Microsoft Low Level MultiMedia Interface

• This is the original low level interface to the miscellaneous multimedia devices supported by Windows. It is a set of Win32 calls and Installable Drivers in DLLs, not based on COM.
• It's still interesting because it's capable of capturing sound and video, as well as playing it. The DirectX and Active Movie stuff doesn't support capture, so the low level multimedia capture interfaces are still important until they do.
• AVI file interface library
  • AVIFile protocol
    • You can write your own AVI file handlers, that read and write AVI files to storage, that contain multiple streams, as well as writing your own AVI stream handlers.
    • open, close
    • copy to and from clipboard
    • get stream
  • AVIStream protocol
    • You can write you own AVI stream handlers, that read and write different kinds of streams to and from AVI files, as well as writing your own AVI file handlers.
    • Supported stream types: video, audio, text, midi.
    • get from avi file
    • read, write, seek, find sample (like next-interesting-time), start, end, length, start time, end time, length time, sample/time mapping
    • get stream type specific format information
    • begin/end streaming to control read-ahead
    • stream read does not provide decompression services
    • open/close getframe resources (like session or quicktime decompressor state)
    • read/write files
    • audio file sample frames are 256(?) byte block of UNcompressed audio data
    • compress a stream given a compression method and options
    • editing streams
      • editable stream that can efficiently behave like an emacs buffer
      • cut/copy/paste/clone
• Video Compression Manager
  • compressors, decompressors, and renderers
  • renderers decompress directly onto the screen
  • DrawDib library is a convenient interface to VCM
  • registry of compressors to choose from
  • locate, open, info, close, compressor choose dialog, free, install in registry, remove from registry
  • open function
    • Open a function internally as a compressor, without installing it in the registry.
    • Function is a DriverProc entry-point function, used by Installable Drivers.
  • You can write your own compressors, decompressors, and renders, which you can put in DLLs and register with the system, or use by opening their DriverProc functions internally without globally registering them.
• Audio Compression Manager
  • Compressors
  • Decompressors
  • Filters