.remake audio quality analyzer
This commit is contained in:
afkarxyz
+21
-184
@@ -2,170 +2,26 @@ package backend
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import (
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"fmt"
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"math"
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"os"
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"os/exec"
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"strconv"
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"strings"
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"time"
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"github.com/go-flac/go-flac"
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mewflac "github.com/mewkiz/flac"
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)
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type AnalysisResult struct {
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FilePath string `json:"file_path"`
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FileSize int64 `json:"file_size"`
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SampleRate uint32 `json:"sample_rate"`
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Channels uint8 `json:"channels"`
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BitsPerSample uint8 `json:"bits_per_sample"`
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TotalSamples uint64 `json:"total_samples"`
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Duration float64 `json:"duration"`
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Bitrate int `json:"bit_rate"`
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BitDepth string `json:"bit_depth"`
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DynamicRange float64 `json:"dynamic_range"`
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PeakAmplitude float64 `json:"peak_amplitude"`
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RMSLevel float64 `json:"rms_level"`
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Spectrum *SpectrumData `json:"spectrum,omitempty"`
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}
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func AnalyzeTrack(filepath string) (*AnalysisResult, error) {
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if !fileExists(filepath) {
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return nil, fmt.Errorf("file does not exist: %s", filepath)
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}
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fileInfo, err := os.Stat(filepath)
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if err != nil {
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return nil, fmt.Errorf("failed to get file info: %w", err)
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}
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f, err := flac.ParseFile(filepath)
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if err != nil {
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return nil, fmt.Errorf("failed to parse FLAC file: %w", err)
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}
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result := &AnalysisResult{
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FilePath: filepath,
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FileSize: fileInfo.Size(),
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}
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if len(f.Meta) > 0 {
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streamInfo := f.Meta[0]
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if streamInfo.Type == flac.StreamInfo {
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data := streamInfo.Data
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if len(data) >= 18 {
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result.SampleRate = uint32(data[10])<<12 | uint32(data[11])<<4 | uint32(data[12])>>4
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result.Channels = ((data[12] >> 1) & 0x07) + 1
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result.BitsPerSample = ((data[12]&0x01)<<4 | data[13]>>4) + 1
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result.TotalSamples = uint64(data[13]&0x0F)<<32 |
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uint64(data[14])<<24 |
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uint64(data[15])<<16 |
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uint64(data[16])<<8 |
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uint64(data[17])
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if result.SampleRate > 0 {
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result.Duration = float64(result.TotalSamples) / float64(result.SampleRate)
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}
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}
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}
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}
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spectrum, err := AnalyzeSpectrum(filepath)
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if err != nil {
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fmt.Printf("Warning: failed to analyze spectrum: %v\n", err)
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} else {
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result.Spectrum = spectrum
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calculateRealAudioMetrics(result, filepath)
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}
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result.BitDepth = fmt.Sprintf("%d-bit", result.BitsPerSample)
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return result, nil
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}
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func calculateRealAudioMetrics(result *AnalysisResult, filepath string) {
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samples, err := decodeFLACForMetrics(filepath)
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if err != nil {
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return
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}
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var peak float64
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var sumSquares float64
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for _, sample := range samples {
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absVal := sample
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if absVal < 0 {
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absVal = -absVal
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}
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if absVal > peak {
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peak = absVal
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}
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sumSquares += sample * sample
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}
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peakDB := 20.0 * math.Log10(peak)
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result.PeakAmplitude = peakDB
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rms := math.Sqrt(sumSquares / float64(len(samples)))
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rmsDB := 20.0 * math.Log10(rms)
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result.RMSLevel = rmsDB
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result.DynamicRange = peakDB - rmsDB
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}
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func decodeFLACForMetrics(filepath string) ([]float64, error) {
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stream, err := mewflac.ParseFile(filepath)
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if err != nil {
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return nil, err
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}
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defer stream.Close()
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maxSamples := 10000000
