Sweden-Number/dlls/winealsa.drv/alsa.c

/*
 * Copyright 2010 Maarten Lankhorst for CodeWeavers
 * Copyright 2011 Andrew Eikum for CodeWeavers
 * Copyright 2022 Huw Davies
 *
 * 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
 */
#if 0
#pragma makedep unix
#endif

#include "config.h"

#include <stdarg.h>
#include <stdio.h>
#include <pthread.h>

#include <alsa/asoundlib.h>

#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "winbase.h"
#include "winternl.h"
#include "mmdeviceapi.h"

#include "wine/debug.h"
#include "wine/list.h"
#include "wine/unixlib.h"

#include "initguid.h"
#include "unixlib.h"

WINE_DEFAULT_DEBUG_CHANNEL(alsa);

#define                     EXTRA_SAFE_RT   40000

static const WCHAR drv_keyW[] = {'S','o','f','t','w','a','r','e','\\',
    'W','i','n','e','\\','D','r','i','v','e','r','s','\\',
    'w','i','n','e','a','l','s','a','.','d','r','v'};

static inline void ascii_to_unicode( WCHAR *dst, const char *src, size_t len )
{
    while (len--) *dst++ = (unsigned char)*src++;
}

static HKEY reg_open_key( HKEY root, const WCHAR *name, ULONG name_len )
{
    UNICODE_STRING nameW = { name_len, name_len, (WCHAR *)name };
    OBJECT_ATTRIBUTES attr;
    HANDLE ret;

    attr.Length = sizeof(attr);
    attr.RootDirectory = root;
    attr.ObjectName = &nameW;
    attr.Attributes = 0;
    attr.SecurityDescriptor = NULL;
    attr.SecurityQualityOfService = NULL;

    if (NtOpenKeyEx( &ret, MAXIMUM_ALLOWED, &attr, 0 )) return 0;
    return ret;
}

static HKEY open_hkcu(void)
{
    char buffer[256];
    WCHAR bufferW[256];
    DWORD_PTR sid_data[(sizeof(TOKEN_USER) + SECURITY_MAX_SID_SIZE) / sizeof(DWORD_PTR)];
    DWORD i, len = sizeof(sid_data);
    SID *sid;

    if (NtQueryInformationToken( GetCurrentThreadEffectiveToken(), TokenUser, sid_data, len, &len ))
        return 0;

    sid = ((TOKEN_USER *)sid_data)->User.Sid;
    len = sprintf( buffer, "\\Registry\\User\\S-%u-%u", sid->Revision,
                 MAKELONG( MAKEWORD( sid->IdentifierAuthority.Value[5], sid->IdentifierAuthority.Value[4] ),
                           MAKEWORD( sid->IdentifierAuthority.Value[3], sid->IdentifierAuthority.Value[2] )));
    for (i = 0; i < sid->SubAuthorityCount; i++)
        len += sprintf( buffer + len, "-%u", sid->SubAuthority[i] );
    ascii_to_unicode( bufferW, buffer, len + 1 );

    return reg_open_key( NULL, bufferW, len * sizeof(WCHAR) );
}

static HKEY reg_open_hkcu_key( const WCHAR *name, ULONG name_len )
{
    HKEY hkcu = open_hkcu(), key;

    key = reg_open_key( hkcu, name, name_len );
    NtClose( hkcu );

    return key;
}

ULONG reg_query_value( HKEY hkey, const WCHAR *name,
                       KEY_VALUE_PARTIAL_INFORMATION *info, ULONG size )
{
    unsigned int name_size = name ? wcslen( name ) * sizeof(WCHAR) : 0;
    UNICODE_STRING nameW = { name_size, name_size, (WCHAR *)name };

    if (NtQueryValueKey( hkey, &nameW, KeyValuePartialInformation,
                         info, size, &size ))
        return 0;

    return size - FIELD_OFFSET(KEY_VALUE_PARTIAL_INFORMATION, Data);
}

static snd_pcm_stream_t alsa_get_direction(EDataFlow flow)
{
    return (flow == eRender) ? SND_PCM_STREAM_PLAYBACK : SND_PCM_STREAM_CAPTURE;
}

static WCHAR *strdupAtoW(const char *str)
{
    unsigned int len;
    WCHAR *ret;

    if(!str) return NULL;

    len = strlen(str) + 1;
    ret = malloc(len * sizeof(WCHAR));
    if(ret) ntdll_umbstowcs(str, len, ret, len);
    return ret;
}

/* copied from kernelbase */
static int muldiv( int a, int b, int c )
{
    LONGLONG ret;

    if (!c) return -1;

    /* We want to deal with a positive divisor to simplify the logic. */
    if (c < 0)
    {
        a = -a;
        c = -c;
    }

    /* If the result is positive, we "add" to round. else, we subtract to round. */
    if ((a < 0 && b < 0) || (a >= 0 && b >= 0))
        ret = (((LONGLONG)a * b) + (c / 2)) / c;
    else
        ret = (((LONGLONG)a * b) - (c / 2)) / c;

    if (ret > 2147483647 || ret < -2147483647) return -1;
    return ret;
}

static void alsa_lock(struct alsa_stream *stream)
{
    pthread_mutex_lock(&stream->lock);
}

static void alsa_unlock(struct alsa_stream *stream)
{
    pthread_mutex_unlock(&stream->lock);
}

static NTSTATUS alsa_unlock_result(struct alsa_stream *stream,
                                   HRESULT *result, HRESULT value)
{
    *result = value;
    alsa_unlock(stream);
    return STATUS_SUCCESS;
}

static BOOL alsa_try_open(const char *devnode, EDataFlow flow)
{
    snd_pcm_t *handle;
    int err;

