Source code of Windows XP (NT5)
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/************************************************************************/
/*
** Copyright (c) 1985-1998 Microsoft Corporation
**
** Title: mwplay.c - Multimedia Systems Media Control Interface
** waveform digital audio driver for RIFF wave files.
** Routines for playing wave files
**
** Version: 1.00
**
** Date: 18-Apr-1990
**
** Author: ROBWI
*/
/************************************************************************/
/*
** Change log:
**
** DATE REV DESCRIPTION
** ----------- ----- ------------------------------------------
** 18-APR-1990 ROBWI Original
** 19-JUN-1990 ROBWI Added wave in
** 10-Jan-1992 MikeTri Ported to NT
** @@@ Need to change comments from slash slash to slash star
** 4-Mar-1992 SteveDav Continue the port. Update to current Win 3.1
*/
/************************************************************************/
#define UNICODE
#define NOGDICAPMASKS
#define NOVIRTUALKEYCODES
#define NOWINSTYLES
#define NOSYSMETRICS
#define NOMENUS
#define NOICONS
#define NOKEYSTATES
#define NOSYSCOMMANDS
#define NORASTEROPS
#define NOSHOWWINDOW
#define OEMRESOURCE
#define NOATOM
#define NOCLIPBOARD
#define NOCOLOR
#define NOCTLMGR
#define NODRAWTEXT
#define NOGDI
#define NOKERNEL
#define NONLS
#define NOMB
#define NOMEMMGR
#define NOMETAFILE
#define NOOPENFILE
#define NOSCROLL
#define NOTEXTMETRIC
#define NOWH
#define NOWINOFFSETS
#define NOCOMM
#define NOKANJI
#define NOHELP
#define NOPROFILER
#define NODEFERWINDOWPOS
#include <windows.h>
#include "mciwave.h"
#include <mmddk.h>
/************************************************************************/
/*
@doc INTERNAL MCIWAVE
@func DWORD | mwRead |
This function reads a buffer of wave data from either the input file,
or the temporary data file. The position is taken from the
<e>WAVEDESC.dCur<d> pointer, which is updated with the number of bytes
actually read.
The data needed may come from several consecutively linked nodes, so
first the virtual data ending position for the current wave data node
is checked against the the current position. This is to determine if
the next node needs to be accessed. The function then reads the data
from the appropriate source, either the temporary data file, or the
original file.
@parm <t>PWAVEDESC<d> | pwd |
Pointer to the wave device descriptor.
@parm LPBYTE | lpbBuffer |
Points to a buffer to contain the data read.
@parm DWORD | dBufferLength |
Indicates the maximum number of bytes to read into the buffer.
@rdesc Returns number of bytes read, else 0 on an error wherein no bytes
could be read. This means that there is not distinction between a
read of zero bytes, or an error, but the function is never called
if no bytes are to be read.
