Give the MO 4Media app a shot. It works well with my CCA devices (although so far, as with most other apps casting to CCA, no gapless).
Thanks, just downloaded it. It seems to work fine as long as I'm playing onto the audio device of the MC server computer.
However, it doesn't see all my CCAs. The Google Home app (and Tidal) find all 15 (and the 16th, Chromecast Ultra in my home theater). Sometimes MO 4media finds 4 CCAs, sometimes 6 CCAs. Also, the CCA casting requires a subscription.
I also had difficulty getting MO 4media to play sound locally on my Galaxy Note 8. Sometimes, the play button would not start playback after I selected "this device" for playback.
It seemed to resolve itself after I switched to another album.
I was able to play to a CCA the following way :
1) select "this device" in MO 4media
2) use "Smartview" on my device, to redirect all audio playback to a CCA . This shows all of my CCAs, so I can select the right one.
Just for kicks, I selected a 6-channel SACD track. It managed to play, but clearly some channels were missing - it only played the first 2, and ignored the others - they didn't get mixed in to the stereo (CCA only supports 2 channels, as does Android device audio, AFAIK).
When I selected the 2-channel track from the same SACD (it's a hybrid disc), it played fine in stereo. Looks like the DSD to PCM transcoding happening on the MC server is massively expensive - taking 75% CPU on my overclocked i7-5820k . That definitely wouldn't work if I moved the MC server to my Raspberry Pi (or rather Odroid XU4, which has much better I/O specs).
Wonder if there is a way to fix this. Other than not try to play SACDs
I tried again with a regular CD stereo track. Server CPU went down to 4% - probably no transcoding there.
Audio didn't skip a beat, though I was just sitting down with the phone on my desk.
This looks more promising than Gizmo and JRemote, though. Thanks for pointing it out ! Wish it saw all my CCAs and could play directly onto them.