Adaptive bitrate streaming (ABR) over the HyperText Transfer Protocol (HTTP), which raises numerous delicate questions, is nowadays almost the only approach to video streaming. This paper presents elementary solutions to three key issues: 1) A straightforward feedforward control strategy for the bitrate and the buffer level via flatness-based control. 2) Closing the loop permits mitigating unavoidable mismatches and disturbances, such as Internet fluctuations. This is adapted from the new HEOL setting, which mixes model-free and flatness-based controls. 3) An easily implementable closed-form estimate of the bandwidth via algebraic identification techniques is derived, perhaps for the first time. It permits handling severe variations in channel capacity. Several computer experiments and metrics for evaluating the Quality of Experience (QoE) are displayed and discussed.

翻译：基于超文本传输协议（HTTP）的自适应比特率流传输（ABR）虽引发诸多精细问题，却已成为当今视频传输近乎唯一的主流方案。本文针对三个核心问题提出基础性解决方案：1）基于平坦性控制的码率与缓冲区前馈控制策略；2）通过闭环控制可有效缓解不可避免的失配与干扰（如网络波动），该方法源于融合无模型控制与平坦性控制的新型HEOL框架；3）（首次）通过代数辨识技术推导出易于实现的信道带宽闭式估计量，可应对信道容量的剧烈波动。文中展示并讨论了多项计算机实验及用户体验质量（QoE）评估指标。