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samples := make([]float64, 0, maxSamples)
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for {
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frame, err := stream.ParseNext()
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if err != nil {
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break
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}
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var channelSamples []int32
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if len(frame.Subframes) > 0 {
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channelSamples = frame.Subframes[0].Samples
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}
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maxVal := float64(int64(1) << (stream.Info.BitsPerSample - 1))
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for _, sample := range channelSamples {
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if len(samples) >= maxSamples {
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return samples, nil
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}
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normalized := float64(sample) / maxVal
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samples = append(samples, normalized)
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}
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if len(samples) >= maxSamples {
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break
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}
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}
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return samples, nil
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}
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func GetFileSize(filepath string) (int64, error) {
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info, err := os.Stat(filepath)
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if err != nil {
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return 0, err
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}
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return info.Size(), nil
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FilePath string `json:"file_path"`
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FileSize int64 `json:"file_size"`
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SampleRate uint32 `json:"sample_rate"`
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Channels uint8 `json:"channels"`
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BitsPerSample uint8 `json:"bits_per_sample"`
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TotalSamples uint64 `json:"total_samples"`
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Duration float64 `json:"duration"`
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Bitrate int `json:"bit_rate"`
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BitDepth string `json:"bit_depth"`
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DynamicRange float64 `json:"dynamic_range"`
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PeakAmplitude float64 `json:"peak_amplitude"`
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RMSLevel float64 `json:"rms_level"`
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}
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func GetTrackMetadata(filepath string) (*AnalysisResult, error) {
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@@ -194,20 +50,23 @@ func GetMetadataWithFFprobe(filePath string) (*AnalysisResult, error) {
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"-v", "error",
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"-select_streams", "a:0",
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"-show_entries", "stream=sample_rate,channels,bits_per_raw_sample,bits_per_sample,duration,bit_rate",
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"-of", "default=noprint_wrappers=1:nokey=1",
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"-of", "default=noprint_wrappers=0",
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filePath,
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}
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cmd := exec.Command(ffprobePath, args...)
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setHideWindow(cmd)
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output, err := cmd.CombinedOutput()
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if err != nil {
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return nil, fmt.Errorf("ffprobe failed: %w - %s", err, string(output))
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return nil, fmt.Errorf("ffprobe failed: %v - %s", err, string(output))
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}
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lines := strings.Split(strings.TrimSpace(string(output)), "\n")
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if len(lines) < 4 {
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return nil, fmt.Errorf("unexpected ffprobe output: %s", string(output))
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infoMap := make(map[string]string)
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lines := strings.Split(string(output), "\n")
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for _, line := range lines {
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if strings.Contains(line, "=") {
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parts := strings.SplitN(line, "=", 2)
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infoMap[strings.TrimSpace(parts[0])] = strings.TrimSpace(parts[1])
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}
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}
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res := &AnalysisResult{
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@@ -218,28 +77,6 @@ func GetMetadataWithFFprobe(filePath string) (*AnalysisResult, error) {
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res.FileSize = info.Size()
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}
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infoMap := make(map[string]string)
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args = []string{
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"-v", "error",
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"-select_streams", "a:0",
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"-show_entries", "stream=sample_rate,channels,bits_per_raw_sample,bits_per_sample,duration,bit_rate",
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"-of", "default=noprint_wrappers=0",
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filePath,
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}
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cmd = exec.Command(ffprobePath, args...)
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setHideWindow(cmd)
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output, err = cmd.CombinedOutput()
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if err == nil {
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lines = strings.Split(string(output), "\n")
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for _, line := range lines {
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if strings.Contains(line, "=") {
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parts := strings.SplitN(line, "=", 2)
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infoMap[strings.TrimSpace(parts[0])] = strings.TrimSpace(parts[1])
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}
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}
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}
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if val, ok := infoMap["sample_rate"]; ok {
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s, _ := strconv.Atoi(val)
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res.SampleRate = uint32(s)
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