directx.c

/*****************************************************************************
 * directx.c: Windows DirectX audio output method
 *****************************************************************************
 * Copyright (C) 2001 the VideoLAN team
 * $Id$
 *
 * Authors: Gildas Bazin <gbazin@videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/


#include <vlc/vlc.h>
#include <vlc_aout.h>

#include <windows.h>
#include <mmsystem.h>
#include <dsound.h>

#define FRAME_SIZE ((int)p_aout->output.output.i_rate/20) /* Size in samples */
#define FRAMES_NUM 8                                      /* Needs to be > 3 */

/*****************************************************************************
 * DirectSound GUIDs.
 * Defining them here allows us to get rid of the dxguid library during
 * the linking stage.
 *****************************************************************************/
#include <initguid.h>

/*****************************************************************************
 * Useful macros
 *****************************************************************************/
#ifndef WAVE_FORMAT_IEEE_FLOAT
#   define WAVE_FORMAT_IEEE_FLOAT 0x0003
#endif

#ifndef WAVE_FORMAT_DOLBY_AC3_SPDIF
#   define WAVE_FORMAT_DOLBY_AC3_SPDIF 0x0092
#endif

#ifndef WAVE_FORMAT_EXTENSIBLE
#define  WAVE_FORMAT_EXTENSIBLE   0xFFFE
#endif

#ifndef SPEAKER_FRONT_LEFT
#   define SPEAKER_FRONT_LEFT             0x1
#   define SPEAKER_FRONT_RIGHT            0x2
#   define SPEAKER_FRONT_CENTER           0x4
#   define SPEAKER_LOW_FREQUENCY          0x8
#   define SPEAKER_BACK_LEFT              0x10
#   define SPEAKER_BACK_RIGHT             0x20
#   define SPEAKER_FRONT_LEFT_OF_CENTER   0x40
#   define SPEAKER_FRONT_RIGHT_OF_CENTER  0x80
#   define SPEAKER_BACK_CENTER            0x100
#   define SPEAKER_SIDE_LEFT              0x200
#   define SPEAKER_SIDE_RIGHT             0x400
#   define SPEAKER_TOP_CENTER             0x800
#   define SPEAKER_TOP_FRONT_LEFT         0x1000
#   define SPEAKER_TOP_FRONT_CENTER       0x2000
#   define SPEAKER_TOP_FRONT_RIGHT        0x4000
#   define SPEAKER_TOP_BACK_LEFT          0x8000
#   define SPEAKER_TOP_BACK_CENTER        0x10000
#   define SPEAKER_TOP_BACK_RIGHT         0x20000
#   define SPEAKER_RESERVED               0x80000000
#endif

#ifndef DSSPEAKER_HEADPHONE
#   define DSSPEAKER_HEADPHONE         0x00000001
#endif
#ifndef DSSPEAKER_MONO
#   define DSSPEAKER_MONO              0x00000002
#endif
#ifndef DSSPEAKER_QUAD
#   define DSSPEAKER_QUAD              0x00000003
#endif
#ifndef DSSPEAKER_STEREO
#   define DSSPEAKER_STEREO            0x00000004
#endif
#ifndef DSSPEAKER_SURROUND
#   define DSSPEAKER_SURROUND          0x00000005
#endif
#ifndef DSSPEAKER_5POINT1
#   define DSSPEAKER_5POINT1           0x00000006
#endif

#ifndef _WAVEFORMATEXTENSIBLE_
typedef struct {
    WAVEFORMATEX    Format;
    union {
        WORD wValidBitsPerSample;       /* bits of precision  */
        WORD wSamplesPerBlock;          /* valid if wBitsPerSample==0 */
        WORD wReserved;                 /* If neither applies, set to zero. */
    } Samples;
    DWORD           dwChannelMask;      /* which channels are */
                                        /* present in stream  */
    GUID            SubFormat;
} WAVEFORMATEXTENSIBLE, *PWAVEFORMATEXTENSIBLE;
#endif

DEFINE_GUID( _KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, WAVE_FORMAT_IEEE_FLOAT, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 );
DEFINE_GUID( _KSDATAFORMAT_SUBTYPE_PCM, WAVE_FORMAT_PCM, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 );
DEFINE_GUID( _KSDATAFORMAT_SUBTYPE_DOLBY_AC3_SPDIF, WAVE_FORMAT_DOLBY_AC3_SPDIF, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 );

/*****************************************************************************
 * notification_thread_t: DirectX event thread
 *****************************************************************************/
typedef struct notification_thread_t
{
    VLC_COMMON_MEMBERS

    aout_instance_t *p_aout;
    int i_frame_size;                          /* size in bytes of one frame */
    int i_write_slot;       /* current write position in our circular buffer */

    mtime_t start_date;
    HANDLE event;

} notification_thread_t;

/*****************************************************************************
 * aout_sys_t: directx audio output method descriptor
 *****************************************************************************
 * This structure is part of the audio output thread descriptor.
 * It describes the direct sound specific properties of an audio device.
 *****************************************************************************/
struct aout_sys_t
{
    HINSTANCE           hdsound_dll;      /* handle of the opened dsound dll */

    int                 i_device_id;                 /*  user defined device */
    LPGUID              p_device_guid;

