using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
using System.IO;

namespace Plugin {

    public class Avi {

        public const int StreamtypeVIDEO = 1935960438; //mmioStringToFOURCC("vids", 0)
        public const int OF_SHARE_DENY_WRITE = 32;
        public const int BMP_MAGIC_COOKIE = 19778; //ascii string "BM"

        #region structure declarations

        [StructLayout( LayoutKind.Sequential, Pack = 1 )]
        public struct RECT {
            public UInt32 left;
            public UInt32 top;
            public UInt32 right;
            public UInt32 bottom;
        }

        [StructLayout( LayoutKind.Sequential, Pack = 1 )]
        public struct BITMAPINFOHEADER {
            public UInt32 biSize;
            public Int32 biWidth;
            public Int32 biHeight;
            public Int16 biPlanes;
            public Int16 biBitCount;
            public UInt32 biCompression;
            public UInt32 biSizeImage;
            public Int32 biXPelsPerMeter;
            public Int32 biYPelsPerMeter;
            public UInt32 biClrUsed;
            public UInt32 biClrImportant;
        }

        [StructLayout( LayoutKind.Sequential, Pack = 1 )]
        public struct AVISTREAMINFO {
            public UInt32 fccType;
            public UInt32 fccHandler;
            public UInt32 dwFlags;
            public UInt32 dwCaps;
            public UInt16 wPriority;
            public UInt16 wLanguage;
            public UInt32 dwScale;
            public UInt32 dwRate;
            public UInt32 dwStart;
            public UInt32 dwLength;
            public UInt32 dwInitialFrames;
            public UInt32 dwSuggestedBufferSize;
            public UInt32 dwQuality;
            public UInt32 dwSampleSize;
            public RECT rcFrame;
            public UInt32 dwEditCount;
            public UInt32 dwFormatChangeCount;
            [MarshalAs( UnmanagedType.ByValArray, SizeConst = 64 )]
            public UInt16[] szName;
        }
        [StructLayout( LayoutKind.Sequential, Pack = 1 )]
        public struct BITMAPFILEHEADER {
            public Int16 bfType; //"magic cookie" - must be "BM"
            public Int32 bfSize;
            public Int16 bfReserved1;
            public Int16 bfReserved2;
            public Int32 bfOffBits;
        }

        #endregion structure declarations

        #region method declarations

        //Initialize the AVI library
        [DllImport( "avifil32.dll" )]
        public static extern void AVIFileInit();

        //Open an AVI file
        [DllImport( "avifil32.dll", PreserveSig = true )]
        public static extern int AVIFileOpen(
            ref int ppfile,
            String szFile,
            int uMode,
            int pclsidHandler );

        //Get a stream from an open AVI file
        [DllImport( "avifil32.dll" )]
        public static extern int AVIFileGetStream(
            int pfile,
            out IntPtr ppavi,
            int fccType,
            int lParam );

        //Get the start position of a stream
        [DllImport( "avifil32.dll", PreserveSig = true )]
        public static extern int AVIStreamStart( int pavi );

        //Get the length of a stream in frames
        [DllImport( "avifil32.dll", PreserveSig = true )]
        public static extern int AVIStreamLength( int pavi );

        //Get information about an open stream
        [DllImport( "avifil32.dll" )]
        public static extern int AVIStreamInfo(
            int pAVIStream,
            ref AVISTREAMINFO psi,
            int lSize );

        //Get a pointer to a GETFRAME object (returns 0 on error)
        [DllImport( "avifil32.dll" )]
        public static extern int AVIStreamGetFrameOpen(
            IntPtr pAVIStream,
            ref BITMAPINFOHEADER bih );

        /*[DllImport("avifil32.dll")]
        public static extern int AVIStreamGetFrameOpen(
            IntPtr pAVIStream,
            int dummy);*/

        //Get a pointer to a packed DIB (returns 0 on error)
        [DllImport( "avifil32.dll" )]
        public static extern int AVIStreamGetFrame(
            int pGetFrameObj,
            int lPos );

