Dep (stt): use ffmpeg instead of portaudio

extra/whisper_server.go

@@ -0,0 +1,156 @@
+//go:build extra
+// +build extra
+
+package extra
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"mime/multipart"
+	"net/http"
+	"os/exec"
+	"strings"
+	"sync"
+)
+
+type WhisperServer struct {
+	logger      *slog.Logger
+	ServerURL   string
+	SampleRate  int
+	AudioBuffer *bytes.Buffer
+	recording   bool          // protected by mu
+	mu          sync.Mutex    // protects recording & AudioBuffer
+	cmd         *exec.Cmd     // protected by cmdMu
+	stopCh      chan struct{} // protected by cmdMu
+	cmdMu       sync.Mutex    // protects cmd and stopCh
+}
+
+func (stt *WhisperServer) StartRecording() error {
+	stt.mu.Lock()
+	defer stt.mu.Unlock()
+	if stt.recording {
+		return nil
+	}
+	// Build ffmpeg command for microphone capture
+	args := []string{
+		"-f", "alsa",
+		"-i", "default",
+		"-acodec", "pcm_s16le",
+		"-ar", fmt.Sprint(stt.SampleRate),
+		"-ac", "1",
+		"-f", "s16le",
+		"-",
+	}
+	cmd := exec.Command("ffmpeg", args...)
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("failed to get stdout pipe: %w", err)
+	}
+	stt.cmdMu.Lock()
+	stt.cmd = cmd
+	stt.stopCh = make(chan struct{})
+	stt.cmdMu.Unlock()
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("failed to start ffmpeg: %w", err)
+	}
+	stt.recording = true
+	stt.AudioBuffer.Reset()
+	// Read PCM data in goroutine
+	go func() {
+		buf := make([]byte, 4096)
+		for {
+			select {
+			case <-stt.stopCh:
+				return
+			default:
+				n, err := stdout.Read(buf)
+				if n > 0 {
+					stt.mu.Lock()
+					stt.AudioBuffer.Write(buf[:n])
+					stt.mu.Unlock()
+				}
+				if err != nil {
+					if err != io.EOF {
+						stt.logger.Error("recording read error", "error", err)
+					}
+					return
+				}
+			}
+		}
+	}()
+	return nil
+}
+
+func (stt *WhisperServer) StopRecording() (string, error) {
+	stt.mu.Lock()
+	defer stt.mu.Unlock()
+	if !stt.recording {
+		return "", errors.New("not recording")
+	}
+	stt.recording = false
+	// Stop ffmpeg
+	stt.cmdMu.Lock()
+	if stt.cmd != nil && stt.cmd.Process != nil {
+		stt.cmd.Process.Kill()
+		stt.cmd.Wait()
+	}
+	close(stt.stopCh)
+	stt.cmdMu.Unlock()
+	// Rest of StopRecording unchanged (WAV header + HTTP upload)
+	// ...
+	stt.recording = false
+	// wait loop to finish?
+	if stt.AudioBuffer == nil {
+		err := errors.New("unexpected nil AudioBuffer")
+		stt.logger.Error(err.Error())
+		return "", err
+	}
+	// Create WAV header first
+	body := &bytes.Buffer{}
+	writer := multipart.NewWriter(body)
+	// Add audio file part
+	part, err := writer.CreateFormFile("file", "recording.wav")
+	if err != nil {
+		stt.logger.Error("fn: StopRecording", "error", err)
+		return "", err
+	}
+	// Stream directly to multipart writer: header + raw data
+	dataSize := stt.AudioBuffer.Len()
+	stt.writeWavHeader(part, dataSize)
+	if _, err := io.Copy(part, stt.AudioBuffer); err != nil {
+		stt.logger.Error("fn: StopRecording", "error", err)
+		return "", err
+	}
+	// Reset buffer for next recording
+	stt.AudioBuffer.Reset()
+	// Add response format field
+	err = writer.WriteField("response_format", "text")
+	if err != nil {
+		stt.logger.Error("fn: StopRecording", "error", err)
+		return "", err
+	}
+	if writer.Close() != nil {
+		stt.logger.Error("fn: StopRecording", "error", err)
+		return "", err
+	}
+	// Send request
+	resp, err := http.Post(stt.ServerURL, writer.FormDataContentType(), body) //nolint:noctx
+	if err != nil {
+		stt.logger.Error("fn: StopRecording", "error", err)
+		return "", err
+	}
+	defer resp.Body.Close()
+	// Read and print response
+	responseTextBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		stt.logger.Error("fn: StopRecording", "error", err)
+		return "", err
+	}
+	resptext := strings.TrimRight(string(responseTextBytes), "\n")
+	// in case there are special tokens like [_BEG_]
+	resptext = specialRE.ReplaceAllString(resptext, "")
+	return strings.TrimSpace(strings.ReplaceAll(resptext, "\n ", "\n")), nil
+}