“Drop” messages appear on the host in the following situations:
- batteryLevel / when a remote camera’s reported battery level is below 20%
- freeDiskSpace / when a remote camera has less than 20mb.
- thermalState / when a remote camera reports either serious or critical values.
- avPressureLevel / when a remote camera reports either serious, critical or shutdown values.
thermalState descriptions from Apple:
- Nominal: No corrective action is needed.
- Fair: The system has reached a state where fans may become audible (on systems which have fans). Recommendation: Defer non-user-visible activity.
- Serious: Fans are running at maximum speed (on systems which have fans), system performance may be impacted. Recommendation: reduce the application’s usage of CPU, GPU and I/O, if possible. Switch to lower-quality visual effects, and reduce frame rates.
- Critical: System performance is significantly impacted and the system needs to call down. Recommendation: reduce applications usage of CPU, GPU and I/O to the minimum level needed to respond to users' actions. Consider stopping the use of cameras and other peripherals if your application is using them.
avPressureLevel descriptions from Apple:
- Nominal: System pressure level is normal (not pressured)
- Fair: System pressure is slightly elevated
- Serious: System pressure is highly elevated. Capture performance may be impacted. Framerate throttling is advised
- Critical: System pressure is critically elevated. Capture quality and performance are significantly impacted. Frame rate throttling is highly advised.
- Shutdown: System pressure is beyond critical. The capture must immediately stop.