Just picked up an old Dolby Digital Receiver and noticed that most streaming apps are falling back to PCM Stereo. Netflix, Disney+, AppleTV+, Prime & Now TV all have this problem. Youtube works fine for what surround content there is.
I can get it to work by manually selecting Dolby Digital Plus or Atmos in the system settings (which should be backward compatible with DD anyway), but then after playing a DD+ stream, if I play a PCM stereo stream (Spotify, etc) plays at half speed and low pitch. This low pitch issue doesn't fix itself until I reboot the chromecast.
Thanks for posting. Let's sort this out!
Quick question: is your Chromecast with Google TV (4K) plugged into the Receiver? If yes, could you try to plug it in directly to your TV? Also, try to plug it into a different HDMI port and check if the same issue will persist.
It's plugged into the TV and using the toslink output to pass through to the receiver. The receiver is quite old and doesn't support ARC. When I connect the Chromecast to the receiver I get the same result with the CC set to autodetect. Only get PCM 48 stereo from all streaming apps except YouTube which outputs AC3 on selected clips. If I connect to the receiver and force DD+ I get no sound at all from any apps and it registers all content as PCM 192 on the display. According to Reddit this all worked prior to the Android 12 update.
TV : LG 50LA660V-ZA
Receiver: Sony HT-SF1300
Thanks for getting back to us. The Chromecast outputs surround sound if a particular app supports it, and if the Audio/Video Receiver (AVR) or TV it's plugged into tells the Chromecast over Extended Display Identification Data (EDID) that it supports 5.1, AC3, and AC3/EAC3 surround sound. If the TV or AVR do not support one of these settings, Chromecast will not output surround sound.
You can check those settings above if it's present on your TV or receiver.