Channels App disrupts MythTV recordings

#1

I have an HDHomeRun PRIME (CableCard with three tuners).

I have found that using the Channels App for watching cable on a single TV will disrupt a MythTV recording. The MythTV works flawlessly if the Channels App is not used.

I tried evaluating Channels DVR as a replacement for MythTV (I was willing to pay the subscription fee) and found it lacking in specifying and managing record schedules.

Since I have three tuners, there should be no reason to why MythTV and Channels should not be able to coexist when they are each streaming a single program.

I have switched from using the Channels App to using the MythTV plugin with Kodi. Kodi runs native on Android based players and TVs. It also work extremely well on the Raspberry Pi 3 B+ using the LibreELEC distribution.

#2

It's been a while since I used MythTV, so I may be mistaken.

It is sounding like MythTV is not properly locking the tuner when it starts streaming. The way Channels works (I believe) is that it requests a tuner from the device, and if the device has a free/unlocked tuner it will give it to Channels and then lock it until Channels is done with it. (Similarly, this is also how Tvheadend handles HDHR tuners: it will lock the tuner when it requests a stream so other programs do not interrupt.)

The problem with using MythTV (and Tvheadend) in conjunction with other apps is that they expect to have full control over the entire device. The way they are engineered, when the HDHR device is added and made available to MythTV, while MythTV is running it thinks it is the only program accessing the tuners.

Channels (and SiliconDust's software) use a different manner of interfacing with the tuners than MythTV. The way they work is that they query the HDHR device to check if it has a tuner available for it, and only if it does will a stream start.

MythTV (and Tvheadend) were not meant to work in cooperation with other software. If you want to more fully evaluate Channels, you really ought to disable MythTV.

#3

Does the Tuner Status page on my.hdhomerun.com show "Resource Lock" set while mythtv is using the tuner?

There was a long standing issue where mythtv wouldn't use the hdhomerun locking api which all modern hdhomerun apps including Channels use: https://code.mythtv.org/trac/ticket/10043

#4

Looks like MythTV did fix this problem but in a more recent version than the one I am running. I may try to upgrade to the latest version to see if that resolves the problem.

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#5

I find that interesting, as Tvheadend still uses the old UDP-based libhdhomerun for HDHR tuners, and it would properly lock tuners without fail.

(A kludged version of tuning by virtual channel numbers was added last year to Tvheadend, but only for the Prime. Perhaps I may spend some time this summer to complete virtual channel tuning and add it as an option in addition to tuning by frequency for HDHR tuners.)

Furthermore, I find this bug in MythTV interesting, as some of the primary SD devs were using Primes with MythTV for years as their DVR of choice ...

#6

I upgraded to MythTV version 30 and it shows the tuners as locked. I will try the app and see if I have further problems.

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