libsvtav1 vs libaom-av1: AV1 Encoder Comparison

While both libsvtav1 and libaom-av1 are open-source video encoders designed for the AV1 royalty-free video format, they are built with entirely different architectural goals. This article compares the two encoders across key areas, including development origins, performance, compression efficiency, and practical use cases, to help you choose the right tool for your video processing pipeline.

Core Architectural Differences

The primary difference between the two encoders lies in their underlying design philosophy and target hardware utilization.

• libaom-av1 (The Reference Encoder): Developed by the Alliance for Open Media (AOMedia), libaom-av1 is the official reference encoder for the AV1 specification. It was designed to implement every feature of the AV1 standard to demonstrate its maximum compression potential. Because it was built for completeness rather than speed, its codebase historically struggled with multi-threading and modern CPU optimization.
• libsvtav1 (The Production Encoder): Scalable Video Technology for AV1 (libsvtav1) was originally developed by Intel in partnership with Netflix, and is now the primary production-focused AV1 encoder backed by AOMedia. It was written from the ground up to utilize modern, highly parallel multi-core processors (both x86 and ARM) using advanced SIMD instructions and a highly scalable multi-threading architecture.

Encoding Speed and CPU Scaling

Speed is the most dramatic differentiator between the two encoders.

• libaom-av1 is notoriously slow. While optimization updates have improved its performance, it does not scale well across high-core-count CPUs. Splitting a video into segments (tiling or chunking) is often required to achieve reasonable encoding speeds with libaom-av1.
• libsvtav1 excels at resource allocation. It can dynamically scale encoding tasks across dozens of CPU threads. This makes it orders of magnitude faster than libaom-av1 on modern consumer and server processors, enabling near-real-time and even live AV1 encoding on capable hardware.

Compression Efficiency and Quality

When comparing how much visual quality is retained at a given bitrate, the encoders trade blows depending on the presets used.

• libaom-av1 still holds a slight advantage in absolute compression efficiency at its slowest presets (e.g., cpu-used levels 0 through 3). If encoding time is of no concern, libaom-av1 can produce marginally smaller file sizes for the same visual quality compared to libsvtav1.
• libsvtav1 offers highly competitive efficiency that closely rivals libaom-av1 at equivalent speed tiers. For practical deployment, the negligible quality loss is almost always deemed an acceptable trade-off for the massive reduction in encoding time.

Feature Support and Presets

The two encoders use different preset scales and feature sets:

• Presets: libaom-av1 uses a cpu-used scale from 0 (slowest, highest quality) to 9 (fastest). libsvtav1 uses a preset scale from 0 (slowest, highest quality) to 13 (fastest, lowest quality).
• Grain Synthesis: Both encoders support AV1 film grain synthesis, a feature that removes film grain during compression and reapplies it during playback to save bitrate. However, libsvtav1’s implementation is generally more optimized for practical workflows.

Summary: Which One Should You Use?

Select libaom-av1 if: * You are conducting academic research or reference testing of the AV1 specification. * You need to archive video with the absolute maximum compression ratio and encoding time/CPU cost is not a limiting factor.

Select libsvtav1 if: * You are encoding video for a streaming service, Video-on-Demand (VOD) platform, or media server. * You are using consumer software like HandBrake, FFmpeg, or OBS Studio for personal media encoding or live streaming. * You want the best balance of modern multi-core CPU utilization, fast encoding speeds, and high-fidelity video compression.