*/
PRIVATE DWORD PASCAL NEAR mwRead(
PWAVEDESC pwd,
LPBYTE lpbBuffer,
DWORD dBufferLength)
{
DWORD dTotalRead;
LPWAVEDATANODE lpwdn;
lpwdn = LPWDN(pwd, pwd->dWaveDataCurrentNode);
for (dTotalRead = 0; dBufferLength;) {
DWORD dStartRead;
DWORD dReadSize;
DWORD dBytesRead;
if (pwd->dVirtualWaveDataStart + lpwdn->dDataLength <= (DWORD)pwd->dCur) {
pwd->dWaveDataCurrentNode = lpwdn->dNextWaveDataNode;
pwd->dVirtualWaveDataStart += lpwdn->dDataLength;
lpwdn = LPWDN(pwd, lpwdn->dNextWaveDataNode);
}
dStartRead = pwd->dCur - pwd->dVirtualWaveDataStart;
dReadSize = min(dBufferLength, lpwdn->dDataLength - dStartRead);
if (ISTEMPDATA(lpwdn)) {
if (MySeekFile(pwd->hTempBuffers, UNMASKDATASTART(lpwdn) + dStartRead))
MyReadFile(pwd->hTempBuffers, lpbBuffer, dReadSize, &dBytesRead);
else
dBytesRead = (DWORD)-1;
} else {
if (mmioSeek(pwd->hmmio, pwd->dRiffData + lpwdn->dDataStart + dStartRead, SEEK_SET) != -1)
dBytesRead = (DWORD)mmioRead(pwd->hmmio, lpbBuffer, (LONG)dReadSize);
else
dBytesRead = (DWORD)-1;
}
if (dBytesRead != -1) {
dTotalRead += dBytesRead;
dBufferLength -= dBytesRead;
lpbBuffer += dBytesRead;
pwd->dCur += dBytesRead;
}
if (dBytesRead != dReadSize) {
pwd->wTaskError = MCIERR_FILE_READ;
break;
}
}
return dTotalRead;
}
/************************************************************************/
/*
@doc INTERNAL MCIWAVE
@func BOOL | CheckNewCommand |
This function is called when a New command flag is found during the
playback loop. It determines if the new commands affect current
playback enough that it must be terminated. This can happen if either
a Stop command is received, or a Cue command is received and an error
occurs while pausing the output wave device.
Any other playback change does not need to stop current playback, as
they should just release all the buffers from the wave device before
setting the command.
@parm <t>PWAVEDESC<d> | pwd |
Pointer to the wave device descriptor.
@rdesc Returns TRUE if the new commands do not affect playback and it should
continue, else FALSE if the new commands affect the playback, and it
should be aborted.
*/
REALLYPRIVATE BOOL PASCAL NEAR CheckNewCommand(
PWAVEDESC pwd)
{
if (ISMODE(pwd, COMMAND_STOP))
return FALSE;
if (ISMODE(pwd, COMMAND_CUE)
&& (0 != (pwd->wTaskError = waveOutPause(pwd->hWaveOut))))
return FALSE;
REMOVEMODE(pwd, COMMAND_NEW);
return TRUE;
}
/************************************************************************/
/*
@doc INTERNAL MCIWAVE
@func VOID | HoldPlayback |
This function blocks the task, waiting to be signalled that it can
continue from the Hold command. Since the Play Hold command is
considered to be "finished" when playback is done, but before any
buffers are freed, the optional notification is performed here. When
the task is signalled, it can then check for new commands, which may
continue playback, or exit the playback loop.
@parm <t>PWAVEDESC<d> | pwd |
Pointer to the wave device descriptor.
@rdesc Nothing.
*/
PRIVATE VOID PASCAL NEAR HoldPlayback(
PWAVEDESC pwd)
{
ADDMODE(pwd, MODE_HOLDING);
mwDelayedNotify(pwd, MCI_NOTIFY_SUCCESSFUL);
while (TaskBlock() != WTM_STATECHANGE);
}
/************************************************************************/
/*
@doc INTERNAL MCIWAVE
@func UINT | PlayFile |
This function is used to Cue or Play a wave file. The function
basically reads buffers from the wave file, and sends them out to the
wave device, blocking for each buffer sent. It also makes sure to
call <f>mmTaskYield<d> while both reading in new buffers, and waiting
for buffers to be released.
Within the playback loop, the function first checks for the new command
flag, which can possibly interrupt or change the current playback.
The only thing that can really make a difference is setting the stop
flag. Changing the playback TO and FROM positions should not affect
the loop, and setting the Cue command only pauses the output of the
wave device.
When the playback loop is first entered, the New command flag is
set, and this condition is entered. This allows the Cue command to
be sent with the Play command, and initially pause the wave output
device. Calling <f>waveOutPause<d> stops any data from going out the
DACs but, but still allows all the buffers to be queued up.
