fix video thumbnail

lib/src/message_input.dart

@@ -1316,10 +1316,18 @@ class MessageInputState extends State<MessageInput> {
           children: [
             Positioned.fill(
               child: Container(
-                child: VideoThumbnail(
-                  file: File(
-                    attachment.file.path,
-                  ),
+                child: FutureBuilder<File>(
+                  future: VideoCompress.getFileThumbnail(attachment.file.path),
+                  builder: (context, snapshot) {
+                    if (!snapshot.hasData) {
+                      return Offstage();
+                    }
+
+                    return Image.file(
+                      snapshot.data,
+                      fit: BoxFit.cover,
+                    );
+                  },
                 ),
               ),
             ),

lib/src/video_thumbnail.dart

@@ -1,37 +0,0 @@
-import 'dart:io';
-
-import 'package:flutter/material.dart';
-import 'package:video_player/video_player.dart';
-
-class VideoThumbnail extends StatefulWidget {
-  final File file;
-
-  const VideoThumbnail({
-    Key key,
-    @required this.file,
-  }) : super(key: key);
-
-  @override
-  _VideoThumbnailState createState() => _VideoThumbnailState();
-}
-
-class _VideoThumbnailState extends State<VideoThumbnail> {
-  VideoPlayerController _videoPlayerController;
-  @override
-  Widget build(BuildContext context) {
-    return VideoPlayer(_videoPlayerController);
-  }
-
-  @override
-  void initState() {
-    _videoPlayerController = VideoPlayerController.file(widget.file)
-      ..initialize();
-    super.initState();
-  }
-
-  @override
-  void dispose() {
-    _videoPlayerController.dispose();
-    super.dispose();
-  }
-}