e85d191b46
- merge v0.01 --> Añadido fileselector - Añadidas fuentes de Gem y Pure Data - pix2jpg incluído en Gem. Archivos de construcción de Gem modificados. - Añadido fichero ompiling.txt con instrucciones de compilación
606 lines
26 KiB
C
Executable file
606 lines
26 KiB
C
Executable file
#ifndef PORT_MIDI_H
|
|
#define PORT_MIDI_H
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif /* __cplusplus */
|
|
|
|
/*
|
|
* PortMidi Portable Real-Time MIDI Library
|
|
* PortMidi API Header File
|
|
* Latest version available at: http://www.cs.cmu.edu/~music/portmidi/
|
|
*
|
|
* Copyright (c) 1999-2000 Ross Bencina and Phil Burk
|
|
* Copyright (c) 2001-2006 Roger B. Dannenberg
|
|
*
|
|
* Latest version available at: http://www.cs.cmu.edu/~music/portmidi/
|
|
*
|
|
* Copyright (c) 1999-2000 Ross Bencina and Phil Burk
|
|
* Copyright (c) 2001-2006 Roger B. Dannenberg
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining
|
|
* a copy of this software and associated documentation files
|
|
* (the "Software"), to deal in the Software without restriction,
|
|
* including without limitation the rights to use, copy, modify, merge,
|
|
* publish, distribute, sublicense, and/or sell copies of the Software,
|
|
* and to permit persons to whom the Software is furnished to do so,
|
|
* subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be
|
|
* included in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
|
|
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
|
|
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
|
|
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
|
|
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
/*
|
|
* The text above constitutes the entire PortMidi license; however,
|
|
* the PortMusic community also makes the following non-binding requests:
|
|
*
|
|
* Any person wishing to distribute modifications to the Software is
|
|
* requested to send the modifications to the original developer so that
|
|
* they can be incorporated into the canonical version. It is also
|
|
* requested that these non-binding requests be included along with the
|
|
* license above.
|
|
*/
|
|
|
|
/* CHANGELOG FOR PORTMIDI
|
|
* (see ../CHANGELOG.txt)
|
|
*
|
|
* IMPORTANT INFORMATION ABOUT A WIN32 BUG:
|
|
*
|
|
* Windows apparently has a serious midi bug -- if you do not close ports, Windows
|
|
* may crash. PortMidi tries to protect against this by using a DLL to clean up.
|
|
*
|
|
* If client exits for example with:
|
|
* i) assert
|
|
* ii) Ctrl^c,
|
|
* then DLL clean-up routine called. However, when client does something
|
|
* really bad (e.g. assigns value to NULL pointer) then DLL CLEANUP ROUTINE
|
|
* NEVER RUNS! In this state, if you wait around long enough, you will
|
|
* probably get the blue screen of death. Can also go into Pview and there will
|
|
* exist zombie process that you can't kill.
|
|
*
|
|
* You can enable the DLL cleanup routine by defining USE_DLL_FOR_CLEANUP.
|
|
* Do not define this preprocessor symbol if you do not want to use this
|
|
* feature.
|
|
*
|
|
* NOTES ON HOST ERROR REPORTING:
|
|
*
|
|
* PortMidi errors (of type PmError) are generic, system-independent errors.
|
|
* When an error does not map to one of the more specific PmErrors, the
|
|
* catch-all code pmHostError is returned. This means that PortMidi has
|
|
* retained a more specific system-dependent error code. The caller can
|
|
* get more information by calling Pm_HasHostError() to test if there is
|
|
* a pending host error, and Pm_GetHostErrorText() to get a text string
|
|
* describing the error. Host errors are reported on a per-device basis
|
|
* because only after you open a device does PortMidi have a place to
|
|
* record the host error code. I.e. only
|
|
* those routines that receive a (PortMidiStream *) argument check and
|
|
* report errors. One exception to this is that Pm_OpenInput() and
|
|
* Pm_OpenOutput() can report errors even though when an error occurs,
|
|
* there is no PortMidiStream* to hold the error. Fortunately, both
|
|
* of these functions return any error immediately, so we do not really
|
|
* need per-device error memory. Instead, any host error code is stored
|
|
* in a global, pmHostError is returned, and the user can call
|
|
* Pm_GetHostErrorText() to get the error message (and the invalid stream
|
|
* parameter will be ignored.) The functions
|
|
* pm_init and pm_term do not fail or raise
|
|
* errors. The job of pm_init is to locate all available devices so that
|
|
* the caller can get information via PmDeviceInfo(). If an error occurs,
|
|
* the device is simply not listed as available.
