A Simple C# Wrapper for the AviFile Library

/* This class has been written by
 * Corinna John (Hannover, Germany)
 * cj@binary-universe.net
 * 
 * You may do with this code whatever you like,
 * except selling it or claiming any rights/ownership.
 * 
 * Please send me a little feedback about what you're
 * using this code for and what changes you'd like to
 * see in later versions. (And please excuse my bad english.)
 * 
 * WARNING: This is experimental code.
 * Please do not expect "Release Quality".
 * */

#region Using directives

using System;
using System.Text;
using System.Runtime.InteropServices;

#endregion

namespace AviFile {
    public class EditableVideoStream : VideoStream {
        private IntPtr editableStream = IntPtr.Zero;

        /// <summary>Pointer to the unmanaged AVI stream</summary>
        internal override IntPtr StreamPointer {
            get { return editableStream; }
        }

        /// <summary>Create an editable stream from an uneditable stream</summary>
        /// <param name="stream">uneditable stream</param>
        public EditableVideoStream(VideoStream stream) : base(stream.FrameSize, stream.FrameRate, stream.Width, stream.Height, stream.CountBitsPerPixel, stream.CountFrames, stream.CompressOptions, stream.WriteCompressed) {
            Avi.AVIFileInit();
            int result = Avi.CreateEditableStream(ref editableStream, stream.StreamPointer);

            if (result != 0) {
                throw new Exception("Exception in CreateEditableStream: " + result.ToString());
            } 
            
            SetInfo(stream.StreamInfo);
        }

        /// <summary>Close the stream</summary>
        public override void Close() {
            base.Close();
            Avi.AVIFileExit();
        }

        /// <summary>Copy a number of frames into a temporary stream</summary>
        /// <param name="start">First frame to copy</param>
        /// <param name="length">Count of frames to copy</param>
        /// <returns>Pointer to the unmanaged temporary stream</returns>
        public IntPtr Copy(int start, int length) {
            IntPtr copyPointer = IntPtr.Zero;
            int result = Avi.EditStreamCopy(editableStream, ref start, ref length, ref copyPointer);

            if (result != 0) {
                throw new Exception("Exception in Copy: " + result.ToString());
            }

            return copyPointer;
        }

        /// <summary>Move a number of frames into a temporary stream</summary>
        /// <param name="start">First frame to cut</param>
        /// <param name="length">Count of frames to cut</param>
        /// <returns>Pointer to the unmanaged temporary stream</returns>
        public IntPtr Cut(int start, int length) {
            IntPtr copyPointer = IntPtr.Zero;
            int result = Avi.EditStreamCut(editableStream, ref start, ref length, ref copyPointer);

            if (result != 0) {
                throw new Exception("Exception in Cut: " + result.ToString());
            } 
            
            countFrames -= length;
            return copyPointer;
        }

        /// <summary>Paste a number of frames from another video stream into this stream</summary>
        /// <param name="sourceStream">Stream to copy from</param>
        /// <param name="copyPosition">Index of the first frame to copy</param>
        /// <param name="pastePosition">Where to paste the copied frames</param>
        /// <param name="length">Count of frames to paste</param>
        public void Paste(VideoStream sourceStream, int copyPosition, int pastePosition, int length) {
            Paste(sourceStream.StreamPointer, copyPosition, pastePosition, length);
        }

        /// <summary>Paste a number of frames from another video stream into this stream</summary>
        /// <param name="sourceStream">Pointer to the unmanaged stream to copy from</param>
        /// <param name="copyPosition">Index of the first frame to copy</param>
        /// <param name="pastePosition">Where to paste the copied frames</param>
        /// <param name="length">Count of frames to paste</param>
        public void Paste(IntPtr sourceStream, int copyPosition, int pastePosition, int length) {
            int pastedLength = 0;
            int result = Avi.EditStreamPaste(editableStream, ref pastePosition, ref pastedLength, sourceStream, copyPosition, length);
            
            if (result != 0) {
                throw new Exception("Exception in Paste: " + result.ToString());
            }

            countFrames += pastedLength;
        }

        /// <summary>Change the AviStreamInfo values and update the frame rate</summary>
        /// <param name="info"></param>
        public void SetInfo(Avi.AVISTREAMINFO info) {
            int result = Avi.EditStreamSetInfo(editableStream, ref info, Marshal.SizeOf(info));
            if (result != 0) {
                throw new Exception("Exception in SetInfo: " + result.ToString());
            }
        
            frameRate = info.dwRate / info.dwScale;
        }
    }
}