I recently switched to RasPlex from the Roku client in order to take advantage of 24 fps output. My Panasonic TC-P50V10 plasma TV from 2009 has a 96 fps mode to eliminate film judder. It’s not capable of reverse 3:2 pulldown and will only enter 96 fps mode if it has a 24 fps input. I also have a Vizio SB3851-D0 soundbar and am experiencing some issues with the TV/soundbar setup which I am hoping can be solved through configuring RasPlex correctly. I am using the Raspberry Pi 3 Model B with RasPlex 1.7.1.
Pi connected to HDMI input of soundbar
soundbar HDMI-ARC output connected to HDMI input of Panasonic TC-P50V10 TV
My TV is not capable of ARC and I disabled CEC on the Pi.
My problem: if I turn off the TV, then turn it back on, it does not receive a picture from the Pi through the soundbar. Audio on the soundbar still works correctly.
Some things that fix it:
Restarting the Pi
Unplug the HDMI cable between Pi and soundbar, then plug it back in (counterintuitive since audio on the soundbar works correctly, but video to the TV does not work)
Some things that don’t fix it (not an exhaustive list):
Unplug the HDMI cable between soundbar and TV (counterintuitive again)
Turn off the soundbar and turn it back on
Detect inputs on the soundbar
Change inputs on the soundbar
Change TV inputs back and forth
I tried entering these lines in config.txt (no idea if CEC is the issue) and it did not help:
hdmi_ignore_cec_init=1
hdmi_ignore_cec=1
This issue does not occur if the Pi is connected directly to the TV. With this setup, if I turn off the TV and turn it back on, it still receives a picture from the Pi. This isn’t a viable solution to circumventing the soundbar since my TV can’t pass through 5.1 audio to optical audio out. It appears to be some kind of issue with how the Pi is working with the soundbar, or how the soundbar is passing through video over HDMI.
Any recommended troubleshooting steps? I’d prefer to solve it without buying anything, but my next step might be to purchase an HDMI matrix to see if I can remove the soundbar from the HDMI video chain, so to speak. However, I’m not sure if this will work because the TV is only capable of 2.0 PCM channel sound and I think a typical matrix will only negotiate the lowest audio setting for both connected output devices.
I would surmise that this is a feature of HDCP. When you turn off the TV the soundbar HDMI notices this and turns off the output in case a non HDCP compliant display is connected. When the TV is turned on the HDCP handshake fails and there is no video.
Reading the manuals of both of your devices I would recommend using the optical audio ports. Your TV has a digital audio out port and your soundbar has a digital optical audio in port. Buy a TOSLink cable and connect them up. Connect the HDMI from the RPi directly to the TV. Should work fine. Check Page 55 of the TC-P50V10 manual.
@Valdhor said:
I would surmise that this is a feature of HDCP. When you turn off the TV the soundbar HDMI notices this and turns off the output in case a non HDCP compliant display is connected. When the TV is turned on the HDCP handshake fails and there is no video.
Reading the manuals of both of your devices I would recommend using the optical audio ports. Your TV has a digital audio out port and your soundbar has a digital optical audio in port. Buy a TOSLink cable and connect them up. Connect the HDMI from the RPi directly to the TV. Should work fine. Check Page 55 of the TC-P50V10 manual.
I also suspect this might be HDCP/handshake related. I’m about to try out an HDMI matrix to see if it can solve the problem.
Re: the optical audio port. Like I mentioned in the OP, “This isn’t a viable solution to circumventing the soundbar since my TV can’t pass through 5.1 audio to optical audio out.” I’ve tried just about every setting in the RasPlex Audio Output options, and the only way I can get the soundbar to receive an audio signal from the TV while a movie is playing is if RasPlex transcodes the audio to 2.0 first. Through SSH, # tvservice -a returns:
PCM supported: Max channels: 2, Max samplerate: 48kHz, Max samplesize 16 bits.
I think any references to sending 5.1 over optical audio out are basically for OTA broadcasts on the antenna input. The owner’s manual also says this: “Depending on your DVD player and DVD-Audio software the copyright protection function may operate and disable optical output.” I think this is a pretty common problem, especially on older TVs. A little more background here: https://www.cnet.com/news/20-tvs-tested-which-sets-can-pass-surround-sound-to-a-sound-bar/
Depending on what your content audio is using, you could use an HDMI audio splitter and run the HDMI to your TV and the Optical to your soundbar. You’d be limited on PCM sound, but you’d be able to play DTS and AC3, etc on surround sound. The SPDIF connection only supports 2.0 uncompressed PCM channels though.
So any content that your sound bar doesn’t support would get mixed down to stereo.
The HDMI matrix that I purchased worked perfectly. When I turn on the TV, it has a blank screen for a split second then receives the video from the Pi, so my guess is that it was some kind of handshake issue with HDCP. The soundbar receives 5.1 audio successfully as well.
