audioduration

README

Audio Duration

This is a fork of https://github.com/hcl/audioduration

A naive go module to get a audio file's duration in second.

Usage

import "github.com/sydlexius/audioduration"

For an audio file (eg. mp3 format)

f, _ := os.Open("audio.mp3")
defer f.Close()
d, err := audioduration.Mp3(f)
if err != nil {
	// handling error
}

Or alternatively

f, _ := os.Open("audio.mp3")
defer f.Close()
d, err := audioduration.Duration(f, audioduration.TypeMp3)
if err != nil {
	// handling error
}

Supported formats

MP3, M4A, MP4, FLAC, DSF, OGG, WAV, AAC, WEBM

License

The code is licensed under GPLv3.

    audioduration - audio duration calculation library in go
    Copyright (C) 2021  hcl

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

Credits

The audio samples (files under samples) for package test are from following source:

• MP3 with tag, M4A, MP4, FLAC, DSF: https://github.com/dhowden/tag/tree/master/testdata
• OGG: https://commons.wikimedia.org/wiki/File:Example.ogg
• MP3(CBR, VBR): https://commons.wikimedia.org/w/index.php?title=File%3ABWV_543-prelude.ogg

Documentation

Index

• Constants
• func AAC(r io.ReadSeeker) (float64, error)
• func DSD(r io.ReadSeeker) (float64, error)
• func Duration(file io.ReadSeeker, filetype int) (float64, error)
• func FLAC(r io.ReadSeeker) (float64, error)
• func Mp3(r io.ReadSeeker) (float64, error)
• func Mp4(r io.ReadSeeker) (float64, error)
• func Ogg(r io.ReadSeeker) (float64, error)
• func Wav(r io.ReadSeeker) (float64, error)
• func WebM(r io.ReadSeeker) (float64, error)
• type VBRI
• type Xing

Constants

const (
	TypeFlac int = 0
	TypeMp4  int = 1
	TypeMp3  int = 2
	TypeOgg  int = 3
	TypeDsd  int = 4
	TypeWav  int = 5
	TypeAac  int = 6
	TypeWebM int = 7
)

File Type Constant

Functions

func AAC

func AAC(r io.ReadSeeker) (float64, error)

AAC parses raw AAC ADTS streams and returns duration in seconds. It scans ADTS frames, accumulating samples and dividing by sample rate. Ref: ISO/IEC 13818-7 (ADTS header)

func DSD

func DSD(r io.ReadSeeker) (float64, error)

DSD Calculate dsd files duration.

func Duration

func Duration(file io.ReadSeeker, filetype int) (float64, error)

Duration Get duration of specific music file type.

func FLAC

func FLAC(r io.ReadSeeker) (float64, error)

FLAC Calculate flac files duration.

func Mp3

func Mp3(r io.ReadSeeker) (float64, error)

Mp3 Calculate mp3 files duration.

I/O cost depends on what the stream declares. When a Xing or VBRI header is present the frame count is read from it and only the first frame's region is touched. When neither is present -- which includes plain CBR streams, whose duration was previously derived from the file size alone -- the whole stream is read to end of file in 256 KiB blocks to count frames. Only 4-byte frame headers are decoded, never audio, but the bytes are still read.

That is negligible for a local file (0.67 ms for a 7.9 MB stream) but it changes the cost profile for an io.ReadSeeker backed by the network, such as an HTTP range-request reader: size timeouts and any caching accordingly.

func Mp4

func Mp4(r io.ReadSeeker) (float64, error)

Mp4 Calculate mp4 files duration.

func Ogg

func Ogg(r io.ReadSeeker) (float64, error)

Ogg Calculate ogg files duration.

func Wav

func Wav(r io.ReadSeeker) (float64, error)

Wav Calculate wav files duration. It parses RIFF/WAVE with fmt and data chunks. PCM and non-PCM with block alignment are supported via byteRate/blockAlign.

func WebM

func WebM(r io.ReadSeeker) (float64, error)

WebM returns the duration in seconds by reading the EBML structure.

Types

type VBRI

type VBRI struct {
	// contains filtered or unexported fields
}

VBRI VBRI Header

type Xing

type Xing struct {
	// contains filtered or unexported fields
}

Xing Xing Header