/// <summary>
/// Decompresses JPEG image to any image described as ICompressDestination
/// </summary>
/// <param name="jpeg">Stream with JPEG data</param>
/// <param name="destination">Stream for output of compressed JPEG</param>
public void Decompress(Stream jpeg, IDecompressDestination destination)
{
if (jpeg is null)
{
throw new ArgumentNullException(nameof(jpeg));
}
if (destination is null)
{
throw new ArgumentNullException(nameof(destination));
}
beforeDecompress(jpeg);
// Start decompression
ClassicDecompressor.JpegStartDecompress();
var parameters = getImageParametersFromDecompressor();
destination.SetImageAttributes(parameters);
destination.BeginWrite();
/* Process data */
while (ClassicDecompressor.Output_scanline < ClassicDecompressor.Output_height)
{
var row = JpegCommonStruct.AllocJpegSamples(ClassicDecompressor.Output_width * ClassicDecompressor.Output_components, 1);
ClassicDecompressor.JpegReadScanlines(row, 1);
destination.ProcessPixelsRow(row[0]);
}
destination.EndWrite();
// Finish decompression and release memory.
ClassicDecompressor.JpegFinishDecompress();
}
/// <summary>
/// Tunes decompressor
/// </summary>
/// <param name="jpeg">Stream with input compressed JPEG data</param>
private void beforeDecompress(Stream jpeg)
{
ClassicDecompressor.JpegStdioSrc(jpeg);
/* Read file header, set default decompression parameters */
ClassicDecompressor.JpegReadHeader(true);
applyParameters(m_decompressionParameters);
ClassicDecompressor.JpegCalcOutputDimensions();
}
/// <summary>
/// Tunes decompressor
/// </summary>
/// <param name="jpeg">Stream with input compressed JPEG data</param>
#pragma warning disable IDE1006 // Naming Styles
private void beforeDecompress(Stream jpeg)
#pragma warning restore IDE1006 // Naming Styles
{
ClassicDecompressor.JpegStdioSrc(jpeg);
/* Read file header, set default decompression parameters */
ClassicDecompressor.JpegReadHeader(true);
applyParameters(m_decompressionParameters);
ClassicDecompressor.JpegCalcOutputDimensions();
}
