Animated webp with a transparent background leaves an afterimage

[WellerZhao]

Steps to Reproduce

you can try this demo.

this webp image display fine in chrome, but not in flutter.

Expected results:

Actual results:

Logs

[VladyslavBondarenko]

Hi @WellerZhao
could you provide your flutter doctor -v?
what device are you running?

[WellerZhao]

Hi @WellerZhao
could you provide your flutter doctor -v?
what device are you running?

[✓] Flutter (Channel stable, v1.17.5, on Mac OS X 10.14.6 18G95, locale zh-Hans-CN)
• Flutter version 1.17.5 at /Users/fnuser/Documents/flutter-sdk
• Framework revision 8af6b2f (9 days ago), 2020-06-30 12:53:55 -0700
• Engine revision ee76268252
• Dart version 2.8.4

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.0)
• Android SDK at /Users/fnuser/Library/Android/sdk/
• Platform android-30, build-tools 30.0.0
• ANDROID_HOME = /Users/fnuser/Library/Android/sdk/
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
• All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.3.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 11.3.1, Build version 11C505
• CocoaPods version 1.9.3

[✓] Android Studio (version 3.5)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 44.0.1
• Dart plugin version 191.8593
• Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)

[✓] VS Code (version 1.47.0)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.12.2

It reproduce in all of my Devices.

Device

iPhoneX 13.5.1

ZUK Z2 Android7.0
MI5s Android8.0 MIUI11.0.2

[VladyslavBondarenko]

Reproduces with current master 1.20.0-8.0.pre.40 when running with Android, iOS or macOS desktop.
When running web .webp image is rendered properly.

flutter doctor -v

[✓] Flutter (Channel master, 1.20.0-8.0.pre.40, on Mac OS X 10.15.5 19F101, locale en-GB)
    • Flutter version 1.20.0-8.0.pre.40 at /Users/nevercode/dev/flutter
    • Framework revision 6eaaf1650e (7 hours ago), 2020-07-09 18:04:37 -0700
    • Engine revision 9b3e3410f0
    • Dart version 2.9.0 (build 2.9.0-20.0.dev 06cb010247)

 
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
    • Android SDK at /Users/nevercode/Library/Android/sdk
    • Platform android-29, build-tools 29.0.3
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.5)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.5, Build version 11E608c
    • CocoaPods version 1.9.1

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 47.0.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.46.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.12.1

[✓] Connected device (5 available)
    • Redmi Note 7 (mobile)      • 6345c469                             • android-arm64  • Android 9 (API 28)
    • iPhone 11 Pro Max (mobile) • 9F9AFD9B-7F22-468E-8096-B47E993E0619 • ios            • com.apple.CoreSimulator.SimRuntime.iOS-13-5 (simulator)
    • macOS (desktop)            • macos                                • darwin-x64     • Mac OS X 10.15.5 19F101
    • Web Server (web)           • web-server                           • web-javascript • Flutter Tools
    • Chrome (web)               • chrome                               • web-javascript • Google Chrome 83.0.4103.116

• No issues found!

[potatoker]

same issue here, seem to be the decode and frame bitmap process problem.

[TahaTesser]

Provided by @minikupa #64374

code sample

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Image.asset("assets/test.webp"),
      ),
    );
  }
}

assets.zip

flutter doctor -v

[✓] Flutter (Channel stable, 1.20.2, on Mac OS X 10.15.6 19G2021, locale en-GB)
    • Flutter version 1.20.2 at /Users/tahatesser/Code/flutter_stable
    • Framework revision bbfbf1770c (11 days ago), 2020-08-13 08:33:09 -0700
    • Engine revision 9d5b21729f
    • Dart version 2.9.1

 
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    • Android SDK at /Users/tahatesser/Code/sdk
    • Platform android-30, build-tools 30.0.1
    • ANDROID_HOME = /Users/tahatesser/Code/sdk
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.6)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.6, Build version 11E708
    • CocoaPods version 1.9.3

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 48.1.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.48.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.13.2

[✓] Connected device (1 available)
    • iPhone 11 (mobile) • A63D6F51-59F3-4A75-961F-3769709F3A92 • ios •
      com.apple.CoreSimulator.SimRuntime.iOS-13-6 (simulator)

• No issues found!

flutter doctor -v

[✓] Flutter (Channel master, 1.22.0-2.0.pre.36, on Mac OS X 10.15.6 19G2021,
    locale en-GB)
    • Flutter version 1.22.0-2.0.pre.36 at /Users/tahatesser/Code/flutter_master
    • Framework revision d30e36ba8c (2 days ago), 2020-08-21 22:36:03 -0400
    • Engine revision d495da20d0
    • Dart version 2.10.0 (build 2.10.0-49.0.dev)

 
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    • Android SDK at /Users/tahatesser/Code/sdk
    • Platform android-30, build-tools 30.0.1
    • ANDROID_HOME = /Users/tahatesser/Code/sdk
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 11.6)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.6, Build version 11E708
    • CocoaPods version 1.9.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 48.1.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.48.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.13.2

[✓] Connected device (4 available)
    • iPhone 11 (mobile) • A63D6F51-59F3-4A75-961F-3769709F3A92 • ios
      • com.apple.CoreSimulator.SimRuntime.iOS-13-6 (simulator)
    • macOS (desktop)    • macos                                • darwin-x64
      • Mac OS X 10.15.6 19G2021
    • Web Server (web)   • web-server                           • web-javascript
      • Flutter Tools
    • Chrome (web)       • chrome                               • web-javascript
      • Google Chrome 84.0.4147.135

• No issues found!