go-lame

Yet another simple wrapper of libmp3lame for golang. It focuses on converting raw PCM, and WAV files into mp3.

Forked from https://github.com/sunicy/go-lame

fixed relative import paths are not supported in module mode (sunicy/go-lame#issues-4)

Install

go get -u github.com/youthlin/go-lame

Cmdline tool

• mp3-encoder

go install github.com/youthlin/go-lame/cmd/mp3-encoder@latest
# execute the binary to show usage
mp3-encoder

Examples

PCM to MP3

func PcmToMp3(pcmFileName, mp3FileName string) {
	pcmFile, _ := os.OpenFile(pcmFileName, os.O_RDONLY, 0555)
	mp3File, _ := os.OpenFile(mp3FileName, os.O_CREATE | os.O_WRONLY | os.O_TRUNC, 0755)
	defer mp3File.Close()
	wr, err := lame.NewWriter(mp3File)
	if err != nil {
		panic("cannot create lame writer, err: " + err.Error())
	}
	wr.InSampleRate = 24000  // input sample rate, default: 24000
	wr.InNumChannels = 1     // number of channels: 1, default: 1
	wr.OutSampleRate = 24000 // output sample rate, default 0: same to input
	wr.OutNumChannels = 1    // default 0: same to input
	wr.OutQuality = 0        // 0: highest(default); 9: lowest 
	
	io.Copy(wr, pcmFile)
	wr.Close()
}

WAV to MP3

func WavToMp3(wavFileName, mp3FileName string) {
	// open files
	wavFile, _ := os.OpenFile(wavFileName, os.O_RDONLY, 0555)
	mp3File, _ := os.OpenFile(mp3FileName, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0755)
	defer mp3File.Close()

	// parsing wav info
	// NOTE: reader position moves even if it is not a wav file
	wavHdr, err := lame.ReadWavHeader(wavFile)
	if err != nil {
		panic("not a wav file, err=" + err.Error())
	}

	wr, _ := lame.NewWriter(mp3File)
	wr.EncodeOptions = wavHdr.ToEncodeOptions()
	io.Copy(wr, wavFile) // wavFile's pos has been changed!
	wr.Close()
}

Roadmap

• Wrapping functions from libmp3lame
• WavFile parsing support
• Shortcut to using wrapped functions
• Supporting parsing both little-endian and big-endian PCM files
• Thorough tests
• Supporting bit depth other than 16