What AV1 Profiles Does librav1e Support?

This article provides a direct overview of the specific AV1 (AOMedia Video 1) profiles supported by librav1e, the C-compatible library interface for the Rust-based rav1e encoder. You will learn about the exact bit depths, chroma subsampling configurations, and profiles that this encoder supports for video compression.

The AV1 specification defines three distinct profiles, each tailored to different use cases, color depths, and chroma subsampling formats. librav1e fully supports all three of these official AV1 profiles, making it one of the most versatile and compliant open-source AV1 encoders available today.

1. Main Profile (Profile 0)

The Main Profile is the most widely compatible AV1 profile, designed for mainstream consumer distribution, streaming services, and playback devices. librav1e supports all requirements for this profile: * Bit Depth: 8-bit and 10-bit color precision. * Chroma Subsampling: 4:2:0 (YUV420) and 4:0:0 (Monochrome).

This profile is ideal for standard definition (SD), high definition (HD), and ultra-high definition (UHD/4K) streaming, including High Dynamic Range (HDR) content using 10-bit color.

2. High Profile (Profile 1)

The High Profile is designed for specialized applications that require high color fidelity, such as screen casting, digital art, or game streaming where sharp text and fine color details are crucial. librav1e supports this profile with the following specifications: * Bit Depth: 8-bit and 10-bit color precision. * Chroma Subsampling: 4:4:4 (YUV444), which preserves full color resolution for every pixel.

3. Professional Profile (Profile 2)

The Professional Profile is engineered for high-end video production, broadcasting, and mastering workflows. librav1e supports the advanced color spaces required for this profile: * Bit Depth: 8-bit, 10-bit, and 12-bit color precision. * Chroma Subsampling: 4:2:2 (YUV422), as well as 12-bit configurations of 4:2:0 (YUV420) and 4:4:4 (YUV444).

By supporting 12-bit color depths and 4:2:2 subsampling, librav1e allows professionals to encode source footage with minimal compression artifacts before final distribution.

Summary of Supported Pixel Formats

In practical terms, when configuring librav1e via command-line tools (like ffmpeg compiled with librav1e support) or directly through its API, you can utilize the following pixel formats to trigger these profiles: * yuv420p / yuv420p10le / yuv420p12le (Main & Professional Profiles) * yuv422p / yuv422p10le / yuv422p12le (Professional Profile) * yuv444p / yuv444p10le / yuv444p12le (High & Professional Profiles)