Mythtv

[mlord]

Originally Posted by mlord

The to-do list is growing, though:

• Try and fix the horribly broken mythweb stuff. Oddly, this mostly worked fine on the "pre-beta" stuff from 0.21, but now streaming is totally non-functional in 0.23

Got it:

apt-get install libmath-round-perl

Then the streaming plugin works again.
Obvious, really.

[mlord]

Well, it's still mostly working, and by now it has enough tendrils into the SQL database that I couldn't wipe it away even if I wanted to.

So mythtv-0.23 is on Duke to stay.

It is noticeably buggier than 0.21 was, though. Lots of (vdpau) playback glitches on CBC-HD recordings -- was never an issue with 0.21-vdapu.

And the front-end has mysteriously crashed/exited twice now. I suppose there might be info in a log file somewhere, but I'll just ignore it and hope it goes away some day soon.

I haven't yet fixed all of the annoying b0rked arrow keys in the GUI, but the main one (Media->Recordings) has been patched away, making it bearable for now.

Last evening, mythtv got confused somehow and couldn't tune anything on the HVR-950Q, which is used only for digital in that system. Rebooting cured it, for now.

In my separate, test system, the analog side of the 950Q suddenly started working again for no obvious reason. But it too requires the odd reboot on occasion when the tuner stops working.

All in all, very reminiscent of mythtv-0.18, when I first installed it. A bit of a shame it's all gone backward after the steller 0.21 series, but that's progress.

Cheers

[mlord]

Originally Posted by mlord

the HVR-1600 card was recording very loud static for "audio" tonight.

Well, it hasn't failed again since that incident, but we haven't fixed anything yet either.

Andy Walls came up with some new rewrites of the driver code to try, but they still need some work -- he doesn't have regular access to OTA analog to test with (he lives in europe, I believe), which makes it somewhat difficult for him.

Meanwhile, I'm trying to apply some logic to the problem.

See.. Andy is working on the assumption that the current code must be doing something wrong, so he is producing changes to how the current code does things.

But.. my observation is that the current code works perfectly well 50-80% of the time, which means that it is doing things correctly. Just not consistently.

There's a difference.

The lack of consistency strongly suggests race condition to me. So I've been exploring that angle of things for the past week, trying various low-level tricks I've learned from 18 years of Linux kernel work.

This did turn up a pair of bugs in the driver today, and I've patched those out of existence. One of them could be the problem here, but I don't think so.

However.. back to the race condition theory. There are a number of levels at which races can occur.

• Between the host computer and one of the microcontrollers on the HVR-1600 board.
• Within the host software (driver) itself.
• Between the host CPU and the PCI interface of the HVR-1600.

It's that last one which is now ringing alarm bells for me here. See, the driver has code all through it to perform "retries" when writing registers on the card, because apparently a register write doesn't always work first try. Huh?

That information suggests a possible issue with PCI write ordering/combining. So I've patched my copy of the code here to prevent such issues, and we'll see how things go with just that one fix in there.

Cheers

[roger1818]

Originally Posted by mlord

The lack of consistency strongly suggests race condition to me. So I've been exploring that angle of things for the past week, trying various low-level tricks I've learned from 18 years of Linux kernel work.

I tend to agree with you that a race condition is likely the cause.

I have only seen the bug once, since I have been keeping my myth box on 24/7 (I know this is wasteful, but until I am confident that the problem has been resolved, I don't want to risk recording without audio), but from my limited experience it seems like it only appears on power-up. I have never seen it when doing a restart. It may just be a co-incidence but if it is true, it could help track down the problem.

I can't help but wonder if it is a firmware issue and Hauppauge uses a software fix in their Windows driver.

[ack0329]

If anyone can help me setup my 950Q with analog to work with mythtv, I would sure appreciate it, just google 950Q and mythtv and all the hits are mine. Perhaps someone on this site has a new insight (I am relatively new to mythtv, and all the basics are set up for the HVR-950Q drivers and "no power off" (it's working great in tvtime). What can I do for Mythtv to work???

[mlord]

Originally Posted by ack0329

If anyone can help me setup my 950Q with analog to work with mythtv, I would sure appreciate it

It works, but is not yet foolproof. The blog of the driver developer was updated recently, noting that MythTV still doesn't get locking correct between the digital and analog sides (despite recording groups, which are supposed to solve issues like this).

