avkit

README

go-avkit

Pure-Go (CGO=0) audio/video toolkit. It reads and writes time-based media containers with no libav/ffmpeg linkage and no external binaries, which is enough to remux — to move tracks between containers without re-encoding them.

Container parsing is delegated to the maintained reference libraries (Eyevinn/mp4ff for ISO-BMFF, at-wat/ebml-go for EBML, asticode/go-astits for MPEG-TS); go-avkit projects their box/element/packet trees onto one small, format-neutral model, and converts the payloads each container spells differently.

Packages

Package

What it does

container

Sniff and demux MP4/ISO-BMFF, Matroska/WebM and MPEG-TS into a unified File/Track model (kind, codec, dimensions, channels, timing); read the samples and per-track configuration of an MP4 or a transport stream, one file or a sequence of segments; mux a fragmented MP4 or an MPEG-TS from tracks delivered separately; copy, cut, concatenate and drop tracks with Remux, Cut and Concat. No re-encoding anywhere.

Install

go get github.com/go-avkit/avkit

Usage

package main

import (
	"fmt"
	"os"

	"github.com/go-avkit/avkit/container"
)

func main() {
	data, err := os.ReadFile("clip.mp4") // or .mkv / .webm
	if err != nil {
		panic(err)
	}

	f, err := container.Demux(data)
	if err != nil {
		panic(err)
	}

	fmt.Printf("%s, %.3fs, %d track(s)\n", f.Format, f.DurationSeconds(), len(f.Tracks))
	for _, t := range f.Tracks {
		fmt.Printf("  #%d %s %s %dx%d %dch/%dHz %.3fs %q\n",
			t.ID, t.Kind, t.Codec, t.Width, t.Height, t.Channels, t.SampleRate,
			t.DurationSeconds(), t.Language)
	}
}

container.Sniff identifies the format from the leading bytes without a full parse; container.Demux dispatches to the right demuxer.

Guarantees

• Pure Go, CGO=0. No libav, no exec to ffmpeg.
• 100% statement coverage, enforced in CI, error branches included.
• Six 64-bit targets exercised each run: amd64, arm64 (native) and riscv64, loong64, ppc64le, s390x (under qemu) — the last also covering big-endian byte-order correctness.

Scope

Today go-avkit reads container structure and metadata. Codec bitstream decoding (H.264/HEVC/AV1/VP9, AAC/Opus …) lives in sibling packages as they land.

License

BSD-3-Clause — see LICENSE. Copyright the go-avkit authors.