/// <summary>
/// Create new AVI file and open it for writing.
/// </summary>
///
/// <param name="fileName">AVI file name to create.</param>
/// <param name="width">Video width.</param>
/// <param name="height">Video height.</param>
///
/// <remarks><para>The method opens (creates) a video files, configure video codec and prepares
/// the stream for saving video frames with a help of <see cref="AddFrame"/> method.</para></remarks>
///
/// <exception cref="System.IO.IOException">Failed opening the specified file.</exception>
/// <exception cref="VideoException">A error occurred while creating new video file. See exception message.</exception>
/// <exception cref="OutOfMemoryException">Insufficient memory for internal buffer.</exception>
/// <exception cref="ArgumentException">Video file resolution must be a multiple of two.</exception>
public void Open(string fileName, int width, int height, bool showOptions = false)
{
// close previous file
Close();
// check width and height
if (((width & 1) != 0) || ((height & 1) != 0))
{
throw new ArgumentException("Video file resolution must be a multiple of two.");
}
bool success = false;
try
{
lock (sync)
{
// calculate stride
stride = width * 3;
if ((stride % 4) != 0)
{
stride += (4 - stride % 4);
}
// create new file
if (NativeMethods.AVIFileOpen(out file, fileName, OpenFileMode.Create | OpenFileMode.Write, IntPtr.Zero) != 0)
{
throw new IOException("Failed opening the specified file.");
}
this.width = width;
this.height = height;
// describe new stream
AVISTREAMINFO info = new AVISTREAMINFO();
info.type = NativeMethods.mmioFOURCC("vids");
info.handler = NativeMethods.mmioFOURCC(codec);
info.scale = 1;
info.rate = rate;
info.suggestedBufferSize = stride * height;
// create stream
if (NativeMethods.AVIFileCreateStream(file, out stream, ref info) != 0)
{
throw new Exception("Failed creating stream.");
}
// describe compression options
AVICOMPRESSOPTIONS options = new AVICOMPRESSOPTIONS();
options.handler = NativeMethods.mmioFOURCC(codec);
options.quality = quality;
if (showOptions)
{
NativeMethods.AVISaveOptions(stream, ref options);
}
// create compressed stream
if (NativeMethods.AVIMakeCompressedStream(out streamCompressed, stream, ref options, IntPtr.Zero) != 0)
{
throw new Exception("Failed creating compressed stream.");
}
// describe frame format
BITMAPINFOHEADER bitmapInfoHeader = new BITMAPINFOHEADER();
bitmapInfoHeader.size = Marshal.SizeOf(bitmapInfoHeader.GetType());
bitmapInfoHeader.width = width;
bitmapInfoHeader.height = height;
bitmapInfoHeader.planes = 1;
bitmapInfoHeader.bitCount = 24;
bitmapInfoHeader.sizeImage = 0;
bitmapInfoHeader.compression = 0; // BI_RGB
// set frame format
if (NativeMethods.AVIStreamSetFormat(streamCompressed, 0, ref bitmapInfoHeader, Marshal.SizeOf(bitmapInfoHeader.GetType())) != 0)
{
throw new Exception("Failed setting format of the compressed stream.");
}
// alloc unmanaged memory for frame
buffer = Marshal.AllocHGlobal(stride * height);
if (buffer == IntPtr.Zero)
{
throw new OutOfMemoryException("Insufficient memory for internal buffer.");
}
position = 0;
success = true;
}
}
finally
{
if (!success)
{
Close();
}
}
}