Multi-layer rate control

Abstract

Concepts and technologies are described herein for multi-layer rate control. In accordance with the concepts and technologies disclosed herein, a video server obtains video data and encodes the video data into a multi-layer video stream. Layers of the video stream can be output buffers and the buffers can be monitored to determine bit usage. A rate controller can obtain bit usage feedback for each layer of the encoded video stream and determine, based upon the bit usage feedback, a quantization parameter associated with each layer of the encoded video stream. In determining the quantization parameters, the rate controller can consider not only bitrates of the entire encoded video stream, but also bitrates and bit usage feedback associated with each layer of the encoded video stream. Further encoding can be based upon the quantization parameters determined by the video server.

Description

Background technique [0001] Variations in the bit rate at which video data is encoded can cause problems for various video transmission and storage mechanisms. For example, if the bit rate exceeds the available bandwidth, the video can be interrupted. Similarly, if the bitrate is reduced during streaming or transmission of a video, it may be apparent to the viewer that certain details of the video may be lost or removed from the video to accommodate the lower bitrate. To address the problems caused by these variations, some systems employ bit rate control mechanisms to adjust and / or manage the bit rate of encoded video data during transmission. One such method includes analyzing the bitstream and determining a sustainable bitrate for the entire bitstream. This approach may be practical for some non-scalable bitstreams. [0002] However, for scalable video bitstreams, this method of controlling bitrate variation and / or bitrate can also affect performance and user experienc...

AI Technical Summary

Problems solved by technology

Because the rate controllers associated with video servers are often imperfect, the base layer may sometimes be encoded at less than the targeted 300kbps, resulting in lower quality of the overall stream, which does not maximize the bandwidth available to the second receiver

In this example, if the base tier drops to 280Kbps, the maximum stream the second device can receive could be 480Kbps, which fails to use available bandwidth and provides a less-than-ideal user experience

Therefore, applying conventional rate control mechanisms to scalable video and / or applying rate control mechanisms independently to layers of a multi-layer video stream can adversely affect individual bitstreams and degrade the quality of the video stream

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