media

README

go-media

This module provides an interface for media services, including:

• Bindings in golang for ffmpeg 6;
• Opening media files, devices and network sockets for reading and writing;
• Retrieving metadata and artwork from audio and video media;
• Re-multiplexing media files from one format to another;
• Fingerprinting audio files to identify music.

Current Status

This module is currently in development and subject to change. If there are any specific features you are interested in, please see below "Contributing & Distribution" below.

Requirements

In order to build the examples, you'll need the library and header files for ffmpeg 6 installed. The chromaprint library is also required for fingerprinting audio files. On Macintosh with homebrew, for example:

brew install ffmpeg@6 chromaprint make

There are some examples in the cmd folder of the main repository on how to use the package. The various make targets are:

• make all will perform tests, build all examples and the backend API;
• make test will perform tests;
• make cmd will build example command-line tools into the build folder;
• make clean will remove all build artifacts.

There are also some targets to build a docker image:

• DOCKER_REGISTRY=docker.io/user make docker will build a docker image;
• DOCKER_REGISTRY=docker.io/user make docker-push will push the docker image to the registry.

For example,

git clone git@github.com:djthorpe/go-media.git
cd go-media
DOCKER_REGISTRY=ghcr.io/mutablelogic make docker

Examples

Media Transcoding

Audio Fingerprinting

You can programmatically fingerprint audio files, compare fingerprints and identify music using the following packages:

• sys/chromaprint provides the implementation of the lower-level function calls to chromaprint. The documentation is here
• pkg/chromaprint provides the higher-level API for fingerprinting and identifying music. The documentation is here.

You'll need an API key in order to use the AcoustID service. You can get a key here.

Contributing & Distribution

This module is currently in development and subject to change.

Please do file feature requests and bugs here. The license is Apache 2 so feel free to redistribute. Redistributions in either source code or binary form must reproduce the copyright notice, and please link back to this repository for more information:

Copyright (c) 2021-2024 David Thorpe, All rights reserved.

References

• https://ffmpeg.org/doxygen/6.1/index.html

Documentation

Overview

media is a package for reading and writing media files.

Index

• Variables
• func NewManager() *manager
• func NewReader(r io.Reader, mimetype string) (*reader, error)
• func Open(url string, mimetype string) (*reader, error)
• type Decoder
• type DecoderFunc
• type Frame
• type FrameFunc
• type InputFormat
• type Media
• type MediaType
• type Metadata
• type OutputFormat
• type Packet

Variables

var NativeEndian binary.ByteOrder

NativeEndian is the ByteOrder of the current system.

Functions

func NewManager

func NewManager() *manager

func NewReader

func NewReader(r io.Reader, mimetype string) (*reader, error)

Create a new reader from an io.Reader

func Open

func Open(url string, mimetype string) (*reader, error)

Open a reader from a url or file path, and either use the mimetype or guess the format otherwise. Returns a media object.

Types

type Decoder

type Decoder interface{}

Decoder represents a decoder for a media stream.

type DecoderFunc

type DecoderFunc func(Decoder, Packet) error

DecoderFunc is a function that decodes a packet

type Frame

type Frame interface{}

Frame represents a frame of audio or video data.

type FrameFunc

type FrameFunc func(Frame) error

FrameFunc is a function that processes a frame of audio or video data.

type InputFormat

type InputFormat interface{}

InputFormat represents a container format for input of media streams.

type Media

type Media interface {
	io.Closer

	// Return the metadata for the media stream.
	Metadata() []Metadata

	// Demultiplex media (when NewReader or Open has
	// been used). Pass a packet to a decoder function.
	Demux(DecoderFunc) error

	// Return a decode function, which can rescale or
	// resample a frame and then call a frame processing
	// function for encoding and multiplexing.
	Decode(FrameFunc) DecoderFunc
}

Media represents a media stream, which can be input or output. A new media object is created using NewReader, Open, NewWriter or Create.

type MediaType

type MediaType uint32

Media type flags

const (
	UNKNOWN  MediaType = (1 << iota) // Usually treated as DATA
	VIDEO                            // Video stream
	AUDIO                            // Audio stream
	DATA                             // Opaque data information usually continuous
	SUBTITLE                         // Subtitle stream
	ATTACHMENT
)

type Metadata

type Metadata interface{}

Metadata represents a metadata entry for a media stream.

type OutputFormat

type OutputFormat interface{}

OuputFormat represents a container format for output of media streams.

type Packet

type Packet interface{}

Packet represents a packet of demultiplexed data.