    LPDIRECTSOUND       p_dsobject;              /* main Direct Sound object */
    LPDIRECTSOUNDBUFFER p_dsbuffer;   /* the sound buffer we use (direct sound
                                       * takes care of mixing all the
                                       * secondary buffers into the primary) */

    notification_thread_t *p_notif;                  /* DirectSoundThread id */

    int b_playing;                                         /* playing status */

    int i_frame_size;                         /* Size in bytes of one frame */

    vlc_bool_t b_chan_reorder;              /* do we need channel reordering */
    int pi_chan_table[AOUT_CHAN_MAX];
    uint32_t i_channel_mask;
    uint32_t i_bits_per_sample;
    uint32_t i_channels;
};

static const uint32_t pi_channels_src[] =
    { AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT,
      AOUT_CHAN_MIDDLELEFT, AOUT_CHAN_MIDDLERIGHT,
      AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT,
      AOUT_CHAN_CENTER, AOUT_CHAN_LFE, 0 };
static const uint32_t pi_channels_in[] =
    { SPEAKER_FRONT_LEFT, SPEAKER_FRONT_RIGHT,
      SPEAKER_SIDE_LEFT, SPEAKER_SIDE_RIGHT,
      SPEAKER_BACK_LEFT, SPEAKER_BACK_RIGHT,
      SPEAKER_FRONT_CENTER, SPEAKER_LOW_FREQUENCY, 0 };
static const uint32_t pi_channels_out[] =
    { SPEAKER_FRONT_LEFT, SPEAKER_FRONT_RIGHT,
      SPEAKER_FRONT_CENTER, SPEAKER_LOW_FREQUENCY,
      SPEAKER_BACK_LEFT, SPEAKER_BACK_RIGHT,
      SPEAKER_SIDE_LEFT, SPEAKER_SIDE_RIGHT, 0 };

/*****************************************************************************
 * Local prototypes.
 *****************************************************************************/
static int  OpenAudio  ( vlc_object_t * );
static void CloseAudio ( vlc_object_t * );
static void Play       ( aout_instance_t * );

/* local functions */
static void Probe             ( aout_instance_t * );
static int  InitDirectSound   ( aout_instance_t * );
static int  CreateDSBuffer    ( aout_instance_t *, int, int, int, int, int, vlc_bool_t );
static int  CreateDSBufferPCM ( aout_instance_t *, int*, int, int, int, vlc_bool_t );
static void DestroyDSBuffer   ( aout_instance_t * );
static void DirectSoundThread ( notification_thread_t * );
static int  FillBuffer        ( aout_instance_t *, int, aout_buffer_t * );

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
#define DEVICE_TEXT N_("Output device")
#define DEVICE_LONGTEXT N_( \
    "DirectX device number: 0 default device, 1..N device by number" \
    "(Note that the default device appears as 0 AND another number)." )
#define FLOAT_TEXT N_("Use float32 output")
#define FLOAT_LONGTEXT N_( \
    "The option allows you to enable or disable the high-quality float32 " \
    "audio output mode (which is not well supported by some soundcards)." )

vlc_module_begin();
    set_description( _("DirectX audio output") );
    set_shortname( "DirectX" );
    set_capability( "audio output", 100 );
    set_category( CAT_AUDIO );
    set_subcategory( SUBCAT_AUDIO_AOUT );
    add_shortcut( "directx" );
    add_integer( "directx-audio-device", 0, NULL, DEVICE_TEXT,
                 DEVICE_LONGTEXT, VLC_TRUE );
    add_bool( "directx-audio-float32", 0, 0, FLOAT_TEXT,
              FLOAT_LONGTEXT, VLC_TRUE );
    set_callbacks( OpenAudio, CloseAudio );
vlc_module_end();

/*****************************************************************************
 * OpenAudio: open the audio device
 *****************************************************************************
 * This function opens and setups Direct Sound.
 *****************************************************************************/
static int OpenAudio( vlc_object_t *p_this )
{
    aout_instance_t * p_aout = (aout_instance_t *)p_this;
    vlc_value_t val;

    msg_Dbg( p_aout, "OpenAudio" );

   /* Allocate structure */
    p_aout->output.p_sys = malloc( sizeof( aout_sys_t ) );
    if( p_aout->output.p_sys == NULL )
    {
        msg_Err( p_aout, "out of memory" );
        return VLC_ENOMEM;
    }

    /* Initialize some variables */
    p_aout->output.p_sys->p_dsobject = NULL;
    p_aout->output.p_sys->p_dsbuffer = NULL;
    p_aout->output.p_sys->p_notif = NULL;
    p_aout->output.p_sys->b_playing = 0;

    p_aout->output.pf_play = Play;
    aout_VolumeSoftInit( p_aout );

    /* Retrieve config values */
    var_Create( p_aout, "directx-audio-float32",
                VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
    var_Create( p_aout, "directx-audio-device",
                VLC_VAR_INTEGER|VLC_VAR_DOINHERIT );
    var_Get( p_aout, "directx-audio-device", &val );
    p_aout->output.p_sys->i_device_id = val.i_int;
    p_aout->output.p_sys->p_device_guid = 0;

