MMPM2.LIB

MMPM2.LIB is the import library for MMPM/2 (MultiMedia Presentation Manager/2), the OS/2 multimedia subsystem. It provides the linker stubs required to call the MCI (Media Control Interface), MMIO (Multimedia I/O), multimedia PM controls, and media device manager APIs from 32-bit OS/2 applications.

The library contains no executable code. It is an OMF import library: each record maps an exported function name to an ordinal in the supplying DLL. MMPM2.LIB is a supplement to OS2386.LIB — a multimedia application links both.

File size in the OS/2 Warp 4.52 Toolkit 4.5: 32,768 bytes (2001-07-26).

API Coverage

MMPM2.LIB covers approximately 223 exported symbols across four subsystems:

API prefix	Approximate count	Source DLL	Subsystem
`mmio*`	~167 (public + helpers)	MMIO.DLL	Multimedia file I/O, codec management, CTOC
`mci*`	~25	MDM.DLL	Media Control Interface (device control, streaming)
`Win*`	~28	MMPMPCS.DLL / MMREG.DLL	Custom PM controls (sliders, secondary window)
`mdm*`	~3	MDM.DLL	Media Device Manager (driver notification)

MCI — Media Control Interface

The MCI layer is the primary high-level API for controlling multimedia devices (waveform audio, MIDI, CD audio, digital video, etc.). Applications send string or command-message requests to a device driver loaded by the MDM (Media Device Manager).

Core functions

mciSendCommand(usDeviceID, usMessage, ulParam1, ulParam2): The primary command interface. Sends a binary MCI message (e.g. MCI_OPEN, MCI_PLAY, MCI_STOP, MCI_CLOSE) to a device. Parameters are passed as flag words and pointer structures defined in os2me.h.

mciSendString(pszCommandString, pszReturnString, usReturnLength, hwndCallback, usUserParm): String-based alternative to mciSendCommand. Parses a text command such as "play cdaudio from 0 to 5000 notify". Useful for scripting and REXX integration.

mciGetErrorString(ulError, pszBuffer, usLength): Translates an MCI error code to a human-readable string. Every MCI call that returns non-zero should be passed through this function before displaying an error message.

mciGetDeviceID(pszDeviceName): Returns the device ID for an open MCI device by name.

System values

mciQuerySysValue(usItem, pulValue): Queries a global MMPM/2 system value (e.g. master volume, synchronization settings).

mciSetSysValue(usItem, ulValue): Sets a global MMPM/2 system value.

Device groups

mciMakeGroup(pusGroupID, usDeviceCount, pausDeviceList, ulFlags): Creates a logical group of MCI device IDs so that a single mciSendCommand call controls all of them simultaneously (synchronized playback).

mciDeleteGroup(usGroupID): Removes a previously created device group.

Connection management

mciConnection(usFromID, usToID, ulFlags, pConnParm): Establishes or removes a data connection between two MCI devices (e.g. routing audio from a waveform device to an amplifier-mixer).

mciDefaultConnection(usDeviceID, ulFlags, pConnParm): Configures the default connection topology for a device.

mciQueryConnections(usDeviceID, ulFlags, pConnParm) / mciQueryDefaultConnections: Queries current connection state.

High-level helpers

These functions wrap common open/play/close sequences for simple playback scenarios:

mciPlayFile(hwnd, pszFileName, ulStyle, pszTitle): Opens and plays a multimedia file (wave, MIDI, AVI, etc.) in a single call.

mciPlayResource(hwnd, hmod, usResourceID, ulStyle): Plays an audio or multimedia resource embedded in an EXE or DLL.

mciRecordAudioFile(hwnd, pszFileName, ulStyle, pszTitle): Records waveform audio to a file.

mciCreatePlayFilePalette(hwnd, pszFileName, ulStyle, pszTitle): Creates a play palette (compact floating control) for a multimedia file.

REXX interface

MMPM/2 includes a REXX command interface for scripting multimedia operations:

mciRxInit() / mciRxExit(): Initialize and uninitialize the REXX MCI interface.

mciRxSendString(pszCommand, pszReturn, usReturnLen, hwndCallback): Send an MCI string command from REXX context.

mciRxGetDeviceID(pszName) / mciRxGetErrorString(ulError): REXX variants of the corresponding MCI functions.

