waveout.c

/*****************************************************************************
 * waveout.c : Windows waveOut plugin for vlc
 *****************************************************************************
 * Copyright (C) 2001-2009 VLC authors and VideoLAN
 * $Id$
 *
 * Authors: Gildas Bazin <gbazin@videolan.org>
 *          André Weber
 *
 * This program 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 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser 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
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <math.h>

#define UNICODE
#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_aout.h>
#include <vlc_charset.h>              /* FromWide() */

#include "audio_output/windows_audio_common.h"

#define FRAME_SIZE 4096              /* The size is in samples, not in bytes */

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Open         ( vlc_object_t * );
static void Close        ( vlc_object_t * );
static void Play         ( audio_output_t *, block_t * );

/*****************************************************************************
 * notification_thread_t: waveOut event thread
 *****************************************************************************/
struct lkwavehdr
{
    WAVEHDR hdr;
    struct lkwavehdr * p_next;
};

/* local functions */
static int OpenWaveOut   ( audio_output_t *, uint32_t,
                           int, int, int, int, bool );
static int OpenWaveOutPCM( audio_output_t *, uint32_t,
                           vlc_fourcc_t*, int, int, int, bool );
static int PlayWaveOut   ( audio_output_t *, HWAVEOUT, struct lkwavehdr *,
                           block_t *, bool );

static void CALLBACK WaveOutCallback ( HWAVEOUT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR );

static void WaveOutClean( aout_sys_t * p_sys );

static void WaveOutClearBuffer( HWAVEOUT, WAVEHDR *);

static int ReloadWaveoutDevices( vlc_object_t *, const char *,
                                 char ***, char *** );
static uint32_t findDeviceID(char *);
static int WaveOutTimeGet(audio_output_t * , mtime_t *);
static void WaveOutFlush( audio_output_t *, bool);
static void WaveOutPause( audio_output_t *, bool, mtime_t);
static int WaveoutVolumeSet(audio_output_t * p_aout, float volume);
static int WaveoutMuteSet(audio_output_t * p_aout, bool mute);

static void WaveoutPollVolume( void * );

static const wchar_t device_name_fmt[] = L"%ls ($%x,$%x)";

/*****************************************************************************
 * aout_sys_t: waveOut audio output method descriptor
 *****************************************************************************
 * This structure is part of the audio output thread descriptor.
 * It describes the waveOut specific properties of an audio device.
 *****************************************************************************/

struct aout_sys_t
{
    HWAVEOUT h_waveout;                        /* handle to waveout instance */

    WAVEFORMATEXTENSIBLE waveformat;                         /* audio format */

    size_t i_frames;

    int i_repeat_counter;

    int i_buffer_size;

    int i_rate;

    uint8_t *p_silence_buffer;              /* buffer we use to play silence */

    float f_volume;

    bool b_spdif;
    bool b_mute;
    bool b_soft;                            /* Use software gain */
    uint8_t chans_to_reorder;              /* do we need channel reordering */

    uint8_t chan_table[AOUT_CHAN_MAX];
    vlc_fourcc_t format;

    mtime_t i_played_length;

    struct lkwavehdr * p_free_list;

    vlc_mutex_t lock;
    vlc_cond_t cond;
    vlc_timer_t volume_poll_timer;
};

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
#define DEVICE_TEXT N_("Select Audio Device")
#define DEVICE_LONG N_("Select special Audio device, or let windows "\
                       "decide (default), change needs VLC restart "\
                       "to apply.")

#define AUDIO_CHAN_TEXT N_("Audio output channels")
#define AUDIO_CHAN_LONGTEXT N_("Channels available for audio output. " \
    "If the input has more channels than the output, it will be down-mixed. " \
    "This parameter is ignored when digital pass-through is active.")

