feat(metadata): show average bitrate for lossless files in the track screen

go_backend/exports_metadata.go

@@ -144,6 +144,13 @@ func ReadFileMetadata(filePath string) (string, error) {
 				}
 				if quality.SampleRate > 0 && quality.TotalSamples > 0 {
 					result["duration"] = int(quality.TotalSamples / int64(quality.SampleRate))
+					// Average bitrate from file size: helps spot lossy audio
+					// repackaged as "24-bit" FLAC (real hi-res sits well above
+					// ~1500 kbps, upconverted files far below).
+					durationSec := float64(quality.TotalSamples) / float64(quality.SampleRate)
+					if info, statErr := os.Stat(filePath); statErr == nil && info.Size() > 0 && durationSec > 0 {
+						result["bitrate"] = int(float64(info.Size()) * 8 / durationSec / 1000)
+					}
 				}
 			}
 		}
@@ -164,6 +171,10 @@ func ReadFileMetadata(filePath string) (string, error) {
 			}
 			if quality.Bitrate > 0 && !isLosslessLibraryFormat(fmt.Sprint(result["format"])) {
 				result["bitrate"] = quality.Bitrate
+			} else if quality.Duration > 0 {
+				if info, statErr := os.Stat(filePath); statErr == nil && info.Size() > 0 {
+					result["bitrate"] = int(float64(info.Size()) * 8 / float64(quality.Duration) / 1000)
+				}
 			}
 		}
 	} else if isMp3 {

lib/screens/track_metadata_cards.dart

@@ -706,6 +706,27 @@ extension _TrackMetadataCards on _TrackMetadataScreenState {
                       ),
                     ),
                   ),
+                if (!_isBitrateFormatLabel(fileExtension) &&
+                    _audioBitrate != null &&
+                    _audioBitrate! > 0)
+                  Container(
+                    padding: const EdgeInsets.symmetric(
+                      horizontal: 12,
+                      vertical: 6,
+                    ),
+                    decoration: BoxDecoration(
+                      color: colorScheme.tertiaryContainer,
+                      borderRadius: BorderRadius.circular(20),
+                    ),
+                    child: Text(
+                      '${_audioBitrate}kbps',
+                      style: TextStyle(
+                        color: colorScheme.onTertiaryContainer,
+                        fontWeight: FontWeight.w600,
+                        fontSize: 12,
+                      ),
+                    ),
+                  ),
                 Container(
                   padding: const EdgeInsets.symmetric(
                     horizontal: 12,

lib/screens/track_metadata_screen.dart

@@ -315,11 +315,11 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen>
       final formatChanged =
           resolvedFormat != null &&
           resolvedFormat != normalizeAudioFormatValue(storedFormat);
-      final resolvedBitrate = _isBitrateFormatValue(resolvedFormat)
-          ? _readPlausibleBitrateKbps(
-              metadata['bitrate'] ?? metadata['bit_rate'],
-            )
-          : null;
+      // Lossless files carry an average bitrate too (computed by the backend
+      // from file size / duration) — useful for spotting fake 24-bit rips.
+      final resolvedBitrate = _readPlausibleBitrateKbps(
+        metadata['bitrate'] ?? metadata['bit_rate'],
+      );
       final resolvedDuration = readPositiveInt(metadata['duration']);
       final resolvedAlbum = metadata['album']?.toString();
       final resolvedTitle = metadata['title']?.toString();