Low‑Latency Audio/Video Technology in OPPO Cloud Rendering: Architecture, Optimization, and Outlook

The presentation introduces the requirements and challenges of audio/video transmission in cloud rendering scenarios, describing three evolutionary stages of internet video (3G, 4G, 5G) and defining cloud rendering as the use of cloud compute to offload terminal processing for use cases such as virtual social spaces, virtual studios, cloud gaming, and remote collaboration.

It outlines the cloud rendering platform architecture, consisting of a cloud rendering part and a cross‑terminal part linked by streaming technology, and explains the core streaming concepts, including the need for immersive ultra‑HD experience (4K/8K, bandwidth up to 100 Mbps) and real‑time interaction with sub‑100 ms latency.

The integration of RTC with cloud rendering is described through a CloudRTC‑based transmission architecture that mirrors traditional RTC (push, pull, media forwarding) but places edge cloud and media services in the same location. The architecture includes signaling acceleration, media forwarding (supporting SFU/PTP), and pull‑play services for a wide range of devices.

Optimization of low‑latency streaming is explored in three layers: capture/encoding, transport, and reception. Encoding optimizations cover GPU‑based zero‑copy encoding, adaptive bitrate, forward error correction, ROI coding, layered (SVC) coding, and LTR frame referencing. Transport optimizations focus on GCC‑based congestion control, bandwidth estimation, pacing, and a QoS strategy that prioritises smoothness via HARQ redundancy and unequal protection. Reception optimizations include jitter buffer redesign for “one‑frame‑in‑one‑frame‑out” processing and low‑latency decoding using hybrid hardware‑software approaches.

Performance tests show that the optimized solution reduces end‑to‑end latency from around 180 ms to roughly 100 ms, with further improvements possible via edge nodes. The final section discusses future directions: tighter integration of content production and transmission, lower‑cost cloud infrastructure with edge nodes, and SDK‑level enhancements for client‑side rendering and RTC‑command coupling.

Overall, the article provides a comprehensive overview of OPPO's low‑latency audio/video streaming techniques for cloud rendering, detailing architectural choices, technical optimizations, test results, and future prospects.