    /* Initialise DirectSound */
    if( InitDirectSound( p_aout ) )
    {
        msg_Err( p_aout, "cannot initialize DirectSound" );
        goto error;
    }

    if( var_Type( p_aout, "audio-device" ) == 0 )
    {
        Probe( p_aout );
    }

    if( var_Get( p_aout, "audio-device", &val ) < 0 )
    {
        /* Probe() has failed. */
        goto error;
    }

    /* Open the device */
    if( val.i_int == AOUT_VAR_SPDIF )
    {
        p_aout->output.output.i_format = VLC_FOURCC('s','p','d','i');

        /* Calculate the frame size in bytes */
        p_aout->output.i_nb_samples = A52_FRAME_NB;
        p_aout->output.output.i_bytes_per_frame = AOUT_SPDIF_SIZE;
        p_aout->output.output.i_frame_length = A52_FRAME_NB;
        p_aout->output.p_sys->i_frame_size =
            p_aout->output.output.i_bytes_per_frame;

        if( CreateDSBuffer( p_aout, VLC_FOURCC('s','p','d','i'),
                            p_aout->output.output.i_physical_channels,
                            aout_FormatNbChannels( &p_aout->output.output ),
                            p_aout->output.output.i_rate,
                            p_aout->output.p_sys->i_frame_size, VLC_FALSE )
            != VLC_SUCCESS )
        {
            msg_Err( p_aout, "cannot open directx audio device" );
            free( p_aout->output.p_sys );
            return VLC_EGENERIC;
        }

        aout_VolumeNoneInit( p_aout );
    }
    else
    {
        if( val.i_int == AOUT_VAR_5_1 )
        {
            p_aout->output.output.i_physical_channels
                = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
                   | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
                   | AOUT_CHAN_LFE;
        }
        else if( val.i_int == AOUT_VAR_3F2R )
        {
            p_aout->output.output.i_physical_channels
                = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
                   | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
        }
        else if( val.i_int == AOUT_VAR_2F2R )
        {
            p_aout->output.output.i_physical_channels
                = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
                   | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
        }
        else if( val.i_int == AOUT_VAR_MONO )
        {
            p_aout->output.output.i_physical_channels = AOUT_CHAN_CENTER;
        }
        else
        {
            p_aout->output.output.i_physical_channels
                = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
        }

        if( CreateDSBufferPCM( p_aout, &p_aout->output.output.i_format,
                               p_aout->output.output.i_physical_channels,
                               aout_FormatNbChannels( &p_aout->output.output ),
                               p_aout->output.output.i_rate, VLC_FALSE )
            != VLC_SUCCESS )
        {
            msg_Err( p_aout, "cannot open directx audio device" );
            free( p_aout->output.p_sys );
            return VLC_EGENERIC;
        }

        /* Calculate the frame size in bytes */
        p_aout->output.i_nb_samples = FRAME_SIZE;
        aout_FormatPrepare( &p_aout->output.output );
        aout_VolumeSoftInit( p_aout );
    }

    /* Now we need to setup our DirectSound play notification structure */
    p_aout->output.p_sys->p_notif =
        vlc_object_create( p_aout, sizeof(notification_thread_t) );
    p_aout->output.p_sys->p_notif->p_aout = p_aout;

    p_aout->output.p_sys->p_notif->event = CreateEvent( 0, FALSE, FALSE, 0 );
    p_aout->output.p_sys->p_notif->i_frame_size =
        p_aout->output.p_sys->i_frame_size;

    /* then launch the notification thread */
    msg_Dbg( p_aout, "creating DirectSoundThread" );
    if( vlc_thread_create( p_aout->output.p_sys->p_notif,
                           "DirectSound Notification Thread",
                           DirectSoundThread,
                           VLC_THREAD_PRIORITY_HIGHEST, VLC_FALSE ) )
    {
        msg_Err( p_aout, "cannot create DirectSoundThread" );
        CloseHandle( p_aout->output.p_sys->p_notif->event );
        vlc_object_destroy( p_aout->output.p_sys->p_notif );
        p_aout->output.p_sys->p_notif = NULL;
        goto error;
    }

    vlc_object_attach( p_aout->output.p_sys->p_notif, p_aout );

    return VLC_SUCCESS;

 error:
    CloseAudio( VLC_OBJECT(p_aout) );
    return VLC_EGENERIC;
}

/*****************************************************************************
 * Probe: probe the audio device for available formats and channels
 *****************************************************************************/
static void Probe( aout_instance_t * p_aout )
{
    vlc_value_t val, text;
    int i_format;
    unsigned int i_physical_channels;
    DWORD ui_speaker_config;

    var_Create( p_aout, "audio-device", VLC_VAR_INTEGER | VLC_VAR_HASCHOICE );
    text.psz_string = _("Audio Device");
    var_Change( p_aout, "audio-device", VLC_VAR_SETTEXT, &text, NULL );

    /* Test for 5.1 support */
    i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                          AOUT_CHAN_CENTER | AOUT_CHAN_REARLEFT |
                          AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE;
    if( p_aout->output.output.i_physical_channels == i_physical_channels )
    {
        if( CreateDSBufferPCM( p_aout, &i_format, i_physical_channels, 6,
                               p_aout->output.output.i_rate, VLC_TRUE )
            == VLC_SUCCESS )
        {
            val.i_int = AOUT_VAR_5_1;
            text.psz_string = "5.1";
            var_Change( p_aout, "audio-device",
                        VLC_VAR_ADDCHOICE, &val, &text );
            msg_Dbg( p_aout, "device supports 5.1 channels" );
        }
    }

