneously if possible.

You cannot be watching live TV on multiple frontends at once, though (unless you have multiple capture cards that are not busy).

Non-Traditional Modules

MythTV has several optional modules that you don't normally find on a PVR. I haven't tried all of them yet.

The most obvious is the DVD module. You can use it to play DVDs with a DVD drive. It defaults to using mplayer, but it's easy to adjust to use the more powerful ogle player. There is also a DVD ripping feature built in that I haven't tried.

Next is the sound module. You can use it to play audio CDs or your mp3/ogg collection. It can also rip CDs and manage playlists. For audio CDs, it will automatically look up album/track names online if it can. If your TV is on, you can have it use various visualization plugins.

There's a similar module to manage a collection of video files, though I haven't tried it yet.

It also has some Internet-related modules. There's Weather, which grabs a forecast and radar picture and shows them in a format nice for a TV (large fonts, nice icons, etc.) Mythweb is a web browser designed to run on your TV. It works pretty well, considering the quality of a TV. There's an RSS reader that will show you news headlines (and story briefs), and send hooks in with mythweb to read the details if you want.

Recording Quality

This depends in large part on what capture card you use. I have the PVR-250, which generates absolutely excellent output. It's the highest quality I've ever seen from TV (I can easily notice that when watching it on a computer monitor), even when generating fairly small output files.

No matter what card you have, MythTV offers many different choices for real-time video and audio compression. You also have an option to do automatic post-processing. For instance, you can have MythTV automatically re-encode your video to MPEG4 format after recording, even if you don't have the CPU power to do that in real time (or your hardware encoder doesn't support it).

Setup

This is the most difficult part, of course. You need to be fairly familiar with Linux and PC hardware to set up MythTV. So you may need to hire a neighborhood geek to set it up for you, but once set up, you should be able to manage it OK.

I'll have more details on this in another post sometime.

Complaints

My main complaints with MythTV are:

1. If you attempt to watch live TV while it's recording something, it tells you to go delete the recording program so you can watch TV, but it doesn't say what that program is. (Though you can just look for the green one in the "watch recordings" screen)

2. There aren't quite as many shortcuts to skip between different menus as I'd like to see.

3. Some of the frontend options aren't well documented.