November odds and ends - mythtv, debian bullseye, eye exam

Note: started writing this on Tues and just now posting on Thurs. D’oh!

relo to northeast texas

A couple things left to do before heading toward NE Texas.

eye exam

I have a VA “community care” appointment on Thursday to have an eye exam. Community Care is VA outsourcing to private services when they are swamped or not locally available. The care is fine but the scheduling and hoopjumping makes it just barely worth it.

I don’t know if I can order the glasses from the outsourced provider (VA will buy one pair per year). If not I’ll probably order them from Zenni Optical, an inexpensive mailorder outfit I’ve had great results from before.

van stuff

I want to get a couple “dumb” keys made to let me unlock the door. I also need to find a body shop or fab shop to do some light welding on a part of the cargo bed I damaged.

grand tour cancelled

I’ve been reconsidering the wisdom of making The Great Loop this year.

It would make more sense to do it when I get an income stream at 62. If I did it now the added expense (and loss of compound interest over the next six years) would endanger my skin-of-my-teeth early retirement.

I am in good health and feel confident that unless I fall off a mountain or get hit by a bus I should make it to 62 and take the bucket list trip.

MythTV box clobbered

raspian stable

I have three Raspberry Pi (Pi1, Pi2, and Pi3). I’ve been using one for the MythTV DVR but hadn’t been paying it much attention otherwise. I noticed it was set to Raspian Buster (now oldstable) rather than Stable. I set it to stable and started the update.

It seemed to be going well so I got the other ones out of the pencilbox where they are stored and similarly started their updates. During the process I rediscovered the mythbox was a Pi2 rather than the more powerful Pi3. Why had I done that?

I think what was going on was the Pi3 had built-in wifi so I wanted to use that one for a multi-network configuration (two wifi radios on the same box). That left the Pi2 for MythTV.

About the time I figured out out I realized the update to Stable had murdered my already-wobbly MythTV install. D’oh! The parts aren’t playing together yet, but I will eventually get it set back up and will restore from the lastest MythTV database dump. I’ll probably do the restore on the Pi3 to get the extra performance (such as it is).

[see update below]


I’ve been carrying around a $7 thrift store Mediasonic Homeworx HW130STB OTA receiver with rudimentary DVR functions. Since the mythbox was wrecked I set it back up.

Before I set up the Mythbox I actually had a similar doodad. I gave it to a friend in El Paso when I got myth running.

what works

  • the tuner is exceptional, much better than the HDHR I use with myth.
  • playback is flawless


  • only one tuner instead of HDHRs two. And each of those two can save multiplexed streams (ie, dump from 14_1 and 14_2 at the same timsince they are sent on the same signal) I knew this going in.
  • MythTV’s UI and functionality is excellent and a cheap box cannot hope to compare


Everything else is janky, needlessly annoying, or stupid. I get that there is minimal hardware in the little box but some improvements would be “freebies”.

  • EPG data is only available on the present channel, and disappears when you switch off that channel. It has to get new EPG info every time the channel is changed.
  • the remote (and key mappings) is aggressively terrible
  • recording scheduling has zero conflict management. Freebie: show in the EPG when a timeslot is taken by a scheduled recording.
  • recordings are saved with channel name and time rather than the show name and title the device already knows.
  • you can’t watch a recording while another one records. This appears to be a UI issue rather than a performance one
  • if a recording starts while you’re watching a different recording it punts you out of the viewing and doesn’t save your place. The UI won’t let you back out to save your own place once the UPCOMING RECORDING IN TEN SECONDS window pops up. You are stuck.

what we need

The box as it stands is ~$30. I think a version with the same hardware but better firmware would be a bargain at $50. A version with better hardware and a UI like MythTV would be worth $100. There are OTA DVRs out there but they are variously hamstrung or require a monthly fee.

rebuilding mythbox

I reimaged the Pi3 with Buster and remembered the real reason I didn’t use it before; it won’t talk to the monitor. Different power cables, different HDMI cables, countless different configurations…..

Many hours later: no go. I will see if I can make the Pi3 a headless backend and the Pi2 the graphical frontend. Both the Pi 1 & 2 found the monitor with zero issues.

Two fresh buster installs, two update cycles. Good thing I am near public wifi.

much, much later

The Pi3 is the backend and Pi2 the front end. I’d forgotten so much about doing a myth install when the various bits aren’t in the default repos.

fixing OTA recordings

Devices like the HDhomerun tuner I’m using don’t do any processing; they grab the OTA signal (an [MPEG transport stream] and make it available to the network. Devices with built-in DVR functions (like the homeworx box described above) save them somewhere.

In this case it’s HDhomerun -> MythTV -> .ts file on the hard drive.

Because I don’t exactly have an attic antenna and am often camped away from cities the transport stream can arrive in bad shape. It saves to disk fine but playback can be dodgy. Copying the .ts with ffmpeg fixes the file to the degree it’s possible. Missing data is missing but it drops bad data and corrects the container.

After that the file bytes-to-time mapping is rebuilt.

nice -19 ffmpeg -err_detect ignore_err -i $TARGET -c copy /video/fixed.ts
mv /video/fixed.ts $TARGET

nice -19 /usr/bin/mythcommflag --file $TARGET --rebuild

ugh - write failures

The Pi3 doesn’t like the SSD I’ve been using to to store the recordings. Fought it for a few hours and will set the MythTV stuff aside

back to the ugly Homeworx box

I was getting frustrated so I pulled the Pi2+Pi3 MythTV setup and fired up the cheap OTA box. Not great but it’s stable.

To serve multimedia I pulled out the lowliest Pi, a 1st-gen model, and installed minidlna on it. Serves multimedia, but just barely. The little single-core 700mHz cpu stays pegged at ~85% while streaming.


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