    /* Test for 3 Front 2 Rear support */
    i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                          AOUT_CHAN_CENTER | AOUT_CHAN_REARLEFT |
                          AOUT_CHAN_REARRIGHT;
    if( p_aout->output.output.i_physical_channels == i_physical_channels )
    {
        if( CreateDSBufferPCM( p_aout, &i_format, i_physical_channels, 5,
                               p_aout->output.output.i_rate, VLC_TRUE )
            == VLC_SUCCESS )
        {
            val.i_int = AOUT_VAR_3F2R;
            text.psz_string = N_("3 Front 2 Rear");
            var_Change( p_aout, "audio-device",
                        VLC_VAR_ADDCHOICE, &val, &text );
            msg_Dbg( p_aout, "device supports 5 channels" );
        }
    }

    /* Test for 2 Front 2 Rear support */
    i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT |
                          AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
    if( ( p_aout->output.output.i_physical_channels & i_physical_channels )
        == i_physical_channels )
    {
        if( CreateDSBufferPCM( p_aout, &i_format, i_physical_channels, 4,
                               p_aout->output.output.i_rate, VLC_TRUE )
            == VLC_SUCCESS )
        {
            val.i_int = AOUT_VAR_2F2R;
            text.psz_string = N_("2 Front 2 Rear");
            var_Change( p_aout, "audio-device",
                        VLC_VAR_ADDCHOICE, &val, &text );
            msg_Dbg( p_aout, "device supports 4 channels" );
        }
    }

    /* Test for stereo support */
    i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT;
    if( CreateDSBufferPCM( p_aout, &i_format, i_physical_channels, 2,
                           p_aout->output.output.i_rate, VLC_TRUE )
        == VLC_SUCCESS )
    {
        val.i_int = AOUT_VAR_STEREO;
        text.psz_string = N_("Stereo");
        var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
        var_Change( p_aout, "audio-device", VLC_VAR_SETDEFAULT, &val, NULL );
        msg_Dbg( p_aout, "device supports 2 channels" );
    }

    /* Test for mono support */
    i_physical_channels = AOUT_CHAN_CENTER;
    if( CreateDSBufferPCM( p_aout, &i_format, i_physical_channels, 1,
                           p_aout->output.output.i_rate, VLC_TRUE )
        == VLC_SUCCESS )
    {
        val.i_int = AOUT_VAR_MONO;
        text.psz_string = N_("Mono");
        var_Change( p_aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text );
        msg_Dbg( p_aout, "device supports 1 channel" );
    }

    /* Check the speaker configuration to determine which channel config should
     * be the default */
    if FAILED( IDirectSound_GetSpeakerConfig( p_aout->output.p_sys->p_dsobject,
                                              &ui_speaker_config ) )
    {
        ui_speaker_config = DSSPEAKER_STEREO;
    }
    switch( DSSPEAKER_CONFIG(ui_speaker_config) )
    {
    case DSSPEAKER_5POINT1:
        val.i_int = AOUT_VAR_5_1;
        break;
    case DSSPEAKER_QUAD:
        val.i_int = AOUT_VAR_2F2R;
        break;
#if 0 /* Lots of people just get their settings wrong and complain that
       * this is a problem with VLC so just don't ever set mono by default. */
    case DSSPEAKER_MONO:
        val.i_int = AOUT_VAR_MONO;
        break;
#endif
    case DSSPEAKER_SURROUND:
    case DSSPEAKER_STEREO:
    default:
        val.i_int = AOUT_VAR_STEREO;
        break;
    }
    var_Set( p_aout, "audio-device", val );

    /* Test for SPDIF support */
    if ( AOUT_FMT_NON_LINEAR( &p_aout->output.output ) )
    {
        if( CreateDSBuffer( p_aout, VLC_FOURCC('s','p','d','i'),
                            p_aout->output.output.i_physical_channels,
                            aout_FormatNbChannels( &p_aout->output.output ),
                            p_aout->output.output.i_rate,
                            AOUT_SPDIF_SIZE, VLC_TRUE )
            == VLC_SUCCESS )
        {
            msg_Dbg( p_aout, "device supports A/52 over S/PDIF" );
            val.i_int = AOUT_VAR_SPDIF;
            text.psz_string = N_("A/52 over S/PDIF");
            var_Change( p_aout, "audio-device",
                        VLC_VAR_ADDCHOICE, &val, &text );
            if( config_GetInt( p_aout, "spdif" ) )
                var_Set( p_aout, "audio-device", val );
        }
    }

    var_Change( p_aout, "audio-device", VLC_VAR_CHOICESCOUNT, &val, NULL );
    if( val.i_int <= 0 )
    {
        /* Probe() has failed. */
        var_Destroy( p_aout, "audio-device" );
        return;
    }

    var_AddCallback( p_aout, "audio-device", aout_ChannelsRestart, NULL );

    val.b_bool = VLC_TRUE;
    var_Set( p_aout, "intf-change", val );
}

/*****************************************************************************
 * Play: we'll start playing the directsound buffer here because at least here
 *       we know the first buffer has been put in the aout fifo and we also
 *       know its date.
 *****************************************************************************/
static void Play( aout_instance_t *p_aout )
{
    if( !p_aout->output.p_sys->b_playing )
    {
        aout_buffer_t *p_buffer;
        int i;

        p_aout->output.p_sys->b_playing = 1;

