view src/audio/dart/SDL_dart.c @ 2349:0381047f2210 gsoc2008_iphone

The class SDL_uikitappdelegate acts as the UIApplicationDelegate for an iPhone SDL project. This class is reponsible for application control flow, including initial setup of working directory, forwarding command line arguments to the user's main function, and handling application termination.
author Holmes Futrell <hfutrell@umail.ucsb.edu>
date Thu, 17 Jul 2008 22:29:37 +0000
parents 866052b01ee5
children e1da92da346c
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* Allow access to a raw mixing buffer */

#include "SDL_timer.h"
#include "SDL_audio.h"
#include "../SDL_audio_c.h"
#include "SDL_dart.h"

// Buffer states:
#define BUFFER_EMPTY       0
#define BUFFER_USED        1

typedef struct _tMixBufferDesc
{
    int iBufferUsage;           // BUFFER_EMPTY or BUFFER_USED
    SDL_AudioDevice *pSDLAudioDevice;
} tMixBufferDesc, *pMixBufferDesc;


//---------------------------------------------------------------------
// DARTEventFunc
//
// This function is called by DART, when an event occurs, like end of
// playback of a buffer, etc...
//---------------------------------------------------------------------
static LONG APIENTRY
DARTEventFunc(ULONG ulStatus, PMCI_MIX_BUFFER pBuffer, ULONG ulFlags)
{
    if (ulFlags && MIX_WRITE_COMPLETE) {        // Playback of buffer completed!

        // Get pointer to buffer description
        pMixBufferDesc pBufDesc;

        if (pBuffer) {
            pBufDesc = (pMixBufferDesc) (*pBuffer).ulUserParm;

            if (pBufDesc) {
                SDL_AudioDevice *pSDLAudioDevice = pBufDesc->pSDLAudioDevice;
                // Set the buffer to be empty
                pBufDesc->iBufferUsage = BUFFER_EMPTY;
                // And notify DART feeder thread that it will have to work a bit.
                if (pSDLAudioDevice)
                    DosPostEventSem(pSDLAudioDevice->hidden->
                                    hevAudioBufferPlayed);
            }
        }
    }
    return TRUE;
}


static int
DART_OpenDevice(_THIS, const char *devname, int iscapture)
{
    SDL_AudioFormat test_format = SDL_FirstAudioFormat(_this->spec.format);
    int valid_datatype = 0;
    MCI_AMP_OPEN_PARMS AmpOpenParms;
    int iDeviceOrd = 0;         // Default device to be used
    int bOpenShared = 1;        // Try opening it shared
    int iBits = 16;             // Default is 16 bits signed
    int iFreq = 44100;          // Default is 44KHz
    int iChannels = 2;          // Default is 2 channels (Stereo)
    int iNumBufs = 2;           // Number of audio buffers: 2
    int iBufSize;
    int iOpenMode;
    int iSilence;
    int rc;

    /* Initialize all variables that we clean on shutdown */
    _this->hidden = (struct SDL_PrivateAudioData *)
        SDL_malloc((sizeof *_this->hidden));
    if (_this->hidden == NULL) {
        SDL_OutOfMemory();
        return 0;
    }
    SDL_memset(_this->hidden, 0, (sizeof *_this->hidden));

    // First thing is to try to open a given DART device!
    SDL_memset(&AmpOpenParms, 0, sizeof(MCI_AMP_OPEN_PARMS));
    // pszDeviceType should contain the device type in low word, and device ordinal in high word!
    AmpOpenParms.pszDeviceType =
        (PSZ) (MCI_DEVTYPE_AUDIO_AMPMIX | (iDeviceOrd << 16));

    iOpenMode = MCI_WAIT | MCI_OPEN_TYPE_ID;
    if (bOpenShared)
        iOpenMode |= MCI_OPEN_SHAREABLE;

    rc = mciSendCommand(0, MCI_OPEN, iOpenMode, (PVOID) & AmpOpenParms, 0);
    if (rc != MCIERR_SUCCESS) { // No audio available??
        DART_CloseDevice(_this);
        SDL_SetError("DART: Couldn't open audio device.");
        return 0;
    }
    // Save the device ID we got from DART!
    // We will use this in the next calls!
    _this->hidden->iCurrDeviceOrd = iDeviceOrd = AmpOpenParms.usDeviceID;

