Sony HAP-S1 is a High-Resolution Audio HDD player.
There is also a variant called HAP-Z1ES.
The main page is accessible via http://IPADDR:60100/HAP.html
and redirects to the version 2.0 of the application:
http://IPADDR:60100/HAP_app.html
There are also other two versions (broken) accessible by clicking on the text "Sony HDD Audio Player HAP-S1 Web Browser App":
http://192.168.1.69:60100/HAP_ver.1.2.1.html
http://192.168.1.69:60100/HAP_v1.0.html
curl -i -d '{"method":"getPowerStatus","id":1,"params":[],"version":"1.1"}' http://IPADDR:60200/sony/system
curl -i -d '{"method":"setPowerStatus","id":1,"params":[{"status":"active"}],"version":"1.1"}' http://IPADDR:60200/sony/system
curl -i -d '{"method":"setPowerStatus","id":55,"params":[{"status":"off"}],"version":"1.1"}' http://IPADDR:60200/sony/system
curl -i -d '{"method":"pausePlayingContent","id":"1","params":[],"version":"1.0"}' http://IPADDR:60200/sony/avContent
curl -i -d '{"method":"setPlayNextContent","id":"1","params":[],"version":"1.0"}' http://IPADDR:60200/sony/avContent
curl -i -d '{"method":"setPlayPreviousContent","id":"1","params":[],"version":"1.0"}' http://IPADDR:60200/sony/avContent
curl -i -d '{"method":"getVolumeInformation","id":"1","params":[],"version":"1.1"}' http://IPADDR:60200/sony/audio
curl -i -d '{"method":"setAudioVolume","id":"1","params":[{"volume":"25"}],"version":"1.0"}' http://IPADDR:60200/sony/audio