feat: support gpt-4o-audio

common/helper/audio.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"io"
+	"math"
 	"os"
 	"os/exec"
 	"strconv"
@@ -13,7 +14,11 @@ import (
 
 // SaveTmpFile saves data to a temporary file. The filename would be apppended with a random string.
 func SaveTmpFile(filename string, data io.Reader) (string, error) {
-	f, err := os.CreateTemp(os.TempDir(), filename)
+	if data == nil {
+		return "", errors.New("data is nil")
+	}
+
+	f, err := os.CreateTemp("", "*-"+filename)
 	if err != nil {
 		return "", errors.Wrapf(err, "failed to create temporary file %s", filename)
 	}
@@ -27,6 +32,22 @@ func SaveTmpFile(filename string, data io.Reader) (string, error) {
 	return f.Name(), nil
 }
 
+// GetAudioTokens returns the number of tokens in an audio file.
+func GetAudioTokens(ctx context.Context, audio io.Reader, tokensPerSecond int) (int, error) {
+	filename, err := SaveTmpFile("audio", audio)
+	if err != nil {
+		return 0, errors.Wrap(err, "failed to save audio to temporary file")
+	}
+	defer os.Remove(filename)
+
+	duration, err := GetAudioDuration(ctx, filename)
+	if err != nil {
+		return 0, errors.Wrap(err, "failed to get audio tokens")
+	}
+
+	return int(math.Ceil(duration)) * tokensPerSecond, nil
+}
+
 // GetAudioDuration returns the duration of an audio file in seconds.
 func GetAudioDuration(ctx context.Context, filename string) (float64, error) {
 	// ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 {{input}}
@@ -36,5 +57,7 @@ func GetAudioDuration(ctx context.Context, filename string) (float64, error) {
 		return 0, errors.Wrap(err, "failed to get audio duration")
 	}
 
+	// Actually gpt-4-audio calculates tokens with 0.1s precision,
+	// while whisper calculates tokens with 1s precision
 	return strconv.ParseFloat(string(bytes.TrimSpace(output)), 64)
 }

common/helper/audio_test.go

@@ -35,3 +35,21 @@ func TestGetAudioDuration(t *testing.T) {
 		require.Error(t, err)
 	})
 }
+
+func TestGetAudioTokens(t *testing.T) {
+	t.Run("should return correct tokens for a valid audio file", func(t *testing.T) {
+		// download test audio file
+		resp, err := http.Get("https://s3.laisky.com/uploads/2025/01/audio-sample.m4a")
+		require.NoError(t, err)
+		defer resp.Body.Close()
+
+		tokens, err := GetAudioTokens(context.Background(), resp.Body, 50)
+		require.NoError(t, err)
+		require.Equal(t, tokens, 200)
+	})
+
+	t.Run("should return an error for a non-existent file", func(t *testing.T) {
+		_, err := GetAudioTokens(context.Background(), nil, 1)
+		require.Error(t, err)
+	})
+}