Agree with you there..
Unfortunately most encoders only support 1080p60 or 4k30 and my input has a number of channels at 4k50.
The one encoder I did get that supported 4k50 has stopped working so was looking at trying a different approach, but may be too resource intensive as you say.
Check out this 10" mini rack. Thinking this would be perfect for folks running ah4c with multiple encoders, tuners, etc! Swap out a few of the ethernet ports for HDMI, etc.
At $50 it is no way near the value of the current $20 box, and more power is not needed for 1080P streaming. However, this box has built in Ethernet. When you calculate the cost of a USB Eth adapter for either the Onn 4K box, or a ChromeCast, this box has potential.
I ran into the same Spectrum issue you described. I was also having issues with the audio and it was only on the channels that had the "Watch Again" pop up. After much frustration I found two ways to work around it.
Set the remote command in the stop script you wrote to be "play". This would still be playing the stream even though you've exited until the stream timed out according to the preferences (4, 8, 12 hours). Then when you go to tune again, it would tune to the next channel and be correct. You would get a glimpse of what you were watching while tuning.
The second way that worked was to completely delete the Spectrum App from all of the ATV tuners and then reinstall the app. Set the remote command in the stop script you created to be "top_menu". This seems to be working fine. I did have it set to "home" after reinstalling but noticed the Spectrum app would sometimes crash with that HA remote command.
Thank you for this. I am still using your first way, but added some maintenance scripts so that the tuners don't just continously stream. I shut them down with a full restart of the app after a period of time.
I will do some testing with your second way. I thought I tried everyone, but never thought of that. I think it will be a cleaner solution overall. I do like the almost instantaneous tuning when they are left running. though it does cost some power and bandwidth.
I guess this path will always require some level of attention to keep it working. But given that it is based on the capability to tune with Siri, will likely be workable for the foreseeable future. It does make me appreciate the Channels guys and all the energy it takes to keep TVE going!
For anyone working with channel-number m3u tags, I just added support for editing this tag in the ah4c m3u editor!
For those interested, this will be incorporated into the ah4c Docker build later today or tomorrow.
FWIW, this page has a handy list of all the keycodes. All Android Key Events for usage with adb shell · GitHub
The format I've used for the scripts in the ah4c project are more similar to this list:
Note that neither list contains the KEYCODE_LIVE_TV keyevent I was looking for last August. I'm really not sure there's an exhaustive list anywhere. Plus, there seem to be several different styles to the way the keycodes are formatted. Either of the easily readable approaches seem good to me -- using keyevent numbers, not so much.
One of the things I noticed right away is that adb itself doesn't know anything about the keyevent stuff. It'll send whatever nonsense you tell it. I don't know if there is a way to directly tell if it worked or failed. ($? is 0 for both good and bad cases.)
OT: Who doesn't like a fun story? I've been using an ONN 2K stick for my experiments. I've had it for a couple of years but never plugged it in until the last few days. I bought it used because the ONN devices have a much better remote than the Chromecast devices (which seems odd to me, but true). I had to redeploy the ONN remote to navigate far enough to pair the simpler Chromecast remote with the ONN stick as an additional remote. Then I unpaired the original ONN remote. Now, after every ONN reboot, I am greeted with this screen:
adb shell input keyevent KEYCODE_BACK)
To celebrate my reaching the end of reading this thread, here is the most amusing thing to me in this whole subject area: The hostname on my ONN 2K stick was "Steve". Much cooler than the hostname on my Tivo Stream 4k, which is "SEI400TV"; boring!
You can definitely pass devices into a docker container, but there is a gotcha to watch out for. For the sorts of devices (on the host) that just get sequentially assigned names, they can sometimes change to a different number on a reboot just due to quirks of timing. So, if you try to map /dev/video2 into your docker container, it will work, but the same device might be /dev/video0 or /dev/video4 or whatever after a reboot. You can do some udev tricks to solve the naming problem. This article ([SOLVED] docker, udev, USB naming | WJCarpenter | Hackaday.io) is about USB ports, but something similar should work for video devices.
Hey mate I’m kinda new to the game did you end up getting a m3u for Foxtel cheers bro
Is this the main thread for the HDMI tuner. I know bnhf has been doing most of the legwork.
I'd suggest starting here:
Do any of these encoder boxes support 5.1 channel sound?
None that I've ever seen.
Nope, it's the biggest limitation. I guess it's because they don't want to license dolby.
But I have an ancient receiver and it does a decent job of muxing stereo PCM into 5.1.
The Magewell Ultra Encode does 5.1 https://www.bhphotovideo.com/c/product/1800741-REG/magewell_531500000_ultra_encode_hdmi_plus.html
I grabbed one just to experiment. Works great, and I was able to encode and play 5.1 Audio. (I think it supports up to 8 channels)
BUT
Even ignoring the high price, I had two issues using it in practice in my setup:
So it remains in a box until such time as Spectrum supports it, or I switch to a different service provider that support it. Until then, as a replacement for TVE that also only supports stereo audio, my 4-tuner setup is fast, reliable, and the video quality is superb. All with far more reasonably priced equipment.
@bnhf @GTFan @chasut Big Thanx! And a special callout to @chasut. 
Ya, I'm in the city, have Spectrum, and experience with its app, and others, parallels yours. I was thinking more regarding a FireTV Stick or Echo box / Google Chromecast dongle / Apple TV box. But I think you're saying, the apps installed on those devices are only 2-ch too. So ya, I stand corrected.
Almost bought a URayCoder 4 port box yesterday for $500. Rethinking that. A visit to the B&H or Adorama (much closer to me) store may be in my future. But the utility of it is reduced for all the reasons you note.
Thanx again.
EDIT: But ya know... I just watched the NY1 "In The Papers" segment on both my Samsung 4K combo Computer monitor / Smart TV's app, as well as on my 2K regular HD Sony TV being fed a really old cable box's HDMI output, both at the same time. Looking back and forth, unless the Newspaper story was zoomed in to so text was large, it's was a completely stomped on and an unreadable garbled mess via the streaming app, whereas even a full newspaper page with tiny text was completely readable from the cable box.
Long way of saying, I don't think I'll be looking to capture my Spectrum stream. I'll stick with, when I think I need it, capturing a stream from the Cable Box > Slingbox > Slinger Server > manual ffmpeg capture to disk with stream fix-up adding critical attributes the Slinger stream omits. It gives an amazing picture. I just hate its 96K audio that seems to be stepped on and degraded more than the movies and TV I tape having 96K audio from every other IPTV source.