info: show picture embedded in videos

android/app/src/main/java/deckers/thibault/aves/channel/calls/MetadataHandler.java

@@ -190,6 +190,9 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
             case "getContentResolverMetadata":
                 new Thread(() -> getContentResolverMetadata(call, new MethodResultWrapper(result))).start();
                 break;
+            case "getEmbeddedPictures":
+                new Thread(() -> getEmbeddedPictures(call, new MethodResultWrapper(result))).start();
+                break;
             case "getExifThumbnails":
                 new Thread(() -> getExifThumbnails(call, new MethodResultWrapper(result))).start();
                 break;
@@ -415,7 +418,7 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
                                     metadataMap.put(KEY_LATITUDE, latitude);
                                     metadataMap.put(KEY_LONGITUDE, longitude);
                                 }
-                            } catch (NumberFormatException ex) {
+                            } catch (NumberFormatException e) {
                                 // ignore
                             }
                         }
@@ -530,6 +533,26 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
         }
     }
 
+    private void getEmbeddedPictures(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {
+        Uri uri = Uri.parse(call.argument("uri"));
+        List<byte[]> pictures = new ArrayList<>();
+        MediaMetadataRetriever retriever = StorageUtils.openMetadataRetriever(context, uri);
+        if (retriever != null) {
+            try {
+                byte[] picture = retriever.getEmbeddedPicture();
+                if (picture != null) {
+                    pictures.add(picture);
+                }
+            } catch (Exception e) {
+                result.error("getVideoEmbeddedPictures-failure", "failed to get embedded picture for uri=" + uri, e);
+            } finally {
+                // cannot rely on `MediaMetadataRetriever` being `AutoCloseable` on older APIs
+                retriever.release();
+            }
+        }
+        result.success(pictures);
+    }
+
     private void getExifThumbnails(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {
         Uri uri = Uri.parse(call.argument("uri"));
         List<byte[]> thumbnails = new ArrayList<>();

android/app/src/main/java/deckers/thibault/aves/decoder/VideoThumbnailFetcher.java

@@ -40,8 +40,8 @@ class VideoThumbnailFetcher implements DataFetcher<InputStream> {
                     }
                     callback.onDataReady(new ByteArrayInputStream(bos.toByteArray()));
                 }
-            } catch (Exception ex) {
+            } catch (Exception e) {
-                callback.onLoadFailed(ex);
+                callback.onLoadFailed(e);
             } finally {
                 // cannot rely on `MediaMetadataRetriever` being `AutoCloseable` on older APIs
                 retriever.release();

android/app/src/main/java/deckers/thibault/aves/utils/MetadataHelper.java

@@ -55,7 +55,7 @@ public class MetadataHelper {
             DateFormat parser = new SimpleDateFormat("yyyyMMdd'T'HHmmss", Locale.US);
             parser.setTimeZone((timeZone != null) ? timeZone : TimeZone.getTimeZone("GMT"));
             date = parser.parse(dateString);
-        } catch (ParseException ex) {
+        } catch (ParseException e) {
             // ignore
         }
 

lib/services/metadata_service.dart

@@ -89,6 +89,18 @@ class MetadataService {
     return {};
   }
 
+  static Future<List<Uint8List>> getEmbeddedPictures(String uri) async {
+    try {
+      final result = await platform.invokeMethod('getEmbeddedPictures', <String, dynamic>{
+        'uri': uri,
+      });
+      return (result as List).cast<Uint8List>();
+    } on PlatformException catch (e) {
+      debugPrint('getEmbeddedPictures failed with code=${e.code}, exception=${e.message}, details=${e.details}');
+    }
+    return [];
+  }
+
   static Future<List<Uint8List>> getExifThumbnails(String uri) async {
     try {
       final result = await platform.invokeMethod('getExifThumbnails', <String, dynamic>{

lib/widgets/fullscreen/info/metadata_section.dart

@@ -36,8 +36,9 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
   static const int maxValueLength = 140;
 
   // directory names from metadata-extractor
-  static const exifThumbnailDirectory = 'Exif Thumbnail';
+  static const exifThumbnailDirectory = 'Exif Thumbnail'; // from metadata-extractor
-  static const xmpDirectory = 'XMP';
+  static const xmpDirectory = 'XMP'; // from metadata-extractor
+  static const videoDirectory = 'Video'; // additional generic video directory
 
   @override
   void initState() {
@@ -106,6 +107,7 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
                 SizedBox(height: 4),
                 if (dir.name == exifThumbnailDirectory) MetadataThumbnails(source: MetadataThumbnailSource.exif, entry: entry),
                 if (dir.name == xmpDirectory) MetadataThumbnails(source: MetadataThumbnailSource.xmp, entry: entry),
+                if (dir.name == videoDirectory) MetadataThumbnails(source: MetadataThumbnailSource.embedded, entry: entry),
                 Container(
                   alignment: Alignment.topLeft,
                   padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),

lib/widgets/fullscreen/info/metadata_thumbnail.dart

@@ -5,7 +5,7 @@ import 'package:aves/model/image_entry.dart';
 import 'package:aves/services/metadata_service.dart';
 import 'package:flutter/material.dart';
 
-enum MetadataThumbnailSource { exif, xmp }
+enum MetadataThumbnailSource { embedded, exif, xmp }
 
 class MetadataThumbnails extends StatefulWidget {
   final MetadataThumbnailSource source;
@@ -24,15 +24,22 @@ class MetadataThumbnails extends StatefulWidget {
 class _MetadataThumbnailsState extends State<MetadataThumbnails> {
   Future<List<Uint8List>> _loader;
 
+  ImageEntry get entry => widget.entry;
+
+  String get uri => entry.uri;
+
   @override
   void initState() {
     super.initState();
     switch (widget.source) {
+      case MetadataThumbnailSource.embedded:
+        _loader = MetadataService.getEmbeddedPictures(uri);
+        break;
       case MetadataThumbnailSource.exif:
-        _loader = MetadataService.getExifThumbnails(widget.entry.uri);
+        _loader = MetadataService.getExifThumbnails(uri);
         break;
       case MetadataThumbnailSource.xmp:
-        _loader = MetadataService.getXmpThumbnails(widget.entry.uri);
+        _loader = MetadataService.getXmpThumbnails(uri);
         break;
     }
   }
@@ -43,7 +50,7 @@ class _MetadataThumbnailsState extends State<MetadataThumbnails> {
         future: _loader,
         builder: (context, snapshot) {
           if (!snapshot.hasError && snapshot.connectionState == ConnectionState.done && snapshot.data.isNotEmpty) {
-            final turns = (widget.entry.orientationDegrees / 90).round();
+            final turns = (entry.orientationDegrees / 90).round();
             final devicePixelRatio = MediaQuery.of(context).devicePixelRatio;
             return Container(
               alignment: AlignmentDirectional.topStart,