#define VOLUME_TEXT N_("Audio volume")

vlc_module_begin ()
    set_shortname( "WaveOut" )
    set_description( N_("WaveOut audio output") )
    set_capability( "audio output", 50 )
    set_category( CAT_AUDIO )
    set_subcategory( SUBCAT_AUDIO_AOUT )
    add_string( "waveout-audio-device", "wavemapper",
                 DEVICE_TEXT, DEVICE_LONG, false )
       change_string_cb( ReloadWaveoutDevices )
    add_float( "waveout-volume", 1.0f, VOLUME_TEXT, NULL, true )
         change_float_range(0.0f, 2.0f)
    add_bool( "waveout-float32", true, FLOAT_TEXT, FLOAT_LONGTEXT, true )
    add_integer ("waveout-audio-channels", 9, AUDIO_CHAN_TEXT,
                 AUDIO_CHAN_LONGTEXT, false)
        change_integer_range(1,9)
    set_callbacks( Open, Close )
vlc_module_end ()

/*****************************************************************************
 * Opens the audio device
 *****************************************************************************
 * This function opens and setups Win32 waveOut
 *****************************************************************************/
static int Start( audio_output_t *p_aout, audio_sample_format_t *restrict fmt )
{
    p_aout->time_get = WaveOutTimeGet;
    p_aout->play = Play;
    p_aout->pause = WaveOutPause;
    p_aout->flush = WaveOutFlush;

    /* Default behaviour is to use software gain */
    p_aout->sys->b_soft = true;

    char *dev = var_GetNonEmptyString( p_aout, "waveout-audio-device");
    uint32_t devid = findDeviceID( dev );

    if(devid == WAVE_MAPPER && dev != NULL && stricmp(dev,"wavemapper"))
        msg_Warn( p_aout, "configured audio device '%s' not available, "
                          "using default instead", dev );
    free( dev );

    WAVEOUTCAPS waveoutcaps;
    if(waveOutGetDevCaps( devid, &waveoutcaps,
                          sizeof(WAVEOUTCAPS)) == MMSYSERR_NOERROR)
    {
      /* log debug some infos about driver, to know who to blame
         if it doesn't work */
        msg_Dbg( p_aout, "Drivername: %ls", waveoutcaps.szPname);
        msg_Dbg( p_aout, "Driver Version: %d.%d",
                          (waveoutcaps.vDriverVersion>>8)&255,
                          waveoutcaps.vDriverVersion & 255);
        msg_Dbg( p_aout, "Manufacturer identifier: 0x%x", waveoutcaps.wMid );
        msg_Dbg( p_aout, "Product identifier: 0x%x", waveoutcaps.wPid );
    }



    /* Open the device */
    if( AOUT_FMT_SPDIF(fmt) && var_InheritBool (p_aout, "spdif") )
    {

        if( OpenWaveOut( p_aout, devid, VLC_CODEC_SPDIFL,
                         fmt->i_physical_channels,
                         aout_FormatNbChannels( fmt ), fmt->i_rate, false )
            == VLC_SUCCESS )
        {
            fmt->i_format = VLC_CODEC_SPDIFL;

            /* Calculate the frame size in bytes */
            fmt->i_bytes_per_frame = AOUT_SPDIF_SIZE;
            fmt->i_frame_length = A52_FRAME_NB;
            p_aout->sys->i_buffer_size = fmt->i_bytes_per_frame;
            p_aout->sys->b_spdif = true;

        }
        else
            msg_Err( p_aout,
                     "cannot open waveout audio device for spdif fallback to PCM" );
    }

    if( fmt->i_format != VLC_CODEC_SPDIFL )
    {
       /*
         check for configured audio device!
       */
       fmt->i_format = var_InheritBool( p_aout, "waveout-float32" )?
           VLC_CODEC_FL32: VLC_CODEC_S16N;