        /* get the playing date of the first aout buffer */
        p_aout->output.p_sys->p_notif->start_date =
            aout_FifoFirstDate( p_aout, &p_aout->output.fifo );

        /* fill in the first samples */
        for( i = 0; i < FRAMES_NUM; i++ )
        {
            p_buffer = aout_FifoPop( p_aout, &p_aout->output.fifo );
            if( !p_buffer ) break;
            FillBuffer( p_aout, i, p_buffer );
        }

        /* wake up the audio output thread */
        SetEvent( p_aout->output.p_sys->p_notif->event );
    }
}

/*****************************************************************************
 * CloseAudio: close the audio device
 *****************************************************************************/
static void CloseAudio( vlc_object_t *p_this )
{
    aout_instance_t * p_aout = (aout_instance_t *)p_this;
    aout_sys_t *p_sys = p_aout->output.p_sys;

    msg_Dbg( p_aout, "closing audio device" );

    /* kill the position notification thread, if any */
    if( p_sys->p_notif )
    {
        vlc_object_detach( p_sys->p_notif );
        vlc_object_kill( p_sys->p_notif );
        /* wake up the audio thread if needed */
        if( !p_sys->b_playing ) SetEvent( p_sys->p_notif->event );

        vlc_thread_join( p_sys->p_notif );
        vlc_object_destroy( p_sys->p_notif );
    }

    /* release the secondary buffer */
    DestroyDSBuffer( p_aout );

    /* finally release the DirectSound object */
    if( p_sys->p_dsobject ) IDirectSound_Release( p_sys->p_dsobject );
    
    /* free DSOUND.DLL */
    if( p_sys->hdsound_dll ) FreeLibrary( p_sys->hdsound_dll );

    free( p_aout->output.p_sys->p_device_guid );
    free( p_sys );
}

/*****************************************************************************
 * CallBackDirectSoundEnum: callback to enumerate available devices
 *****************************************************************************/
static int CALLBACK CallBackDirectSoundEnum( LPGUID p_guid, LPCSTR psz_desc,
                                             LPCSTR psz_mod, LPVOID _p_aout )
{
    aout_instance_t *p_aout = (aout_instance_t *)_p_aout;

    msg_Dbg( p_aout, "found device: %s", psz_desc );

    if( p_aout->output.p_sys->i_device_id == 0 && p_guid )
    {
        p_aout->output.p_sys->p_device_guid = malloc( sizeof( GUID ) );
        *p_aout->output.p_sys->p_device_guid = *p_guid;
        msg_Dbg( p_aout, "using device: %s", psz_desc );
    }

    p_aout->output.p_sys->i_device_id--;
    return 1;
}

/*****************************************************************************
 * InitDirectSound: handle all the gory details of DirectSound initialisation
 *****************************************************************************/
static int InitDirectSound( aout_instance_t *p_aout )
{
    HRESULT (WINAPI *OurDirectSoundCreate)(LPGUID, LPDIRECTSOUND *, LPUNKNOWN);
    HRESULT (WINAPI *OurDirectSoundEnumerate)(LPDSENUMCALLBACK, LPVOID);

    p_aout->output.p_sys->hdsound_dll = LoadLibrary("DSOUND.DLL");
    if( p_aout->output.p_sys->hdsound_dll == NULL )
    {
        msg_Warn( p_aout, "cannot open DSOUND.DLL" );
        goto error;
    }

    OurDirectSoundCreate = (void *)
        GetProcAddress( p_aout->output.p_sys->hdsound_dll,
                        "DirectSoundCreate" );
    if( OurDirectSoundCreate == NULL )
    {
        msg_Warn( p_aout, "GetProcAddress FAILED" );
        goto error;
    }

    /* Get DirectSoundEnumerate */
    OurDirectSoundEnumerate = (void *)
       GetProcAddress( p_aout->output.p_sys->hdsound_dll,
                       "DirectSoundEnumerateA" );
    if( OurDirectSoundEnumerate )
    {
        /* Attempt enumeration */
        if( FAILED( OurDirectSoundEnumerate( CallBackDirectSoundEnum, 
                                             p_aout ) ) )
        {
            msg_Dbg( p_aout, "enumeration of DirectSound devices failed" );
        }
    }

    /* Create the direct sound object */
    if FAILED( OurDirectSoundCreate( p_aout->output.p_sys->p_device_guid, 
                                     &p_aout->output.p_sys->p_dsobject,
                                     NULL ) )
    {
        msg_Warn( p_aout, "cannot create a direct sound device" );
        goto error;
    }

