public void TestIsJpegCompleteAt_Complete()
{
byte[] encodedBytes = new byte[ENCODED_BYTES_LENGTH];
encodedBytes[ENCODED_BYTES_LENGTH - 2] = JfifUtil.MARKER_FIRST_BYTE;
encodedBytes[ENCODED_BYTES_LENGTH - 1] = JfifUtil.MARKER_EOI;
IPooledByteBuffer buf = new TrivialPooledByteBuffer(encodedBytes);
EncodedImage encodedImage = new EncodedImage(
CloseableReference <IPooledByteBuffer> .of(buf, _releaser));
encodedImage.Format = ImageFormat.JPEG;
Assert.IsTrue(encodedImage.IsCompleteAt(ENCODED_BYTES_LENGTH));
}
/// <summary>
/// Creates a bitmap from encoded JPEG bytes.
/// Supports a partial JPEG image.
/// </summary>
/// <param name="encodedImage">
/// The reference to the encoded image with the reference to the
/// encoded bytes.
/// </param>
/// <param name="bitmapConfig">
/// The <see cref="BitmapPixelFormat"/> used to create the decoded
/// SoftwareBitmap.
/// </param>
/// <param name="length">
/// The number of encoded bytes in the buffer.
/// </param>
/// <returns>The bitmap.</returns>
/// <exception cref="OutOfMemoryException">
/// If the Bitmap cannot be allocated.
/// </exception>
public Task <CloseableReference <SoftwareBitmap> > DecodeJPEGFromEncodedImageAsync(
EncodedImage encodedImage, BitmapPixelFormat bitmapConfig, int length)
{
return(_executor.Execute(async() =>
{
bool isJpegComplete = encodedImage.IsCompleteAt(length);
Stream jpegDataStream = encodedImage.GetInputStream();
// At this point the Stream from the encoded image should not
// be null since in the pipeline,this comes from a call stack where
// this was checked before. Also this method needs the Stream to
// decode the image so this can't be null.
Preconditions.CheckNotNull(jpegDataStream);
if (encodedImage.Size > length)
{
jpegDataStream = new LimitedInputStream(jpegDataStream, length);
}
if (!isJpegComplete)
{
jpegDataStream = new TailAppendingInputStream(jpegDataStream, EOI_TAIL);
}
BitmapDecoder decoder = await BitmapDecoder.CreateAsync(
jpegDataStream.AsRandomAccessStream())
.AsTask()
.ConfigureAwait(false);
SoftwareBitmap bitmap = await decoder
.GetSoftwareBitmapAsync(bitmapConfig, BitmapAlphaMode.Premultiplied)
.AsTask()
.ConfigureAwait(false);
return CloseableReference <SoftwareBitmap> .of(bitmap);
})
.Unwrap());
}
