Play sample loud and choppy

[brydavis]

Trying to use PortAudio to play... It's super loud and choppy.

package main

import (
	"flag"
	"fmt"
	"io"
	"os"

	"strings"

	"github.com/go-audio/audio"
	"github.com/go-audio/wav"
	"github.com/gordonklaus/portaudio"
)

var (
	flagInput  = flag.String("input", "/Users/brydavis/sounds/The Malinchak Show Episode 108.wav", "The file to convert")
	flagFormat = flag.String("format", "wav", "The format to convert to (wav or aiff)")
	flagOutput = flag.String("output", "out", "The output filename")
)

func main() {
	flag.Parse()
	if *flagInput == "" {
		fmt.Println("Provide an input file using the -input flag")
		os.Exit(1)
	}
	switch strings.ToLower(*flagFormat) {
	case "aiff", "aif":
		*flagFormat = "aiff"
	case "wave", "wav":
		*flagFormat = "wav"
	default:
		fmt.Println("Provide a valid -format flag")
		os.Exit(1)
	}
	f, err := os.Open(*flagInput)
	if err != nil {
		panic(err)
	}
	defer f.Close()

	var buf *audio.IntBuffer

	wd := wav.NewDecoder(f)

	if !wd.WasPCMAccessed() {
		err := wd.FwdToPCM()
		if err != nil {
			panic(err)
		}
	}

	framePerBuffer := 2048

	buf = &audio.IntBuffer{Format: wd.Format(), Data: make([]int, framePerBuffer)}
	var n int
	var doneReading bool

	portaudio.Initialize()
	defer portaudio.Terminate()

	out := make([]float32, framePerBuffer)

	stream, err := portaudio.OpenDefaultStream(0, 2, 44100, framePerBuffer, &out)

	if err != nil {
		fmt.Printf("unable to open port audio stream for playback: %s\n", err.Error())
		os.Exit(1)
		return
	}

	defer stream.Close()

	if err := stream.Start(); err != nil {
		fmt.Printf("unable to open port audio stream for playback: %s\n", err.Error())
		os.Exit(1)
		return
	}

	defer stream.Stop()

	for err == nil {
		n, err = wd.PCMBuffer(buf)
		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
			fmt.Println(err)
		}

		if n != len(buf.Data) {
			buf.Data = buf.Data[:n]
			doneReading = true
		}

		intToF32Copy(out, buf.Data)

		// write to the stream
		if err := stream.Write(); err != nil {
			fmt.Println(err)
		}

		if doneReading {
			break
		}
	}

}

// portaudio doesn't support float64 so we need to copy our data over to the
// destination buffer.
func intToF32Copy(dst []float32, src []int) {
	for i := range src {
		dst[i] = float32(src[i])
	}
}

[brydavis]

Well, for some reason, when I set framePerBuffer := 8192 and out := make([]int16, framePerBuffer), things seem to work fine...

Based it on this example.