    TRACE("devnode: %s, flow: %d\n", devnode, flow);

    if((err = snd_pcm_open(&handle, devnode, alsa_get_direction(flow), SND_PCM_NONBLOCK)) < 0){
        WARN("The device \"%s\" failed to open: %d (%s).\n", devnode, err, snd_strerror(err));
        return FALSE;
    }

    snd_pcm_close(handle);
    return TRUE;
}

static WCHAR *construct_device_id(EDataFlow flow, const WCHAR *chunk1, const WCHAR *chunk2)
{
    WCHAR *ret;
    const WCHAR *prefix;
    size_t len_wchars = 0, chunk1_len = 0, chunk2_len = 0, copied = 0, prefix_len;

    static const WCHAR dashW[] = {' ','-',' ',0};
    static const size_t dashW_len = ARRAY_SIZE(dashW) - 1;
    static const WCHAR outW[] = {'O','u','t',':',' ',0};
    static const WCHAR inW[] = {'I','n',':',' ',0};

    if(flow == eRender){
        prefix = outW;
        prefix_len = ARRAY_SIZE(outW) - 1;
        len_wchars += prefix_len;
    }else{
        prefix = inW;
        prefix_len = ARRAY_SIZE(inW) - 1;
        len_wchars += prefix_len;
    }
    if(chunk1){
        chunk1_len = wcslen(chunk1);
        len_wchars += chunk1_len;
    }
    if(chunk1 && chunk2)
        len_wchars += dashW_len;
    if(chunk2){
        chunk2_len = wcslen(chunk2);
        len_wchars += chunk2_len;
    }
    len_wchars += 1; /* NULL byte */

    ret = malloc(len_wchars * sizeof(WCHAR));

    memcpy(ret, prefix, prefix_len * sizeof(WCHAR));
    copied += prefix_len;
    if(chunk1){
        memcpy(ret + copied, chunk1, chunk1_len * sizeof(WCHAR));
        copied += chunk1_len;
    }
    if(chunk1 && chunk2){
        memcpy(ret + copied, dashW, dashW_len * sizeof(WCHAR));
        copied += dashW_len;
    }
    if(chunk2){
        memcpy(ret + copied, chunk2, chunk2_len * sizeof(WCHAR));
        copied += chunk2_len;
    }
    ret[copied] = 0;

    TRACE("Enumerated device: %s\n", wine_dbgstr_w(ret));

    return ret;
}

struct endpoints_info
{
    unsigned int num, size;
    struct endpoint *endpoints;
};

static void endpoints_add(struct endpoints_info *endpoints, WCHAR *name, char *device)
{
    if(endpoints->num >= endpoints->size){
        if (!endpoints->size) endpoints->size = 16;
        else endpoints->size *= 2;
        endpoints->endpoints = realloc(endpoints->endpoints, endpoints->size * sizeof(*endpoints->endpoints));
    }

    endpoints->endpoints[endpoints->num].name = name;
    endpoints->endpoints[endpoints->num++].device = device;
}

static HRESULT alsa_get_card_devices(EDataFlow flow, struct endpoints_info *endpoints_info,
                                     snd_ctl_t *ctl, int card, const WCHAR *cardname)
{
    int err, device;
    snd_pcm_info_t *info;

    info = calloc(1, snd_pcm_info_sizeof());
    if(!info)
        return E_OUTOFMEMORY;

    snd_pcm_info_set_subdevice(info, 0);
    snd_pcm_info_set_stream(info, alsa_get_direction(flow));

    device = -1;
    for(err = snd_ctl_pcm_next_device(ctl, &device); device != -1 && err >= 0;
            err = snd_ctl_pcm_next_device(ctl, &device)){
        char devnode[32];
        WCHAR *devname;

        snd_pcm_info_set_device(info, device);

        if((err = snd_ctl_pcm_info(ctl, info)) < 0){
            if(err == -ENOENT)
                /* This device doesn't have the right stream direction */
                continue;

            WARN("Failed to get info for card %d, device %d: %d (%s)\n",
                    card, device, err, snd_strerror(err));
            continue;
        }

        sprintf(devnode, "plughw:%d,%d", card, device);
        if(!alsa_try_open(devnode, flow))
            continue;

        devname = strdupAtoW(snd_pcm_info_get_name(info));
        if(!devname){
            WARN("Unable to get device name for card %d, device %d\n", card, device);
            continue;
        }

        endpoints_add(endpoints_info, construct_device_id(flow, cardname, devname), strdup(devnode));
        free(devname);
    }

    free(info);

    if(err != 0)
        WARN("Got a failure during device enumeration on card %d: %d (%s)\n",
                card, err, snd_strerror(err));

    return S_OK;
}

static void get_reg_devices(EDataFlow flow, struct endpoints_info *endpoints_info)
{
    static const WCHAR ALSAOutputDevices[] = {'A','L','S','A','O','u','t','p','u','t','D','e','v','i','c','e','s',0};
    static const WCHAR ALSAInputDevices[] = {'A','L','S','A','I','n','p','u','t','D','e','v','i','c','e','s',0};
    char buffer[4096];
    KEY_VALUE_PARTIAL_INFORMATION *key_info = (void *)buffer;
    HKEY key;
    DWORD size;
    const WCHAR *value_name = (flow == eRender) ? ALSAOutputDevices : ALSAInputDevices;

    /* @@ Wine registry key: HKCU\Software\Wine\Drivers\winealsa.drv */
    if((key = reg_open_hkcu_key(drv_keyW, sizeof(drv_keyW)))){
        if((size = reg_query_value(key, value_name, key_info, sizeof(buffer)))){
            WCHAR *p = (WCHAR *)key_info->Data;

            if(key_info->Type != REG_MULTI_SZ){
                ERR("Registry ALSA device list value type must be REG_MULTI_SZ\n");
                NtClose(key);
                return;
            }

            while(*p){
                int len = wcslen(p);
                char *devname = malloc(len * 3 + 1);

                ntdll_wcstoumbs(p, len + 1, devname, len * 3 + 1, FALSE);

                if(alsa_try_open(devname, flow))
                    endpoints_add(endpoints_info, construct_device_id(flow, p, NULL), strdup(devname));

                free(devname);
                p += len + 1;
            }
        }

        NtClose(key);
    }
}

struct card_type {
    struct list entry;
    int first_card_number;
    char string[1];
};

static struct list card_types = LIST_INIT(card_types);

static BOOL need_card_number(int card, const char *string)
{
    struct card_type *cptr;

