| This file contains information about the implementation of the multimedia |
| layer of WINE. |
| |
| The libraries consist of MMSYSTEM.DLL (win16), WINMM.DLL (win32) and some |
| (abstracted, not Windows compatible) lowlevel drivers. The implementation |
| can be found in the multimedia/ subdirectory. |
| |
| The multimedia stuff is split into 3 layers. The lowlevel (device drivers), |
| midlevel (MCI commands) and highlevel abstraction layers. |
| |
| 1. Lowlevel layers |
| |
| Following lowlevel layers are implemented: |
| 1.1 (Waveform) Audio |
| |
| The API consists of the waveIn*/waveOut* functions found in |
| multimedia/mmsystem.c. They call the real lowlevel audiodriver using |
| the wodMessage/widMessage function in multimedia/audio.c, which handles |
| the different requests. |
| |
| The lowlevel audio driver is currently only implemented for the |
| OpenSoundSystem (OSS) as supplied in the Linux and FreeBSD kernels by |
| 4Front Technologies (http://www.4front-tech.com/). The presence of this |
| driver is checked by configure (depends on the <sys/soundcard.h> file). |
| |
| The implementation contains all features commonly used, but has several |
| problems. For instance: |
| Writes and reads are not done asynchronously as they are supposed to |
| be done. This breaks some programs (soundrec.exe from the Windows applets), |
| but doesn't worry other programs. Some callbacks are probably done |
| incorrectly (there are reports of some broken multimedia applications, |
| but I haven't found one yet.) |
| |
| TODO: |
| - add asynchronous writes and reads (must use threads) |
| - check the callback functions |
| - verify all functions for correctness |
| - add drivers for other soundsystems (Sun Audio, remote audio systems |
| (using X extensions, ...) |
| |
| 1.2 Mixer |
| |
| The API consists of the mixer* functions found in multimedia/mmsystem.c. |
| They call the lowlevel driver functions in multimedia/mixer.c using the |
| mixMessage function. |
| |
| The current implementation tries to use the OpenSoundSystem mixer, but is |
| missing nearly everything. There is no report of a working application. |
| |
| TODO: |
| - implement mixing functionality for OSS correctly. |
| - implement mixing lowlevel drivers for other mixers. |
| |
| 1.3 MIDI |
| |
| The API consists of the midi* functions found in multimedia/mmsystem.c. |
| They call the lowlevel driver functions in multimedia/midi.c using the |
| midMessage and the modMessage functions. |
| |
| The current implementation is completely broken. (I think open(), read() |
| and write() of the /dev/midi device would make this implementation nearly |
| complete...) |
| |
| TODO: |
| - Implement correct MIDI output |
| - Do not implement a software synthesizer. This should be done |
| using MIDI loopback devices in an external program (like timidity). |
| |
| 1.4 Timers |
| |
| The API consists of the timer* functions found in multimedia/timer.c. |
| There is currently only one implementation, which uses normal windows timers. |
| The implementation works for most cases found. The only problem is that |
| it doesn't support asynchronous timer events (as it is supposed to do). |
| |
| There is a workaround for this lack in timeGetTime() to make Diablo work |
| and 'Pinball! SpaceCadet' at least start up. |
| |
| TODO: |
| - Implemented asynchronous timers (using a thread probably) |
| |
| 1.5 MMIO |
| |
| The API consists of the mmio* functions found in multimedia/mmio.c. |
| |
| FIXME: I am not sure about the status of this implementation. |
| |
| TODO: |
| - add win32 support. |
| - ... |
| |
| 1.6 AUX |
| |
| The API consists of the aux* functions found in multimedia/mmsystem.c. |
| They call auxMessage in multimedia/mmaux.c. |
| |
| The aux* functions are the predecessor of the mixer* functions. |
| |
| The implementation uses the OSS mixer API, and is incomplete. |
| |
| TODO: |
| - verify the implementation |
| |
| 1.7 JOYSTICK |
| |
| The API consists of the joy* functions found in multimedia/joystick.c. |
| The implementation currently uses the Linux joystick device driver API. |
| It is lacking support for enhanced joysticks and has not been extensively |
| tested. |
| |
| TODO: |
| - better support of enhanced joysticks |
| - support more joystick drivers (like the XInput extension) |
| |
| 2. Midlevel drivers (MCI) |
| |
| The midlevel drivers are represented by some common API functions, |
| mostly mciSendCommand and mciSendString. The mciSendString function |
| uses commandstrings, which are translated into normal MCI commands as |
| used by mciSendCommand. The API can be found in multimedia/mmsystem.c |
| and multimedia/mcistring.c. |
| The functions there (mciOpen,mciSysInfo) handle midlevel driver |
| allocation and calls. |
| |
| The implementation is not complete, but works for most cases. |
| Win32 support for mciSendCommand is missing (mciSendString works |
| in the Win32 case, since the use of strings doesn't differ between |
| win16 and win32). |
| |
| TODO: |
| - Win32 support |
| - support windows MCI drivers (should be possible for they usually |
| do not use lowlevel calls) |
| - MCI command loading support |
| - implement other stuff as yet unknown |
| |
| WINE implements several MCI midlevel drivers: |
| |
| 2.1 CDAUDIO |
| |
| The currently best implementation is the MCI CDAUDIO driver that can |
| be found in multimedia/mcicda.c. The implementation is mostly complete, |
| there have been no reports of errors. |
| The implementation currently uses only the Linux /dev/cdrom controlling |
| functions. (Sun and BSD like should be similair, but are not implemented.) |
| |
| A very small example of a cdplayer consists just of the line |
| mciSendString("play cdaudio",NULL,0,0); |
| |
| TODO: |
| - add support for other cdaudio drivers |
| |
| 2.2 MCIWAVE |
| |
| The implementation is rather complete and can be found in multimedia/audio.c. |
| It uses the lowlevel audio API (although not abstracted correctly). |
| FIXME: The MCI_STATUS command is broken. |
| |
| TODO: - check for correctness |
| |
| 2.3 MIDI/SEQUENCER |
| |
| The implementation can be found in multimedia/midi.c. I am not sure |
| about the completeness. |
| It uses the lowlevel midi driver and is probably broken too. |
| |
| TODO: |
| - implement it correctly |
| |
| 2.4 MCIANIM |
| |
| The implementation consists of stubs and is in multimedia/mcianim.c. |
| |
| TODO: |
| - implement it, probably using xanim or something similair. Could |
| also be implemented by using the Windows MCI video drivers. |