MMIO — Multimedia I/O

The MMIO subsystem handles reading and writing multimedia file formats. It provides a RIFF-aware stream abstraction with installable I/O procedures (IOProcs) and codecs, allowing applications to read any supported format through a uniform API.

Basic file operations

mmioOpen(pszFileName, pmmioinfo, ulOpenFlags): Opens a multimedia file for reading, writing, or creation. The MMIOINFO structure controls I/O procedure selection, memory-file mode, and buffering.

mmioClose(hmmio, usFlags): Closes an open MMIO handle.

mmioRead(hmmio, pchBuffer, lBytes): Reads bytes from the current file position.

mmioWrite(hmmio, pchBuffer, lBytes): Writes bytes at the current file position.

mmioSeek(hmmio, lOffset, lOrigin): Repositions the file pointer. Origin values mirror fseek (SEEK_SET, SEEK_CUR, SEEK_END).

mmioFlush(hmmio, usFlags): Flushes the I/O buffer to the underlying storage.

mmioAdvance(hmmio, pmmioinfo, usFlags): Advances the MMIO buffer for double-buffered I/O (used during streaming playback/recording).

RIFF chunk navigation

Multimedia files such as RIFF WAVE and AVI are structured as nested chunks. MMIO provides functions to traverse this tree:

mmioDescend(hmmio, pmmcki, pmmckiParent, usFlags): Descends into a RIFF chunk. Can search for a specific chunk type (MMIO_FINDCHUNK) or list (MMIO_FINDLIST).

mmioAscend(hmmio, pmmcki, usFlags): Ascends out of a chunk, optionally writing the chunk size into the file header.

mmioCreateChunk(hmmio, pmmcki, usFlags): Creates a new RIFF chunk at the current position. Used when writing multimedia files.

Buffer management

mmioGetInfo(hmmio, pmmioinfo, usFlags): Retrieves the current MMIO state (buffer pointer, buffer size, flags).

mmioSetInfo(hmmio, pmmioinfo, usFlags): Updates the MMIO state after the application has directly read from or written to the buffer.

mmioSetBuffer(hmmio, pchBuffer, lBuffer, usFlags): Replaces the MMIO I/O buffer with a caller-supplied buffer, or changes the buffer size.

mmioGetData(hmmio, pmmioinfo, usFlags): Returns direct access pointers to the internal MMIO buffer.

Header access

mmioGetHeader(hmmio, pHeader, lHeaderLength, plBytesRead, ulReserved, ulFlags): Retrieves the format-specific header structure from an open MMIO file (e.g. MMAUDIOHEADER for PCM files).

mmioSetHeader(hmmio, pHeader, lHeaderLength, plBytesWritten, ulReserved, ulFlags): Writes or updates the format-specific header.

mmioQueryHeaderLength(hmmio, plHeaderLength, ulReserved, ulFlags): Returns the size of the current file's header structure.

Format identification

mmioIdentifyFile(pszFileName, pmmioinfo, pFourCC, phmmio, ulFlags): Detects the file format of a multimedia file and returns its FOURCC code and the IOProc that handles it.

mmioIdentifyFileFormat(hmmio, pFourCC, ulFlags): Identifies the format of an already-open MMIO handle.

mmioIdentifyStorageSystem(pszFileName, pmmioinfo, pFourCC): Identifies the storage system (file, memory, URL, etc.) associated with a path.

mmioGetFormats(ulSearchFlags, pFourCC, pFormatList, pulListSize, ulFlags): Enumerates all installed file format IOProcs.

mmioGetFormatName(ulSearchFlags, pFourCC, pszName, pulBufSize, ulFlags): Returns the display name for a given format FOURCC.

mmioQueryFormatCount(pFourCC, pulCount, ulReserved, ulFlags): Returns the number of installed format IOProcs matching the criteria.

mmioStringToFOURCC(pszFOURCC, usFlags): Converts a four-character string to its FOURCC integer value.

