A Bit Rate Smoothing Method for Real-time Video Transmission under Wireless Network

Abstract

The present invention proposes a code rate smoothing method for real-time video transmission under a wireless network. The method includes: periodically counting the transmission delay of the video frame, and when the transmission delay becomes small, the playback buffer is reduced by fast forwarding. When the delay becomes large, the playback buffer is enlarged through slow playback, and the adjustment steps of the fast forward and the slow playback are jointly determined by transmission delay variation, playback buffer depth, and time stamp information. The present invention can count the transmission time delay of video frames, perceive the state of the wireless network according to the time delay information, and then find the minimum video time delay according to the actual network conditions to achieve a smooth effect, realizing the balance between real-time and fluency of video streams .

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to a code rate smoothing method for real-time video transmission under a wireless network. Background technique [0002] At present, for applications with high real-time requirements such as video conferencing, a method of directly playing video frames after receiving them is usually adopted. This method focuses on real-time performance. However, when video transmission is performed on a wireless network, due to the large size of some video frames (such as I frames), the instantaneous bit rate may become twice or more than the average bit rate, and burst data is easy. As a result of network congestion, the time required to transmit these frames is relatively long, resulting in obvious jitter when the video frame is transmitted. In this case, if the method of displaying the video frame is still used at the receiving end, there will be a video The phenomenon of timing freeze ser...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem of not only ensuring the real-time performance of video transmission, but also improving its transmission quality and ensuring its fluency as much as possible, the present invention proposes a bit rate smoothing method for real-time video transmission under wireless network, based on the play cache mechanism On the one hand, by periodically counting the transmission delay of video frames to dynamically perceive the changes in the wireless network, thereby dynamically adjusting the size of the playback cache, avoiding unnecessary cache time as much as possible, and making video transmission real-time and smooth at a small cost A better balance between them, that is, under the premise of ensuring fluency, use a relatively small delay when the network status is good, and use a relatively large delay when the network status is poor

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