That said, it mostly works.

The digital side is easy to set up -- if your 950Q is your only tuner, then it will show up (digital) as the only DVB device. The only trick here, is to create a custom recorder group (instead of the default of "generic") for it.

Then tackle the analog side. If it is your only tuner device, then this will be /dev/video0, and probably /dev/dsp1 for the audio -- yes you need this field.

Then put it in the same recorder group as the digital side.

After doing mythfilldatabase and setting up the channels for everything, fire up mythfrontend. Go into the Setup -> ... -> Recording Profiles, and set the resolution for the analog to be 720x480 for everything (default, live-tv, etc..). Change the audio sampling rate to 48000.

Now restart everything (reboot?), and the analog will probably work.

Cheers

[mlord]

Something I should add, is that you'll need to create an "input source" for digital, and a second "input source" for analog. Yes, they can both point at exactly the same schedulesdirect.org channel lineup, but they do need to be separate otherwise.

Then use the "input connections" menu in mythtv-setup to point the digital side of the 950Q at the digital "source", and the analog side at the analog "source".

Cheers

[ack0329]

Cool thanks for the reply! 2 months and this is the best explicit response yet. I am trying to do everything you said in a fresh setup, to the letter (even though I don't have any digital cable channels). I am hoping at this point that it is a simple MythTV oversight as I am still new to all this tuner stuff.

Not working yet, only a black screen....

My first question ( of many - if you are patient enough) is ... Could you be more specific about the changing of the default group? Is that in the Backend/input_Connections/Select_A _Card/second page? And would you do anything different if you only had an NTSC analog cable signal.

Second Question is ...What would you be using for usernameassword/localhost or IPaddress/ for mythconverg for a backend on the same machine as the frontend BUT I plan (Optimistically perhaps) to get it to work with another laptop frontend for fun. Presently I changed it from mythtv:mythtv (to ack(my username):to user password because I changed my storage to my user account and that solved livetv problems with another card - PVRUSB2 that now works with LiveTV.

Thanks for the new optimism

Mark

[mlord]

Originally Posted by ack0329

Not working yet, only a black screen....

If you haven't discovered free, over-the-air HDTV yet, then yes.. you can just not configure the digital half of the tuner at all. Just delete it from the "tuner cards" list, and then you don't have to fuss with the "recording groups" at all.

But you MUST still fix the "Recording Profiles" to use 720x480. That is a 100% requirement.

Now.. forget LiveTV, and just tell MythTV to record something. See if the recording it creates is viewable or not.

On my system here, for a while I could record and watch a recording, but not watch "LiveTV" (even though the two are more or less identical in functionality). At some later point, LiveTV started working too.

[mlord]

I do seem to recall having a directory-permissions error somewhere in the default Mythbuntu installation, which I fixed and don't remember where.

But just for good measure, do this (once):

sudo chmod -R mythtv:mythtv /var/lib/mythtv

Cheers

[mlord]

Another thing to check, is to ensure these directories all exist:

/var/lib/mythtv/livetv
/var/lib/mythtv/recordings


Cheers

[roger1818]

Is there an easy way to change the title/episode name in MythTV 0.22? Apparently this feature was added in 0.21 (highlight the recording, press I, select "Recording Options", and select "Change Recording Title"), but I can't seem to find the "Change Recording Title" option in 0.22? Was it removed?

One of the programs I record for my older daughter doesn't seem to have the episode name in the guide data and since she likes to watch them again and again, I thought it would be nice to know which was which.

[stampeder]

That feature is still there, but isn't it under one of the other options?

[roger1818]

Originally Posted by stampeder

That feature is still there, but isn't it under one of the other options?

I looked, but I couldn't find it anywhere (checked all the sub menus of both the info (I) and menu (M) menus). Any other ideas where to look?

One other thing, I can't seem to assing function keys (F1 - F12) to MythTV functions. Is there a special trick to it? Most other keys seem to work.

[stampeder]

I'm not sure why anything would be missing from MythTV for you. An alternative is to use PHPmyadmin or MythWeb to change the program title name.