I/O procedure management

Applications can install custom IOProcs to support additional file formats:

mmioInstallIOProc(fccIOProc, pIOProc, ulFlags): Registers or removes a custom I/O procedure. The IOProc is a callback that handles open/close/read/write/seek/send-message operations for a new format.

mmioQueryIOProcModuleHandle(fccIOProc, phmod): Returns the module handle of the DLL providing a given IOProc.

mmioDetermineFFIOProc(pszFileName, pmmioinfo, pFourCC, ulFlags): Determines the IOProc for a flat-file storage format.

mmioDetermineSSIOProc(pszFileName, pmmioinfo, pFourCC, ulFlags): Determines the IOProc for a storage-system (non-flat-file) format.

mmioDetermineLastIOProc(pszFileName, pmmioinfo, pFourCC, ulFlags): Returns the last-resort IOProc for unrecognized files.

CODEC management

mmioLoadCODECProc(pCodecInfo, ppfnCodecProc, ulFlags): Loads a CODEC (compressor/decompressor) procedure for a given format.

mmioQueryCODECName(pCodecInfo, pszName, pulBufSize): Returns the display name of a CODEC.

mmioQueryCODECNameLength(pCodecInfo, pulLength): Returns the string length of a CODEC name.

mmioIniFileCODEC(pCodecInfo, ulFlags): Reads or updates CODEC entries in the MMPM/2 INI file.

mmioIniFileHandler(pmmformatinfo, ulFlags): Reads or updates IOProc entries in the MMPM/2 INI file.

MMIO messaging

mmioSendMessage(hmmio, usMessage, ulParam1, ulParam2): Sends a control message directly to the IOProc managing a file.

CTOC (Compound Table of Contents)

CTOC is an OS/2-specific extension for compound multimedia files (multiple data streams in one file):

mmioCFOpen(pszFileName, phmmcf, pmmcfinfo, ulFlags): Opens a compound file.

mmioCFClose(hmmcf, ulFlags): Closes a compound file.

mmioCFGetInfo(hmmcf, pmmcfinfo, lInfoLength): Returns information about an open compound file.

mmioCFSetInfo(hmmcf, pmmcfinfo, lInfoLength): Updates compound file settings.

mmioCFAddElement(hmmcf, pszElementName, ulFlags): Adds a new element (stream) to a compound file.

mmioCFAddEntry(hmmcf, pmmctocentry, ulFlags): Adds a CTOC directory entry.

mmioCFChangeEntry(hmmcf, pmmctocentry, ulFlags): Modifies an existing CTOC entry.

mmioCFDeleteEntry(hmmcf, pmmctocentry, ulFlags): Removes a CTOC entry.

mmioCFFFindEntry(hmmcf, pmmctocentry, ulFlags): Searches for a CTOC entry by name or type.

mmioCFCopy(pszSource, pszDest, ulFlags): Copies a compound file.

mmioCFCompact(pszFileName, ulFlags): Compacts a compound file by removing deleted space.

Internal helpers (mmiohlp*)

MMPM2.LIB exports approximately 80 mmiohlp* symbols. These are internal helpers used by IOProc DLLs and CODEC DLLs rather than by end-user applications. Examples include mmiohlpLoadIOProc, mmiohlpBuildCtoc, mmiohlpExpandMemFile, mmiohlpGetFullPathName, and semaphore utilities such as mmiohlpAcquireMmioSem / mmiohlpDiscardMmioSem. They are documented in the MMPM/2 IOProc/CODEC development guide rather than the application programming reference.

mmioGetLastError(hmmio): Returns the last error code set by the IOProc for a given handle.

mmioMigrateIniFile(ulFlags): Migrates MMPM/2 INI entries from an earlier installation.

Custom PM Controls

MMPM/2 provides three custom Presentation Manager window classes for building multimedia application UIs. They must be registered before use. These controls are defined in mmioos2.h.

Circular Slider

A rotary control (knob) suitable for volume or balance settings.

WinRegisterCircularSlider(): Registers the CircularSlider window class. Must be called once per process before creating circular slider windows with WinCreateWindow.

