package main import ( "bytes" "encoding/json" "fmt" "os/exec" "strconv" "strings" ) type FFProbeOutput struct { Streams []struct { CodecName string `json:"codec_name"` } `json:"streams"` } // runs ffprobe with the provided args and returns (stdout, stderr, error) func runFfprobe(args []string) ([]byte, []byte, error) { ffprobe := "ffprobe" fmt.Println(ffprobe, strings.Join(args, " ")) cmd := exec.Command(ffprobe, args...) var stdout bytes.Buffer var stderr bytes.Buffer cmd.Stdout = &stdout cmd.Stderr = &stderr err := cmd.Run() if err != nil { fmt.Println("ffprobe error:", err, stdout.String(), stderr.String()) } return stdout.Bytes(), stderr.Bytes(), err } func getAudioFormat(filename string) (string, error) { output, _, err := runFfprobe([]string{"-v", "quiet", "-print_format", "json", "-show_streams", filename}) if err != nil { return "", fmt.Errorf("ffprobe execution failed: %v", err) } var ffprobeOutput FFProbeOutput err = json.Unmarshal(output, &ffprobeOutput) if err != nil { return "", fmt.Errorf("failed to parse ffprobe output: %v", err) } numStreams := len(ffprobeOutput.Streams) if numStreams > 1 || numStreams <= 0 { return "", fmt.Errorf("%d streams in ffprobe output", numStreams) } return ffprobeOutput.Streams[0].CodecName, nil } func getStreamBitrate(path string, stream int) (uint, error) { ffprobeArgs := []string{ "-v", "quiet", "-select_streams", fmt.Sprintf("a:%d", stream), "-show_entries", "stream=bit_rate", "-of", "default=noprint_wrappers=1:nokey=1", path} stdout, _, err := runFfprobe(ffprobeArgs) if err != nil { fmt.Println("getAudioBitrate error:", err, string(stdout)) return 0, err } bitrateStr := strings.TrimSpace(string(stdout)) bitrate, err := strconv.ParseUint(bitrateStr, 10, 32) if err != nil { fmt.Println("getAudioBitrate error:", err) return 0, err } return uint(bitrate), nil } func getFormatBitrate(path string) (uint, error) { ffprobeArgs := []string{ "-v", "quiet", "-show_entries", "format=bit_rate", "-of", "default=noprint_wrappers=1:nokey=1", path} stdout, _, err := runFfprobe(ffprobeArgs) if err != nil { fmt.Println("getFormatBitrate error:", err, string(stdout)) return 0, err } bitrateStr := strings.TrimSpace(string(stdout)) bitrate, err := strconv.ParseUint(bitrateStr, 10, 32) if err != nil { fmt.Println("getFormatBitrate error:", err) return 0, err } return uint(bitrate), nil }