Method for filtering noise of lens operation and video recording system

A video recording system comprising:

• a video recorder comprising lens performing a video recording and a microphone performing an audio recording to generate an audio recording signal;
• and
• a controller comprising:
• a communication circuit communicably connected to the video recorder;
• a storage circuit storing an inverted noise signal and a plurality of instructions;
• and
• a processor electrically connected to the communication circuit and the storage circuit, wherein the processor is configured to perform one of the plurality of instructions or control the communication circuit to send one of the plurality of instructions, and the plurality of instructions comprises:
• a recording instruction being sent to the video recorder through the communication circuit to control the video recorder to perform a video recording and an audio recording;
• a lens operation instruction being sent to the video recorder through the communication circuit to control the lens of the video recorder to perform an operation;
• and
• a synthesizing instruction performing by the processor to read the inverted noise signal and synthesizing the audio recording signal and the inverted noise signal to output a synthesized audio signal;
• wherein the video recorder further comprises:
• a trigger circuit detecting a triggering operation;
• a communication circuit sending the audio recording signal and a notification signal and receiving a permission signal;
• and
• a control circuit electrically connected to the trigger circuit and the communication circuit, wherein:
• the control circuit controls the communication circuit to send the notification signal to the controller when the trigger circuit detects the triggering operation;
• and
• the control circuit controls the video recorder to perform the operation according to the lens operation instruction when the communication circuit receives the permission signal.