    LIST_FOR_EACH_ENTRY(cptr, &card_types, struct card_type, entry)
    {
        if(!strcmp(string, cptr->string))
            return card != cptr->first_card_number;
    }

    /* this is the first instance of string */
    cptr = malloc(sizeof(struct card_type) + strlen(string));
    if(!cptr)
        /* Default to displaying card number if we can't track cards */
        return TRUE;

    cptr->first_card_number = card;
    strcpy(cptr->string, string);
    list_add_head(&card_types, &cptr->entry);
    return FALSE;
}

static WCHAR *alsa_get_card_name(int card)
{
    char *cardname;
    WCHAR *ret;
    int err;

    if((err = snd_card_get_name(card, &cardname)) < 0){
        /* FIXME: Should be localized */
        WARN("Unable to get card name for ALSA device %d: %d (%s)\n", card, err, snd_strerror(err));
        cardname = strdup("Unknown soundcard");
    }

    if(need_card_number(card, cardname)){
        char *cardnameN;
        /*
         * For identical card names, second and subsequent instances get
         * card number prefix to distinguish them (like Windows).
         */
        if(asprintf(&cardnameN, "%u-%s", card, cardname) > 0){
            free(cardname);
            cardname = cardnameN;
        }
    }

    ret = strdupAtoW(cardname);
    free(cardname);

    return ret;
}

static NTSTATUS get_endpoint_ids(void *args)
{
    static const WCHAR defaultW[] = {'d','e','f','a','u','l','t',0};
    struct get_endpoint_ids_params *params = args;
    struct endpoints_info endpoints_info;
    unsigned int i, needed, name_len, device_len;
    struct endpoint *endpoint;
    int err, card;
    char *ptr;

    card = -1;

    endpoints_info.num = endpoints_info.size = 0;
    endpoints_info.endpoints = NULL;

    if(alsa_try_open("default", params->flow))
        endpoints_add(&endpoints_info, construct_device_id(params->flow, defaultW, NULL), strdup("default"));

    get_reg_devices(params->flow, &endpoints_info);

    for(err = snd_card_next(&card); card != -1 && err >= 0; err = snd_card_next(&card)){
        char cardpath[64];
        WCHAR *cardname;
        snd_ctl_t *ctl;

        sprintf(cardpath, "hw:%u", card);

        if((err = snd_ctl_open(&ctl, cardpath, 0)) < 0){
            WARN("Unable to open ctl for ALSA device %s: %d (%s)\n", cardpath,
                    err, snd_strerror(err));
            continue;
        }

        cardname = alsa_get_card_name(card);
        alsa_get_card_devices(params->flow, &endpoints_info, ctl, card, cardname);
        free(cardname);

        snd_ctl_close(ctl);
    }

    if(err != 0)
        WARN("Got a failure during card enumeration: %d (%s)\n", err, snd_strerror(err));

    needed = endpoints_info.num * sizeof(*params->endpoints);
    endpoint = params->endpoints;
    ptr = (char *)(endpoint + endpoints_info.num);

    for(i = 0; i < endpoints_info.num; i++){
        name_len = wcslen(endpoints_info.endpoints[i].name) + 1;
        device_len = strlen(endpoints_info.endpoints[i].device) + 1;
        needed += name_len * sizeof(WCHAR) + ((device_len + 1) & ~1);

        if(needed <= params->size){
            endpoint->name = (WCHAR *)ptr;
            memcpy(endpoint->name, endpoints_info.endpoints[i].name, name_len * sizeof(WCHAR));
            ptr += name_len * sizeof(WCHAR);
            endpoint->device = ptr;
            memcpy(endpoint->device, endpoints_info.endpoints[i].device, device_len);
            ptr += (device_len + 1) & ~1;
            endpoint++;
        }
        free(endpoints_info.endpoints[i].name);
        free(endpoints_info.endpoints[i].device);
    }
    free(endpoints_info.endpoints);

    params->num = endpoints_info.num;
    params->default_idx = 0;

    if(needed > params->size){
        params->size = needed;
        params->result = HRESULT_FROM_WIN32(ERROR_INSUFFICIENT_BUFFER);
    } else
        params->result = S_OK;

    return STATUS_SUCCESS;
}

static WAVEFORMATEXTENSIBLE *clone_format(const WAVEFORMATEX *fmt)
{
    WAVEFORMATEXTENSIBLE *ret;
    size_t size;

    if(fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE)
        size = sizeof(WAVEFORMATEXTENSIBLE);
    else
        size = sizeof(WAVEFORMATEX);

    ret = malloc(size);
    if(!ret)
        return NULL;

    memcpy(ret, fmt, size);

    ret->Format.cbSize = size - sizeof(WAVEFORMATEX);

    return ret;
}

static HRESULT alsa_open_device(const char *alsa_name, EDataFlow flow, snd_pcm_t **pcm_handle,
                                snd_pcm_hw_params_t **hw_params)
{
    snd_pcm_stream_t pcm_stream;
    int err;

    if(flow == eRender)
        pcm_stream = SND_PCM_STREAM_PLAYBACK;
    else if(flow == eCapture)
        pcm_stream = SND_PCM_STREAM_CAPTURE;
    else
        return E_UNEXPECTED;

    err = snd_pcm_open(pcm_handle, alsa_name, pcm_stream, SND_PCM_NONBLOCK);
    if(err < 0){
        WARN("Unable to open PCM \"%s\": %d (%s)\n", alsa_name, err, snd_strerror(err));
        switch(err){
        case -EBUSY:
            return AUDCLNT_E_DEVICE_IN_USE;
        default:
            return AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        }
    }

