SYNTH_STATS structure (dmusprop.h)

Article
02/22/2024

The SYNTH_STATS structure specifies synthesizer performance statistics such as the number of voices playing, CPU usage, number of notes lost, amount of free memory, and peak volume level.

Syntax

typedef struct _SYNTH_STATS {
  DWORD ValidStats;
  DWORD Voices;
  DWORD TotalCPU;
  DWORD CPUPerVoice;
  DWORD LostNotes;
  DWORD FreeMemory;
  LONG  PeakVolume;
} SYNTH_STATS, *PSYNTH_STATS;

Members

ValidStats

Specifies which members of the SYNTH_STATS structure contain valid data. This member is a bitfield whose value is either zero or a bitwise OR of one or more of the following flag bits:

SYNTH_STATS_VOICES

The Voices field contains valid data.

SYNTH_STATS_TOTAL_CPU

The TotalCPU field contains valid data.

SYNTH_STATS_CPU_PER_VOICE

The CPUPerVoice field contains valid data.

SYNTH_STATS_LOST_NOTES

The LostNotes field contains valid data.

SYNTH_STATS_PEAK_VOLUME

The PeakVolume field contains valid data.

SYNTH_STATS_FREE_MEMORY

The FreeMemory field contains valid data.

Voices

Specifies the average number of voices playing.

TotalCPU

Specifies the total CPU usage (all voices), which is expressed as a percentage (a fraction multiplied by 100).

CPUPerVoice

Specifies the CPU usage per voice, which is expressed as a percentage (a fraction multiplied by 100).

LostNotes

Specifies the number of notes lost. Notes can be dropped if the number of simultaneous voices exceeds the maximum specified by the KSPROPERTY_SYNTH_PORTPARAMETERS property. For additional information, see Voice Allocation.

FreeMemory

Specifies the amount of free memory in bytes. This is the storage that remains available for downloading additional DLS data resources.

PeakVolume

Specifies the peak volume level expressed as decibels multiplied by 100.

Remarks

The KSPROPERTY_SYNTH_RUNNINGSTATS property uses the SYNTH_STATS structure to query a DirectMusic miniport driver for statistics about a synthesizer.

The SYNTH_STATS structure is similar to the DMUS_SYNTHSTATS structure, which is described in the Microsoft Windows SDK documentation.

Requirements

Requirement	Value
Header	dmusprop.h (include Dmusprop.h)