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Как прочитать свойства видеофайла?


Как прочитать свойства видеофайла?





Below is some code to get some of the data. To use the DirectDraw/ DirectShow calls you need either the older DSHOW.PAS (DX6) or more current DirectShow.pas header conversion from the Project JEDI web site:


type
TDSMediaInfo = record
    SurfaceDesc: TDDSurfaceDesc;
    Pitch: integer;
    PixelFormat: TPixelFormat;
    MediaLength: Int64;
    AvgTimePerFrame: Int64;
    FrameCount: integer;
    Width: integer;
    Height: integer;
    FileSize: Int64;
  end;

function GetHugeFileSize(const FileName: string): int64;
var
  FileHandle: hFile;
begin
  FileHandle := FileOpen(FileName, fmOpenRead or fmShareDenyNone);
  try
    LARGE_INTEGER(Result).LowPart := GetFileSize(FileHandle, @LARGE_INTEGER(Result).HighPart);
    if LARGE_INTEGER(Result).LowPart = $FFFFFFFF then
      Win32Check(GetLastError = NO_ERROR);
  finally
    FileClose(FileHandle);
  end;
end;

function GetMediaInfo(FileName: WideString): TDSMediaInfo;
var
  DirectDraw: IDirectDraw;
  AMStream: IAMMultiMediaStream;
  MMStream: IMultiMediaStream;
  PrimaryVidStream: IMediaStream;
  DDStream: IDirectDrawMediaStream;
  GraphBuilder: IGraphBuilder;
  MediaSeeking: IMediaSeeking;
  TimeStart, TimeStop: Int64;
  DesiredSurface: TDDSurfaceDesc;
  DDSurface: IDirectDrawSurface;
begin
  if FileName = '' then
    raise Exception.Create('No File Name Specified');
  OleCheck(DirectDrawCreate(nil, DirectDraw, nil));
  DirectDraw.SetCooperativeLevel(GetDesktopWindow(), DDSCL_NORMAL);
  Result.FileSize := GetHugeFileSize(FileName);
  AMStream := IAMMultiMediaStream(CreateComObject(CLSID_AMMultiMediaStream));
  OleCheck(AMStream.Initialize(STREAMTYPE_READ, AMMSF_NOGRAPHTHREAD, nil));
  OleCheck(AMStream.AddMediaStream(DirectDraw, MSPID_PrimaryVideo, 0, IMediaStream(nil^)));
  OleCheck(AMStream.OpenFile(PWideChar(FileName), AMMSF_NOCLOCK));
  AMStream.GetFilterGraph(GraphBuilder);
  MediaSeeking := GraphBuilder as IMediaSeeking;
  MediaSeeking.GetDuration(Result.MediaLength);
  MMStream := AMStream as IMultiMediaStream;
  OleCheck(MMStream.GetMediaStream(MSPID_PrimaryVideo, PrimaryVidStream));
  DDStream := PrimaryVidStream as IDirectDrawMediaStream;
  DDStream.GetTimePerFrame(Result.AvgTimePerFrame);
  {Result.FrameCount := Result.MediaLength div Result.AvgTimePerFrame;}
  { TODO : Test for better accuracy }
  Result.FrameCount := Round(Result.MediaLength / Result.AvgTimePerFrame);
  Result.MediaLength := Result.FrameCount * Result.AvgTimePerFrame;
  ZeroMemory(@DesiredSurface, SizeOf(DesiredSurface));
  DesiredSurface.dwSize := Sizeof(DesiredSurface);
  OleCheck(DDStream.GetFormat(TDDSurfaceDesc(nil^), IDirectDrawPalette(nil^),
    DesiredSurface, DWord(nil^)));
  Result.SurfaceDesc := DesiredSurface;
  DesiredSurface.ddsCaps.dwCaps := DesiredSurface.ddsCaps.dwCaps or
    DDSCAPS_OFFSCREENPLAIN or DDSCAPS_SYSTEMMEMORY;
  DesiredSurface.dwFlags := DesiredSurface.dwFlags or DDSD_CAPS or DDSD_PIXELFORMAT;
  {Create a surface here to get vital statistics}
  OleCheck(DirectDraw.CreateSurface(DesiredSurface, DDSurface, nil));
  OleCheck(DDSurface.GetSurfaceDesc(DesiredSurface));
  Result.Pitch := DesiredSurface.lPitch;
  if DesiredSurface.ddpfPixelFormat.dwRGBBitCount = 24 then
    Result.PixelFormat := pf24bit
  else if DesiredSurface.ddpfPixelFormat.dwRGBBitCount = 32 then
    Result.PixelFormat := pf32bit;
  Result.Width := DesiredSurface.dwWidth;
  Result.Height := DesiredSurface.dwHeight;
end;


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