    *hw_params = malloc(snd_pcm_hw_params_sizeof());
    if(!*hw_params){
        snd_pcm_close(*pcm_handle);
        return E_OUTOFMEMORY;
    }

    return S_OK;
}

static snd_pcm_format_t alsa_format(const WAVEFORMATEX *fmt)
{
    snd_pcm_format_t format = SND_PCM_FORMAT_UNKNOWN;
    const WAVEFORMATEXTENSIBLE *fmtex = (const WAVEFORMATEXTENSIBLE *)fmt;

    if(fmt->wFormatTag == WAVE_FORMAT_PCM ||
      (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
       IsEqualGUID(&fmtex->SubFormat, &KSDATAFORMAT_SUBTYPE_PCM))){
        if(fmt->wBitsPerSample == 8)
            format = SND_PCM_FORMAT_U8;
        else if(fmt->wBitsPerSample == 16)
            format = SND_PCM_FORMAT_S16_LE;
        else if(fmt->wBitsPerSample == 24)
            format = SND_PCM_FORMAT_S24_3LE;
        else if(fmt->wBitsPerSample == 32)
            format = SND_PCM_FORMAT_S32_LE;
        else
            WARN("Unsupported bit depth: %u\n", fmt->wBitsPerSample);
        if(fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
           fmt->wBitsPerSample != fmtex->Samples.wValidBitsPerSample){
            if(fmtex->Samples.wValidBitsPerSample == 20 && fmt->wBitsPerSample == 24)
                format = SND_PCM_FORMAT_S20_3LE;
            else
                WARN("Unsupported ValidBits: %u\n", fmtex->Samples.wValidBitsPerSample);
        }
    }else if(fmt->wFormatTag == WAVE_FORMAT_IEEE_FLOAT ||
            (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
             IsEqualGUID(&fmtex->SubFormat, &KSDATAFORMAT_SUBTYPE_IEEE_FLOAT))){
        if(fmt->wBitsPerSample == 32)
            format = SND_PCM_FORMAT_FLOAT_LE;
        else if(fmt->wBitsPerSample == 64)
            format = SND_PCM_FORMAT_FLOAT64_LE;
        else
            WARN("Unsupported float size: %u\n", fmt->wBitsPerSample);
    }else
        WARN("Unknown wave format: %04x\n", fmt->wFormatTag);
    return format;
}

static int alsa_channel_index(DWORD flag)
{
    switch(flag){
    case SPEAKER_FRONT_LEFT:
        return 0;
    case SPEAKER_FRONT_RIGHT:
        return 1;
    case SPEAKER_BACK_LEFT:
        return 2;
    case SPEAKER_BACK_RIGHT:
        return 3;
    case SPEAKER_FRONT_CENTER:
        return 4;
    case SPEAKER_LOW_FREQUENCY:
        return 5;
    case SPEAKER_SIDE_LEFT:
        return 6;
    case SPEAKER_SIDE_RIGHT:
        return 7;
    }
    return -1;
}

static BOOL need_remapping(const WAVEFORMATEX *fmt, int *map)
{
    unsigned int i;
    for(i = 0; i < fmt->nChannels; ++i){
        if(map[i] != i)
            return TRUE;
    }
    return FALSE;
}

static DWORD get_channel_mask(unsigned int channels)
{
    switch(channels){
    case 0:
        return 0;
    case 1:
        return KSAUDIO_SPEAKER_MONO;
    case 2:
        return KSAUDIO_SPEAKER_STEREO;
    case 3:
        return KSAUDIO_SPEAKER_STEREO | SPEAKER_LOW_FREQUENCY;
    case 4:
        return KSAUDIO_SPEAKER_QUAD;    /* not _SURROUND */
    case 5:
        return KSAUDIO_SPEAKER_QUAD | SPEAKER_LOW_FREQUENCY;
    case 6:
        return KSAUDIO_SPEAKER_5POINT1; /* not 5POINT1_SURROUND */
    case 7:
        return KSAUDIO_SPEAKER_5POINT1 | SPEAKER_BACK_CENTER;
    case 8:
        return KSAUDIO_SPEAKER_7POINT1_SURROUND; /* Vista deprecates 7POINT1 */
    }
    FIXME("Unknown speaker configuration: %u\n", channels);
    return 0;
}

static HRESULT map_channels(EDataFlow flow, const WAVEFORMATEX *fmt, int *alsa_channels, int *map)
{
    BOOL need_remap;

    if(flow != eCapture && (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE || fmt->nChannels > 2) ){
        WAVEFORMATEXTENSIBLE *fmtex = (void*)fmt;
        DWORD mask, flag = SPEAKER_FRONT_LEFT;
        UINT i = 0;

        if(fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
                fmtex->dwChannelMask != 0)
            mask = fmtex->dwChannelMask;
        else
            mask = get_channel_mask(fmt->nChannels);