|
|
*
|
|
* Host errors come in two flavors:
|
|
* a) host error
|
|
* b) host error during callback
|
|
* These can occur w/midi input or output devices. (b) can only happen
|
|
* asynchronously (during callback routines), whereas (a) only occurs while
|
|
* synchronously running PortMidi and any resulting system dependent calls.
|
|
* Both (a) and (b) are reported by the next read or write call. You can
|
|
* also query for asynchronous errors (b) at any time by calling
|
|
* Pm_HasHostError().
|
|
*
|
|
* NOTES ON COMPILE-TIME SWITCHES
|
|
*
|
|
* DEBUG assumes stdio and a console. Use this if you want automatic, simple
|
|
* error reporting, e.g. for prototyping. If you are using MFC or some
|
|
* other graphical interface with no console, DEBUG probably should be
|
|
* undefined.
|
|
* PM_CHECK_ERRORS more-or-less takes over error checking for return values,
|
|
* stopping your program and printing error messages when an error
|
|
* occurs. This also uses stdio for console text I/O.
|
|
* USE_DLL_FOR_CLEANUP is described above. (Windows only.)
|
|
*
|
|
*/
|
|
|
|
#ifndef FALSE
|
|
#define FALSE 0
|
|
#endif
|
|
#ifndef TRUE
|
|
#define TRUE 1
|
|
#endif
|
|
|
|
/* default size of buffers for sysex transmission: */
|
|
#define PM_DEFAULT_SYSEX_BUFFER_SIZE 1024
|
|
|
|
|
|
typedef enum {
|
|
pmNoError = 0,
|
|
pmHostError = -10000,
|
|
pmInvalidDeviceId, /* out of range or
|
|
* output device when input is requested or
|
|
* input device when output is requested or
|
|
* device is already opened
|
|
*/
|
|
pmInsufficientMemory,
|
|
pmBufferTooSmall,
|
|
pmBufferOverflow,
|
|
pmBadPtr,
|
|
pmBadData, /* illegal midi data, e.g. missing EOX */
|
|
pmInternalError,
|
|
pmBufferMaxSize /* buffer is already as large as it can be */
|
|
/* NOTE: If you add a new error type, be sure to update Pm_GetErrorText() */
|
|
} PmError;
|
|
|
|
/*
|
|
Pm_Initialize() is the library initialisation function - call this before
|
|
using the library.
|
|
*/
|
|
|
|
PmError Pm_Initialize( void );
|
|
|
|
/*
|
|
Pm_Terminate() is the library termination function - call this after
|
|
using the library.
|
|
*/
|
|
|
|
PmError Pm_Terminate( void );
|
|
|
|
/* A single PortMidiStream is a descriptor for an open MIDI device.
|
|
*/
|
|
typedef void PortMidiStream;
|
|
#define PmStream PortMidiStream
|
|
|
|
/*
|
|
Test whether stream has a pending host error. Normally, the client finds
|
|
out about errors through returned error codes, but some errors can occur
|
|
asynchronously where the client does not
|
|
explicitly call a function, and therefore cannot receive an error code.
|
|
The client can test for a pending error using Pm_HasHostError(). If true,
|
|
the error can be accessed and cleared by calling Pm_GetErrorText().
|
|
Errors are also cleared by calling other functions that can return
|
|
errors, e.g. Pm_OpenInput(), Pm_OpenOutput(), Pm_Read(), Pm_Write(). The
|
|
client does not need to call Pm_HasHostError(). Any pending error will be
|
|
reported the next time the client performs an explicit function call on
|
|
the stream, e.g. an input or output operation. Until the error is cleared,
|
|
no new error codes will be obtained, even for a different stream.
|
|
*/
|
|
int Pm_HasHostError( PortMidiStream * stream );
|
|
|
|
|
|
/* Translate portmidi error number into human readable message.
|
|
These strings are constants (set at compile time) so client has
|
|
no need to allocate storage
|
|
*/
|
|
const char *Pm_GetErrorText( PmError errnum );
|
|
|
|
/* Translate portmidi host error into human readable message.
