85 lines
2.1 KiB
Go
85 lines
2.1 KiB
Go
package speech
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import (
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"bytes"
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"context"
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"fmt"
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"os"
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"os/exec"
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"path/filepath"
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"github.com/google/uuid"
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)
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type FFmpegConverter struct {
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ffmpegPath string
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tempDir string
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}
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func NewFFmpegConverter(ffmpegPath, tempDir string) *FFmpegConverter {
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if ffmpegPath == "" {
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ffmpegPath = "ffmpeg"
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}
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if tempDir == "" {
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tempDir = os.TempDir()
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}
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return &FFmpegConverter{ffmpegPath: ffmpegPath, tempDir: tempDir}
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}
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// Convert converts audio bytes between formats and returns the converted bytes.
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// Intermediate temp files are cleaned up automatically — use ConvertFile when
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// you need to keep the output on disk.
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func (c *FFmpegConverter) Convert(ctx context.Context, input []byte, fromMime, toMime string) ([]byte, error) {
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id := uuid.New().String()
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inFile := filepath.Join(c.tempDir, id+".input")
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outFile := filepath.Join(c.tempDir, id+".wav")
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defer os.Remove(inFile)
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defer os.Remove(outFile)
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if err := os.WriteFile(inFile, input, 0600); err != nil {
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return nil, fmt.Errorf("write temp input: %w", err)
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}
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if err := c.runFFmpeg(ctx, inFile, outFile); err != nil {
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return nil, err
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}
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out, err := os.ReadFile(outFile)
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if err != nil {
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return nil, fmt.Errorf("read converted file: %w", err)
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}
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return out, nil
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}
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// ConvertFile converts audio bytes and writes the WAV output to outPath.
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// The caller is responsible for deleting outPath when no longer needed.
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func (c *FFmpegConverter) ConvertFile(ctx context.Context, input []byte, outPath string) error {
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id := uuid.New().String()
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inFile := filepath.Join(c.tempDir, id+".input")
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defer os.Remove(inFile)
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if err := os.WriteFile(inFile, input, 0600); err != nil {
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return fmt.Errorf("write temp input: %w", err)
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}
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return c.runFFmpeg(ctx, inFile, outPath)
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}
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func (c *FFmpegConverter) runFFmpeg(ctx context.Context, inFile, outFile string) error {
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cmd := exec.CommandContext(ctx, c.ffmpegPath,
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"-i", inFile,
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"-ar", "16000",
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"-ac", "1",
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"-f", "wav",
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"-y",
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outFile,
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)
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var stderr bytes.Buffer
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cmd.Stderr = &stderr
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if err := cmd.Run(); err != nil {
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return fmt.Errorf("ffmpeg conversion: %w: %s", err, stderr.String())
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}
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return nil
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}
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