SDWebImageWebPCoder/README.md

# SDWebImageWebPCoder

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Starting with the SDWebImage 5.0 version, we moved the WebP support code and [libwebp](https://github.com/webmproject/libwebp) from the Core Repo to this stand-alone repo.

SDWebImageWebPCoder supports both WebP decoding and encoding, for Static WebP or Animated WebP as well.

## Requirements

+ iOS 9.0
+ macOS 10.11
+ tvOS 9.0
+ watchOS 2.0
+ Xcode 11.0

## Installation

#### CocoaPods

SDWebImageWebPCoder is available through [CocoaPods](http://cocoapods.org). To install it, simply add the following line to your Podfile:

```ruby
pod 'SDWebImageWebPCoder'
```

#### Carthage

SDWebImageWebPCoder is available through [Carthage](https://github.com/Carthage/Carthage).

```
github "SDWebImage/SDWebImageWebPCoder"
```

#### Swift Package Manager (Xcode 11+)

SDWebImageWebPCoder is available through [Swift Package Manager](https://swift.org/package-manager).

```swift
let package = Package(
    dependencies: [
        .package(url: "https://github.com/SDWebImage/SDWebImageWebPCoder.git", from: "0.3.0")
    ]
)
```

## Usage

### Add Coder

Before using SDWebImage to load WebP images, you need to register the WebP Coder to your coders manager. This step is recommended to be done after your App launch (like AppDelegate method).

+ Objective-C

```objective-c
// Add coder
SDImageWebPCoder *webPCoder = [SDImageWebPCoder sharedCoder];
[[SDImageCodersManager sharedManager] addCoder:webPCoder];
```

+ Swift

```swift
// Add coder
let WebPCoder = SDImageWebPCoder.shared
SDImageCodersManager.shared.addCoder(WebPCoder)
```

### Modify HTTP Accept Header

Some of image server provider may try to detect the client supported format, by default, SDWebImage use `image/*,*/*;q=0.8` for [Accept](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept). You can modify it with the `image/webp` as well.

+ Objective-C

```objective-c
[[SDWebImageDownloader sharedDownloader] setValue:@"image/webp,image/*,*/*;q=0.8" forHTTPHeaderField:@"Accept"];
```

+ Swift

```swift
SDWebImageDownloader.shared.setValue("image/webp,image/*,*/*;q=0.8", forHTTPHeaderField:"Accept")
```

### Loading

+ Objective-C

```objective-c
// WebP online image loading
NSURL *webpURL;
UIImageView *imageView;
[imageView sd_setImageWithURL:webpURL];
```

+ Swift

```swift
// WebP online image loading
let webpURL: URL
let imageView: UIImageView
imageView.sd_setImage(with: webpURL)
```

### Progressive Animation Loading (0.5.0+)

+ Objective-C

```objective-c
// WebP progressive loading for animated image
NSURL *webpURL;
SDAnimatedImageView *imageView;
imageView.shouldIncrementalLoad = YES;
[imageView sd_setImageWithURL:webpURL placeholderImage:nil options:SDWebImageProgressiveLoad];
```

+ Swift

```swift
// WebP progressive loading for animated image
let webpURL: URL
let imageView: SDAnimatedImageView
imageView.shouldIncrementalLoad = true
imageView.sd_setImage(with: webpURL, placeholderImage: nil, options: [.progressiveLoad])
```

### Decoding

+ Objective-C

```objective-c
// WebP image decoding
NSData *webpData;
UIImage *image = [[SDImageWebPCoder sharedCoder] decodedImageWithData:webpData options:nil];
```

+ Swift

```swift
// WebP image decoding
let webpData: Data
let image = SDImageWebPCoder.shared.decodedImage(with: data, options: nil)
```

### Thumbnail Decoding (0.4.0+)

+ Objective-C

```objective-c
// WebP thumbnail image decoding
NSData *webpData;
CGSize thumbnailSize = CGSizeMake(300, 300);
UIImage *thumbnailImage = [[SDImageWebPCoder sharedCoder] decodedImageWithData:webpData options:@{SDImageCoderDecodeThumbnailPixelSize : @(thumbnailSize)}];
```

+ Swift

```swift
// WebP thumbnail image decoding
let webpData: Data
let thumbnailSize = CGSize(width: 300, height: 300)
let image = SDImageWebPCoder.shared.decodedImage(with: data, options: [.decodeThumbnailPixelSize: thumbnailSize])
```

### Decoding with limit bytes (0.12.0+)

+ Objective-C

```objective-c
// WebP thumbnail image decoding
NSData *webpData;
NSUInteger limitBytes = 1024 * 1024; // 1MB
UIImage *image = [[SDImageWebPCoder sharedCoder] decodedImageWithData:webpData options:@{SDImageCoderDecodeScaleDownLimitBytes : @(limitBytes)}];
// The image pixel buffer is guaranteed to less than 1MB in RAM (may scale down or full size), suitable for large image
```

+ Swift

```swift
// WebP thumbnail image decoding
let webpData: Data
let limitBytes = 1024 * 1024 // 1MB
let image = SDImageWebPCoder.shared.decodedImage(with: data, options: [.decodeScaleDownLimitBytes: limitBytes])
// The image pixel buffer is guaranteed to less than 1MB in RAM (may scale down or full size), suitable for large image
```

