Force 10-Bit Color Output in libsvtav1

This article explains how to force a 10-bit color depth output when encoding video files using the libsvtav1 encoder in FFmpeg. You will learn the specific command-line parameters required to ensure your output is encoded in 10-bit, even when starting from an 8-bit source, which helps reduce color banding and improves compression efficiency.

To force a 10-bit color output when using libsvtav1 via FFmpeg, you need to explicitly set the pixel format to a 10-bit format using the -pix_fmt flag. The standard high-compatibility 10-bit pixel format for consumer video is yuv420p10le.

The FFmpeg Command

Run the following command in your terminal to encode your video to 10-bit AV1:

ffmpeg -i input.mp4 -c:v libsvtav1 -pix_fmt yuv420p10le -crf 26 -preset 4 output.mkv

How It Works

• -c:v libsvtav1: Selects the SVT-AV1 encoder wrapper in FFmpeg.
• -pix_fmt yuv420p10le: This is the crucial parameter. It forces FFmpeg to pipe a 10-bit YUV 4:2:0 stream into the encoder. When libsvtav1 detects this 10-bit input format, it automatically configures the AV1 encoder to output a 10-bit color depth stream.

Why You Should Force 10-Bit

Even if your source video is only 8-bit, encoding to 10-bit AV1 is highly recommended.

1. Reduces Banding: The internal math of the AV1 encoder operates with higher precision in 10-bit mode, which significantly reduces color banding in gradients (such as skies or dark scenes).
2. Better Compression: SVT-AV1 handles complex gradients more efficiently in 10-bit, often resulting in a smaller file size for the same visual quality compared to an 8-bit encode.

For Standalone SVT-AV1 CLI Users

If you are using the standalone SVT-AV1 encoder executable (SvtAv1EncApp) instead of FFmpeg, you must specify the bit depth using the --bit-depth parameter:

SvtAv1EncApp -i input.y4m --bit-depth 10 -b output.ivf