/// <summary>
/// JPEGデータから量子化後のDCT係数列を取得する。
/// </summary>
/// <param name="jpegData">JPEGデータ</param>
/// <param name="qdctCoeff">量子化後のDCT係数列構造体</param>
/// <param name="qFactor">QFactor</param>
/// <returns>処理結果</returns>
public bool GetQuantizedDCTCoeff(byte[] jpegData, out QDCTCoefficientParameter qdctCoeff, out ushort qFactor)
{
qdctCoeff = new QDCTCoefficientParameter();
qFactor = 0;
if (jpegData == null || jpegData.Length < 2)
{
//return ReturnID.ErrorInvalidParam;
return(false);
}
_jpegData = (byte[])jpegData.Clone();
_jpegDataIndex = 0;
_remainSize = jpegData.Length;
_remainBitLength = 8;
_qdctCoeffParam = new QDCTCoefficientParameter();
_hiYCR = 0;
_viYCR = 0;
// JPEGデータの先頭にSOIマーカがなければならない。
if ((byte)JpegMarkerCodes.MARKER_ID != _jpegData[0] || (byte)JpegMarkerCodes.SOI != _jpegData[1])
{
// JPEGデータの先頭にSOIマーカがない
//return ReturnID.JpegDataErrorNoSOIMarker;
return(false);
}
_jpegDataIndex += 2;
_remainSize -= 2;
// スキャンデータ直前までの全マーカを読み出す。正常終了時、SOSマーカセグメントまで既読。
ReturnID returnID = ReadMarkersBeforeScanData(out bool readDHT, out bool readSOF0, out ushort restartInterval, out qFactor);
if (ReturnID.Success == returnID)
{
if (!readDHT || !readSOF0)
{
returnID = ReturnID.JpegDataErrorLackOfMarker;
}
else if (restartInterval != 0)
{
returnID = ReturnID.JpegDataErrorUnsupported;
}
else
{
returnID = ReadScanData();
}
}
if (ReturnID.Success != returnID)
{
_qdctCoeffParam.YComponents = null;
}
_qdctCoeffParam.Copy(ref qdctCoeff);
return(ReturnID.Success == returnID);
}
/// <summary>
/// 値をコピーする
/// </summary>
/// <param name="qdctCoeffParam">コピー先</param>
public void Copy(ref QDCTCoefficientParameter qdctCoeffParam)
{
if (qdctCoeffParam != null)
{
qdctCoeffParam.Width = Width;
qdctCoeffParam.Height = Height;
qdctCoeffParam.BlockNumX = BlockNumX;
qdctCoeffParam.BlockNumY = BlockNumY;
if (YComponents != null)
{
qdctCoeffParam.YComponents = (YComponents == null ? null : (short[])YComponents.Clone());
}
}
}