### Encoding

+ Objective-c

```objective-c
// WebP image encoding
UIImage *image;
NSData *webpData = [[SDImageWebPCoder sharedCoder] encodedDataWithImage:image format:SDImageFormatWebP options:nil];
// Animated encoding
NSArray<SDImageFrames *> *frames;
NSData *awebpData = [[SDImageWebPCoder sharedCoder] encodedDataWithFrames:frames loopCount:0 format:SDImageFormatWebP options:nil];
// Encode Quality
NSData *lossyWebpData = [[SDImageWebPCoder sharedCoder] encodedDataWithImage:image format:SDImageFormatWebP options:@{SDImageCoderEncodeCompressionQuality : @(0.1)}]; // [0, 1] compression quality
NSData *limitedWebpData = [[SDImageWebPCoder sharedCoder] encodedDataWithImage:image format:SDImageFormatWebP options:@{SDImageCoderEncodeMaxFileSize : @(1024 * 10)}]; // v0.6.0 feature, limit output file size <= 10KB
```

+ Swift

```swift
// WebP image encoding
let image: UIImage
let webpData = SDImageWebPCoder.shared.encodedData(with: image, format: .webP, options: nil)
// Animated encoding
let frames: [SDImageFrame]
let awebpData = SDImageWebPCoder.shared.encodedData(with: frames, loopCount: 0, format: .webP, options: nil)
// Encode Quality
let lossyWebpData = SDImageWebPCoder.shared.encodedData(with: image, format: .webP, options: [.encodeCompressionQuality: 0.1]) // [0, 1] compression quality
let limitedWebpData = SDImageWebPCoder.shared.encodedData(with: image, format: .webP, options: [.encodeMaxFileSize: 1024 * 10]) // v0.6.0 feature, limit output file size <= 10KB
```

### Thumbnail Encoding (0.6.1+)

+ Objective-C

```objective-c
// WebP image thumbnail encoding
UIImage *image;
NSData *thumbnailWebpData = [[SDImageWebPCoder sharedCoder] encodedDataWithImage:image format:SDImageFormatWebP options:@{SDImageCoderEncodeMaxPixelSize : @(CGSizeMake(200, 200))}]; // v0.6.1 feature, encoding max pixel size
```

+ Swift

```swift
// WebP image thumbnail encoding
let image: UIImage
let thumbnailWebpData = SDImageWebPCoder.shared.encodedData(with: image, format: .webP, options: [.encodeMaxPixelSize: CGSize(width: 200, height: 200)]) // v0.6.1 feature, encoding max pixel size
```

See more documentation in [SDWebImage Wiki - Coders](https://github.com/SDWebImage/SDWebImage/wiki/Advanced-Usage#custom-coder-420)

### Animated WebP Encoding (0.10+)

+ Objective-c

```objective-c
// Animated encoding
NSMutableArray<SDImageFrames *> *frames = [NSMutableArray array];
for (size_t i = 0; i < images.count; i++) {
    SDImageFrame *frame = [SDImageFrame frameWithImage:images[i] duration:0.1];
    [frames appendObject:frame];
}
NSData *awebpData = [[SDImageWebPCoder sharedCoder] encodedDataWithFrames:frames loopCount:0 format:SDImageFormatWebP options:nil];
```

+ Swift

```swift
// Animated encoding
var frames: [SDImageFrame] = []
for i in 0..<images.count {
    let frame = SDImageFrame(image: images[i], duration: 0.1)
    frames.append(frame)
}
let awebpData = SDImageWebPCoder.shared.encodedData(with: frames, loopCount: 0, format: .webP, options: nil)
```

### Advanced WebP codec options (0.8+)

The WebP codec [libwebp](https://developers.google.com/speed/webp/docs/api) we use, supports some advanced control options for encoding/decoding. You can pass them to libwebp by using the wrapper top level API:

+ Objective-C

```objective-c
UIImage *image;
SDImageCoderOptions *options = @{SDImageCoderEncodeWebPMethod: @(0), SDImageCoderEncodeWebPAlphaCompression: @(100)};
NSData *data = [SDImageWebPCoder.sharedCoder encodedDataWithImage:image format:SDImageFormatWebP options:options];
// Will translate into:
// config->method = 0;
// config->alpha_quality = 100;
```

+ Swift

```swift
let image: UIImage
let options = [.encodeWebPMethod: 0, .encodeWebPAlphaCompression: 100]
let data = SDImageWebPCoder.shared.encodedData(with: image, format: .webP, options: options)
// Will translate into:
// config->method = 0;
// config->alpha_quality = 100;
```

## Example

To run the example project, clone the repo, and run `pod install` from the root directory first. Then open `SDWebImageWebPCoder.xcworkspace`.

This is a demo to show how to use `WebP` and animated `WebP` images via `SDWebImageWebPCoderExample` target.

## Screenshot

<img src="https://raw.githubusercontent.com/SDWebImage/SDWebImageWebPCoder/master/Example/Screenshot/WebPDemo.png" width="300" />

These WebP images are from [WebP Gallery](https://developers.google.com/speed/webp/gallery1) and [GIF vs APNG vs WebP](http://littlesvr.ca/apng/gif_apng_webp.html)

## Author

[Bogdan Poplauschi](https://github.com/bpoplauschi)
[DreamPiggy](https://github.com/dreampiggy)

## License

SDWebImageWebPCoder is available under the MIT license. See [the LICENSE file](https://github.com/SDWebImage/SDWebImageWebPCoder/blob/master/LICENSE) for more info.