        int max_chan = var_InheritInteger( p_aout, "waveout-audio-channels");
        int i_channels = aout_FormatNbChannels(fmt);
        i_channels = ( i_channels < max_chan )? i_channels: max_chan;
        do
        {
            switch(i_channels)
            {
                case 9:
                    fmt->i_physical_channels = AOUT_CHANS_8_1;
                    break;
                case 8:
                    fmt->i_physical_channels = AOUT_CHANS_7_1;
                    break;
                case 7:
                    fmt->i_physical_channels = AOUT_CHANS_7_0;
                    break;
                case 6:
                    fmt->i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
                        | AOUT_CHAN_CENTER | AOUT_CHAN_REARLEFT
                        | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE;
                    break;
                case 5:
                    fmt->i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
                        | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT
                        | AOUT_CHAN_LFE;
                    break;
                case 4:
                    fmt->i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
                        | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT;
                    break;
                case 3:
                    fmt->i_physical_channels = AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
                        | AOUT_CHAN_LFE;
                    break;
                case 2:
                    fmt->i_physical_channels = AOUT_CHANS_STEREO;
                    break;
                case 1:
                default:
                    fmt->i_physical_channels = AOUT_CHAN_CENTER;
            }
            msg_Dbg( p_aout, "Trying %d channels", i_channels );
        }
        while( ( OpenWaveOutPCM( p_aout, devid, &fmt->i_format,
                                 fmt->i_physical_channels, i_channels,
                                 fmt->i_rate, false ) != VLC_SUCCESS ) &&
               --i_channels );

        if( !i_channels )
        {
            msg_Err(p_aout, "Waveout couldn't find appropriate channel mapping");
            return VLC_EGENERIC;
        }

        /* Calculate the frame size in bytes */
        aout_FormatPrepare( fmt );
        p_aout->sys->i_buffer_size = FRAME_SIZE * fmt->i_bytes_per_frame;

        if( waveoutcaps.dwSupport & WAVECAPS_VOLUME )
        {
            aout_GainRequest( p_aout, 1.0f );
            p_aout->sys->b_soft = false;
        }

        WaveoutMuteSet( p_aout, p_aout->sys->b_mute );

        p_aout->sys->b_spdif = false;
    }

    p_aout->sys->i_rate = fmt->i_rate;

    waveOutReset( p_aout->sys->h_waveout );

    /* Allocate silence buffer */
    p_aout->sys->p_silence_buffer =
        malloc( p_aout->sys->i_buffer_size );
    if( p_aout->sys->p_silence_buffer == NULL )
    {
        msg_Err( p_aout, "Couldn't alloc silence buffer... aborting");
        return VLC_ENOMEM;
    }
    p_aout->sys->i_repeat_counter = 0;


    /* Zero the buffer. WinCE doesn't have calloc(). */
    memset( p_aout->sys->p_silence_buffer, 0,
            p_aout->sys->i_buffer_size );

    /* Now we need to setup our waveOut play notification structure */
    p_aout->sys->i_frames = 0;
    p_aout->sys->i_played_length = 0;
    p_aout->sys->p_free_list = NULL;

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Play: play a sound buffer
 *****************************************************************************
 * This doesn't actually play the buffer. This just stores the buffer so it
 * can be played by the callback thread.
 *****************************************************************************/
static void Play( audio_output_t *p_aout, block_t *block )
{
    struct lkwavehdr * p_waveheader =
        (struct lkwavehdr *) malloc(sizeof(struct lkwavehdr));
    if(!p_waveheader)
    {
        msg_Err(p_aout, "Couldn't alloc WAVEHDR");
        if( block )
            block_Release( block );
        return;
    }

    p_waveheader->p_next = NULL;

    if( block && p_aout->sys->chans_to_reorder )
    {
        aout_ChannelReorder( block->p_buffer, block->i_buffer,
                             p_aout->sys->waveformat.Format.nChannels,
                             p_aout->sys->chan_table, p_aout->sys->format );
    }
    while( PlayWaveOut( p_aout, p_aout->sys->h_waveout, p_waveheader, block,
                        p_aout->sys->b_spdif ) != VLC_SUCCESS )

    {
        msg_Warn( p_aout, "Couln't write frame... sleeping");
        msleep( block->i_length );
    }

    WaveOutClean( p_aout->sys );
    WaveoutPollVolume( p_aout );

    vlc_mutex_lock( &p_aout->sys->lock );
    p_aout->sys->i_frames++;
    p_aout->sys->i_played_length += block->i_length;
    vlc_mutex_unlock( &p_aout->sys->lock );
}

/*****************************************************************************
 * Close: close the audio device
 *****************************************************************************/
static void Stop( audio_output_t *p_aout )
{
    aout_sys_t *p_sys = p_aout->sys;

