WLMFReadWrite.dll

Source	src/WLMFReadWrite/
CMake target	WLMFReadWrite
Type	Win32 DLL (252 KB / 217 KB code, 70+ RTTI classes in the original)
Family	Media Foundation targets

At a glance

A flat C API over Media Foundation read/write: the module exposes nine exports — seven MF reader/writer functions plus two COM standard entries. This is the workhorse DLL for codecs/transcode tooling that wants MF without the full object model.

Public surface

From WLMFReadWrite.def:

DllCanUnloadNow               DllGetClassObject
MFReader_Close@4          @3
MFReader_GetProperties@8  @4
MFReader_Open@4           @5
MFReader_ReadFrame@24     @6
MFWriter_Create@8         @7
MFWriter_Finalize@4       @8
MFWriter_WriteFrame@20    @9

All __stdcall with byte-count decorations.

API shape

Function	Purpose
MFReader_Open / MFReader_Close	Open a media source / release it
MFReader_GetProperties	Query stream properties (duration, formats, frame count)
MFReader_ReadFrame	Read one frame (24 bytes of params — buffer, stride, timestamps)
MFWriter_Create	Create a writer for an output profile
MFWriter_WriteFrame	Write one frame
MFWriter_Finalize	Finalize the output (flush + index + close)

Implementation notes

• Wraps IMFSourceReader / IMFSinkWriter from mfreadwrite.h.
• Contract-pinned: HRESULTs for open/read/write on sample media are asserted by tests/mmr-python (the parity-stub build's E_NOTIMPLs are not the oracle here).

Testing

• tests/WLMFReadWrite/ — per-module C++ tests.
• Contract coverage in tests/mmr-python.

Analysis artifacts

analysis/WLMFReadWrite/ (PDB GUID {54E10C67-67A5-4F8A-8567-1D47C28B2189}).