midistrm.cpp

pxa270平台 windows mobile 5.2 wm9713 触摸屏+音频驱动

//-----------------------------------------------------------------------------
// Copyright (c) Wolfson Microelectronics plc.  All rights reserved.
//
// This software as well as any related documentation is furnished under 
// license and may only be used or copied in accordance with the terms of the 
// license. The information in this file is furnished for informational use 
// only, is subject to change without notice, and should not be construed as 
// a commitment by Wolfson Microelectronics plc. Wolfson Microelectronics plc
// assumes no responsibility or liability for any errors or inaccuracies that
// may appear in this document or any software that may be provided in
// association with this document. 
//
// Except as permitted by such license, no part of this document may be 
// reproduced, stored in a retrieval system, or transmitted in any form or by 
// any means without the express written consent of Wolfson Microelectronics plc. 
//
// $Id: midistrm.cpp 2719 2006-02-08 13:13:48Z ian $
//
// This file contains the code specific to MIDI streams for the WaveDev2
// driver for Wolfson codecs.
//
// Warning:
//  This driver is specifically written for Wolfson Audio Codecs.  It is
//  not a general audio CODEC device driver.
//-----------------------------------------------------------------------------

//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//
//
// Use of this source code is subject to the terms of the Microsoft end-user
// license agreement (EULA) under which you licensed this SOFTWARE PRODUCT.
// If you did not accept the terms of the EULA, you are not authorized to use
// this source code. For a copy of the EULA, please see the LICENSE.RTF on your
// install media.
//
// -----------------------------------------------------------------------------
//
//      THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
//      ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
//      THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
//      PARTICULAR PURPOSE.
//
// -----------------------------------------------------------------------------

#include "wavemain.h"

void CMidiStream::GainChange()
{
    PLIST_ENTRY pListEntry;
    CMidiNote *pCNote;
    pListEntry = m_NoteList.Flink;
    while (pListEntry != &m_NoteList)
    {
        // Get a pointer to the stream context
        pCNote = CONTAINING_RECORD(pListEntry,CMidiNote,m_Link);
        pCNote->GainChange();
        pListEntry = pListEntry->Flink;
    }
}

DWORD CMidiStream::MapNoteGain(DWORD NoteGain, DWORD Channel)
{
    DWORD TotalGain = NoteGain & 0xFFFF;
    DWORD StreamGain = m_dwGain;
    if (Channel==1)
    {
        StreamGain >>= 16;
    }
    StreamGain &= 0xFFFF;

    TotalGain *= StreamGain; // Calc. aggregate gain
    TotalGain += 0xFFFF;   // Force to round up
    TotalGain >>= 16;

    return MapGain(TotalGain, Channel);
}

HRESULT CMidiStream::Open(DeviceContext *pDeviceContext, LPWAVEOPENDESC lpWOD, DWORD dwFlags)
{
    HRESULT Result;
    LPWAVEFORMAT_MIDI pwfxmidi = (LPWAVEFORMAT_MIDI) lpWOD->lpFormat;

    if (pwfxmidi->wfx.cbSize!=WAVEFORMAT_MIDI_EXTRASIZE)
    {
        return E_FAIL;
    }

    // Add all notes to free list
    InitializeListHead(&m_NoteList);
    InitializeListHead(&m_FreeList);
    for (int i=0;i<NUMNOTES;i++)
    {
        InsertTailList(&m_FreeList,&m_MidiNote[i].m_Link);
    }
    
    m_NumChannels = pDeviceContext->NumChannels();

    Result = StreamContext::Open(pDeviceContext, lpWOD, dwFlags);

    if ( Result != MMSYSERR_NOERROR )
    {
        goto end;
    }

    m_USecPerQuarterNote  = pwfxmidi->USecPerQuarterNote;
    m_TicksPerQuarterNote = pwfxmidi->TicksPerQuarterNote;

    UpdateTempo();

    m_DeltaSampleCount=0;

    //
    // Initialise the pitches for this stream - based on the device
    // sample rate.
    //
    CMidiNote::InitialisePitchTable( m_PitchTable, pDeviceContext->SampleRate() );
    
        // Note: Output streams should be initialized in the run state.
        Run();

end:
    return Result;
}

DWORD CMidiStream::Reset()
{
    DWORD dwResult = StreamContext::Reset();
    if (dwResult==MMSYSERR_NOERROR)
    {
        AllNotesOff(0);

        // Note: Output streams should be reset to the run state.
        Run();
    }
    return dwResult;
}