|
|
These strings are computed at run time, so client has to allocate storage.
|
|
After this routine executes, the host error is cleared.
|
|
*/
|
|
void Pm_GetHostErrorText(char * msg, unsigned int len);
|
|
|
|
#define HDRLENGTH 50
|
|
#define PM_HOST_ERROR_MSG_LEN 256u /* any host error msg will occupy less
|
|
than this number of characters */
|
|
|
|
/*
|
|
Device enumeration mechanism.
|
|
|
|
Device ids range from 0 to Pm_CountDevices()-1.
|
|
|
|
*/
|
|
typedef int PmDeviceID;
|
|
#define pmNoDevice -1
|
|
typedef struct {
|
|
int structVersion;
|
|
const char *interf; /* underlying MIDI API, e.g. MMSystem or DirectX */
|
|
const char *name; /* device name, e.g. USB MidiSport 1x1 */
|
|
int input; /* true iff input is available */
|
|
int output; /* true iff output is available */
|
|
int opened; /* used by generic PortMidi code to do error checking on arguments */
|
|
|
|
} PmDeviceInfo;
|
|
|
|
|
|
int Pm_CountDevices( void );
|
|
/*
|
|
Pm_GetDefaultInputDeviceID(), Pm_GetDefaultOutputDeviceID()
|
|
|
|
Return the default device ID or pmNoDevice if there are no devices.
|
|
The result can be passed to Pm_OpenMidi().
|
|
|
|
On the PC, the user can specify a default device by
|
|
setting an environment variable. For example, to use device #1.
|
|
|
|
set PM_RECOMMENDED_OUTPUT_DEVICE=1
|
|
|
|
The user should first determine the available device ID by using
|
|
the supplied application "testin" or "testout".
|
|
|
|
In general, the registry is a better place for this kind of info,
|
|
and with USB devices that can come and go, using integers is not
|
|
very reliable for device identification. Under Windows, if
|
|
PM_RECOMMENDED_OUTPUT_DEVICE (or PM_RECOMMENDED_INPUT_DEVICE) is
|
|
*NOT* found in the environment, then the default device is obtained
|
|
by looking for a string in the registry under:
|
|
HKEY_LOCAL_MACHINE/SOFTWARE/PortMidi/Recommended_Input_Device
|
|
and HKEY_LOCAL_MACHINE/SOFTWARE/PortMidi/Recommended_Output_Device
|
|
for a string. The number of the first device with a substring that
|
|
matches the string exactly is returned. For example, if the string
|
|
in the registry is "USB", and device 1 is named
|
|
"In USB MidiSport 1x1", then that will be the default
|
|
input because it contains the string "USB".
|
|
|
|
In addition to the name, PmDeviceInfo has the member "interf", which
|
|
is the interface name. (The "interface" is the underlying software
|
|
system or API used by PortMidi to access devices. Examples are
|
|
MMSystem, DirectX (not implemented), ALSA, OSS (not implemented), etc.)
|
|
At present, the only Win32 interface is "MMSystem", the only Linux
|
|
interface is "ALSA", and the only Max OS X interface is "CoreMIDI".
|
|
To specify both the interface and the device name in the registry,
|
|
separate the two with a comma and a space, e.g.:
|
|
MMSystem, In USB MidiSport 1x1
|
|
In this case, the string before the comma must be a substring of
|
|
the "interf" string, and the string after the space must be a
|
|
substring of the "name" name string in order to match the device.
|
|
|
|
Note: in the current release, the default is simply the first device
|
|
(the input or output device with the lowest PmDeviceID).
|
|
*/
|
|
PmDeviceID Pm_GetDefaultInputDeviceID( void );
|
|
PmDeviceID Pm_GetDefaultOutputDeviceID( void );
|
|
|
|
/*
|
|
PmTimestamp is used to represent a millisecond clock with arbitrary
|
|
start time. The type is used for all MIDI timestampes and clocks.
|
|
*/
|
|
typedef long PmTimestamp;
|
|
typedef PmTimestamp (*PmTimeProcPtr)(void *time_info);
|
|
|
|
/* TRUE if t1 before t2 */
|
|
#define PmBefore(t1,t2) ((t1-t2) < 0)
|
|
|
|
/*
|
|
Pm_GetDeviceInfo() returns a pointer to a PmDeviceInfo structure
|
|
referring to the device specified by id.
