Configure libx265 Tier Parameter in FFmpeg

This article explains how to configure the tier parameter when encoding video using the libx265 encoder in FFmpeg. You will learn what the tier parameter is, the difference between the “main” and “high” tiers in the HEVC/H.265 standard, and the exact FFmpeg commands required to set this parameter for your video compression workflows.

What is the Tier Parameter in HEVC?

In the HEVC (H.265) video compression standard, tiers and levels define the limits on hardware decoding capabilities, such as maximum bitrate, resolution, and frame rate.

While Levels (e.g., 4.0, 5.0, 5.1) restrict the maximum sample rate and resolution, Tiers specify the maximum bitrate. HEVC defines two tiers: * main: Designed for standard consumer applications, mobile devices, and typical streaming where bitrates are relatively low. This is the default setting. * high: Designed for demanding applications, professional broadcasting, or high-bitrate archival where the limits of the main tier are insufficient.

How to Configure the Tier in FFmpeg

You can configure the tier parameter in FFmpeg using two different methods: using the direct FFmpeg -tier option, or passing it as a private option inside the -x265-params argument.

Method 1: Using the -tier Flag

The most straightforward way is to use the native FFmpeg option. You can set this to either main or high.

To set the tier to high:

ffmpeg -i input.mp4 -c:v libx265 -tier high output.mp4

To set the tier to main:

ffmpeg -i input.mp4 -c:v libx265 -tier main output.mp4

Method 2: Using the -x265-params Flag

Alternatively, you can pass the parameter directly to the underlying libx265 library using the -x265-params option. This method is highly reliable across different versions of FFmpeg.

To set the tier to high via x265 params:

ffmpeg -i input.mp4 -c:v libx265 -x265-params tier=high output.mp4

If you are passing multiple parameters, separate them with a colon:

ffmpeg -i input.mp4 -c:v libx265 -x265-params tier=high:level-idc=5.1 output.mp4

When to Use Main vs. High Tier

• Use Main Tier for maximum compatibility. Most consumer playback devices (smart TVs, older smartphones, and streaming boxes) only support the main tier.
• Use High Tier when you are encoding high-resolution content (like 4K or 8K) at very high bitrates that exceed the limits of the main tier for your selected level. Be aware that high-tier files may fail to play on older or budget-friendly hardware decoders.