goav1

goav1 is a pure-Go AV1 decoder with a realtime, WebRTC-oriented encoder and RTP/RTCP helpers. The root Go module has no third-party module dependencies and does not use cgo. The project is under active development: decoder parity, encoder quality, and throughput coverage continue to expand.

Install

Requires the official Go distribution, version 1.27.0 or newer; no Go patch release is pinned. The native arm64 SIMD paths use the experimental GOEXPERIMENT=simd setting. Build with GOEXPERIMENT=simd go build ./... to enable them. Without it, normal Go fallbacks are used. Codec implementations, including SIMD paths, are written in Go without handwritten assembly. See SIMD validation and measurements for the selected paths.

go get github.com/thesyncim/goav1

Decode an IVF file

DecodeIVF returns independent, row-packed copies of each visible frame:

package main

import (
	"fmt"
	"log"
	"os"

	av1 "github.com/thesyncim/goav1"
)

func main() {
	ivf, err := os.ReadFile("input.ivf")
	if err != nil {
		log.Fatal(err)
	}

	frames, err := av1.DecodeIVF(ivf)
	if err != nil {
		log.Fatal(err)
	}
	for i, frame := range frames {
		fmt.Printf("frame %d: %dx%d\n", i, frame.Width, frame.Height)
	}
}

For a reusable decode loop, use NewDecoderFromIVF and DecodeNext. Frames returned by DecodeNext alias decoder-owned memory and remain valid until the next decode call. See the executable decoder examples.

Encode an I420 stream

VideoEncoder accepts same-sized 8-bit I420 frames. Set QIndex for fixed quality, or set both TargetBitrate and Framerate for CBR rate control.

package main

import (
	"log"

	av1 "github.com/thesyncim/goav1"
)

func main() {
	const width, height = 64, 64
	enc, err := av1.NewVideoEncoder(av1.VideoEncoderConfig{
		Width: width, Height: height, QIndex: 80,
	})
	if err != nil {
		log.Fatal(err)
	}
	defer enc.Close()

	frame := av1.I420Frame{
		Y: make([]byte, width*height),
		U: make([]byte, width/2*height/2),
		V: make([]byte, width/2*height/2),
		YStride: width, ChromaStride: width / 2,
		Width: width, Height: height,
	}
	out, err := enc.Encode(frame, false)
	if err != nil {
		log.Fatal(err)
	}

	// Keep the temporal unit beyond the next Encode call.
	temporalUnit := append([]byte(nil), out.Data...)
	_ = temporalUnit
}

For RTP payloads, dependency descriptors, temporal layers, and WebRTC control, see RTCEncoder and the executable encoder examples.

Ownership

API	Returned data
DecodeIVF	Independent copies of visible Y/U/V samples
Decoder.DecodeNext	Decoder-owned frame-pool memory, reused by a later decode call
VideoEncoder.Encode	Encoder-owned temporal-unit bytes, reused by the next encode call
NewIVFIterator and OBU parsers	Views into caller-provided input bytes

Copy aliased data before retaining it or passing it to asynchronous work. Close reusable Decoder, VideoEncoder, and RTCEncoder values when finished.

Capabilities and scope

• Decode AV1 from IVF, low-overhead OBU streams, and ordered RTP payloads or packets. The decoder includes prediction, reconstruction, and AV1 post-filter stages.
• Encode realtime AV1 streams with fixed-quality or CBR control, with WebRTC-specific layering and RTP metadata through RTCEncoder.
• Parse and build AV1 RTP payloads, RTP extension elements, selected SDP capability values, and RTCP packets and feedback.
• Use lower-level IVF, OBU, bitstream, frame, and DSP helpers when an integration needs explicit ownership of buffers and work.

The checked-in decoder vectors cover profiles 0 and 1, plus selected profile 2 clips, and include 8-, 10-, and 12-bit content. This describes fixture coverage; it does not claim every stream in those profiles is supported.

The encoder targets realtime WebRTC use. It is not an offline encoder or a general replacement for aomenc. The package supplies RTP/RTCP primitives and AV1 capability helpers; callers provide full SDP negotiation, SRTP, jitter buffering, network I/O, packet timing, and retransmission policy.

Coverage is measured by the checked-in vector and integration gates. Passing those gates does not establish complete AV1 conformance for every profile, bit depth, malformed stream, or deployment.

Verify changes

Run the commands below when changing decoder, encoder, or transport behavior:

make test
make ci-local
make testvectors-fast
make dryrun-fast
make dryrun-profiles

make dryrun-full runs the broader committed libaom vector suite; make dryrun-extended runs an opt-in diagnostic cohort. make webrtc-production is the larger encoder, WebRTC, and reference-decoder lane. Some lanes need reference tools or downloadable vectors. See the quality and parity guide for what each gate proves and the performance commands.

CLI decoder

make build-cmd
./bin/aom-go-dec -h

The command-line decoder reads IVF and writes decoded YUV. For SVC inspection, see cmd/dump_svc.

Project references

• Quality and parity gates
• Go-native SIMD build and validation
• Current end-to-end decoder and encoder gap versus dav1d and SVT-AV1
• Pinned upstream sources and porting policy
• Executable public API examples, decode examples, and encoder examples
• Change history
• Security policy
• Package API documentation

License

The source distribution uses the BSD 2-Clause terms in LICENSE. The libaom-derived portions also carry the Alliance for Open Media patent license reproduced in PATENTS. Third-party attributions are in NOTICE.