|
|
If id is out of range the function returns NULL.
|
|
|
|
The returned structure is owned by the PortMidi implementation and must
|
|
not be manipulated or freed. The pointer is guaranteed to be valid
|
|
between calls to Pm_Initialize() and Pm_Terminate().
|
|
*/
|
|
const PmDeviceInfo* Pm_GetDeviceInfo( PmDeviceID id );
|
|
|
|
/*
|
|
Pm_OpenInput() and Pm_OpenOutput() open devices.
|
|
|
|
stream is the address of a PortMidiStream pointer which will receive
|
|
a pointer to the newly opened stream.
|
|
|
|
inputDevice is the id of the device used for input (see PmDeviceID above).
|
|
|
|
inputDriverInfo is a pointer to an optional driver specific data structure
|
|
containing additional information for device setup or handle processing.
|
|
inputDriverInfo is never required for correct operation. If not used
|
|
inputDriverInfo should be NULL.
|
|
|
|
outputDevice is the id of the device used for output (see PmDeviceID above.)
|
|
|
|
outputDriverInfo is a pointer to an optional driver specific data structure
|
|
containing additional information for device setup or handle processing.
|
|
outputDriverInfo is never required for correct operation. If not used
|
|
outputDriverInfo should be NULL.
|
|
|
|
For input, the buffersize specifies the number of input events to be
|
|
buffered waiting to be read using Pm_Read(). For output, buffersize
|
|
specifies the number of output events to be buffered waiting for output.
|
|
(In some cases -- see below -- PortMidi does not buffer output at all
|
|
and merely passes data to a lower-level API, in which case buffersize
|
|
is ignored.)
|
|
|
|
latency is the delay in milliseconds applied to timestamps to determine
|
|
when the output should actually occur. (If latency is < 0, 0 is assumed.)
|
|
If latency is zero, timestamps are ignored and all output is delivered
|
|
immediately. If latency is greater than zero, output is delayed until
|
|
the message timestamp plus the latency. (NOTE: time is measured relative
|
|
to the time source indicated by time_proc. Timestamps are absolute, not
|
|
relative delays or offsets.) In some cases, PortMidi can obtain
|
|
better timing than your application by passing timestamps along to the
|
|
device driver or hardware. Latency may also help you to synchronize midi
|
|
data to audio data by matching midi latency to the audio buffer latency.
|
|
|
|
time_proc is a pointer to a procedure that returns time in milliseconds. It
|
|
may be NULL, in which case a default millisecond timebase (PortTime) is
|
|
used. If the application wants to use PortTime, it should start the timer
|
|
(call Pt_Start) before calling Pm_OpenInput or Pm_OpenOutput. If the
|
|
application tries to start the timer *after* Pm_OpenInput or Pm_OpenOutput,
|
|
it may get a ptAlreadyStarted error from Pt_Start, and the application's
|
|
preferred time resolution and callback function will be ignored.
|
|
time_proc result values are appended to incoming MIDI data, and time_proc
|
|
times are used to schedule outgoing MIDI data (when latency is non-zero).
|
|
|
|
time_info is a pointer passed to time_proc.
|
|
|
|
return value:
|
|
Upon success Pm_Open() returns PmNoError and places a pointer to a
|
|
valid PortMidiStream in the stream argument.
|
|
If a call to Pm_Open() fails a nonzero error code is returned (see
|
|
PMError above) and the value of port is invalid.
|
|
|
|
Any stream that is successfully opened should eventually be closed
|
|
by calling Pm_Close().
|
|
|
|
*/
|
|
PmError Pm_OpenInput( PortMidiStream** stream,
|
|
PmDeviceID inputDevice,
|
|
void *inputDriverInfo,
|
|
long bufferSize,
|
|
PmTimeProcPtr time_proc,
|
|
void *time_info );
|
|
|
|
PmError Pm_OpenOutput( PortMidiStream** stream,
|
|
PmDeviceID outputDevice,
|
|
void *outputDriverInfo,
|
|
long bufferSize,
|
|
PmTimeProcPtr time_proc,
|
|
void *time_info,
|
|
long latency );
|
|
|
|
/*
|
|
Pm_SetFilter() sets filters on an open input stream to drop selected
|
|
input types. By default, only active sensing messages are filtered.
