Code rate control method and device for UVC compression coding video transmission and chip

The invention discloses a code rate control method and device for UVC compression coding video transmission and a chip, and the method comprises the steps: determining whether a quality coefficient index is corrected for the first time or not according to the size relation between a real-time coding rate and a real-time target code rate; updating the real-time target code rate according to the size relationship between the current USB channel transmission rate and the standard target code rate; the rate difference between the current USB channel transmission rate and the real-time coding rate is calculated, if the rate difference is larger than 0, the continuous and insufficient frame number of the USB rate is set to be zero, and otherwise, the continuous and insufficient frame number of the USB rate is accumulated by 1; according to the size relationship between the rate difference and a quality coefficient correction threshold factor, the size relationship between the continuous and insufficient frame numbe