        //Create a new stream in an open AVI file
        [DllImport( "avifil32.dll" )]
        public static extern int AVIFileCreateStream(
            int pfile,
            out IntPtr ppavi,
            ref AVISTREAMINFO ptr_streaminfo );

        //Set the format for a new stream
        [DllImport( "avifil32.dll" )]
        public static extern int AVIStreamSetFormat(
            IntPtr aviStream, Int32 lPos,
            ref BITMAPINFOHEADER lpFormat, Int32 cbFormat );

        //Write a sample to a stream
        [DllImport( "avifil32.dll" )]
        public static extern int AVIStreamWrite(
            IntPtr aviStream, Int32 lStart, Int32 lSamples,
            IntPtr lpBuffer, Int32 cbBuffer, Int32 dwFlags,
            Int32 dummy1, Int32 dummy2 );

        //Release the GETFRAME object
        [DllImport( "avifil32.dll" )]
        public static extern int AVIStreamGetFrameClose(
            int pGetFrameObj );

        //Release an open AVI stream
        [DllImport( "avifil32.dll" )]
        public static extern int AVIStreamRelease( IntPtr aviStream );

        //Release an open AVI file
        [DllImport( "avifil32.dll" )]
        public static extern int AVIFileRelease( int pfile );

        //Close the AVI library
        [DllImport( "avifil32.dll" )]
        public static extern void AVIFileExit();

        #endregion methos declarations

        #region other useful avi functions

        //public const int StreamtypeAUDIO = 1935963489; //mmioStringToFOURCC("auds", 0)
        //public const int StreamtypeMIDI = 1935960429;  //mmioStringToFOURCC("mids", 0)
        //public const int StreamtypeTEXT = 1937012852;  //mmioStringToFOURCC("txts", 0)

        /*[StructLayout(LayoutKind.Sequential, Pack=1)]
        public struct AVIFILEINFO{
            public Int32 dwMaxBytesPerSecond;
            public Int32 dwFlags;
            public Int32 dwCaps;
            public Int32 dwStreams;
            public Int32 dwSuggestedBufferSize;
            public Int32 dwWidth;
            public Int32 dwHeight;
            public Int32 dwScale;
            public Int32 dwRate;
            public Int32 dwLength;
            public Int32 dwEditCount;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst=64)]
            public char[] szFileType;
        }*/

        /*[StructLayout(LayoutKind.Sequential, Pack=1)]
        public struct AVICOMPRESSOPTIONS {
            public UInt32   fccType;
            public UInt32   fccHandler;
            public UInt32   dwKeyFrameEvery;  // only used with AVICOMRPESSF_KEYFRAMES
            public UInt32   dwQuality;
            public UInt32   dwBytesPerSecond; // only used with AVICOMPRESSF_DATARATE
            public UInt32   dwFlags;
            public IntPtr   lpFormat;
            public UInt32   cbFormat;
            public IntPtr   lpParms;
            public UInt32   cbParms;
            public UInt32   dwInterleaveEvery;
        }*/

        /*[DllImport("avifil32.dll")]
        public static extern int AVIMakeCompressedStream(
            out IntPtr ppsCompressed, IntPtr aviStream, 
            ref AVICOMPRESSOPTIONS ao, int dummy);*/

        /*[DllImport("avifil32.dll")]
        public static extern int AVISaveOptions(
            IntPtr hWnd,
            int uiFlags,
            int nStreams, 
            ref IntPtr ppavi,
            ref IntPtr ppOptions);*/

        /*[DllImport("avifil32.dll")]
        public static extern int AVIFileInfo(
            int pfile, 
            ref AVIFILEINFO pfi,
            int lSize);*/

        /*[DllImport("winmm.dll", EntryPoint="mmioStringToFOURCCA")]
        public static extern int mmioStringToFOURCC(String sz, int uFlags);*/