|
|
To prohibit, say, active sensing and sysex messages, call
|
|
Pm_SetFilter(stream, PM_FILT_ACTIVE | PM_FILT_SYSEX);
|
|
|
|
Filtering is useful when midi routing or midi thru functionality is being
|
|
provided by the user application.
|
|
For example, you may want to exclude timing messages (clock, MTC, start/stop/continue),
|
|
while allowing note-related messages to pass.
|
|
Or you may be using a sequencer or drum-machine for MIDI clock information but want to
|
|
exclude any notes it may play.
|
|
*/
|
|
|
|
/* filter active sensing messages (0xFE): */
|
|
#define PM_FILT_ACTIVE (1 << 0x0E)
|
|
/* filter system exclusive messages (0xF0): */
|
|
#define PM_FILT_SYSEX (1 << 0x00)
|
|
/* filter clock messages (CLOCK 0xF8, START 0xFA, STOP 0xFC, and CONTINUE 0xFB) */
|
|
#define PM_FILT_CLOCK ((1 << 0x08) | (1 << 0x0A) | (1 << 0x0C) | (1 << 0x0B))
|
|
/* filter play messages (start 0xFA, stop 0xFC, continue 0xFB) */
|
|
#define PM_FILT_PLAY (1 << 0x0A)
|
|
/* filter tick messages (0xF9) */
|
|
#define PM_FILT_TICK (1 << 0x09)
|
|
/* filter undefined FD messages */
|
|
#define PM_FILT_FD (1 << 0x0D)
|
|
/* filter undefined real-time messages */
|
|
#define PM_FILT_UNDEFINED PM_FILT_FD
|
|
/* filter reset messages (0xFF) */
|
|
#define PM_FILT_RESET (1 << 0x0F)
|
|
/* filter all real-time messages */
|
|
#define PM_FILT_REALTIME (PM_FILT_ACTIVE | PM_FILT_SYSEX | PM_FILT_CLOCK | \
|
|
PM_FILT_PLAY | PM_FILT_UNDEFINED | PM_FILT_RESET | PM_FILT_TICK)
|
|
/* filter note-on and note-off (0x90-0x9F and 0x80-0x8F */
|
|
#define PM_FILT_NOTE ((1 << 0x19) | (1 << 0x18))
|
|
/* filter channel aftertouch (most midi controllers use this) (0xD0-0xDF)*/
|
|
#define PM_FILT_CHANNEL_AFTERTOUCH (1 << 0x1D)
|
|
/* per-note aftertouch (0xA0-0xAF) */
|
|
#define PM_FILT_POLY_AFTERTOUCH (1 << 0x1A)
|
|
/* filter both channel and poly aftertouch */
|
|
#define PM_FILT_AFTERTOUCH (PM_FILT_CHANNEL_AFTERTOUCH | PM_FILT_POLY_AFTERTOUCH)
|
|
/* Program changes (0xC0-0xCF) */
|
|
#define PM_FILT_PROGRAM (1 << 0x1C)
|
|
/* Control Changes (CC's) (0xB0-0xBF)*/
|
|
#define PM_FILT_CONTROL (1 << 0x1B)
|
|
/* Pitch Bender (0xE0-0xEF*/
|
|
#define PM_FILT_PITCHBEND (1 << 0x1E)
|
|
/* MIDI Time Code (0xF1)*/
|
|
#define PM_FILT_MTC (1 << 0x01)
|
|
/* Song Position (0xF2) */
|
|
#define PM_FILT_SONG_POSITION (1 << 0x02)
|
|
/* Song Select (0xF3)*/
|
|
#define PM_FILT_SONG_SELECT (1 << 0x03)
|
|
/* Tuning request (0xF6)*/
|
|
#define PM_FILT_TUNE (1 << 0x06)
|
|
/* All System Common messages (mtc, song position, song select, tune request) */
|
|
#define PM_FILT_SYSTEMCOMMON (PM_FILT_MTC | PM_FILT_SONG_POSITION | PM_FILT_SONG_SELECT | PM_FILT_TUNE)
|
|
|
|
|
|
PmError Pm_SetFilter( PortMidiStream* stream, long filters );
|
|
|
|
/*
|
|
Pm_SetChannelMask() filters incoming messages based on channel.
