Partially refactor stuff

audio/audio.go

@@ -1,53 +0,0 @@
-package audio
-
-import (
-	"os/exec"
-	"fmt"
-	"regexp"
-)
-
-
-type MicStreamConfig struct {
-	Format string
-	Device string
-	Encoding string
-	Bitrate int
-	Channels int
-}
-
-func StreamMic(config MicStreamConfig) *exec.Cmd {
-	cmd := exec.Command("ffmpeg", "-re",
-		"-f", config.Format,
-		"-i", config.Device,
-		"-f", config.Encoding,
-		"-ar", fmt.Sprintf("%d", config.Bitrate),
-		"-ac", fmt.Sprintf("%d", config.Channels),
-		"-",
-	)
-	return cmd
-}
-
-func GetMicDevice() (string, error) {
-	cmd := exec.Command("ffmpeg",
-		"-f", "avfoundation",
-		"-list_devices", "true",
-		"-i", "\"\"",
-	)
-	// ignore error, this ffmpeg command returns exit status 1
-	outputBytes, _ := cmd.CombinedOutput()
-	output := string(outputBytes)
-	parsedOutput := parseDeviceNumber(output)
-	if parsedOutput == "" {
-		return "", fmt.Errorf("Command: %s\nFailed to parse FFmpeg output:\n%s", cmd, output)
-	}
-	return parsedOutput, nil
-}
-
-func parseDeviceNumber(ffmpegOutput string) string {
-	re := regexp.MustCompile(`\[(\d)\].*?[Mm]icrophone`)
-	matches := re.FindStringSubmatch(ffmpegOutput)	
-	if (len(matches) == 2) {
-		return matches[1]
-	}
-	return ""
-}

audio/encoding.go

@@ -0,0 +1,13 @@
+package audio
+
+type Encoding struct {
+	Codec string
+	Bitrate int
+	Channels int
+}
+
+var defaultEncoding = Encoding{
+	Codec: "s16le",
+	Bitrate: 44100,
+	Channels: 2,
+}

audio/ffmpeg.go

@@ -0,0 +1,102 @@
+package audio
+
+import (
+	"os/exec"
+	"fmt"
+	"regexp"
+	"runtime"
+	"io"
+)
+
+
+type microphone struct {
+	command *exec.Cmd
+	audioStream io.Reader
+	diagnosticOutput io.Reader
+	Format string
+	Device string
+	Encoding Encoding
+}
+
+func NewMicrophone() (*microphone, error) {
+	if runtime.GOOS != "darwin" {
+		panic(fmt.Errorf("audio.microphone is only supported on macOS"))
+	}
+	format := "avfoundation"
+	device, err := getMicDevice(format)
+	if err != nil {
+		return nil, err
+	}
+	return &microphone{
+		Format: format,
+		Device: device,
+		Encoding: defaultEncoding,
+	}, nil
+}
+
+func (m *microphone) Start() error {
+	m.command = exec.Command("ffmpeg", "-re",
+		"-f", m.Format,
+		"-i", m.Device,
+		"-f", m.Encoding.Codec,
+		"-ar", fmt.Sprintf("%d", m.Encoding.Bitrate),
+		"-ac", fmt.Sprintf("%d", m.Encoding.Channels),
+		"-",
+	)
+
+	// these should never fail, unless you use the module incorrectly
+	audioStream, err := m.command.StdoutPipe()
+	if err != nil {
+		panic(err)
+	}
+	diagnosticOutput, err := m.command.StderrPipe()
+	if err != nil {
+		panic(err)
+	}
+
+	m.audioStream, m.diagnosticOutput = audioStream, diagnosticOutput
+	return m.command.Start()
+}
+
+func (m *microphone) Stop() error {
+	return m.command.Process.Kill()
+}
+
+func (m *microphone) AudioStream() io.Reader {
+	if m.audioStream == nil {
+		panic(fmt.Errorf("AudioStream() called before Start()"))
+	}
+	return m.audioStream
+}
+
+func (m *microphone) DiagnosticOutput() io.Reader {
+	if m.diagnosticOutput == nil {
+		panic(fmt.Errorf("DiagnosticOutput() called before Start()"))
+	}
+	return m.diagnosticOutput
+}
+
+func getMicDevice(format string) (string, error) {
+	cmd := exec.Command("ffmpeg",
+		"-f", format,
+		"-list_devices", "true",
+		"-i", "\"\"",
+	)
+	// ignore error, this ffmpeg command returns exit status 1
+	outputBytes, _ := cmd.CombinedOutput()
+	output := string(outputBytes)
+	parsedOutput := parseDeviceNumber(output)
+	if parsedOutput == "" {
+		return "", fmt.Errorf("Command: %s\nFailed to parse FFmpeg output:\n%s", cmd, output)
+	}
+	return parsedOutput, nil
+}
+
+func parseDeviceNumber(ffmpegOutput string) string {
+	re := regexp.MustCompile(`\[(\d)\].*?[Mm]icrophone`)
+	matches := re.FindStringSubmatch(ffmpegOutput)	
+	if (len(matches) == 2) {
+		return matches[1]
+	}
+	return ""
+}

audio/pulsectl.go

@@ -0,0 +1,50 @@
+package audio
+
+import (
+	"os/exec"
+	"fmt"
+	"path"
+	"runtime"
+)
+
+
+type pulsectl struct {
+	PipeName string
+	PipeDir string
+	Encoding Encoding
+}
+
+func NewPulsectl() *pulsectl {
+	if runtime.GOOS != "linux" {
+		panic(fmt.Errorf("audio.pulsectl is only supported on Linux"))
+	}
+	return &pulsectl{
+		PipeName: "remote-mic",
+		PipeDir: "/dev/shm",
+		Encoding: defaultEncoding,
+	}
+}
+
+func (p *pulsectl) LoadPipeSourceModule() error {
+	cmd := exec.Command("pactl", "load-module", "module-pipe-source",
+		fmt.Sprintf("source_name=%s", p.PipeName),
+		fmt.Sprintf("file=%s", path.Join(p.PipeDir, p.PipeName)),
+		fmt.Sprintf("format=%s", p.Encoding.Codec),
+		fmt.Sprintf("rate=%d", p.Encoding.Bitrate),
+		fmt.Sprintf("channels=%d", p.Encoding.Channels),
+	)
+	outBytes, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to load pipe source module:\n%s", string(outBytes))
+	}
+	return nil
+}
+
+func (p *pulsectl) UnloadPipeSourceModule() error {
+	cmd := exec.Command("pactl", "unload-module", "module-pipe-source")
+	outBytes, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed to unload pipe source module:\n%s", string(outBytes))
+	}
+	return nil
+}