protected void ReadHeader() { byte[] bytes = new byte[4]; m_stream.Read(bytes, 0, 4); UInt32 magicNumber = BitConverter.ToUInt32(bytes, 0); if (magicNumber != BinaryConstants.PROTEAN_MAGIC) { throw new VariantException("Invalid magic number"); } // ignore version info for now m_stream.Read(bytes, 0, 4); m_stream.Read(bytes, 0, 4); m_mode = (BinaryMode)System.BitConverter.ToUInt32(bytes, 0); if ((m_mode & BinaryMode.Compress) != 0) { if ((m_mode & BinaryMode.ZlibHeader) != 0) { throw new VariantException("Binary data appears to contain ZLIB header which is currently not supported in the protean.NET BinaryReader"); } System.IO.Compression.DeflateStream deflateStream = new System.IO.Compression.DeflateStream(m_stream, System.IO.Compression.CompressionMode.Decompress, true); if (m_requireSeekableReader) { MemoryStream deflatedStream = new MemoryStream(); int value; while ((value = deflateStream.ReadByte()) != -1) { deflatedStream.WriteByte((byte)value); } m_filter = new MemoryStream(deflatedStream.ToArray(), 0, (int)deflatedStream.Length, false); } else { m_filter = deflateStream; } } }
protected void ReadHeader() { byte[] bytes = new byte[4]; m_stream.Read(bytes, 0, 4); UInt32 magicNumber = BitConverter.ToUInt32(bytes, 0); if (magicNumber != BinaryConstants.PROTEAN_MAGIC) { throw new VariantException("Invalid magic number"); } // ignore version info for now m_stream.Read(bytes, 0, 4); m_stream.Read(bytes, 0, 4); m_mode = (BinaryMode)System.BitConverter.ToUInt32(bytes, 0); if ((m_mode & BinaryMode.Compress) != 0) { if ((m_mode & BinaryMode.ZlibHeader) != 0) { throw new VariantException("Binary data appears to contain ZLIB header which is currently not supported in the protean.NET BinaryReader"); } System.IO.Compression.DeflateStream deflateStream = new System.IO.Compression.DeflateStream(m_stream, System.IO.Compression.CompressionMode.Decompress, true); if (m_requireSeekableReader) { MemoryStream deflatedStream = new MemoryStream(); int value; while ((value = deflateStream.ReadByte()) != -1) { deflatedStream.WriteByte((byte)value); } m_filter = new MemoryStream(deflatedStream.ToArray(), 0, (int)deflatedStream.Length, false); } else { m_filter = deflateStream; } } }
private void ReadScanlines(MemoryStream dataStream, byte[] pixels, IColorReader colorReader, PngColorTypeInformation colorTypeInformation) { // Read the zlib header : http://tools.ietf.org/html/rfc1950 // CMF(Compression Method and flags) // This byte is divided into a 4 - bit compression method and a // 4-bit information field depending on the compression method. // bits 0 to 3 CM Compression method // bits 4 to 7 CINFO Compression info // // 0 1 // +---+---+ // |CMF|FLG| // +---+---+ int cmf = dataStream.ReadByte(); int flag = dataStream.ReadByte(); //please note that position=2 int scanlineLength = CalculateScanlineLength(colorTypeInformation); int scanlineStep = CalculateScanlineStep(colorTypeInformation); byte[] lastScanline = new byte[scanlineLength]; byte[] currScanline = new byte[scanlineLength]; byte a = 0; byte b = 0; byte c = 0; int row = 0, filter = 0, column = -1; //using (InflaterInputStream compressedStream = new InflaterInputStream(dataStream)) //{ // int readByte = 0; // while ((readByte = compressedStream.ReadByte()) >= 0) // { // if (column == -1) // { // filter = readByte; // column++; // } // else // { // currScanline[column] = (byte)readByte; // if (column >= scanlineStep) // { // a = currScanline[column - scanlineStep]; // c = lastScanline[column - scanlineStep]; // } // else // { // a = 0; // c = 0; // } // b = lastScanline[column]; // if (filter == 1) // { // currScanline[column] = (byte)(currScanline[column] + a); // } // else if (filter == 2) // { // currScanline[column] = (byte)(currScanline[column] + b); // } // else if (filter == 3) // { // currScanline[column] = (byte)(currScanline[column] + (byte)Math.Floor((double)(a + b) / 2)); // } // else if (filter == 4) // { // currScanline[column] = (byte)(currScanline[column] + PaethPredicator(a, b, c)); // } // column++; // if (column == scanlineLength) // { // colorReader.ReadScanline(currScanline, pixels, _header); // column = -1; // row++; // Extensions.Swap(ref currScanline, ref lastScanline); // } // } // } //} //using (Ionic.Zlib.DeflateStream compressedStream = new Ionic.Zlib.DeflateStream(dataStream, Ionic.Zlib.CompressionMode.Decompress)) using (System.IO.Compression.DeflateStream compressedStream = new System.IO.Compression.DeflateStream( dataStream, System.IO.Compression.CompressionMode.Decompress, true)) { int