decodeImageFromPixels function

void decodeImageFromPixels (Uint8List pixels, int width, int height, PixelFormat format, ImageDecoderCallback callback, { int rowBytes, double decodedCacheRatioCap: double.infinity })

Convert an array of pixel values into an Image object.

pixels is the pixel data in the encoding described by format.

rowBytes is the number of bytes consumed by each row of pixels in the data buffer. If unspecified, it defaults to width multiplied by the number of bytes per pixel in the provided format.

The decodedCacheRatioCap is the default maximum multiple of the compressed image size to cache when decoding animated image frames. For example, setting this to 2.0 means that a 400KB GIF would be allowed at most to use 800KB of memory caching unessential decoded frames. Caching decoded frames saves CPU but can result in out-of-memory crashes when decoding large (or multiple) animated images. Note that GIFs are highly compressed, and it's unlikely that a factor that low will be sufficient to cache all decoded frames. The default value is 25.0.

Implementation

void decodeImageFromPixels(
  Uint8List pixels,
  int width,
  int height,
  PixelFormat format,
  ImageDecoderCallback callback,
  {int rowBytes, double decodedCacheRatioCap = double.infinity}
) {
  final _ImageInfo imageInfo = new _ImageInfo(width, height, format.index, rowBytes);
  final Future<Codec> codecFuture = _futurize(
    (_Callback<Codec> callback) => _instantiateImageCodec(pixels, callback, imageInfo, decodedCacheRatioCap)
  );
  codecFuture.then((Codec codec) => codec.getNextFrame())
      .then((FrameInfo frameInfo) => callback(frameInfo.image));
}