    /* Before calling waveOutClose we must reset the device */
    MMRESULT result = waveOutReset( p_sys->h_waveout );
    if(result != MMSYSERR_NOERROR)
    {
       msg_Err( p_aout, "waveOutReset failed 0x%x", result );
       /*
        now we must wait, that all buffers are played
        because cancel doesn't work in this case...
       */
       if(result == MMSYSERR_NOTSUPPORTED)
       {
           /*
             clear currently played (done) buffers,
             if returnvalue > 0 (means some buffer still playing)
             wait for the driver event callback that one buffer
             is finished with playing, and check again
             the timeout of 5000ms is just, an emergency exit
             of this loop, to avoid deadlock in case of other
             (currently not known bugs, problems, errors cases?)
           */
            WaveOutFlush( p_aout, true );
       }
    }

    /* wait for the frames to be queued in cleaning list */
    WaveOutFlush( p_aout, true );
    WaveOutClean( p_aout->sys );

    /* now we can Close the device */
    if( waveOutClose( p_sys->h_waveout ) != MMSYSERR_NOERROR )
    {
        msg_Err( p_aout, "waveOutClose failed" );
    }

    free( p_sys->p_silence_buffer );
    p_aout->sys->i_played_length = 0;
    p_sys->b_soft = true;
}

/*****************************************************************************
 * OpenWaveOut: open the waveout sound device
 ****************************************************************************/
static int OpenWaveOut( audio_output_t *p_aout, uint32_t i_device_id, int i_format,
                        int i_channels, int i_nb_channels, int i_rate,
                        bool b_probe )
{
    MMRESULT result;

    /* Set sound format */

#define waveformat p_aout->sys->waveformat

    waveformat.dwChannelMask = 0;
    for( unsigned i = 0; pi_vlc_chan_order_wg4[i]; i++ )
        if( i_channels & pi_vlc_chan_order_wg4[i] )
            waveformat.dwChannelMask |= pi_channels_in[i];

    switch( i_format )
    {
    case VLC_CODEC_SPDIFL:
        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_CODEC_FL32:
        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_CODEC_S16N:
        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;

    /* 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);
    }

    if(!b_probe) {
        msg_Dbg( p_aout, "OpenWaveDevice-ID: %u", i_device_id);
        msg_Dbg( p_aout,"waveformat.Format.cbSize          = %d",
                 waveformat.Format.cbSize);
        msg_Dbg( p_aout,"waveformat.Format.wFormatTag      = %u",
                 waveformat.Format.wFormatTag);
        msg_Dbg( p_aout,"waveformat.Format.nChannels       = %u",
                 waveformat.Format.nChannels);
        msg_Dbg( p_aout,"waveformat.Format.nSamplesPerSec  = %d",
                 (int)waveformat.Format.nSamplesPerSec);
        msg_Dbg( p_aout,"waveformat.Format.nAvgBytesPerSec = %u",
                 (int)waveformat.Format.nAvgBytesPerSec);
        msg_Dbg( p_aout,"waveformat.Format.nBlockAlign     = %d",
                 waveformat.Format.nBlockAlign);
        msg_Dbg( p_aout,"waveformat.Format.wBitsPerSample  = %d",
                 waveformat.Format.wBitsPerSample);
        msg_Dbg( p_aout,"waveformat.Samples.wValidBitsPerSample = %d",
                 waveformat.Samples.wValidBitsPerSample);
        msg_Dbg( p_aout,"waveformat.Samples.wSamplesPerBlock = %d",
                 waveformat.Samples.wSamplesPerBlock);
        msg_Dbg( p_aout,"waveformat.dwChannelMask          = %u",
                 waveformat.dwChannelMask);
    }