|
|
The mask is a 16-bit bitfield corresponding to appropriate channels
|
|
The Pm_Channel macro can assist in calling this function.
|
|
i.e. to set receive only input on channel 1, call with
|
|
Pm_SetChannelMask(Pm_Channel(1));
|
|
Multiple channels should be OR'd together, like
|
|
Pm_SetChannelMask(Pm_Channel(10) | Pm_Channel(11))
|
|
|
|
All channels are allowed by default
|
|
*/
|
|
#define Pm_Channel(channel) (1<<(channel))
|
|
|
|
PmError Pm_SetChannelMask(PortMidiStream *stream, int mask);
|
|
|
|
/*
|
|
Pm_Abort() terminates outgoing messages immediately
|
|
The caller should immediately close the output port;
|
|
this call may result in transmission of a partial midi message.
|
|
There is no abort for Midi input because the user can simply
|
|
ignore messages in the buffer and close an input device at
|
|
any time.
|
|
*/
|
|
PmError Pm_Abort( PortMidiStream* stream );
|
|
|
|
/*
|
|
Pm_Close() closes a midi stream, flushing any pending buffers.
|
|
(PortMidi attempts to close open streams when the application
|
|
exits -- this is particularly difficult under Windows.)
|
|
*/
|
|
PmError Pm_Close( PortMidiStream* stream );
|
|
|
|
/*
|
|
Pm_Message() encodes a short Midi message into a long word. If data1
|
|
and/or data2 are not present, use zero.
|
|
|
|
Pm_MessageStatus(), Pm_MessageData1(), and
|
|
Pm_MessageData2() extract fields from a long-encoded midi message.
|
|
*/
|
|
#define Pm_Message(status, data1, data2) \
|
|
((((data2) << 16) & 0xFF0000) | \
|
|
(((data1) << 8) & 0xFF00) | \
|
|
((status) & 0xFF))
|
|
#define Pm_MessageStatus(msg) ((msg) & 0xFF)
|
|
#define Pm_MessageData1(msg) (((msg) >> 8) & 0xFF)
|
|
#define Pm_MessageData2(msg) (((msg) >> 16) & 0xFF)
|
|
|
|
/* All midi data comes in the form of PmEvent structures. A sysex
|
|
message is encoded as a sequence of PmEvent structures, with each
|
|
structure carrying 4 bytes of the message, i.e. only the first
|
|
PmEvent carries the status byte.
|
|
|
|
Note that MIDI allows nested messages: the so-called "real-time" MIDI
|
|
messages can be inserted into the MIDI byte stream at any location,
|
|
including within a sysex message. MIDI real-time messages are one-byte
|
|
messages used mainly for timing (see the MIDI spec). PortMidi retains
|
|
the order of non-real-time MIDI messages on both input and output, but
|
|
it does not specify exactly how real-time messages are processed. This
|
|
is particulary problematic for MIDI input, because the input parser
|
|
must either prepare to buffer an unlimited number of sysex message
|
|
bytes or to buffer an unlimited number of real-time messages that
|
|
arrive embedded in a long sysex message. To simplify things, the input
|
|
parser is allowed to pass real-time MIDI messages embedded within a
|
|
sysex message, and it is up to the client to detect, process, and
|
|
remove these messages as they arrive.
|
|
|
|
When receiving sysex messages, the sysex message is terminated
|
|
by either an EOX status byte (anywhere in the 4 byte messages) or
|
|
by a non-real-time status byte in the low order byte of the message.
|
|
If you get a non-real-time status byte but there was no EOX byte, it
|
|
means the sysex message was somehow truncated. This is not
|
|
considered an error; e.g., a missing EOX can result from the user
|
|
disconnecting a MIDI cable during sysex transmission.
|
|
|
|
A real-time message can occur within a sysex message. A real-time
|
|
message will always occupy a full PmEvent with the status byte in
|
|
the low-order byte of the PmEvent message field. (This implies that
|
|
the byte-order of sysex bytes and real-time message bytes may not
|
|
be preserved -- for example, if a real-time message arrives after
|
|
3 bytes of a sysex message, the real-time message will be delivered
|
|
first. The first word of the sysex message will be delivered only
|
|
after the 4th byte arrives, filling the 4-byte PmEvent message field.