    // Determine the audio parameters from the AudioSpec
    if (_this->spec.channels > 4)
        _this->spec.channels = 4;

    while ((!valid_datatype) && (test_format)) {
        _this->spec.format = test_format;
        valid_datatype = 1;
        switch (test_format) {
        case AUDIO_U8:
            // Unsigned 8 bit audio data
            iSilence = 0x80;
            _this->hidden->iCurrBits = iBits = 8;
            break;

        case AUDIO_S16LSB:
            // Signed 16 bit audio data
            iSilence = 0x00;
            _this->hidden->iCurrBits = iBits = 16;
            break;

            // !!! FIXME: int32?

        default:
            valid_datatype = 0;
            test_format = SDL_NextAudioFormat();
            break;
        }
    }

    if (!valid_datatype) {      // shouldn't happen, but just in case...
        // Close DART, and exit with error code!
        DART_CloseDevice(_this);
        SDL_SetError("Unsupported audio format");
        return 0;
    }

    _this->hidden->iCurrFreq = iFreq = _this->spec.freq;
    _this->hidden->iCurrChannels = iChannels = _this->spec.channels;
    /* Update the fragment size as size in bytes */
    SDL_CalculateAudioSpec(&_this->spec);
    _this->hidden->iCurrBufSize = iBufSize = _this->spec.size;

    // Now query this device if it supports the given freq/bits/channels!
    SDL_memset(&(_this->hidden->MixSetupParms), 0,
               sizeof(MCI_MIXSETUP_PARMS));
    _this->hidden->MixSetupParms.ulBitsPerSample = iBits;
    _this->hidden->MixSetupParms.ulFormatTag = MCI_WAVE_FORMAT_PCM;
    _this->hidden->MixSetupParms.ulSamplesPerSec = iFreq;
    _this->hidden->MixSetupParms.ulChannels = iChannels;
    _this->hidden->MixSetupParms.ulFormatMode = MCI_PLAY;
    _this->hidden->MixSetupParms.ulDeviceType = MCI_DEVTYPE_WAVEFORM_AUDIO;
    _this->hidden->MixSetupParms.pmixEvent = DARTEventFunc;
    rc = mciSendCommand(iDeviceOrd, MCI_MIXSETUP,
                        MCI_WAIT | MCI_MIXSETUP_QUERYMODE,
                        &(_this->hidden->MixSetupParms), 0);
    if (rc != MCIERR_SUCCESS) { // The device cannot handle this format!
        // Close DART, and exit with error code!
        DART_CloseDevice(_this);
        SDL_SetError("Audio device doesn't support requested audio format");
        return 0;
    }
    // The device can handle this format, so initialize!
    rc = mciSendCommand(iDeviceOrd, MCI_MIXSETUP,
                        MCI_WAIT | MCI_MIXSETUP_INIT,
                        &(_this->hidden->MixSetupParms), 0);
    if (rc != MCIERR_SUCCESS) { // The device could not be opened!
        // Close DART, and exit with error code!
        DART_CloseDevice(_this);
        SDL_SetError("Audio device could not be set up");
        return 0;
    }
    // Ok, the device is initialized.
    // Now we should allocate buffers. For this, we need a place where
    // the buffer descriptors will be:
    _this->hidden->pMixBuffers =
        (MCI_MIX_BUFFER *) SDL_malloc(sizeof(MCI_MIX_BUFFER) * iNumBufs);
    if (!(_this->hidden->pMixBuffers)) {        // Not enough memory!
        // Close DART, and exit with error code!
        DART_CloseDevice(_this);
        SDL_OutOfMemory();
        return 0;
    }
    // Now that we have the place for buffer list, we can ask DART for the
    // buffers!
    _this->hidden->BufferParms.ulNumBuffers = iNumBufs; // Number of buffers
    _this->hidden->BufferParms.ulBufferSize = iBufSize; // each with this size
    _this->hidden->BufferParms.pBufList = _this->hidden->pMixBuffers;   // getting descriptorts into this list
    // Allocate buffers!
    rc = mciSendCommand(iDeviceOrd, MCI_BUFFER,
                        MCI_WAIT | MCI_ALLOCATE_MEMORY,
                        &(_this->hidden->BufferParms), 0);
    if ((rc != MCIERR_SUCCESS)
        || (iNumBufs != _this->hidden->BufferParms.ulNumBuffers)
        || (_this->hidden->BufferParms.ulBufferSize == 0)) {    // Could not allocate memory!
        // Close DART, and exit with error code!
        DART_CloseDevice(_this);
        SDL_SetError("DART could not allocate buffers");
        return 0;
    }
    _this->hidden->iCurrNumBufs = iNumBufs;

