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vireshas/player

Forked from isaiah/player
Created July 21, 2016 07:16
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Revisions

  1. @isaiah isaiah created this gist Jun 3, 2013.
    78 changes: 78 additions & 0 deletions player
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,78 @@
    package main

    import (
    "bytes"
    "code.google.com/p/portaudio-go/portaudio"
    "encoding/binary"
    "fmt"
    "io"
    "log"
    "os"
    "os/exec"
    )

    func main() {
    if len(os.Args) <= 1 {
    fmt.Println("Usage:\n \t./ffmpeg audio_file")
    os.Exit(0)
    }
    inputfile := os.Args[1]
    chk := func(err error) {
    if err != nil {
    panic(err)
    }
    }
    framePerBuffer := 2048
    ff := newFfmpeg(inputfile)
    defer ff.Close()
    stream, err := portaudio.OpenDefaultStream(0, 2, 44100, framePerBuffer, ff)
    chk(err)
    defer stream.Close()
    chk(stream.Start())
    if err := ff.cmd.Wait(); err != nil {
    log.Fatal(err)
    }
    chk(stream.Stop())
    }

    type ffmpeg struct {
    in io.ReadCloser
    cmd *exec.Cmd
    }

    func newFfmpeg(filename string) *ffmpeg {
    cmd := exec.Command("ffmpeg", "-i", filename, "-f", "s16le", "-")
    stdout, err := cmd.StdoutPipe()
    if err != nil {
    log.Fatal(err)
    }
    if err := cmd.Start(); err != nil {
    log.Fatal(err)
    }
    return &ffmpeg{stdout, cmd}
    }

    func (f *ffmpeg) Close() error {
    return f.in.Close()
    }

    func (f *ffmpeg) ProcessAudio(_, out [][]int16) {
    // int16 takes 2 bytes
    bufferSize := len(out[0]) * 4
    var pack = make([]byte, bufferSize)
    if _, err := f.in.Read(pack); err != nil {
    log.Fatal(err)
    }
    n := make([]int16, len(out[0])*2)
    for i := range n {
    var x int16
    buf := bytes.NewBuffer(pack[2*i : 2*(i+1)])
    binary.Read(buf, binary.LittleEndian, &x)
    n[i] = x
    }

    for i := range out[0] {
    out[0][i] = n[2*i]
    out[1][i] = n[2*i+1]
    }
    }