Improvement

docs/subsystems/HealthTelemetry.md

@@ -362,6 +362,9 @@ Expected observations:
 Expected observations:
 
 - current playout queue depth
+- system-memory playout frame counts by state: free, ready, and scheduled
+- system-memory playout underrun, repeat, and drop counters
+- system-memory frame age at schedule and completion time
 - input signal state
 - late frames
 - dropped frames

docs/subsystems/VideoBackend.md

@@ -235,10 +235,15 @@ Examples:
 Examples:
 
 - output queue depth
+- free system-memory playout frame count
+- ready system-memory playout frame count
+- scheduled system-memory playout frame count
 - scheduled frame index
 - completed frame index
 - late frame count
 - dropped frame count
+- underrun/repeat/drop counters for system-memory playout policy
+- frame age at schedule time and completion callback time
 - spare buffer count
 - current headroom target