    /* Open the device */
    result = waveOutOpen( &p_aout->sys->h_waveout, i_device_id,
                          (WAVEFORMATEX *)&waveformat,
                          (DWORD_PTR)WaveOutCallback, (DWORD_PTR)p_aout,
                          CALLBACK_FUNCTION | (b_probe?WAVE_FORMAT_QUERY:0) );
    if( result == WAVERR_BADFORMAT )
    {
        msg_Warn( p_aout, "waveOutOpen failed WAVERR_BADFORMAT" );
        return VLC_EGENERIC;
    }
    if( result == MMSYSERR_ALLOCATED )
    {
        msg_Warn( p_aout, "waveOutOpen failed WAVERR_ALLOCATED" );
        return VLC_EGENERIC;
    }
    if( result != MMSYSERR_NOERROR )
    {
        msg_Warn( p_aout, "waveOutOpen failed" );
        return VLC_EGENERIC;
    }

    p_aout->sys->chans_to_reorder =
        aout_CheckChannelReorder( pi_channels_in, pi_channels_out,
                                  waveformat.dwChannelMask,
                                  p_aout->sys->chan_table );
    if( p_aout->sys->chans_to_reorder )
        msg_Dbg( p_aout, "channel reordering needed" );
    p_aout->sys->format = i_format;

    return VLC_SUCCESS;

#undef waveformat

}

/*****************************************************************************
 * OpenWaveOutPCM: open a PCM waveout sound device
 ****************************************************************************/
static int OpenWaveOutPCM( audio_output_t *p_aout, uint32_t i_device_id,
                           vlc_fourcc_t *i_format,
                           int i_channels, int i_nb_channels, int i_rate,
                           bool b_probe )
{
    bool b_use_float32 = var_CreateGetBool( p_aout, "waveout-float32");

    if( !b_use_float32 || OpenWaveOut( p_aout, i_device_id, VLC_CODEC_FL32,
                                   i_channels, i_nb_channels, i_rate, b_probe )
        != VLC_SUCCESS )
    {
        if ( OpenWaveOut( p_aout, i_device_id, VLC_CODEC_S16N,
                          i_channels, i_nb_channels, i_rate, b_probe )
             != VLC_SUCCESS )
        {
            return VLC_EGENERIC;
        }
        else
        {
            *i_format = VLC_CODEC_S16N;
            return VLC_SUCCESS;
        }
    }
    else
    {
        *i_format = VLC_CODEC_FL32;
        return VLC_SUCCESS;
    }
}

/*****************************************************************************
 * PlayWaveOut: play a buffer through the WaveOut device
 *****************************************************************************/
static int PlayWaveOut( audio_output_t *p_aout, HWAVEOUT h_waveout,
                        struct lkwavehdr *p_waveheader, block_t *p_buffer, bool b_spdif)
{
    MMRESULT result;

    /* Prepare the buffer */
    if( p_buffer != NULL )
    {
        p_waveheader->hdr.lpData = (LPSTR)p_buffer->p_buffer;
        p_waveheader->hdr.dwBufferLength = p_buffer->i_buffer;
        /*
          copy the buffer to the silence buffer :) so in case we don't
          get the next buffer fast enough (I will repeat this one a time
          for AC3 / DTS and SPDIF this will sound better instead of
          a hickup)
        */
        if(b_spdif)
        {
           memcpy( p_aout->sys->p_silence_buffer,
                       p_buffer->p_buffer,
                       p_aout->sys->i_buffer_size );
           p_aout->sys->i_repeat_counter = 2;
        }
    } else {
        /* Use silence buffer instead */
        if(p_aout->sys->i_repeat_counter)
        {
           p_aout->sys->i_repeat_counter--;
           if(!p_aout->sys->i_repeat_counter)
           {
               memset( p_aout->sys->p_silence_buffer,
                           0x00, p_aout->sys->i_buffer_size );
           }
        }
        p_waveheader->hdr.lpData = (LPSTR)p_aout->sys->p_silence_buffer;
        p_waveheader->hdr.dwBufferLength = p_aout->sys->i_buffer_size;
    }

    p_waveheader->hdr.dwUser = p_buffer ? (DWORD_PTR)p_buffer : (DWORD_PTR)1;
    p_waveheader->hdr.dwFlags = 0;

    result = waveOutPrepareHeader( h_waveout, &p_waveheader->hdr, sizeof(WAVEHDR) );
    if( result != MMSYSERR_NOERROR )
    {
        msg_Err( p_aout, "waveOutPrepareHeader failed" );
        return VLC_EGENERIC;
    }

