|
IAVIStream::ReadFormat
The ReadFormat method obtains format information from a stream. Fills and returns a
structure with the data in an application-defined buffer. If no buffer is supplied,
determines the buffer size needed to retrieve the buffer of format data. Called
when an application uses the AVIStreamReadFormat function.
HRESULT ReadFormat(
PAVISTREAM ps,
|
| LONG lPos,
|
| LPVOID lpFormat,
|
| LONG *lpcbFormat
|
| );
|
|
Parameters
ps
Address of the interface to a stream.
lPos
Position of the sample or frame.
lpFormat
Address of the buffer for the format data. Specify NULL to request the
required size of the buffer.
lpcbFormat
Address that contains the size, in bytes, of the buffer specified by lpFormat. When this method is called, the contents of this parameter indicates the
size of the buffer specified by lpFormat. When this method returns control to the application, the contents of this
parameter specifies the amount of data read or the required size of the buffer.
Return Values
Returns the HRESULT defined by OLE.
Remarks
The type of data stored in a stream dictates the format information and the
structure that contains the format information. A stream handler should return
all applicable format information in this structure, including palette
information when the format uses a palette. A stream handler should not return stream
data with the structure.
Standard video stream handlers provide format information in a BITMAPINFOHEADER structure. Standard audio stream handlers provide format information in a PCMWAVEFORMAT structure. Other data streams can use other structures that describe the
stream data.
For handlers written in C++, ReadFormat has the following syntax:
HRESULT ReadFormat(LONG lPos, LPVOID lpFormat,
LONG *lpcbFormat)
See Also
AVIStreamReadFormat, BITMAPINFOHEADER, PCMWAVEFORMAT
Related Links
Software for Delphi and C++ Builder developers
Software for Visual Studio .NET developers
Software for Visual Basic 6 developers
Delphi Tips&Tricks
MegaDetailed.NET
More Online Helps
Win32 Programmer's Reference (win32.hlp)
OLE Programmer's Reference (ole.hlp)
Microsoft Windows Pen API Programmer's Reference (penapi.hlp)
Microsoft Windows Sockets 2 Reference (sock2.hlp)
Microsoft Windows Telephony API (TAPI) Programmer's Reference (tapi.hlp)
Unix Manual Pages
|
