dictionary MediaTrackConstraintSet {

    ConstrainULong width;

    ConstrainULong height;

    ConstrainDouble aspectRatio;

    ConstrainDouble frameRate;

    ConstrainDOMString facingMode;

    ConstrainDOMString resizeMode;

    ConstrainULong sampleRate;

    ConstrainULong sampleSize;

    ConstrainBoolean echoCancellation;

    ConstrainBoolean autoGainControl;

    ConstrainBoolean noiseSuppression;

    ConstrainDouble latency;

    ConstrainULong channelCount;

    ConstrainDOMString deviceId;

    ConstrainDOMString groupId;

};