        *alsa_channels = 0;

        while(i < fmt->nChannels && !(flag & SPEAKER_RESERVED)){
            if(mask & flag){
                map[i] = alsa_channel_index(flag);
                TRACE("Mapping mmdevapi channel %u (0x%x) to ALSA channel %d\n",
                        i, flag, map[i]);
                if(map[i] >= *alsa_channels)
                    *alsa_channels = map[i] + 1;
                ++i;
            }
            flag <<= 1;
        }

        while(i < fmt->nChannels){
            map[i] = *alsa_channels;
            TRACE("Mapping mmdevapi channel %u to ALSA channel %d\n",
                    i, map[i]);
            ++*alsa_channels;
            ++i;
        }

        for(i = 0; i < fmt->nChannels; ++i){
            if(map[i] == -1){
                map[i] = *alsa_channels;
                ++*alsa_channels;
                TRACE("Remapping mmdevapi channel %u to ALSA channel %d\n",
                        i, map[i]);
            }
        }

        need_remap = need_remapping(fmt, map);
    }else{
        *alsa_channels = fmt->nChannels;

        need_remap = FALSE;
    }

    TRACE("need_remapping: %u, alsa_channels: %d\n", need_remap, *alsa_channels);

    return need_remap ? S_OK : S_FALSE;
}

static void silence_buffer(struct alsa_stream *stream, BYTE *buffer, UINT32 frames)
{
    WAVEFORMATEXTENSIBLE *fmtex = (WAVEFORMATEXTENSIBLE*)stream->fmt;
    if((stream->fmt->wFormatTag == WAVE_FORMAT_PCM ||
            (stream->fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
             IsEqualGUID(&fmtex->SubFormat, &KSDATAFORMAT_SUBTYPE_PCM))) &&
            stream->fmt->wBitsPerSample == 8)
        memset(buffer, 128, frames * stream->fmt->nBlockAlign);
    else
        memset(buffer, 0, frames * stream->fmt->nBlockAlign);
}

static NTSTATUS create_stream(void *args)
{
    struct create_stream_params *params = args;
    struct alsa_stream *stream;
    snd_pcm_sw_params_t *sw_params = NULL;
    snd_pcm_format_t format;
    unsigned int rate, alsa_period_us, i;
    WAVEFORMATEXTENSIBLE *fmtex;
    int err;
    SIZE_T size;

    stream = calloc(1, sizeof(*stream));
    if(!stream){
        params->result = E_OUTOFMEMORY;
        return STATUS_SUCCESS;
    }

    params->result = alsa_open_device(params->alsa_name, params->flow, &stream->pcm_handle, &stream->hw_params);
    if(FAILED(params->result)){
        free(stream);
        return STATUS_SUCCESS;
    }

    stream->need_remapping = map_channels(params->flow, params->fmt, &stream->alsa_channels, stream->alsa_channel_map) == S_OK;

    if((err = snd_pcm_hw_params_any(stream->pcm_handle, stream->hw_params)) < 0){
        WARN("Unable to get hw_params: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    if((err = snd_pcm_hw_params_set_access(stream->pcm_handle, stream->hw_params,
                SND_PCM_ACCESS_RW_INTERLEAVED)) < 0){
        WARN("Unable to set access: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    format = alsa_format(params->fmt);
    if (format == SND_PCM_FORMAT_UNKNOWN){
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;
        goto exit;
    }

    if((err = snd_pcm_hw_params_set_format(stream->pcm_handle, stream->hw_params,
                format)) < 0){
        WARN("Unable to set ALSA format to %u: %d (%s)\n", format, err,
                snd_strerror(err));
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;
        goto exit;
    }

    stream->alsa_format = format;
    stream->flow = params->flow;

    rate = params->fmt->nSamplesPerSec;
    if((err = snd_pcm_hw_params_set_rate_near(stream->pcm_handle, stream->hw_params,
                &rate, NULL)) < 0){
        WARN("Unable to set rate to %u: %d (%s)\n", rate, err,
                snd_strerror(err));
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;
        goto exit;
    }

    if((err = snd_pcm_hw_params_set_channels(stream->pcm_handle, stream->hw_params,
               stream->alsa_channels)) < 0){
        WARN("Unable to set channels to %u: %d (%s)\n", params->fmt->nChannels, err,
                snd_strerror(err));
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;
        goto exit;
    }

    stream->mmdev_period_rt = params->period;
    alsa_period_us = stream->mmdev_period_rt / 10;
    if((err = snd_pcm_hw_params_set_period_time_near(stream->pcm_handle,
                stream->hw_params, &alsa_period_us, NULL)) < 0)
        WARN("Unable to set period time near %u: %d (%s)\n", alsa_period_us,
                err, snd_strerror(err));
    /* ALSA updates the output variable alsa_period_us */

    stream->mmdev_period_frames = muldiv(params->fmt->nSamplesPerSec,
            stream->mmdev_period_rt, 10000000);

    /* Buffer 4 ALSA periods if large enough, else 4 mmdevapi periods */
    stream->alsa_bufsize_frames = stream->mmdev_period_frames * 4;
    if(err < 0 || alsa_period_us < params->period / 10)
        err = snd_pcm_hw_params_set_buffer_size_near(stream->pcm_handle,
                stream->hw_params, &stream->alsa_bufsize_frames);
    else{
        unsigned int periods = 4;
        err = snd_pcm_hw_params_set_periods_near(stream->pcm_handle, stream->hw_params, &periods, NULL);
    }
    if(err < 0)
        WARN("Unable to set buffer size: %d (%s)\n", err, snd_strerror(err));

    if((err = snd_pcm_hw_params(stream->pcm_handle, stream->hw_params)) < 0){
        WARN("Unable to set hw params: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    if((err = snd_pcm_hw_params_get_period_size(stream->hw_params,
                    &stream->alsa_period_frames, NULL)) < 0){
        WARN("Unable to get period size: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    if((err = snd_pcm_hw_params_get_buffer_size(stream->hw_params,
                    &stream->alsa_bufsize_frames)) < 0){
        WARN("Unable to get buffer size: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    sw_params = calloc(1, snd_pcm_sw_params_sizeof());
    if(!sw_params){
        params->result = E_OUTOFMEMORY;
        goto exit;
    }

    if((err = snd_pcm_sw_params_current(stream->pcm_handle, sw_params)) < 0){
        WARN("Unable to get sw_params: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    if((err = snd_pcm_sw_params_set_start_threshold(stream->pcm_handle,
                    sw_params, 1)) < 0){
        WARN("Unable set start threshold to 1: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    if((err = snd_pcm_sw_params_set_stop_threshold(stream->pcm_handle,
                    sw_params, stream->alsa_bufsize_frames)) < 0){
        WARN("Unable set stop threshold to %lu: %d (%s)\n",
                stream->alsa_bufsize_frames, err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    if((err = snd_pcm_sw_params(stream->pcm_handle, sw_params)) < 0){
        WARN("Unable to set sw params: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    if((err = snd_pcm_prepare(stream->pcm_handle)) < 0){
        WARN("Unable to prepare device: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_ENDPOINT_CREATE_FAILED;
        goto exit;
    }