    /* Send the buffer to the waveOut queue */
    result = waveOutWrite( h_waveout, &p_waveheader->hdr, sizeof(WAVEHDR) );
    if( result != MMSYSERR_NOERROR )
    {
        msg_Err( p_aout, "waveOutWrite failed" );
        return VLC_EGENERIC;
    }

    return VLC_SUCCESS;
}

/*****************************************************************************
 * WaveOutCallback: what to do once WaveOut has played its sound samples
 *****************************************************************************/
static void CALLBACK WaveOutCallback( HWAVEOUT h_waveout, UINT uMsg,
                                      DWORD_PTR _p_aout,
                                      DWORD_PTR dwParam1, DWORD_PTR dwParam2 )
{
    (void) h_waveout;
    (void) dwParam2;
    audio_output_t *p_aout = (audio_output_t *)_p_aout;
    struct lkwavehdr * p_waveheader =  (struct lkwavehdr *) dwParam1;

    if( uMsg != WOM_DONE ) return;

    vlc_mutex_lock( &p_aout->sys->lock );
    p_waveheader->p_next = p_aout->sys->p_free_list;
    p_aout->sys->p_free_list = p_waveheader;
    p_aout->sys->i_frames--;
    vlc_cond_broadcast( &p_aout->sys->cond );
    vlc_mutex_unlock( &p_aout->sys->lock );
}

static void WaveOutClean( aout_sys_t * p_sys )
{
    struct lkwavehdr *p_whdr, *p_list;

    vlc_mutex_lock(&p_sys->lock);
    p_list =  p_sys->p_free_list;
    p_sys->p_free_list = NULL;
    vlc_mutex_unlock(&p_sys->lock);

    while( p_list )
    {
        p_whdr = p_list;
        p_list = p_list->p_next;
        WaveOutClearBuffer( p_sys->h_waveout, &p_whdr->hdr );
        free(p_whdr);
    }
}

static void WaveOutClearBuffer( HWAVEOUT h_waveout, WAVEHDR *p_waveheader )
{
    block_t *p_buffer = (block_t *)(p_waveheader->dwUser);
    /* Unprepare and free the buffers which has just been played */
    waveOutUnprepareHeader( h_waveout, p_waveheader, sizeof(WAVEHDR) );

    if( p_waveheader->dwUser != 1 )
        block_Release( p_buffer );
}

/*
  reload the configuration drop down list, of the Audio Devices
*/
static int ReloadWaveoutDevices( vlc_object_t *p_this, char const *psz_name,
                                 char ***values, char ***descs )
{
    int n = 0, nb_devices = waveOutGetNumDevs();

    VLC_UNUSED( p_this); VLC_UNUSED( psz_name );

    *values = xmalloc( (nb_devices + 1) * sizeof(char *) );
    *descs = xmalloc( (nb_devices + 1) * sizeof(char *) );

    (*values)[n] = strdup( "wavemapper" );
    (*descs)[n] = strdup( _("Microsoft Soundmapper") );
    n++;

    for(int i = 0; i < nb_devices; i++)
    {
        WAVEOUTCAPS caps;
        wchar_t dev_name[MAXPNAMELEN+32];

        if(waveOutGetDevCaps(i, &caps, sizeof(WAVEOUTCAPS))
                                                           != MMSYSERR_NOERROR)
            continue;

        _snwprintf(dev_name, MAXPNAMELEN + 32, device_name_fmt,
                   caps.szPname, caps.wMid, caps.wPid);
        (*values)[n] = FromWide( dev_name );
        (*descs)[n] = strdup( (*values)[n] );
        n++;
    }

    return n;
}

/*
  convert devicename to device ID for output
  if device not found return WAVE_MAPPER, so let
  windows decide which preferred audio device
  should be used.
*/
static uint32_t findDeviceID(char *psz_device_name)
{
    if( !psz_device_name )
       return WAVE_MAPPER;

    uint32_t wave_devices = waveOutGetNumDevs();

    for( uint32_t i = 0; i < wave_devices; i++ )
    {
        WAVEOUTCAPS caps;
        wchar_t dev_name[MAXPNAMELEN+32];

        if( waveOutGetDevCaps( i, &caps, sizeof(WAVEOUTCAPS) )
                                                          != MMSYSERR_NOERROR )
            continue;