        /*[DllImport("avifil32.dll")]
        public static extern int AVIStreamRead(
            IntPtr pavi, 
            Int32 lStart,     
            Int32 lSamples,   
            IntPtr lpBuffer, 
            Int32 cbBuffer,   
            Int32  plBytes,  
            Int32  plSamples 
            );*/

        #endregion other useful avi functions

    }

    /// <summary>Extract bitmaps from AVI files</summary>
    public class AviReader {

        //position of the first frame, count of frames in the stream
        private int firstFrame = 0, countFrames = 0;
        //pointers
        private int aviFile = 0;
        private int getFrameObject;
        private IntPtr aviStream;
        //stream and header info
        private Avi.AVISTREAMINFO streamInfo;

        public int CountFrames {
            get {
                return countFrames;
            }
        }

        public UInt32 FrameRate {
            get {
                return streamInfo.dwRate / streamInfo.dwScale;
            }
        }

        public Size BitmapSize {
            get {
                return new Size( (int)streamInfo.rcFrame.right, (int)streamInfo.rcFrame.bottom );
            }
        }

        /// <summary>Opens an AVI file and creates a GetFrame object</summary>
        /// <param name="fileName">Name of the AVI file</param>
        public void Open( string fileName ) {
            //Intitialize AVI library
            Avi.AVIFileInit();

            //Open the file
            int result = Avi.AVIFileOpen(
                ref aviFile, fileName,
                Avi.OF_SHARE_DENY_WRITE, 0 );

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

            //Get the video stream
            result = Avi.AVIFileGetStream(
                aviFile,
                out aviStream,
                Avi.StreamtypeVIDEO, 0 );

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

            firstFrame = Avi.AVIStreamStart( aviStream.ToInt32() );
            countFrames = Avi.AVIStreamLength( aviStream.ToInt32() );

            streamInfo = new Avi.AVISTREAMINFO();
            result = Avi.AVIStreamInfo( aviStream.ToInt32(), ref streamInfo, Marshal.SizeOf( streamInfo ) );

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

            //Open frames

            Avi.BITMAPINFOHEADER bih = new Avi.BITMAPINFOHEADER();
            bih.biBitCount = 24;
            bih.biClrImportant = 0;
            bih.biClrUsed = 0;
            bih.biCompression = 0; //BI_RGB;
            bih.biHeight = (Int32)streamInfo.rcFrame.bottom;
            bih.biWidth = (Int32)streamInfo.rcFrame.right;
            bih.biPlanes = 1;
            bih.biSize = (UInt32)Marshal.SizeOf( bih );
            bih.biXPelsPerMeter = 0;
            bih.biYPelsPerMeter = 0;

            getFrameObject = Avi.AVIStreamGetFrameOpen( aviStream, ref bih ); //force function to return 24bit DIBS
            //getFrameObject = Avi.AVIStreamGetFrameOpen(aviStream, 0); //return any bitmaps
            if ( getFrameObject == 0 ) {
                throw new Exception( "Exception in AVIStreamGetFrameOpen!" );
            }
        }

        /// <summary>Closes all streams, files and libraries</summary>
        public void Close() {
            if ( getFrameObject != 0 ) {
                Avi.AVIStreamGetFrameClose( getFrameObject );
                getFrameObject = 0;
            }
            if ( aviStream != IntPtr.Zero ) {
                Avi.AVIStreamRelease( aviStream );
                aviStream = IntPtr.Zero;
            }
            if ( aviFile != 0 ) {
                Avi.AVIFileRelease( aviFile );
                aviFile = 0;
            }
            Avi.AVIFileExit();
        }


        public Bitmap Export( int position ) {
            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
            MemoryStream fs = new MemoryStream();
            //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();
            fs.Flush();

            fs.Seek( 0, SeekOrigin.Begin );
            Bitmap bmp = new Bitmap( fs );
            fs.Close();
            return bmp;
        }


        /// <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();
        }
    }

}