    // Ok, we have all the buffers allocated, let's mark them!
    {
        int i;
        for (i = 0; i < iNumBufs; i++) {
            pMixBufferDesc pBufferDesc =
                (pMixBufferDesc) SDL_malloc(sizeof(tMixBufferDesc));;
            // Check if this buffer was really allocated by DART
            if ((!(_this->hidden->pMixBuffers[i].pBuffer))
                || (!pBufferDesc)) {    // Wrong buffer!
                DART_CloseDevice(_this);
                SDL_SetError("Error at internal buffer check");
                return 0;
            }
            pBufferDesc->iBufferUsage = BUFFER_EMPTY;
            pBufferDesc->pSDLAudioDevice = _this;

            _this->hidden->pMixBuffers[i].ulBufferLength =
                _this->hidden->BufferParms.ulBufferSize;
            _this->hidden->pMixBuffers[i].ulUserParm = (ULONG) pBufferDesc;     // User parameter: Description of buffer
            _this->hidden->pMixBuffers[i].ulFlags = 0;  // Some stuff should be flagged here for DART, like end of
            // audio data, but as we will continously send
            // audio data, there will be no end.:)
            SDL_memset(_this->hidden->pMixBuffers[i].pBuffer, iSilence,
                       iBufSize);
        }
    }
    _this->hidden->iNextFreeBuffer = 0;
    _this->hidden->iLastPlayedBuf = -1;
    // Create event semaphore
    if (DosCreateEventSem
        (NULL, &(_this->hidden->hevAudioBufferPlayed), 0, FALSE) != NO_ERROR)
    {
        DART_CloseDevice(_this);
        SDL_SetError("Could not create event semaphore");
        return 0;
    }

    return 1;
}

static void
DART_ThreadInit(_THIS)
{
    /* Increase the priority of this thread to make sure that
       the audio will be continuous all the time! */
#ifdef USE_DOSSETPRIORITY
    if (SDL_getenv("SDL_USE_TIMECRITICAL_AUDIO")) {
#ifdef DEBUG_BUILD
        printf
            ("[DART_ThreadInit] : Setting priority to TimeCritical+0! (TID%d)\n",
             SDL_ThreadID());
#endif
        DosSetPriority(PRTYS_THREAD, PRTYC_TIMECRITICAL, 0, 0);
    } else {
#ifdef DEBUG_BUILD
        printf
            ("[DART_ThreadInit] : Setting priority to ForegroundServer+0! (TID%d)\n",
             SDL_ThreadID());
#endif
        DosSetPriority(PRTYS_THREAD, PRTYC_FOREGROUNDSERVER, 0, 0);
    }
#endif
}

/* This function waits until it is possible to write a full sound buffer */
static void
DART_WaitDevice(_THIS)
{
    int i;
    pMixBufferDesc pBufDesc;
    ULONG ulPostCount;

    DosResetEventSem(_this->hidden->hevAudioBufferPlayed, &ulPostCount);
    // If there is already an empty buffer, then return now!
    for (i = 0; i < _this->hidden->iCurrNumBufs; i++) {
        pBufDesc = (pMixBufferDesc) _this->hidden->pMixBuffers[i].ulUserParm;
        if (pBufDesc->iBufferUsage == BUFFER_EMPTY)
            return;
    }
    // If there is no empty buffer, wait for one to be empty!
    DosWaitEventSem(_this->hidden->hevAudioBufferPlayed, 1000); // Wait max 1 sec!!! Important!
    return;
}

static void
DART_PlayDevice(_THIS)
{
    int iFreeBuf = _this->hidden->iNextFreeBuffer;
    pMixBufferDesc pBufDesc;

    pBufDesc =
        (pMixBufferDesc) _this->hidden->pMixBuffers[iFreeBuf].ulUserParm;
    pBufDesc->iBufferUsage = BUFFER_USED;
    // Send it to DART to be queued
    _this->hidden->MixSetupParms.pmixWrite(_this->hidden->MixSetupParms.
                                           ulMixHandle,
                                           &(_this->hidden->
                                             pMixBuffers[iFreeBuf]), 1);