After checking for a new command, the loop checks to see if there is
any more data to play from the wave file, and if there are any empty
buffers to read it in to. If so, that data is read and written to the
wave device, with the appropriate error checking, the in-use buffer
count in incremented, and a pointer to the next data buffer to use is
retrieved.
After checking for more data to play, there is a check to see if any
more buffers are outstanding. If so, the task blocks until a buffer
is released by the wave device. Normally during the end of playback,
this condition is performed for each outstanding buffer until all
buffers have been released, then the function would enter the default
condition and fall out of the loop. It just blocks the task, waiting
for the wave device to signal this task after releasing the buffer,
and the in-use buffer count is decremented. Note that since the task
blocked itself, a new command could have been sent, so the playback
loop starts again after doing a task yield, as it does after each of
conditional parts of the playback loop.
Before blocking the Cue command must be checked for in order to
determine if the optional notification should be sent. This is
because a Cue Output command is considered "finished" when the buffers
have been filled.
After all playback buffers have been released by the wave device, if
the hold command was given with the current play command, the task is
blocked (and thus does not release the memory used by the playback
buffers, nor leave the playback loop), waiting for a signal, which
may stop or continue playback with a new set of parameters.
The final default condition occurs when all the data has been read,
all the buffers have been released, and the hold flag was not set.
In this case, playback is done, and the playback loop is exited.
@parm <t>PWAVEDESC<d> | pwd |
Pointer to the wave device descriptor.
@rdesc Returns the number of outstanding buffers written to the wave device.
This can be used when removing task signal from the message queue.
In cases of error, the <e>WAVEDESC.wTaskError<d> flag is set. This
specific error is not currently returned, as the calling task may not
have waited for the command to complete. But it is at least used for
notification in order to determine if Failure status should be sent.
@xref RecordFile.
*/
PUBLIC UINT PASCAL FAR PlayFile(
register PWAVEDESC pwd)
{
LPWAVEHDR *lplpWaveHdr;
register UINT wBuffersOutstanding;
ADDMODE(pwd, MODE_PLAYING);
for (wBuffersOutstanding = 0, lplpWaveHdr = pwd->rglpWaveHdr;;) {
if (ISMODE(pwd, COMMAND_NEW) && !CheckNewCommand(pwd))
break;
if ((wBuffersOutstanding < pwd->wAudioBuffers) && (pwd->dCur < pwd->dTo)) {
if (!((*lplpWaveHdr)->dwFlags & WHDR_DONE)) {
#if DBG
dprintf1(("\nMCIWAVE Buffer not complete ! %8X", *lplpWaveHdr));
DebugBreak();
#endif
}
if (!((*lplpWaveHdr)->dwBufferLength = mwRead(pwd, (LPBYTE)(*lplpWaveHdr)->lpData, min(pwd->dAudioBufferLen, pwd->dTo - pwd->dCur))))
break;
(*lplpWaveHdr)->dwFlags &= ~(WHDR_DONE | WHDR_BEGINLOOP | WHDR_ENDLOOP);
if (0 != (pwd->wTaskError = waveOutWrite(pwd->hWaveOut, *lplpWaveHdr, sizeof(WAVEHDR))))
break;
wBuffersOutstanding++;
lplpWaveHdr = NextWaveHdr(pwd, lplpWaveHdr);
} else if (wBuffersOutstanding) {
if (ISMODE(pwd, COMMAND_CUE)) {
ADDMODE(pwd, MODE_CUED);
mwDelayedNotify(pwd, MCI_NOTIFY_SUCCESSFUL);
}
if (TaskBlock() == WM_USER)
wBuffersOutstanding--;
} else if (ISMODE(pwd, COMMAND_HOLD)) {
HoldPlayback(pwd);
}
else
break;
//@@ mmTaskYield();
mmYield(pwd);
}
REMOVEMODE(pwd, MODE_PLAYING);
return wBuffersOutstanding;
}
/************************************************************************/