    /* Bear in mind weird situations where
     * ALSA period (50ms) > mmdevapi buffer (3x10ms)
     * or surprising rounding as seen with 22050x8x1 with Pulse:
     * ALSA period 220 vs.  221 frames in mmdevapi and
     *      buffer 883 vs. 2205 frames in mmdevapi! */
    stream->bufsize_frames = muldiv(params->duration, params->fmt->nSamplesPerSec, 10000000);
    if(params->share == AUDCLNT_SHAREMODE_EXCLUSIVE)
        stream->bufsize_frames -= stream->bufsize_frames % stream->mmdev_period_frames;
    stream->hidden_frames = stream->alsa_period_frames + stream->mmdev_period_frames +
        muldiv(params->fmt->nSamplesPerSec, EXTRA_SAFE_RT, 10000000);
    /* leave no less than about 1.33ms or 256 bytes of data after a rewind */
    stream->safe_rewind_frames = max(256 / params->fmt->nBlockAlign, muldiv(133, params->fmt->nSamplesPerSec, 100000));

    /* Check if the ALSA buffer is so small that it will run out before
     * the next MMDevAPI period tick occurs. Allow a little wiggle room
     * with 120% of the period time. */
    if(stream->alsa_bufsize_frames < 1.2 * stream->mmdev_period_frames)
        FIXME("ALSA buffer time is too small. Expect underruns. (%lu < %u * 1.2)\n",
                stream->alsa_bufsize_frames, stream->mmdev_period_frames);

    fmtex = clone_format(params->fmt);
    if(!fmtex){
        params->result = E_OUTOFMEMORY;
        goto exit;
    }
    stream->fmt = &fmtex->Format;

    size = stream->bufsize_frames * params->fmt->nBlockAlign;
    if(NtAllocateVirtualMemory(GetCurrentProcess(), (void **)&stream->local_buffer, 0, &size,
                               MEM_COMMIT, PAGE_READWRITE)){
        params->result = E_OUTOFMEMORY;
        goto exit;
    }
    silence_buffer(stream, stream->local_buffer, stream->bufsize_frames);

    stream->silence_buf = malloc(stream->alsa_period_frames * stream->fmt->nBlockAlign);
    if(!stream->silence_buf){
        params->result = E_OUTOFMEMORY;
        goto exit;
    }
    silence_buffer(stream, stream->silence_buf, stream->alsa_period_frames);

    stream->vols = malloc(params->fmt->nChannels * sizeof(float));
    if(!stream->vols){
        params->result = E_OUTOFMEMORY;
        goto exit;
    }
    for(i = 0; i < params->fmt->nChannels; ++i)
        stream->vols[i] = 1.f;

    stream->share = params->share;
    stream->flags = params->flags;

    pthread_mutex_init(&stream->lock, NULL);

    TRACE("ALSA period: %lu frames\n", stream->alsa_period_frames);
    TRACE("ALSA buffer: %lu frames\n", stream->alsa_bufsize_frames);
    TRACE("MMDevice period: %u frames\n", stream->mmdev_period_frames);
    TRACE("MMDevice buffer: %u frames\n", stream->bufsize_frames);

exit:
    free(sw_params);
    if(FAILED(params->result)){
        snd_pcm_close(stream->pcm_handle);
        if(stream->local_buffer){
            size = 0;
            NtFreeVirtualMemory(GetCurrentProcess(), (void **)&stream->local_buffer, &size, MEM_RELEASE);
        }
        free(stream->silence_buf);
        free(stream->hw_params);
        free(stream->fmt);
        free(stream->vols);
        free(stream);
    }else{
        *params->stream = stream;
    }

    return STATUS_SUCCESS;
}

static NTSTATUS release_stream(void *args)
{
    struct release_stream_params *params = args;
    struct alsa_stream *stream = params->stream;
    SIZE_T size;

    snd_pcm_drop(stream->pcm_handle);
    snd_pcm_close(stream->pcm_handle);
    if(stream->local_buffer){
        size = 0;
        NtFreeVirtualMemory(GetCurrentProcess(), (void **)&stream->local_buffer, &size, MEM_RELEASE);
    }
    if(stream->tmp_buffer){
        size = 0;
        NtFreeVirtualMemory(GetCurrentProcess(), (void **)&stream->tmp_buffer, &size, MEM_RELEASE);
    }
    /* free(stream->remapping_buf); */
    free(stream->silence_buf);
    free(stream->hw_params);
    free(stream->fmt);
    free(stream->vols);
    pthread_mutex_destroy(&stream->lock);
    free(stream);

    params->result = S_OK;
    return STATUS_SUCCESS;
}

static NTSTATUS is_format_supported(void *args)
{
    struct is_format_supported_params *params = args;
    const WAVEFORMATEXTENSIBLE *fmtex = (const WAVEFORMATEXTENSIBLE *)params->fmt_in;
    snd_pcm_t *pcm_handle;
    snd_pcm_hw_params_t *hw_params;
    snd_pcm_format_mask_t *formats = NULL;
    snd_pcm_format_t format;
    WAVEFORMATEXTENSIBLE *closest = NULL;
    unsigned int max = 0, min = 0;
    int err;
    int alsa_channels, alsa_channel_map[32];