DWORD CMidiStream::Close()
{
    DWORD dwResult = StreamContext::Close();
    if (dwResult==MMSYSERR_NOERROR)
    {
        AllNotesOff(0);
    }
    return dwResult;
}

HRESULT CMidiStream::UpdateTempo()
{
    if (m_USecPerQuarterNote==0)
    {
        m_USecPerQuarterNote = 500000; // If not specified, assume 500000usec = 1/2 sec per quarter note
    }

    if (m_TicksPerQuarterNote==0)
    {
        m_TicksPerQuarterNote = 96;      // If not specified, assume 96 ticks/quarter note
    }

    UINT64 Num = SampleRate();
    Num *= m_USecPerQuarterNote;
    UINT64 Den = 1000000;
    Den *= m_TicksPerQuarterNote;
    UINT64 SamplesPerTick = Num/Den;
    m_SamplesPerTick = (UINT32)SamplesPerTick;
    return S_OK;
}

// Return the delta # of samples until the next midi event
// or 0 if no midi events are left in the queue
UINT32 CMidiStream::ProcessMidiStream()
{
    WAVEFORMAT_MIDI_MESSAGE *pMsg;
    WAVEFORMAT_MIDI_MESSAGE *pMsgEnd;
    UINT32 ThisMidiEventDelta;

    // Process all midi messages up to and including the current sample
    pMsg    = (WAVEFORMAT_MIDI_MESSAGE *)m_lpCurrData;
    pMsgEnd = (WAVEFORMAT_MIDI_MESSAGE *)m_lpCurrDataEnd;

    for (;;)
    {
        if (pMsg>=pMsgEnd)
        {
            pMsg = (WAVEFORMAT_MIDI_MESSAGE *)GetNextBuffer();
            if (!pMsg)
            {
                DEBUGMSG(ZONE_VERBOSE, (TEXT("CMidiStream::ProcessMidiStream no more events\r\n")));
                return 0;
            }
            pMsgEnd = (WAVEFORMAT_MIDI_MESSAGE *)m_lpCurrDataEnd;
        }

        _try
        {
            ThisMidiEventDelta = DeltaTicksToSamples(pMsg->DeltaTicks);
            if (ThisMidiEventDelta > m_DeltaSampleCount)
            {
                m_lpCurrData = (PBYTE)pMsg;
                INT32 Delta = ThisMidiEventDelta-m_DeltaSampleCount;
                DEBUGMSG(ZONE_VERBOSE, (TEXT("CMidiStream::ProcessMidiStream next event @delta %d\r\n"),Delta));
                return Delta;
            }
    
            DEBUGMSG(ZONE_VERBOSE, (TEXT("CMidiStream::ProcessMidiStream sending midi message 0x%x\r\n"),pMsg->MidiMsg));
            InternalMidiMessage(pMsg->MidiMsg);
            m_DeltaSampleCount=0;
            pMsg++;
        }
        _except (EXCEPTION_EXECUTE_HANDLER)
        {
            RETAILMSG(ZONE_ALWAYS, (TEXT("EXCEPTION IN IST for midi stream 0x%x, buffer 0x%x!!!!\r\n"), this, m_lpCurrData));
            pMsg = pMsgEnd; // Pretend we finished reading the application buffer
        }
    }
}

PBYTE CMidiStream::Render(PBYTE pBuffer, PBYTE pBufferEnd, PBYTE pBufferLast)
{

    DEBUGMSG(ZONE_VERBOSE, (TEXT("Entering CMidiStream::Render, pBuffer=0x%x, current delta = %d\r\n"), pBuffer, m_DeltaSampleCount));

    // If we're not running, or we don't have any buffers queued and the note list is empty,
    // just return
    if ( (!m_bRunning) || (!StillPlaying() && IsListEmpty(&m_NoteList)) )
    {
        DEBUGMSG(ZONE_VERBOSE, (TEXT("CMidiStream::Render nothing to do\r\n")));
        return pBuffer;
    }

    while (pBuffer<pBufferEnd)
    {
        // Process pending midi messages and get relative sample # of next midi event
        UINT32 NextMidiEvent;
        NextMidiEvent = ProcessMidiStream();

        PBYTE pBufferEndEvent;  // Where to stop on this pass

        // If NextMidiEvent returns 0, it means there are no more midi messages left in the queue.
        if (NextMidiEvent==0)
        {
            // Just process the rest of this buffer
            pBufferEndEvent=pBufferEnd;
        }