    /* Set DirectSound Cooperative level, ie what control we want over Windows
     * sound device. In our case, DSSCL_EXCLUSIVE means that we can modify the
     * settings of the primary buffer, but also that only the sound of our
     * application will be hearable when it will have the focus.
     * !!! (this is not really working as intended yet because to set the
     * cooperative level you need the window handle of your application, and
     * I don't know of any easy way to get it. Especially since we might play
     * sound without any video, and so what window handle should we use ???
     * The hack for now is to use the Desktop window handle - it seems to be
     * working */
    if( IDirectSound_SetCooperativeLevel( p_aout->output.p_sys->p_dsobject,
                                          GetDesktopWindow(),
                                          DSSCL_EXCLUSIVE) )
    {
        msg_Warn( p_aout, "cannot set direct sound cooperative level" );
    }

    return VLC_SUCCESS;

 error:
    p_aout->output.p_sys->p_dsobject = NULL;
    if( p_aout->output.p_sys->hdsound_dll )
    {
        FreeLibrary( p_aout->output.p_sys->hdsound_dll );
        p_aout->output.p_sys->hdsound_dll = NULL;
    }
    return VLC_EGENERIC;

}

/*****************************************************************************
 * CreateDSBuffer: Creates a direct sound buffer of the required format.
 *****************************************************************************
 * This function creates the buffer we'll use to play audio.
 * In DirectSound there are two kinds of buffers:
 * - the primary buffer: which is the actual buffer that the soundcard plays
 * - the secondary buffer(s): these buffers are the one actually used by
 *    applications and DirectSound takes care of mixing them into the primary.
 *
 * Once you create a secondary buffer, you cannot change its format anymore so
 * you have to release the current one and create another.
 *****************************************************************************/
static int CreateDSBuffer( aout_instance_t *p_aout, int i_format,
                           int i_channels, int i_nb_channels, int i_rate,
                           int i_bytes_per_frame, vlc_bool_t b_probe )
{
    WAVEFORMATEXTENSIBLE waveformat;
    DSBUFFERDESC         dsbdesc;
    unsigned int         i;

    /* First set the sound buffer format */
    waveformat.dwChannelMask = 0;
    for( i = 0; i < sizeof(pi_channels_src)/sizeof(uint32_t); i++ )
    {
        if( i_channels & pi_channels_src[i] )
            waveformat.dwChannelMask |= pi_channels_in[i];
    }

    switch( i_format )
    {
    case VLC_FOURCC('s','p','d','i'):
        i_nb_channels = 2;
        /* To prevent channel re-ordering */
        waveformat.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT;
        waveformat.Format.wBitsPerSample = 16;
        waveformat.Samples.wValidBitsPerSample =
            waveformat.Format.wBitsPerSample;
        waveformat.Format.wFormatTag = WAVE_FORMAT_DOLBY_AC3_SPDIF;
        waveformat.SubFormat = _KSDATAFORMAT_SUBTYPE_DOLBY_AC3_SPDIF;
        break;

    case VLC_FOURCC('f','l','3','2'):
        waveformat.Format.wBitsPerSample = sizeof(float) * 8;
        waveformat.Samples.wValidBitsPerSample =
            waveformat.Format.wBitsPerSample;
        waveformat.Format.wFormatTag = WAVE_FORMAT_IEEE_FLOAT;
        waveformat.SubFormat = _KSDATAFORMAT_SUBTYPE_IEEE_FLOAT;
        break;

    case VLC_FOURCC('s','1','6','l'):
        waveformat.Format.wBitsPerSample = 16;
        waveformat.Samples.wValidBitsPerSample =
            waveformat.Format.wBitsPerSample;
        waveformat.Format.wFormatTag = WAVE_FORMAT_PCM;
        waveformat.SubFormat = _KSDATAFORMAT_SUBTYPE_PCM;
        break;
    }

    waveformat.Format.nChannels = i_nb_channels;
    waveformat.Format.nSamplesPerSec = i_rate;
    waveformat.Format.nBlockAlign =
        waveformat.Format.wBitsPerSample / 8 * i_nb_channels;
    waveformat.Format.nAvgBytesPerSec =
        waveformat.Format.nSamplesPerSec * waveformat.Format.nBlockAlign;

    p_aout->output.p_sys->i_bits_per_sample = waveformat.Format.wBitsPerSample;
    p_aout->output.p_sys->i_channels = i_nb_channels;

    /* Then fill in the direct sound descriptor */
    memset(&dsbdesc, 0, sizeof(DSBUFFERDESC));
    dsbdesc.dwSize = sizeof(DSBUFFERDESC);
    dsbdesc.dwFlags = DSBCAPS_GETCURRENTPOSITION2/* Better position accuracy */
                    | DSBCAPS_GLOBALFOCUS;      /* Allows background playing */

    /* Only use the new WAVE_FORMAT_EXTENSIBLE format for multichannel audio */
    if( i_nb_channels <= 2 )
    {
        waveformat.Format.cbSize = 0;
    }
    else
    {
        waveformat.Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
        waveformat.Format.cbSize =
            sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX);