    params->result = S_OK;

    if(!params->fmt_in || (params->share == AUDCLNT_SHAREMODE_SHARED && !params->fmt_out))
        params->result = E_POINTER;
    else if(params->share != AUDCLNT_SHAREMODE_SHARED && params->share != AUDCLNT_SHAREMODE_EXCLUSIVE)
        params->result = E_INVALIDARG;
    else if(params->fmt_in->wFormatTag == WAVE_FORMAT_EXTENSIBLE){
        if(params->fmt_in->cbSize < sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX))
            params->result = E_INVALIDARG;
        else if(params->fmt_in->nAvgBytesPerSec == 0 || params->fmt_in->nBlockAlign == 0 ||
                (fmtex->Samples.wValidBitsPerSample > params->fmt_in->wBitsPerSample))
            params->result = E_INVALIDARG;
    }
    if(FAILED(params->result))
        return STATUS_SUCCESS;

    if(params->fmt_in->nChannels == 0){
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;
        return STATUS_SUCCESS;
    }

    params->result = alsa_open_device(params->alsa_name, params->flow, &pcm_handle, &hw_params);
    if(FAILED(params->result))
        return STATUS_SUCCESS;

    if((err = snd_pcm_hw_params_any(pcm_handle, hw_params)) < 0){
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        goto exit;
    }

    formats = calloc(1, snd_pcm_format_mask_sizeof());
    if(!formats){
        params->result = E_OUTOFMEMORY;
        goto exit;
    }

    snd_pcm_hw_params_get_format_mask(hw_params, formats);
    format = alsa_format(params->fmt_in);
    if (format == SND_PCM_FORMAT_UNKNOWN ||
        !snd_pcm_format_mask_test(formats, format)){
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;
        goto exit;
    }

    closest = clone_format(params->fmt_in);
    if(!closest){
        params->result = E_OUTOFMEMORY;
        goto exit;
    }

    if((err = snd_pcm_hw_params_get_rate_min(hw_params, &min, NULL)) < 0){
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        WARN("Unable to get min rate: %d (%s)\n", err, snd_strerror(err));
        goto exit;
    }

    if((err = snd_pcm_hw_params_get_rate_max(hw_params, &max, NULL)) < 0){
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        WARN("Unable to get max rate: %d (%s)\n", err, snd_strerror(err));
        goto exit;
    }

    if(params->fmt_in->nSamplesPerSec < min || params->fmt_in->nSamplesPerSec > max){
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;
        goto exit;
    }

    if((err = snd_pcm_hw_params_get_channels_min(hw_params, &min)) < 0){
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        WARN("Unable to get min channels: %d (%s)\n", err, snd_strerror(err));
        goto exit;
    }

    if((err = snd_pcm_hw_params_get_channels_max(hw_params, &max)) < 0){
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        WARN("Unable to get max channels: %d (%s)\n", err, snd_strerror(err));
        goto exit;
    }
    if(params->fmt_in->nChannels > max){
        params->result = S_FALSE;
        closest->Format.nChannels = max;
    }else if(params->fmt_in->nChannels < min){
        params->result = S_FALSE;
        closest->Format.nChannels = min;
    }

    map_channels(params->flow, params->fmt_in, &alsa_channels, alsa_channel_map);

    if(alsa_channels > max){
        params->result = S_FALSE;
        closest->Format.nChannels = max;
    }

    if(closest->Format.wFormatTag == WAVE_FORMAT_EXTENSIBLE)
        closest->dwChannelMask = get_channel_mask(closest->Format.nChannels);

    if(params->fmt_in->nBlockAlign != params->fmt_in->nChannels * params->fmt_in->wBitsPerSample / 8 ||
       params->fmt_in->nAvgBytesPerSec != params->fmt_in->nBlockAlign * params->fmt_in->nSamplesPerSec ||
       (params->fmt_in->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
        fmtex->Samples.wValidBitsPerSample < params->fmt_in->wBitsPerSample))
        params->result = S_FALSE;

    if(params->share == AUDCLNT_SHAREMODE_EXCLUSIVE && params->fmt_in->wFormatTag == WAVE_FORMAT_EXTENSIBLE){
        if(fmtex->dwChannelMask == 0 || fmtex->dwChannelMask & SPEAKER_RESERVED)
            params->result = S_FALSE;
    }

exit:
    if(params->result == S_FALSE && !params->fmt_out)
        params->result = AUDCLNT_E_UNSUPPORTED_FORMAT;

    if(params->result == S_FALSE && params->fmt_out) {
        closest->Format.nBlockAlign = closest->Format.nChannels * closest->Format.wBitsPerSample / 8;
        closest->Format.nAvgBytesPerSec = closest->Format.nBlockAlign * closest->Format.nSamplesPerSec;
        if(closest->Format.wFormatTag == WAVE_FORMAT_EXTENSIBLE)
            closest->Samples.wValidBitsPerSample = closest->Format.wBitsPerSample;
        memcpy(params->fmt_out, closest, closest->Format.cbSize);
    }
    free(closest);
    free(formats);
    free(hw_params);
    snd_pcm_close(pcm_handle);

    return STATUS_SUCCESS;
}

static NTSTATUS get_mix_format(void *args)
{
    struct get_mix_format_params *params = args;
    WAVEFORMATEXTENSIBLE *fmt = params->fmt;
    snd_pcm_t *pcm_handle;
    snd_pcm_hw_params_t *hw_params;
    snd_pcm_format_mask_t *formats;
    unsigned int max_rate, max_channels;
    int err;

    params->result = alsa_open_device(params->alsa_name, params->flow, &pcm_handle, &hw_params);
    if(FAILED(params->result))
        return STATUS_SUCCESS;