Graphic Button

A push-button that displays a bitmap in each state (normal, pressed, disabled).

WinRegisterGraphicButton(): Registers the GraphicButton window class.

Selection Slider

A linear slider with discrete tick positions, suitable for transport controls (fast-forward, rewind steps).

WinRegisterSelectionSlider(): Registers the SelectionSlider window class.

Secondary Window

A standardized secondary dialog framework used by MMPM/2's own player windows. Applications can host secondary windows to embed player-style dialogs inside their own UI.

WinCreateSecondaryWindow, WinLoadSecondaryWindow, WinDestroySecondaryWindow: Create, load from resources, and destroy a secondary window.

WinDismissSecondaryWindow(hwnd, ulResult): Dismisses a modal secondary window.

WinDefSecondaryWindowProc, WinProcessSecondaryWindow: Default window procedure and message pump for secondary windows.

WinQuerySecondaryDialog, WinQuerySecondaryFrame, WinQuerySecondaryHWND: Query the dialog, frame, and client HWNDs of a secondary window.

WinSecondaryWindow, WinSecondaryMessageBox: Simplified modal secondary window and message box variants.

WinDefaultSize, WinInsertDefaultSize, WinQueryDefaultSize: Manage the default size record attached to a secondary window.

WinReportMessage(hwnd, pszTitle, pszText, ulStyle): Displays a standardized MMPM/2 error or information message box.

WinSWAssocResModule(hwnd, hmod): Associates a resource module with a secondary window for NLS resource lookup.

MDM — Media Device Manager

mdmDriverNotify(usDeviceID, hwnd, usMessage, usParam1, ulParam2): Called by media device drivers to post asynchronous notification messages to MMPM/2. Not used by applications; used when writing an MCI device driver DLL.

mdmAPMEntry(usFunction, ulParam1, ulParam2): APM (Advanced Power Management) entry point for media drivers that need to handle suspend/resume events.

Usage

MMPM2.LIB is a supplement to OS2386.LIB. Always link both:

IBM VisualAge C++ / ILINK

icc -O2 -Gm -c myapp.c
ilink /PM:PM myapp.obj os2386.lib mmpm2.lib

OpenWatcom (wlink)

wcl386 -bt=os2 -mf -c myapp.c
wlink system os2_pm file myapp.obj library os2386.lib library mmpm2.lib

EMX/GCC

gcc -Zomf -c myapp.c
gcc -Zomf -o myapp.exe myapp.o os2386.lib mmpm2.lib

Include files

The primary headers for MMPM/2 application development (from the OS/2 Toolkit h\ directory):

Header	Contents
`os2me.h`	Master MMPM/2 header. Includes all of the below. Include this one for most applications.
`mmioos2.h`	MMIO types, structures (`MMIOINFO`, `MMCKINFO`), and function prototypes. Also declares the custom PM control class names.
`mcios2.h`	MCI message codes (`MCI_OPEN`, `MCI_PLAY`, etc.), device types, flag constants, and `mciSendCommand`/`mciSendString` prototypes.
`mmreg.h`	FOURCC registration and codec registration structures.

Version History

Version	MMPM/2 release	Date	Notes
1.0	MMPM/2 1.0 (OS/2 2.0)	1992	Initial release. Core MCI (`mciSendCommand`, `mciSendString`) and basic MMIO.
1.1	MMPM/2 1.1 (OS/2 2.1)	1993	Added CTOC compound file support (`mmioCF*`), additional device types.
2.0	MMPM/2 2.0 (OS/2 Warp 3)	1994	Added digital video (DIVE), synchronization groups (`mciMakeGroup`), custom PM controls (circular slider, graphic button, selection slider).
2.1	MMPM/2 2.1 (OS/2 Warp 4)	1996	Added connection management (`mciConnection`), REXX MCI interface (`mciRx*`), secondary window framework (`WinSecondaryWindow`).
2.11	MMPM/2 2.11 (OS/2 Warp 4.52)	2001	APM support (`mdmAPMEntry`), CODEC migration utilities, final IBM release. File size: 32,768 bytes.