I just installed a new HDHomeRun ATSC 3.0 tuner. I've recorded some test video, and it appears audio is playing back at the wrong speed. I'm using a new Chromecast with Google TV. Video looks fine, but audio is playing back much too fast. Using the HDHomeRun on my 2020 LG TV, audio and video both play fine on 3.0 channels.
Please submit diagnostics from the app after playback
Do the Channels clients support AC-4 audio?
I'm guessing it probably depends on the client. It appears the new Chromecast supports AC-4, but it's playing the audio at the wrong speed. I'm using a soundbar connected via ARC.
Out of curiosity I just tried my Fire TV 4K, and the result was the same. Video looks mostly okay, but audio is playing back way too fast.
Can't remember where I saw it (probably the SD forum) but someone mentioned they got it to play in the latest VLC client. Not sure on what client/OS.
EDIT: SD Forum post
Since Channels uses a custom client based upon mpv, the codecs it supports are universal across its apps and platforms. Also, it means that Channels' is not dependent upon the underlying OS. (Unfortunately, it also means that just because your client's OS supports the codec, Channels may not.)
Video sample sent. I was able to play the video with VLC, but on my Windows 10 PC I get no audio as expected.