readByte = 0; //byte[] singleByte = new byte[1]; //compressedStream.Read(singleByte, 0, 1); while ((readByte = compressedStream.ReadByte()) >= 0) { if (column == -1) { filter = readByte; column++; } else { currScanline[column] = (byte)readByte; if (column >= scanlineStep) { a = currScanline[column - scanlineStep]; c = lastScanline[column - scanlineStep]; } else { a = 0; c = 0; } b = lastScanline[column]; if (filter == 1) { currScanline[column] = (byte)(currScanline[column] + a); } else if (filter == 2) { currScanline[column] = (byte)(currScanline[column] + b); } else if (filter == 3) { currScanline[column] = (byte)(currScanline[column] + (byte)Math.Floor((double)(a + b) / 2)); } else if (filter == 4) { currScanline[column] = (byte)(currScanline[column] + PaethPredicator(a, b, c)); } column++; if (column == scanlineLength) { colorReader.ReadScanline(currScanline, pixels, _header); column = -1; row++; // //Extensions.Swap(ref currScanline, ref lastScanline); var tmpA = currScanline; var tmpB = lastScanline; lastScanline = tmpA; currScanline = tmpB; } } } } }
private void ReadScanlines(MemoryStream dataStream, byte[] pixels, IColorReader colorReader, PngColorTypeInformation colorTypeInformation) { // Read the zlib header : http://tools.ietf.org/html/rfc1950 // CMF(Compression Method and flags) // This byte is divided into a 4 - bit compression method and a // 4-bit information field depending on the compression method. // bits 0 to 3 CM Compression method // bits 4 to 7 CINFO Compression info // // 0 1 // +---+---+ // |CMF|FLG| // +---+---+ int cmf = dataStream.ReadByte(); int flag = dataStream.ReadByte(); //please note that position=2 int scanlineLength = CalculateScanlineLength(colorTypeInformation); int scanlineStep = CalculateScanlineStep(colorTypeInformation); byte[] lastScanline = new byte[scanlineLength]; byte[] currScanline = new byte[scanlineLength]; byte a = 0; byte b = 0; byte c = 0; int row = 0, filter = 0, column = -1; //using (InflaterInputStream compressedStream = new InflaterInputStream(dataStream)) //{ // int readByte = 0; // while ((readByte = compressedStream.ReadByte()) >= 0) // { // if (column == -1) // { // filter = readByte; // column++; // } // else // { // currScanline[column] = (byte)readByte; // if (column >= scanlineStep) // { // a = currScanline[column - scanlineStep]; // c = lastScanline[column - scanlineStep]; // } // else // { // a = 0; // c = 0; // } // b = lastScanline[column]; // if (filter == 1) // { // currScanline[column] = (byte)(currScanline[column] + a); // } // else if (filter == 2) // { // currScanline[column] = (byte)(currScanline[column] + b); // } // else if (filter == 3) // { // currScanline[column] = (byte)(currScanline[column] + (byte)Math.Floor((double)(a + b) / 2)); // } // else if (filter == 4) // { // currScanline[column] = (byte)(currScanline[column] + PaethPredicator(a, b, c)); // } // column++; // if (column == scanlineLength) // { // colorReader.ReadScanline(currScanline, pixels, _header); // column = -1; // row++; // Extensions.Swap(ref currScanline, ref lastScanline); // } // } // } //} using (System.IO.Compression.DeflateStream compressedStream = new System.IO.Compression.DeflateStream( dataStream, System.IO.Compression.CompressionMode.Decompress, true)) //using (Ionic.Zlib.DeflateStream compressedStream = new Ionic.Zlib.DeflateStream(dataStream, Ionic.Zlib.CompressionMode.Decompress)) { int readByte = 0; //byte[] singleByte = new byte[1]; //compressedStream.Read(singleByte, 0, 1); while ((readByte = compressedStream.ReadByte()) >= 0) { if (column == -1) { filter = readByte; column++; } else { currScanline[column] = (byte)readByte; if (column >= scanlineStep) { a = currScanline[column - scanlineStep]; c = lastScanline[column - scanlineStep]; } else { a = 0; c = 0; } b = lastScanline[column]; if (filter == 1) { currScanline[column] = (byte)(currScanline[column] + a); } else if (filter == 2) { currScanline[column] = (byte)(currScanline[column] + b); } else if (filter == 3) { currScanline[column] = (byte)(currScanline[column] + (byte)Math.Floor((double)(a + b) / 2)); } else if (filter == 4) { currScanline[column] = (byte)(currScanline[column] + PaethPredicator(a, b, c)); } column++; if (column == scanlineLength) { colorReader.ReadScanline(currScanline, pixels, _header); column = -1; row++; // //Extensions.Swap(ref currScanline, ref lastScanline); var tmpA = currScanline; var tmpB = lastScanline; lastScanline = tmpA; currScanline = tmpB; } } } } }