    _this->hidden->iLastPlayedBuf = iFreeBuf;
    iFreeBuf = (iFreeBuf + 1) % _this->hidden->iCurrNumBufs;
    _this->hidden->iNextFreeBuffer = iFreeBuf;
}

static Uint8 *
DART_GetDeviceBuf(_THIS)
{
    int iFreeBuf;
    Uint8 *pResult;
    pMixBufferDesc pBufDesc;

    if (_this) {
        if (_this->hidden) {
            iFreeBuf = _this->hidden->iNextFreeBuffer;
            pBufDesc =
                (pMixBufferDesc) _this->hidden->pMixBuffers[iFreeBuf].
                ulUserParm;

            if (pBufDesc) {
                if (pBufDesc->iBufferUsage == BUFFER_EMPTY) {
                    pResult = _this->hidden->pMixBuffers[iFreeBuf].pBuffer;
                    return pResult;
                }
            } else
                printf("[DART_GetDeviceBuf] : ERROR! pBufDesc = %p\n",
                       pBufDesc);
        } else
            printf("[DART_GetDeviceBuf] : ERROR! _this->hidden = %p\n",
                   _this->hidden);
    } else
        printf("[DART_GetDeviceBuf] : ERROR! _this = %p\n", _this);
    return NULL;
}

static void
DART_WaitDone(_THIS)
{
    pMixBufferDesc pBufDesc;
    ULONG ulPostCount = 0;
    APIRET rc = NO_ERROR;

    pBufDesc = (pMixBufferDesc)
        _this->hidden->pMixBuffers[_this->hidden->iLastPlayedBuf].ulUserParm;

    while ((pBufDesc->iBufferUsage != BUFFER_EMPTY) && (rc == NO_ERROR)) {
        DosResetEventSem(_this->hidden->hevAudioBufferPlayed, &ulPostCount);
        rc = DosWaitEventSem(_this->hidden->hevAudioBufferPlayed, 1000);        // 1 sec timeout! Important!
    }
}

static void
DART_CloseDevice(_THIS)
{
    MCI_GENERIC_PARMS GenericParms;
    int rc;
    int i;

    if (_this->hidden != NULL) {
        // Stop DART playback
        if (_this->hidden->iCurrDeviceOrd) {
            rc = mciSendCommand(_this->hidden->iCurrDeviceOrd, MCI_STOP,
                                MCI_WAIT, &GenericParms, 0);
#ifdef SFX_DEBUG_BUILD
            if (rc != MCIERR_SUCCESS) {
                printf("Could not stop DART playback!\n");
                fflush(stdout);
            }
#endif
        }
        // Close event semaphore
        if (_this->hidden->hevAudioBufferPlayed) {
            DosCloseEventSem(_this->hidden->hevAudioBufferPlayed);
            _this->hidden->hevAudioBufferPlayed = 0;
        }
        // Free memory of buffer descriptions
        for (i = 0; i < _this->hidden->iCurrNumBufs; i++) {
            SDL_free((void *) (_this->hidden->pMixBuffers[i].ulUserParm));
            _this->hidden->pMixBuffers[i].ulUserParm = 0;
        }
        _this->hidden->iCurrNumBufs = 0;

        // Deallocate buffers
        if (_this->hidden->iCurrDeviceOrd) {
            rc = mciSendCommand(_this->hidden->iCurrDeviceOrd, MCI_BUFFER,
                                MCI_WAIT | MCI_DEALLOCATE_MEMORY,
                                &(_this->hidden->BufferParms), 0);
        }
        // Free bufferlist
        if (_this->hidden->pMixBuffers != NULL) {
            SDL_free(_this->hidden->pMixBuffers);
            _this->hidden->pMixBuffers = NULL;
        }
        // Close dart
        if (_this->hidden->iCurrDeviceOrd) {
            rc = mciSendCommand(_this->hidden->iCurrDeviceOrd, MCI_CLOSE,
                                MCI_WAIT, &(GenericParms), 0);
        }
        _this->hidden->iCurrDeviceOrd = 0;

        SDL_free(_this->hidden);
        _this->hidden = NULL;
    }
}


static int
DART_Init(SDL_AudioDriverImpl * impl)
{
    /* Set the function pointers */
    impl->OpenDevice = DART_OpenDevice;
    impl->ThreadInit = DART_ThreadInit;
    impl->WaitDevice = DART_WaitDevice;
    impl->GetDeviceBuf = DART_GetDeviceBuf;
    impl->PlayDevice = DART_PlayDevice;
    impl->WaitDone = DART_WaitDone;
    impl->CloseDevice = DART_CloseDevice;
    impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME: is this right? */

    return 1;
}


AudioBootStrap DART_bootstrap = {
    "dart", "OS/2 Direct Audio RouTines (DART)", DART_Init, 0
};

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