    formats = calloc(1, snd_pcm_format_mask_sizeof());
    if(!formats){
        free(hw_params);
        snd_pcm_close(pcm_handle);
        params->result = E_OUTOFMEMORY;
        return STATUS_SUCCESS;
    }

    if((err = snd_pcm_hw_params_any(pcm_handle, hw_params)) < 0){
        WARN("Unable to get hw_params: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        goto exit;
    }

    snd_pcm_hw_params_get_format_mask(hw_params, formats);

    fmt->Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
    if(snd_pcm_format_mask_test(formats, SND_PCM_FORMAT_FLOAT_LE)){
        fmt->Format.wBitsPerSample = 32;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_IEEE_FLOAT;
    }else if(snd_pcm_format_mask_test(formats, SND_PCM_FORMAT_S16_LE)){
        fmt->Format.wBitsPerSample = 16;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
    }else if(snd_pcm_format_mask_test(formats, SND_PCM_FORMAT_U8)){
        fmt->Format.wBitsPerSample = 8;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
    }else if(snd_pcm_format_mask_test(formats, SND_PCM_FORMAT_S32_LE)){
        fmt->Format.wBitsPerSample = 32;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
    }else if(snd_pcm_format_mask_test(formats, SND_PCM_FORMAT_S24_3LE)){
        fmt->Format.wBitsPerSample = 24;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
    }else{
        ERR("Didn't recognize any available ALSA formats\n");
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        goto exit;
    }

    if((err = snd_pcm_hw_params_get_channels_max(hw_params, &max_channels)) < 0){
        WARN("Unable to get max channels: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        goto exit;
    }

    if(max_channels > 6)
        fmt->Format.nChannels = 2;
    else
        fmt->Format.nChannels = max_channels;

    if(fmt->Format.nChannels > 1 && (fmt->Format.nChannels & 0x1)){
        /* For most hardware on Windows, users must choose a configuration with an even
         * number of channels (stereo, quad, 5.1, 7.1). Users can then disable
         * channels, but those channels are still reported to applications from
         * GetMixFormat! Some applications behave badly if given an odd number of
         * channels (e.g. 2.1). */

        if(fmt->Format.nChannels < max_channels)
            fmt->Format.nChannels += 1;
        else
            /* We could "fake" more channels and downmix the emulated channels,
             * but at that point you really ought to tweak your ALSA setup or
             * just use PulseAudio. */
            WARN("Some Windows applications behave badly with an odd number of channels (%u)!\n", fmt->Format.nChannels);
    }

    fmt->dwChannelMask = get_channel_mask(fmt->Format.nChannels);

    if((err = snd_pcm_hw_params_get_rate_max(hw_params, &max_rate, NULL)) < 0){
        WARN("Unable to get max rate: %d (%s)\n", err, snd_strerror(err));
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        goto exit;
    }

    if(max_rate >= 48000)
        fmt->Format.nSamplesPerSec = 48000;
    else if(max_rate >= 44100)
        fmt->Format.nSamplesPerSec = 44100;
    else if(max_rate >= 22050)
        fmt->Format.nSamplesPerSec = 22050;
    else if(max_rate >= 11025)
        fmt->Format.nSamplesPerSec = 11025;
    else if(max_rate >= 8000)
        fmt->Format.nSamplesPerSec = 8000;
    else{
        ERR("Unknown max rate: %u\n", max_rate);
        params->result = AUDCLNT_E_DEVICE_INVALIDATED;
        goto exit;
    }

    fmt->Format.nBlockAlign = (fmt->Format.wBitsPerSample * fmt->Format.nChannels) / 8;
    fmt->Format.nAvgBytesPerSec = fmt->Format.nSamplesPerSec * fmt->Format.nBlockAlign;

    fmt->Samples.wValidBitsPerSample = fmt->Format.wBitsPerSample;
    fmt->Format.cbSize = sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX);

exit:
    free(formats);
    free(hw_params);
    snd_pcm_close(pcm_handle);

    return STATUS_SUCCESS;
}

static NTSTATUS get_buffer_size(void *args)
{
    struct get_buffer_size_params *params = args;
    struct alsa_stream *stream = params->stream;

    alsa_lock(stream);

    *params->size = stream->bufsize_frames;

    return alsa_unlock_result(stream, &params->result, S_OK);
}

static NTSTATUS get_latency(void *args)
{
    struct get_latency_params *params = args;
    struct alsa_stream *stream = params->stream;

    alsa_lock(stream);

    /* Hide some frames in the ALSA buffer. Allows us to return GetCurrentPadding=0
     * yet have enough data left to play (as if it were in native's mixer). Add:
     * + mmdevapi_period such that at the end of it, ALSA still has data;
     * + EXTRA_SAFE (~4ms) to allow for late callback invocation / fluctuation;
     * + alsa_period such that ALSA always has at least one period to play. */
    if(stream->flow == eRender)
        *params->latency = muldiv(stream->hidden_frames, 10000000, stream->fmt->nSamplesPerSec);
    else
        *params->latency = muldiv(stream->alsa_period_frames, 10000000, stream->fmt->nSamplesPerSec)
            + stream->mmdev_period_rt;

    return alsa_unlock_result(stream, &params->result, S_OK);
}

static NTSTATUS get_current_padding(void *args)
{
    struct get_current_padding_params *params = args;
    struct alsa_stream *stream = params->stream;

    alsa_lock(stream);

    /* padding is solely updated at callback time in shared mode */
    *params->padding = stream->held_frames;

    return alsa_unlock_result(stream, &params->result, S_OK);
}

unixlib_entry_t __wine_unix_call_funcs[] =
{
    get_endpoint_ids,
    create_stream,
    release_stream,
    is_format_supported,
    get_mix_format,
    get_buffer_size,
    get_latency,
    get_current_padding,
};