Feat add no standard jpeg decoder (#41)

* feat: add non-standard jpeg decoder

- add non-standard jpeg decoder
- add test for non-standard jpeg

Signed-off-by: Caijinglong <[email protected]>

Author: CaiJingLong

example/asset/test.MP.jpg

@@ -1,6 +1,7 @@
 # CHANGELOG
 
 - [CHANGELOG](#changelog)
+  - [2.2.0](#220)
   - [2.1.3](#213)
   - [2.1.2](#212)
   - [2.1.1](#211)
@@ -14,6 +15,12 @@
   - [0.1.1](#011)
   - [0.1.0](#010)
 
+## 2.2.0
+
+Feature:
+
+- Add non-standard jpeg decoder
+
 ## 2.1.3
 
 Fix:

packages/image_size_getter/CHANGELOG.md

@@ -9,10 +9,13 @@ import 'package:image_size_getter/src/entity/block_entity.dart';
 /// {@endtemplate}
 class JpegDecoder extends BaseDecoder with SimpleTypeValidator {
   /// {@macro image_size_getter.JpegDecoder}
-  const JpegDecoder();
+  const JpegDecoder({
+    this.isStandardJpeg = true,
+  });
 
+  final bool isStandardJpeg;
   @override
-  String get decoderName => 'jpeg';
+  String get decoderName => isStandardJpeg ? 'jpeg' : 'non-standard-jpeg';
 
   @override
   Size getSize(ImageInput input) {
@@ -138,7 +141,8 @@ class JpegDecoder extends BaseDecoder with SimpleTypeValidator {
   }
 
   @override
-  SimpleFileHeaderAndFooter get simpleFileHeaderAndFooter => _JpegInfo();
+  SimpleFileHeaderAndFooter get simpleFileHeaderAndFooter =>
+      isStandardJpeg ? _JpegInfo() : _NonStandardJpegInfo();
 
   int? _getOrientation(List<int> app1blockData) {
     // About EXIF, See: https://www.media.mit.edu/pia/Research/deepview/exif.html#orientation
@@ -213,3 +217,19 @@ class _JpegInfo with SimpleFileHeaderAndFooter {
   @override
   List<int> get startBytes => start;
 }
+
+/// Non-standard JPEG Info
+///
+/// Some mvimg files have a non-standard header.
+///
+/// The file is not end with 0xFFD9, so we need to use this to get the size.
+class _NonStandardJpegInfo with SimpleFileHeaderAndFooter {
+  static const start = [0xFF, 0xD8];
+  static const end = <int>[];
+
+  @override
+  List<int> get endBytes => end;
+
+  @override
+  List<int> get startBytes => start;
+}

packages/image_size_getter/lib/src/decoder/impl/jpeg_decoder.dart

@@ -41,6 +41,7 @@ class _DecoderContainer extends IterableBase<BaseDecoder> {
 final _decoders = _DecoderContainer([
   const GifDecoder(),
   const JpegDecoder(),
+  const JpegDecoder(isStandardJpeg: false),
   const WebpDecoder(),
   const PngDecoder(),
   const BmpDecoder(),

packages/image_size_getter/lib/src/image_size_getter.dart

@@ -1,6 +1,6 @@
 name: image_size_getter
 description: Get image width and height, the library does not completely decode the image file, just read the metadata to get the image width and height.
-version: 2.1.3
+version: 2.2.0
 homepage: https://github.com/CaiJingLong/dart_image_size_getter
 # publish_to: https://pub.dev
 

packages/image_size_getter/pubspec.yaml

@@ -26,6 +26,18 @@ void main() {
       expect(decoder.getSize(input), Size(4032, 3024));
     });
 
+
+    test('Test non-standard jpeg decoder', () {
+      final jpeg = File('../../example/asset/test.MP.jpg');
+
+      const JpegDecoder decoder = JpegDecoder(isStandardJpeg: false);
+      final input = FileInput(jpeg);
+
+      assert(decoder.isValid(input));
+      expect(decoder.getSize(input), Size(3840, 2160, needRotate: true));
+    });
+
+
     test('Test png decoder', () {
       final png = File('../../example/asset/ic_launcher.png');
 
@@ -103,6 +115,13 @@ void main() {
       await expectLater(size, Size(4032, 3024));
     });
 
+    test('Test non-standard jpeg size', () async {
+      final file = File('../../example/asset/test.MP.jpg');
+      final size = ImageSizeGetter.getSize(FileInput(file));
+      print('size = $size');
+      await expectLater(size, Size(3840, 2160, needRotate: true));
+    });
+
     group('Test gif size', () {
       test('89a', () async {
         final file = File('../../example/asset/dialog.gif');