AVIF and HEIF encoding, bit depth, and speed/effort tuning

AVIF stores AV1 intra-coded frames inside a HEIF (ISO Base Media File Format) container. At comparable visual quality, AVIF typically saves 40%–50% over JPEG and 15%–25% over WebP, while supporting 8-bit, 10-bit, and 12-bit depth and wide-gamut HDR profiles.

In libvips, both AVIF and HEIC/HEIF are handled by heifload / heifsave (delegating via libheif to aom, rav1e, or svt-av1) with compression="av1".

Cross-binding AVIF parameter reference

Setting	govips `AvifExportParams`	sharp `.avif(options)`	pyvips / vips CLI `heifsave`	Production guidance
Quality factor	`Quality` (default 80)	`quality` (default 50)	`Q=55` / `--Q 55`	Watch the default difference: AVIF is highly efficient; `50–65` roughly matches JPEG `80–85`
Encoding speed / effort	`Effort` (`0..9`, default 5; legacy `Speed` is deprecated)	`effort` (`0..9`, default 4)	`effort=4` / `--effort 4`	Same direction on `libvips >= 8.13`: `0` is fastest, `9` is slowest/best compression (use `3–5` for real-time services)
Lossless mode	`Lossless: true`	`lossless: true`	`lossless=True` / `--lossless`	Lossless AVIF is slower and often larger than lossless WebP
Bit depth	`Bitdepth` (`8` / `10` / `12`)	`bitdepth` (`8` / `10` / `12`)	`bitdepth=8`	`8` has universal browser support; `10`/`12` suits HDR and wide-gamut workflows
Chroma subsampling	— (`AvifExportParams` does not expose `subsample_mode`)	`chromaSubsampling` (default `'4:4:4'`)	`subsample_mode`	In sharp, pyvips, and CLI, set `'4:2:0'` (or `on`) for photography to reduce size and improve hardware decode compatibility

AVIF export code across four interfaces

package main

import (
    "fmt"
    "os"

    "github.com/davidbyttow/govips/v2/vips"
)

func main() {
    if err := vips.Startup(nil); err != nil {
        fmt.Fprintln(os.Stderr, err)
        os.Exit(1)
    }
    defer vips.Shutdown()

    // Check whether the linked libvips build includes AVIF support
    if !vips.IsTypeSupported(vips.ImageTypeAVIF) {
        fmt.Fprintln(os.Stderr, "AVIF is not supported by this libvips build")
        os.Exit(1)
    }

    image, err := vips.NewImageFromFile("input.jpg")
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
        os.Exit(1)
    }
    defer image.Close()

    params := vips.NewAvifExportParams()
    params.Quality = 55
    params.Bitdepth = 8
    params.Effort = 4 // 0..9, lower is faster (NewAvifExportParams default is 5)
    params.StripMetadata = true

    data, _, err := image.ExportAvif(params)
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
        os.Exit(1)
    }
    if err := os.WriteFile("output.avif", data, 0o644); err != nil {
        fmt.Fprintln(os.Stderr, err)
        os.Exit(1)
    }
}

import sharp from 'sharp';

await sharp('input.jpg')
  .avif({
    quality: 55,
    effort: 4, // 0..9, lower is faster
    bitdepth: 8,
    chromaSubsampling: '4:2:0',
  })
  .toFile('output.avif');

import pyvips

image = pyvips.Image.new_from_file("input.jpg")

# The .avif suffix selects heifsave with compression="av1" automatically
image.write_to_file(
    "output.avif",
    Q=55,
    effort=4,
    bitdepth=8,
    subsample_mode="on",
    keep="icc",
)

#!/usr/bin/env bash
set -euo pipefail

vips heifsave input.jpg output.avif \
  --compression av1 \
  --Q 55 \
  --effort 4 \
  --bitdepth 8 \
  --subsample-mode on \
  --keep icc

Streaming and `libheif` codec boundaries

Streaming boundary in govips v2.19.0: govips provides SaveToWriterHeif(w, heifParams) but does not have a dedicated SaveToWriterAvif method; use image.ExportAvif(avifParams) (or SaveToWriter with Format: vips.ImageTypeAVIF in ExportParams).
libheif plugin availability: many Linux distributions build libheif with AV1 plugins enabled (supporting .avif) while omitting patent-encumbered HEVC/x265 encoders (so .heic export fails with Unsupported compression). See Missing codecs and unsupported formats for diagnostics.

AVIF and HEIF encoding, bit depth, and speed/effort tuning

Cross-binding AVIF parameter reference

AVIF export code across four interfaces

Streaming and libheif codec boundaries

Sources

Streaming and `libheif` codec boundaries