AV1 vs HEVC: Fast Presets for Live Streams

This article examines whether the open-source AV1 video codec can realistically compete with HEVC (H.265) when configured with fast, real-time encoding presets for user-generated live streams. It evaluates how both codecs balance compression efficiency, visual fidelity, hardware acceleration, and CPU resource usage under the strict low-latency demands of home-broadcasting setups.

The Challenge of Real-Time Encoding

User-generated live streaming relies on predictable performance under strict frame-time constraints. Broadcasters using software like OBS Studio must encode 60 frames per second without dropped frames, forcing encoders to bypass heavy computation tools in favor of "fast" or "ultrafast" presets. Historically, this heavily favored mature standards like H.264 and HEVC, as AV1’s advanced toolset was initially too computationally expensive for consumer hardware.

Software Encoding: SVT-AV1 vs. x265

When constrained to CPU-based encoding, HEVC (via x265) has long held an advantage in mature optimization over AV1. However, development in SVT-AV1 has closed this gap considerably at presets 10 through 13.

At these ultra-fast software tiers:

• Compression Efficiency: AV1 retains superior edge clarity and texture preservation at typical live-streaming bitrates (4,000 to 8,000 kbps), outperforming x265 on veryfast or faster presets.
• CPU Overhead: AV1 still requires more compute cycles than HEVC at comparable speeds. To use real-time software AV1 reliably, creators need high-core-count processors (8 cores or higher), whereas x265 can operate on older or mid-range CPUs with less overhead.

Dedicated Hardware Acceleration

The dynamic shifts decisively in favor of AV1 when evaluating modern hardware encoders (Nvidia NVENC on RTX 40-series, Intel QuickSync on Arc, and AMD AMF on RDNA3).

Hardware-based AV1 encoders run entirely on dedicated silicon chips without consuming CPU or GPU compute cores needed for gaming. In this environment:

• Hardware AV1 consistently matches or exceeds the visual quality of HEVC while producing smaller file sizes or cleaner visuals at equivalent low bitrates.
• Latency metrics for hardware AV1 match HEVC and AVC, easily supporting sub-second interaction required for live chat environments.
• In hardware implementations, the computational penalty of AV1 is rendered irrelevant to the user.

Ecosystem and Ingestion Support

Compression quality is meaningless if platforms cannot ingest or distribute the feed. HEVC has historically suffered from fragmented browser support and licensing complications, making platforms reluctant to adopt it for browser-based playback.

AV1, as a royalty-free standard backed by major tech conglomerates, benefits from native browser playback across Chrome, Firefox, and Safari. Major platforms like YouTube have rolled out AV1 live ingestion, and protocols such as Enhanced RTMP and WebRTC enable straightforward AV1 streaming.

The Verdict

AV1 can definitively compete with—and often surpass—HEVC at fast real-time presets for user-generated content, provided modern hardware encoders are used. While software-based AV1 requires more CPU headroom than x265, its visual superiority at low bitrates and widespread browser compatibility make it a more viable, future-proof choice for real-time streaming workflows.