Adaptive network bandwidth control method for H.264 video stream transmission

A real-time video transmission control method using double buffers and double operation threads based on transmission control protocol(TCP) is proposed according to the characteristics of H.264 video stream encoding and real-time video stream transmission.Considering the video bit rate adjustment can not be same completely with network bandwidth variation in actual fact,three key control strategies,which are video frames discarding,video bitrate increase and decrease,were elaborated.In these control strategies,a frame address array is set up to achieve video data transmission and discarding according to the frame unit in the control method in order to avoid the emergence of broken frame.At the same time,a linear weighted summation method is used to judge the change trend of the accumulated video data in the control method in order to ensure the correctness of the video bitrate adjustment.The specific procedures,test cases and comparison with exiting traditional methods were given at last.The test result and the comparison show that the proposed control method can ensure the video bitrate adaptive adjustment according to the network bandwidth fluctuation or video scene change under variable bit control,utilize network variable bandwidth in the greatest extent for transmitting video to receiver by real-time and play back smoothly in receiver accordingly,and can be applied effectively to real-time video surveillance under the circumstances of variable bandwidth network.