        _snwprintf( dev_name, MAXPNAMELEN + 32, device_name_fmt,
                  caps.szPname, caps.wMid, caps.wPid );
        char *u8 = FromWide(dev_name);
        if( !stricmp(u8, psz_device_name) )
        {
            free( u8 );
            return i;
        }
        free( u8 );
    }

    return WAVE_MAPPER;
}

static int DeviceSelect (audio_output_t *aout, const char *id)
{
    var_SetString(aout, "waveout-audio-device", (id != NULL) ? id : "");
    aout_DeviceReport (aout, id);
    aout_RestartRequest (aout, AOUT_RESTART_OUTPUT);
    return 0;
}

static int Open(vlc_object_t *obj)
{
    audio_output_t *aout = (audio_output_t *)obj;
    aout_sys_t *sys = malloc(sizeof (*sys));

    if (unlikely(sys == NULL))
        return VLC_ENOMEM;
    aout->sys = sys;
    aout->start = Start;
    aout->stop = Stop;
    aout->volume_set = WaveoutVolumeSet;
    aout->mute_set = WaveoutMuteSet;
    aout->device_select = DeviceSelect;

    sys->f_volume = var_InheritFloat(aout, "waveout-volume");
    sys->b_mute = var_InheritBool(aout, "mute");

    aout_MuteReport(aout, sys->b_mute);
    aout_VolumeReport(aout, sys->f_volume );

    if( vlc_timer_create( &sys->volume_poll_timer,
                          WaveoutPollVolume, aout ) )
    {
        msg_Err( aout, "Couldn't create volume polling timer" );
        free( sys );
        return VLC_ENOMEM;
    }

    vlc_mutex_init( &sys->lock );
    vlc_cond_init( &sys->cond );

    /* WaveOut does not support hot-plug events so list devices at startup */
    char **ids, **names;
    int count = ReloadWaveoutDevices(VLC_OBJECT(aout), NULL, &ids, &names);
    if (count >= 0)
    {
        for (int i = 0; i < count; i++)
        {
            aout_HotplugReport(aout, ids[i], names[i]);
            free(names[i]);
            free(ids[i]);
        }
        free(names);
        free(ids);
    }

    char *dev = var_CreateGetNonEmptyString(aout, "waveout-audio-device");
    aout_DeviceReport(aout, dev);
    free(dev);

    return VLC_SUCCESS;
}

static void Close(vlc_object_t *obj)
{
    audio_output_t *aout = (audio_output_t *)obj;
    aout_sys_t *sys = aout->sys;

    var_Destroy(aout, "waveout-audio-device");

    vlc_timer_destroy( sys->volume_poll_timer );
    vlc_cond_destroy( &sys->cond );
    vlc_mutex_destroy( &sys->lock );

    free(sys);
}

static int WaveOutTimeGet(audio_output_t * p_aout, mtime_t *delay)
{
    MMTIME mmtime;
    mmtime.wType = TIME_SAMPLES;

    if( !p_aout->sys->i_frames )
        return -1;

    if( waveOutGetPosition( p_aout->sys->h_waveout, &mmtime, sizeof(MMTIME) )
            != MMSYSERR_NOERROR )
    {
        msg_Err( p_aout, "waveOutGetPosition failed");
        return -1;
    }

    mtime_t i_pos = (mtime_t) mmtime.u.sample * CLOCK_FREQ / p_aout->sys->i_rate;
    *delay = p_aout->sys->i_played_length - i_pos;
    return 0;
}

static void WaveOutFlush( audio_output_t *p_aout, bool wait)
{
    MMRESULT res;
    if( !wait )
    {
        res  = waveOutReset( p_aout->sys->h_waveout );
        p_aout->sys->i_played_length = 0;
        if( res != MMSYSERR_NOERROR )
            msg_Err( p_aout, "waveOutReset failed");
    }
    else
    {
        vlc_mutex_lock( &p_aout->sys->lock );
        while( p_aout->sys->i_frames )
        {
            vlc_cond_wait( &p_aout->sys->cond, &p_aout->sys-> lock );
        }
        vlc_mutex_unlock( &p_aout->sys->lock );
    }
}

