The IAVIFile interface supports opening and manipulating files and file headers, and creating and obtaining stream interfaces. Uses IUnknown::QueryInterface, IUnknown::AddRef, and IUnknown::Release in addition to the following custom methods:
| Method | Description |
| CreateStream | Creates a stream for writing. |
| EndRecord | Writes the "REC" chunk in a tightly interleaved AVI file. |
| GetStream | Opens a stream by accessing it in a file. |
| Info | Fills and returns an AVIFILEINFO structure with information about a file. |
| Open | Initializes a file handler. |
| ReadData | Reads file headers data, format data, or nonaudio and nonvideo data. |
| WriteData | Writes file headers data, format data, or nonaudio and nonvideo data. |
Custom File and Stream Handlers Overview, Custom File and Stream Handler Interfaces