/// <summary>
/// Opens the media resource given by the specified <paramref name="stream"/>
/// </summary>
/// <param name="stream">Stream containing the contents of the file where the metadata should be
/// extracted.</param>
/// <returns><c>true</c>, if the open operation was successful. In this case, <see cref="IsValid"/> will
/// be <c>true</c> also. <c>false</c>, if the open operation was not successful. This means,
/// <see cref="IsValid"/> will also be <c>false</c>.</returns>
public bool Open(Stream stream)
{
_isValid = (_mediaInfo.Open_Buffer_Init(stream.Length, 0) == MEDIAINFO_FILE_OPENED);
if (!_isValid)
{
return(false);
}
// Increased buffer size for some .mp4 that contain first audio, then video stream. If buffer is smaller (i.e. 64 kb),
// MediaInfo only detects the audio stream. It works correctly in file mode.
const int bufferSize = 512 * 1024;
byte[] buffer = new byte[bufferSize]; // init the buffer to communicate with MediaInfo
GCHandle gcHandle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
IntPtr bufferPtr = gcHandle.AddrOfPinnedObject();
try
{
// Now we need to run the parsing loop, as long as MediaInfo requests information from the stream
int bytesRead;
do
{
bytesRead = stream.Read(buffer, 0, bufferSize);
if ((_mediaInfo.Open_Buffer_Continue(bufferPtr, (IntPtr)bytesRead) & BufferResult.Finalized) == BufferResult.Finalized)
{
// MediaInfo doesn't need more information from us
break;
}
long newPos = _mediaInfo.Open_Buffer_Continue_GoTo_Get();
// Now we need to test, if MediaInfo wants data from a different place of the stream
if (newPos == -1)
{
break;
}
Int64 pos = stream.Seek(newPos, SeekOrigin.Begin); // Position the stream
_mediaInfo.Open_Buffer_Init(stream.Length, pos); // Inform MediaInfo that we are at the new position
} while (bytesRead > 0);
}
finally
{
gcHandle.Free();
// Finalising MediaInfo procesing
_mediaInfo.Open_Buffer_Finalize();
}
return(_isValid);
}
public static String ExampleWithStream()
{
//Initilaizing MediaInfo
MediaInfo MI = new MediaInfo();
//From: preparing an example file for reading
FileStream From = new FileStream(FilePath, FileMode.Open, FileAccess.Read);
//From: preparing a memory buffer for reading
byte[] From_Buffer = new byte[64 * 1024];
int From_Buffer_Size; //The size of the read file buffer
//Preparing to fill MediaInfo with a buffer
MI.Open_Buffer_Init(From.Length, 0);
//The parsing loop
do
{
//Reading data somewhere, do what you want for this.
From_Buffer_Size = From.Read(From_Buffer, 0, 64 * 1024);
//Sending the buffer to MediaInfo
System.Runtime.InteropServices.GCHandle GC = System.Runtime.InteropServices.GCHandle.Alloc(From_Buffer, System.Runtime.InteropServices.GCHandleType.Pinned);
IntPtr From_Buffer_IntPtr = GC.AddrOfPinnedObject();
Status Result = (Status)MI.Open_Buffer_Continue(From_Buffer_IntPtr, (IntPtr)From_Buffer_Size);
GC.Free();
if ((Result & Status.Finalized) == Status.Finalized)
break;
//Testing if MediaInfo request to go elsewhere
if (MI.Open_Buffer_Continue_GoTo_Get() != -1)
{
Int64 Position = From.Seek(MI.Open_Buffer_Continue_GoTo_Get(), SeekOrigin.Begin); //Position the file
MI.Open_Buffer_Init(From.Length, Position); //Informing MediaInfo we have seek
}
}
while (From_Buffer_Size > 0);
//Finalizing
MI.Open_Buffer_Finalize(); //This is the end of the stream, MediaInfo must finnish some work
//Get() example
return "Container format is " + MI.Get(StreamKind.General, 0, "Format");
}
