/// <summary>Exports a frame into a bitmap file</summary>
/// <param name="position">Position of the frame</param>
/// <param name="dstFileName">Name ofthe file to store the bitmap</param>
public void ExportBitmap(int position, String dstFileName){
if(position > countFrames){
throw new Exception("Invalid frame position");
}
//Decompress the frame and return a pointer to the DIB
int pDib = Avi.AVIStreamGetFrame(getFrameObject, firstFrame + position);
//Copy the bitmap header into a managed struct
Avi.BITMAPINFOHEADER bih = new Avi.BITMAPINFOHEADER();
bih = (Avi.BITMAPINFOHEADER)Marshal.PtrToStructure(new IntPtr(pDib), bih.GetType());
/*if(bih.biBitCount < 24){
throw new Exception("Not enough colors! DIB color depth is less than 24 bit.");
}else */
if(bih.biSizeImage < 1){
throw new Exception("Exception in AVIStreamGetFrame: Not bitmap decompressed.");
}
//Copy the image
byte[] bitmapData = new byte[bih.biSizeImage];
int address = pDib + Marshal.SizeOf(bih);
for(int offset=0; offset<bitmapData.Length; offset++){
bitmapData[offset] = Marshal.ReadByte(new IntPtr(address));
address++;
}
//Copy bitmap info
byte[] bitmapInfo = new byte[Marshal.SizeOf(bih)];
IntPtr ptr;
ptr = Marshal.AllocHGlobal(bitmapInfo.Length);
Marshal.StructureToPtr(bih, ptr, false);
address = ptr.ToInt32();
for(int offset=0; offset<bitmapInfo.Length; offset++){
bitmapInfo[offset] = Marshal.ReadByte(new IntPtr(address));
address++;
}
//Create file header
Avi.BITMAPFILEHEADER bfh = new Avi.BITMAPFILEHEADER();
bfh.bfType = Avi.BMP_MAGIC_COOKIE;
bfh.bfSize = (Int32)(55 + bih.biSizeImage); //size of file as written to disk
bfh.bfReserved1 = 0;
bfh.bfReserved2 = 0;
bfh.bfOffBits = Marshal.SizeOf(bih) + Marshal.SizeOf(bfh);
//Create or overwrite the destination file
FileStream fs = new FileStream(dstFileName, System.IO.FileMode.Create);
BinaryWriter bw = new BinaryWriter(fs);
//Write header
bw.Write(bfh.bfType);
bw.Write(bfh.bfSize);
bw.Write(bfh.bfReserved1);
bw.Write(bfh.bfReserved2);
bw.Write(bfh.bfOffBits);
//Write bitmap info
bw.Write(bitmapInfo);
//Write bitmap data
bw.Write(bitmapData);
bw.Close();
fs.Close();
}
/// <summary>Exports a frame into a bitmap file</summary>
/// <param name="position">Position of the frame</param>
/// <param name="dstFileName">Name ofthe file to store the bitmap</param>
public void ExportBitmap(int position, String dstFileName)
{
if (position > countFrames)
{
throw new Exception("Invalid frame position");
}
//Decompress the frame and return a pointer to the DIB
int pDib = Avi.AVIStreamGetFrame(getFrameObject, firstFrame + position);
//Copy the bitmap header into a managed struct
Avi.BITMAPINFOHEADER bih = new Avi.BITMAPINFOHEADER();
bih = (Avi.BITMAPINFOHEADER)Marshal.PtrToStructure(new IntPtr(pDib), bih.GetType());
/*if(bih.biBitCount < 24){
* throw new Exception("Not enough colors! DIB color depth is less than 24 bit.");
* }else */
if (bih.biSizeImage < 1)
{
throw new Exception("Exception in AVIStreamGetFrame: Not bitmap decompressed.");
}
//Copy the image
byte[] bitmapData = new byte[bih.biSizeImage];
int address = pDib + Marshal.SizeOf(bih);
for (int offset = 0; offset < bitmapData.Length; offset++)
{
bitmapData[offset] = Marshal.ReadByte(new IntPtr(address));
address++;
}
//Copy bitmap info
byte[] bitmapInfo = new byte[Marshal.SizeOf(bih)];
IntPtr ptr;
ptr = Marshal.AllocHGlobal(bitmapInfo.Length);
Marshal.StructureToPtr(bih, ptr, false);
address = ptr.ToInt32();
for (int offset = 0; offset < bitmapInfo.Length; offset++)
{
bitmapInfo[offset] = Marshal.ReadByte(new IntPtr(address));
address++;
}
//Create file header
Avi.BITMAPFILEHEADER bfh = new Avi.BITMAPFILEHEADER();
bfh.bfType = Avi.BMP_MAGIC_COOKIE;
bfh.bfSize = (Int32)(55 + bih.biSizeImage); //size of file as written to disk
bfh.bfReserved1 = 0;
bfh.bfReserved2 = 0;
bfh.bfOffBits = Marshal.SizeOf(bih) + Marshal.SizeOf(bfh);
//Create or overwrite the destination file
FileStream fs = new FileStream(dstFileName, System.IO.FileMode.Create);
BinaryWriter bw = new BinaryWriter(fs);
//Write header
bw.Write(bfh.bfType);
bw.Write(bfh.bfSize);
bw.Write(bfh.bfReserved1);
bw.Write(bfh.bfReserved2);
bw.Write(bfh.bfOffBits);
//Write bitmap info
bw.Write(bitmapInfo);
//Write bitmap data
bw.Write(bitmapData);
bw.Close();
fs.Close();
}
