Interview on iQIYI's QAV1 AV1 Encoder and Its Technical Advantages

Interviewee: Wang Zhihang, iQIYI scientist with a Ph.D. from the Institute of Computing Technology, Chinese Academy of Sciences, leading the team responsible for audio‑video quality optimization, including pre‑processing and codec technologies.

Why develop an AV1‑based encoder? AV1 is royalty‑free, improving compression efficiency and streaming transmission. iQIYI has launched AV1 streams on PC browsers, enhancing picture quality while reducing bandwidth.

Challenges of AV1: The standard has very high computational complexity, limiting large‑scale deployment.

Solution – QAV1 encoder: iQIYI independently developed the QAV1 encoder, which dramatically reduces complexity. Compared with the open‑source SVT‑AV1, QAV1 achieves roughly 5× faster encoding at the same compression ratio. For 1080p video, QAV1’s single‑pass encoding consumes about 45% of the resources of the x265 “veryslow” preset and half the memory, making it suitable for massive deployment.

Technical details: QAV1 incorporates nearly a hundred optimization algorithms across all encoding modules. It supports multiple speed tiers, various bitrate‑control modes, 8K encoding, and upcoming 10‑bit support.

Android support: AV1 decoding on Android currently relies on hardware decoders; only a limited set of devices support it. iQIYI does not use software decoding on unsupported phones due to power‑consumption concerns.

Future hardware: MediaTek Dimensity 1000 is the world’s first mobile SoC with an integrated AV1 decoder. Other chip vendors (e.g., HiSilicon) are also adding AV1 support, leading to a long‑term coexistence of hardware and software decoding.

Future improvements: QAV1 will continue to adapt to iQIYI’s massive content library by performing scene‑complexity analysis for smarter bitrate allocation—lower bitrate for simple scenes, higher for complex ones—while further optimizing speed and quality.