        /* Needed for 5.1 on emu101k */
        dsbdesc.dwFlags |= DSBCAPS_LOCHARDWARE;
    }

    dsbdesc.dwBufferBytes = FRAMES_NUM * i_bytes_per_frame;   /* buffer size */
    dsbdesc.lpwfxFormat = (WAVEFORMATEX *)&waveformat;

    if FAILED( IDirectSound_CreateSoundBuffer(
                   p_aout->output.p_sys->p_dsobject, &dsbdesc,
                   &p_aout->output.p_sys->p_dsbuffer, NULL) )
    {
        if( dsbdesc.dwFlags & DSBCAPS_LOCHARDWARE )
        {
            /* Try without DSBCAPS_LOCHARDWARE */
            dsbdesc.dwFlags &= ~DSBCAPS_LOCHARDWARE;
            if FAILED( IDirectSound_CreateSoundBuffer(
                   p_aout->output.p_sys->p_dsobject, &dsbdesc,
                   &p_aout->output.p_sys->p_dsbuffer, NULL) )
            {
                return VLC_EGENERIC;
            }
            if( !b_probe )
                msg_Dbg( p_aout, "couldn't use hardware sound buffer" );
        }
        else
        {
            return VLC_EGENERIC;
        }
    }

    /* Stop here if we were just probing */
    if( b_probe )
    {
        IDirectSoundBuffer_Release( p_aout->output.p_sys->p_dsbuffer );
        p_aout->output.p_sys->p_dsbuffer = NULL;
        return VLC_SUCCESS;
    }

    p_aout->output.p_sys->i_frame_size = i_bytes_per_frame;
    p_aout->output.p_sys->i_channel_mask = waveformat.dwChannelMask;
    p_aout->output.p_sys->b_chan_reorder =
        aout_CheckChannelReorder( pi_channels_in, pi_channels_out,
                                  waveformat.dwChannelMask, i_nb_channels,
                                  p_aout->output.p_sys->pi_chan_table );

    if( p_aout->output.p_sys->b_chan_reorder )
    {
        msg_Dbg( p_aout, "channel reordering needed" );
    }

    return VLC_SUCCESS;
}

/*****************************************************************************
 * CreateDSBufferPCM: creates a PCM direct sound buffer.
 *****************************************************************************
 * We first try to create a WAVE_FORMAT_IEEE_FLOAT buffer if supported by
 * the hardware, otherwise we create a WAVE_FORMAT_PCM buffer.
 ****************************************************************************/
static int CreateDSBufferPCM( aout_instance_t *p_aout, int *i_format,
                              int i_channels, int i_nb_channels, int i_rate,
                              vlc_bool_t b_probe )
{
    vlc_value_t val;

    var_Get( p_aout, "directx-audio-float32", &val );

    /* Float32 audio samples are not supported for 5.1 output on the emu101k */

    if( !val.b_bool || i_nb_channels > 2 ||
        CreateDSBuffer( p_aout, VLC_FOURCC('f','l','3','2'),
                        i_channels, i_nb_channels, i_rate,
                        FRAME_SIZE * 4 * i_nb_channels, b_probe )
        != VLC_SUCCESS )
    {
        if ( CreateDSBuffer( p_aout, VLC_FOURCC('s','1','6','l'),
                             i_channels, i_nb_channels, i_rate,
                             FRAME_SIZE * 2 * i_nb_channels, b_probe )
             != VLC_SUCCESS )
        {
            return VLC_EGENERIC;
        }
        else
        {
            *i_format = VLC_FOURCC('s','1','6','l');
            return VLC_SUCCESS;
        }
    }
    else
    {
        *i_format = VLC_FOURCC('f','l','3','2');
        return VLC_SUCCESS;
    }
}

/*****************************************************************************
 * DestroyDSBuffer
 *****************************************************************************
 * This function destroys the secondary buffer.
 *****************************************************************************/
static void DestroyDSBuffer( aout_instance_t *p_aout )
{
    if( p_aout->output.p_sys->p_dsbuffer )
    {
        IDirectSoundBuffer_Release( p_aout->output.p_sys->p_dsbuffer );
        p_aout->output.p_sys->p_dsbuffer = NULL;
    }
}

/*****************************************************************************
 * FillBuffer: Fill in one of the direct sound frame buffers.
 *****************************************************************************
 * Returns VLC_SUCCESS on success.
 *****************************************************************************/
static int FillBuffer( aout_instance_t *p_aout, int i_frame,
                       aout_buffer_t *p_buffer )
{
    notification_thread_t *p_notif = p_aout->output.p_sys->p_notif;
    aout_sys_t *p_sys = p_aout->output.p_sys;
    void *p_write_position, *p_wrap_around;
    long l_bytes1, l_bytes2;
    HRESULT dsresult;

    /* Before copying anything, we have to lock the buffer */
    dsresult = IDirectSoundBuffer_Lock(
                p_sys->p_dsbuffer,                              /* DS buffer */
                i_frame * p_notif->i_frame_size,             /* Start offset */
                p_notif->i_frame_size,                    /* Number of bytes */
                &p_write_position,                  /* Address of lock start */
                &l_bytes1,       /* Count of bytes locked before wrap around */
                &p_wrap_around,            /* Buffer adress (if wrap around) */
                &l_bytes2,               /* Count of bytes after wrap around */
                0 );                                                /* Flags */
    if( dsresult == DSERR_BUFFERLOST )
    {
        IDirectSoundBuffer_Restore( p_sys->p_dsbuffer );
        dsresult = IDirectSoundBuffer_Lock(
                               p_sys->p_dsbuffer,
                               i_frame * p_notif->i_frame_size,
                               p_notif->i_frame_size,
                               &p_write_position,
                               &l_bytes1,
                               &p_wrap_around,
                               &l_bytes2,
                               0 );
    }
    if( dsresult != DS_OK )
    {
        msg_Warn( p_notif, "cannot lock buffer" );
        if( p_buffer ) aout_BufferFree( p_buffer );
        return VLC_EGENERIC;
    }

