For smoother video recording at high bitrates when the storage can become a bottleneck, the application has implemented temporary storage of frames in the main memory of the device. When the buffer is full the information is transferred to the MP4 container. Using the buffer allows you to trim files more accurately when recording with division into files.
Attention! Using the buffer creates a pause when you stop recording. All the time until the record button turns gray again, the buffer transfers the information to the MP4 container. If a memory card is used for recording, the pause time can increase several times.