|
|
|
|
The timestamp field is observed when the output port is opened with
|
|
a non-zero latency. A timestamp of zero means "use the current time",
|
|
which in turn means to deliver the message with a delay of
|
|
latency (the latency parameter used when opening the output port.)
|
|
Do not expect PortMidi to sort data according to timestamps --
|
|
messages should be sent in the correct order, and timestamps MUST
|
|
be non-decreasing.
|
|
|
|
A sysex message will generally fill many PmEvent structures. On
|
|
output to a PortMidiStream with non-zero latency, the first timestamp
|
|
on sysex message data will determine the time to begin sending the
|
|
message. PortMidi implementations may ignore timestamps for the
|
|
remainder of the sysex message.
|
|
|
|
On input, the timestamp ideally denotes the arrival time of the
|
|
status byte of the message. The first timestamp on sysex message
|
|
data will be valid. Subsequent timestamps may denote
|
|
when message bytes were actually received, or they may be simply
|
|
copies of the first timestamp.
|
|
|
|
Timestamps for nested messages: If a real-time message arrives in
|
|
the middle of some other message, it is enqueued immediately with
|
|
the timestamp corresponding to its arrival time. The interrupted
|
|
non-real-time message or 4-byte packet of sysex data will be enqueued
|
|
later. The timestamp of interrupted data will be equal to that of
|
|
the interrupting real-time message to insure that timestamps are
|
|
non-decreasing.
|
|
*/
|
|
typedef long PmMessage;
|
|
typedef struct {
|
|
PmMessage message;
|
|
PmTimestamp timestamp;
|
|
} PmEvent;
|
|
|
|
/*
|
|
Pm_Read() retrieves midi data into a buffer, and returns the number
|
|
of events read. Result is a non-negative number unless an error occurs,
|
|
in which case a PmError value will be returned.
|
|
|
|
Buffer Overflow
|
|
|
|
The problem: if an input overflow occurs, data will be lost, ultimately
|
|
because there is no flow control all the way back to the data source.
|
|
When data is lost, the receiver should be notified and some sort of
|
|
graceful recovery should take place, e.g. you shouldn't resume receiving
|
|
in the middle of a long sysex message.
|
|
|
|
With a lock-free fifo, which is pretty much what we're stuck with to
|
|
enable portability to the Mac, it's tricky for the producer and consumer
|
|
to synchronously reset the buffer and resume normal operation.
|
|
|
|
Solution: the buffer managed by PortMidi will be flushed when an overflow
|
|
occurs. The consumer (Pm_Read()) gets an error message (pmBufferOverflow)
|
|
and ordinary processing resumes as soon as a new message arrives. The
|
|
remainder of a partial sysex message is not considered to be a "new
|
|
message" and will be flushed as well.
|
|
|
|
*/
|
|
PmError Pm_Read( PortMidiStream *stream, PmEvent *buffer, long length );
|
|
|
|
/*
|
|
Pm_Poll() tests whether input is available,
|
|
returning TRUE, FALSE, or an error value.
|
|
*/
|
|
PmError Pm_Poll( PortMidiStream *stream);
|
|
|
|
/*
|
|
Pm_Write() writes midi data from a buffer. This may contain:
|
|
- short messages
|
|
or
|
|
- sysex messages that are converted into a sequence of PmEvent
|
|
structures, e.g. sending data from a file or forwarding them
|
|
from midi input.
|
|
|
|
Use Pm_WriteSysEx() to write a sysex message stored as a contiguous
|
|
array of bytes.
|
|
|
|
Sysex data may contain embedded real-time messages.
|
|
*/
|
|
PmError Pm_Write( PortMidiStream *stream, PmEvent *buffer, long length );
|
|
|
|
/*
|
|
Pm_WriteShort() writes a timestamped non-system-exclusive midi message.
|
|
Messages are delivered in order as received, and timestamps must be
|
|
non-decreasing. (But timestamps are ignored if the stream was opened
|
|
with latency = 0.)
|
|
*/
|
|
PmError Pm_WriteShort( PortMidiStream *stream, PmTimestamp when, long msg);
|
|
|
|
/*
|
|
Pm_WriteSysEx() writes a timestamped system-exclusive midi message.
|
|
*/
|
|
PmError Pm_WriteSysEx( PortMidiStream *stream, PmTimestamp when, unsigned char *msg);
|
|
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif /* __cplusplus */
|
|
#endif /* PORT_MIDI_H */
|