    if( p_buffer == NULL )
    {
        memset( p_write_position, 0, l_bytes1 );
    }
    else
    {
        if( p_sys->b_chan_reorder )
        {
            /* Do the channel reordering here */
            aout_ChannelReorder( p_buffer->p_buffer, p_buffer->i_nb_bytes,
                                 p_sys->i_channels, p_sys->pi_chan_table,
                                 p_sys->i_bits_per_sample );
        }

        p_aout->p_libvlc->pf_memcpy( p_write_position, p_buffer->p_buffer,
                                  l_bytes1 );
        aout_BufferFree( p_buffer );
    }

    /* Now the data has been copied, unlock the buffer */
    IDirectSoundBuffer_Unlock( p_sys->p_dsbuffer, p_write_position, l_bytes1,
                               p_wrap_around, l_bytes2 );

    p_notif->i_write_slot = (i_frame + 1) % FRAMES_NUM;
    return VLC_SUCCESS;
}

/*****************************************************************************
 * DirectSoundThread: this thread will capture play notification events. 
 *****************************************************************************
 * We use this thread to emulate a callback mechanism. The thread probes for
 * event notification and fills up the DS secondary buffer when needed.
 *****************************************************************************/
static void DirectSoundThread( notification_thread_t *p_notif )
{
    aout_instance_t *p_aout = p_notif->p_aout;
    vlc_bool_t b_sleek;
    mtime_t last_time;
    HRESULT dsresult;
    long l_queued = 0;

    /* We don't want any resampling when using S/PDIF output */
    b_sleek = p_aout->output.output.i_format == VLC_FOURCC('s','p','d','i');

    /* Tell the main thread that we are ready */
    vlc_thread_ready( p_notif );

    msg_Dbg( p_notif, "DirectSoundThread ready" );

    /* Wait here until Play() is called */
    WaitForSingleObject( p_notif->event, INFINITE );

    if( !p_notif->b_die )
    {
        mwait( p_notif->start_date - AOUT_PTS_TOLERANCE / 2 );

        /* start playing the buffer */
        dsresult = IDirectSoundBuffer_Play( p_aout->output.p_sys->p_dsbuffer,
                                        0,                         /* Unused */
                                        0,                         /* Unused */
                                        DSBPLAY_LOOPING );          /* Flags */
        if( dsresult == DSERR_BUFFERLOST )
        {
            IDirectSoundBuffer_Restore( p_aout->output.p_sys->p_dsbuffer );
            dsresult = IDirectSoundBuffer_Play(
                                            p_aout->output.p_sys->p_dsbuffer,
                                            0,                     /* Unused */
                                            0,                     /* Unused */
                                            DSBPLAY_LOOPING );      /* Flags */
        }
        if( dsresult != DS_OK )
        {
            msg_Err( p_aout, "cannot start playing buffer" );
        }
    }
    last_time = mdate();

    while( !p_notif->b_die )
    {
        long l_read, l_free_slots;
        mtime_t mtime = mdate();
        int i;

        /*
         * Fill in as much audio data as we can in our circular buffer
         */

        /* Find out current play position */
        if FAILED( IDirectSoundBuffer_GetCurrentPosition(
                   p_aout->output.p_sys->p_dsbuffer, &l_read, NULL ) )
        {
            msg_Err( p_aout, "GetCurrentPosition() failed!" );
            l_read = 0;
        }

        /* Detect underruns */
        if( l_queued && mtime - last_time >
            I64C(1000000) * l_queued / p_aout->output.output.i_rate )
        {
            msg_Dbg( p_aout, "detected underrun!" );
        }
        last_time = mtime;

        /* Try to fill in as many frame buffers as possible */
        l_read /= p_aout->output.output.i_bytes_per_frame;
        l_queued = p_notif->i_write_slot * FRAME_SIZE - l_read;
        if( l_queued < 0 ) l_queued += (FRAME_SIZE * FRAMES_NUM);
        l_free_slots = (FRAMES_NUM * FRAME_SIZE - l_queued) / FRAME_SIZE;

        for( i = 0; i < l_free_slots; i++ )
        {
            aout_buffer_t *p_buffer = aout_OutputNextBuffer( p_aout,
                mtime + I64C(1000000) * (i * FRAME_SIZE + l_queued) /
                p_aout->output.output.i_rate, b_sleek );

            /* If there is no audio data available and we have some buffered
             * already, then just wait for the next time */
            if( !p_buffer && (i || l_queued / FRAME_SIZE) ) break;

            if( FillBuffer( p_aout, p_notif->i_write_slot % FRAMES_NUM,
                            p_buffer ) != VLC_SUCCESS ) break;
        }

        /* Sleep a reasonable amount of time */
        l_queued += (i * FRAME_SIZE);
        msleep( I64C(1000000) * l_queued / p_aout->output.output.i_rate / 2 );
    }

    /* make sure the buffer isn't playing */
    IDirectSoundBuffer_Stop( p_aout->output.p_sys->p_dsbuffer );