static void WaveOutPause( audio_output_t * p_aout, bool pause, mtime_t date)
{
    MMRESULT res;
    (void) date;
    if(pause)
    {
        vlc_timer_schedule( p_aout->sys->volume_poll_timer, false, 1, 200000 );
        res = waveOutPause( p_aout->sys->h_waveout );
        if( res != MMSYSERR_NOERROR )
        {
            msg_Err( p_aout, "waveOutPause failed (0x%x)", res);
            return;
        }
    }
    else
    {
        vlc_timer_schedule( p_aout->sys->volume_poll_timer, false, 0, 0 );
        res = waveOutRestart( p_aout->sys->h_waveout );
        if( res != MMSYSERR_NOERROR )
        {
            msg_Err( p_aout, "waveOutRestart failed (0x%x)", res);
            return;
        }
    }
}

static int WaveoutVolumeSet( audio_output_t *p_aout, float volume )
{
    aout_sys_t *sys = p_aout->sys;

    if( sys->b_soft )
    {
        float gain = volume * volume * volume;
        if ( !sys->b_mute && aout_GainRequest( p_aout, gain ) )
            return -1;
    }
    else
    {
        const HWAVEOUT hwo = sys->h_waveout;

        uint32_t vol = lroundf( volume * 0x7fff.fp0 );

        if( !sys->b_mute )
        {
            if( vol > 0xffff )
            {
                vol = 0xffff;
                volume = 2.0f;
            }

            MMRESULT r = waveOutSetVolume( hwo, vol | ( vol << 16 ) );
            if( r != MMSYSERR_NOERROR )
            {
                msg_Err( p_aout, "waveOutSetVolume failed (%u)", r );
                return -1;
            }
        }
    }

    vlc_mutex_lock(&p_aout->sys->lock);
    sys->f_volume = volume;

    if( var_InheritBool( p_aout, "volume-save" ) )
        config_PutFloat( p_aout, "waveout-volume", volume );

    aout_VolumeReport( p_aout, volume );
    vlc_mutex_unlock(&p_aout->sys->lock);

    return 0;
}

static int WaveoutMuteSet( audio_output_t * p_aout, bool mute )
{
    aout_sys_t *sys = p_aout->sys;

    if( sys->b_soft )
    {
        float gain = sys->f_volume * sys->f_volume * sys->f_volume;
        if ( aout_GainRequest( p_aout, mute ? 0.f : gain ) )
            return -1;
    }
    else
    {

        const HWAVEOUT hwo = sys->h_waveout;
        uint32_t vol = mute ? 0 : lroundf( sys->f_volume * 0x7fff.fp0 );

        if( vol > 0xffff )
            vol = 0xffff;

        MMRESULT r = waveOutSetVolume( hwo, vol | ( vol << 16 ) );
        if( r != MMSYSERR_NOERROR )
        {
            msg_Err( p_aout, "waveOutSetVolume failed (%u)", r );
            return -1;
        }
    }

    vlc_mutex_lock(&p_aout->sys->lock);
    sys->b_mute = mute;
    aout_MuteReport( p_aout, mute );
    vlc_mutex_unlock(&p_aout->sys->lock);

    return 0;
}

static void WaveoutPollVolume( void * aout )
{
    audio_output_t * p_aout = (audio_output_t *) aout;
    uint32_t vol;

    MMRESULT r = waveOutGetVolume( p_aout->sys->h_waveout, (LPDWORD) &vol );

    if( r != MMSYSERR_NOERROR )
    {
        msg_Err( p_aout, "waveOutGetVolume failed (%u)", r );
        return;
    }

    float volume = (float) ( vol & UINT32_C( 0xffff ) );
    volume /= 0x7fff.fp0;

    vlc_mutex_lock(&p_aout->sys->lock);
    if( !p_aout->sys->b_mute && volume != p_aout->sys->f_volume )
    {
        p_aout->sys->f_volume = volume;

        if( var_InheritBool( p_aout, "volume-save" ) )
            config_PutFloat( p_aout, "waveout-volume", volume );

        aout_VolumeReport( p_aout, volume );
    }
    vlc_mutex_unlock(&p_aout->sys->lock);

    return;
}