Sweden-Number/dlls/wineoss.drv/mmdevdrv.c

/*
 * Copyright 2011 Andrew Eikum for CodeWeavers
 *
 * 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
 */

#define NONAMELESSUNION
#define COBJMACROS
#include "config.h"

#include <stdarg.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <math.h>
#include <sys/soundcard.h>

#include "windef.h"
#include "winbase.h"
#include "winnls.h"
#include "winreg.h"
#include "wine/debug.h"
#include "wine/unicode.h"
#include "wine/list.h"

#include "ole2.h"
#include "mmdeviceapi.h"
#include "devpkey.h"
#include "dshow.h"
#include "dsound.h"

#include "initguid.h"
#include "endpointvolume.h"
#include "audiopolicy.h"
#include "audioclient.h"

WINE_DEFAULT_DEBUG_CHANNEL(oss);

#define NULL_PTR_ERR MAKE_HRESULT(SEVERITY_ERROR, FACILITY_WIN32, RPC_X_NULL_REF_POINTER)

static const REFERENCE_TIME DefaultPeriod = 200000;
static const REFERENCE_TIME MinimumPeriod = 100000;

struct ACImpl;
typedef struct ACImpl ACImpl;

typedef struct _AudioSession {
    GUID guid;
    struct list clients;

    IMMDevice *device;

    float master_vol;
    UINT32 channel_count;
    float *channel_vols;
    BOOL mute;

    CRITICAL_SECTION lock;

    struct list entry;
} AudioSession;

typedef struct _AudioSessionWrapper {
    IAudioSessionControl2 IAudioSessionControl2_iface;
    IChannelAudioVolume IChannelAudioVolume_iface;
    ISimpleAudioVolume ISimpleAudioVolume_iface;

    LONG ref;

    ACImpl *client;
    AudioSession *session;
} AudioSessionWrapper;

struct ACImpl {
    IAudioClient IAudioClient_iface;
    IAudioRenderClient IAudioRenderClient_iface;
    IAudioCaptureClient IAudioCaptureClient_iface;
    IAudioClock IAudioClock_iface;
    IAudioClock2 IAudioClock2_iface;
    IAudioStreamVolume IAudioStreamVolume_iface;

    LONG ref;

    IMMDevice *parent;

    WAVEFORMATEX *fmt;

    EDataFlow dataflow;
    DWORD flags;
    AUDCLNT_SHAREMODE share;
    HANDLE event;
    float *vols;

    int fd;
    oss_audioinfo ai;
    char devnode[OSS_DEVNODE_SIZE];

    BOOL initted, playing;
    UINT64 written_frames, last_pos_frames;
    UINT32 period_us, period_frames, bufsize_frames, held_frames, tmp_buffer_frames;
    UINT32 oss_bufsize_bytes, lcl_offs_frames; /* offs into local_buffer where valid data starts */

    BYTE *local_buffer, *tmp_buffer;
    LONG32 getbuf_last; /* <0 when using tmp_buffer */
    HANDLE timer;

    CRITICAL_SECTION lock;

    AudioSession *session;
    AudioSessionWrapper *session_wrapper;

    struct list entry;
};

typedef struct _SessionMgr {
    IAudioSessionManager2 IAudioSessionManager2_iface;

    LONG ref;

    IMMDevice *device;
} SessionMgr;

typedef struct _OSSDevice {
    EDataFlow flow;
    char devnode[OSS_DEVNODE_SIZE];
    GUID guid;

    struct list entry;
} OSSDevice;

static struct list g_devices = LIST_INIT(g_devices);

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','o','s','s','.','d','r','v',0};
static const WCHAR drv_key_devicesW[] = {'S','o','f','t','w','a','r','e','\\',
    'W','i','n','e','\\','D','r','i','v','e','r','s','\\',
    'w','i','n','e','o','s','s','.','d','r','v','\\','d','e','v','i','c','e','s',0};
static const WCHAR guidW[] = {'g','u','i','d',0};

static HANDLE g_timer_q;

static CRITICAL_SECTION g_sessions_lock;
static CRITICAL_SECTION_DEBUG g_sessions_lock_debug =
{
    0, 0, &g_sessions_lock,
    { &g_sessions_lock_debug.ProcessLocksList, &g_sessions_lock_debug.ProcessLocksList },
      0, 0, { (DWORD_PTR)(__FILE__ ": g_sessions_lock") }
};
static CRITICAL_SECTION g_sessions_lock = { &g_sessions_lock_debug, -1, 0, 0, 0, 0 };
static struct list g_sessions = LIST_INIT(g_sessions);

static AudioSessionWrapper *AudioSessionWrapper_Create(ACImpl *client);

static const IAudioClientVtbl AudioClient_Vtbl;
static const IAudioRenderClientVtbl AudioRenderClient_Vtbl;
static const IAudioCaptureClientVtbl AudioCaptureClient_Vtbl;
static const IAudioSessionControl2Vtbl AudioSessionControl2_Vtbl;
static const ISimpleAudioVolumeVtbl SimpleAudioVolume_Vtbl;
static const IAudioClockVtbl AudioClock_Vtbl;
static const IAudioClock2Vtbl AudioClock2_Vtbl;
static const IAudioStreamVolumeVtbl AudioStreamVolume_Vtbl;
static const IChannelAudioVolumeVtbl ChannelAudioVolume_Vtbl;
static const IAudioSessionManager2Vtbl AudioSessionManager2_Vtbl;

static inline ACImpl *impl_from_IAudioClient(IAudioClient *iface)
{
    return CONTAINING_RECORD(iface, ACImpl, IAudioClient_iface);
}

static inline ACImpl *impl_from_IAudioRenderClient(IAudioRenderClient *iface)
{
    return CONTAINING_RECORD(iface, ACImpl, IAudioRenderClient_iface);
}

static inline ACImpl *impl_from_IAudioCaptureClient(IAudioCaptureClient *iface)
{
    return CONTAINING_RECORD(iface, ACImpl, IAudioCaptureClient_iface);
}

static inline AudioSessionWrapper *impl_from_IAudioSessionControl2(IAudioSessionControl2 *iface)
{
    return CONTAINING_RECORD(iface, AudioSessionWrapper, IAudioSessionControl2_iface);
}

static inline AudioSessionWrapper *impl_from_ISimpleAudioVolume(ISimpleAudioVolume *iface)
{
    return CONTAINING_RECORD(iface, AudioSessionWrapper, ISimpleAudioVolume_iface);
}

static inline AudioSessionWrapper *impl_from_IChannelAudioVolume(IChannelAudioVolume *iface)
{
    return CONTAINING_RECORD(iface, AudioSessionWrapper, IChannelAudioVolume_iface);
}

static inline ACImpl *impl_from_IAudioClock(IAudioClock *iface)
{
    return CONTAINING_RECORD(iface, ACImpl, IAudioClock_iface);
}

static inline ACImpl *impl_from_IAudioClock2(IAudioClock2 *iface)
{
    return CONTAINING_RECORD(iface, ACImpl, IAudioClock2_iface);
}

static inline ACImpl *impl_from_IAudioStreamVolume(IAudioStreamVolume *iface)
{
    return CONTAINING_RECORD(iface, ACImpl, IAudioStreamVolume_iface);
}

static inline SessionMgr *impl_from_IAudioSessionManager2(IAudioSessionManager2 *iface)
{
    return CONTAINING_RECORD(iface, SessionMgr, IAudioSessionManager2_iface);
}

BOOL WINAPI DllMain(HINSTANCE dll, DWORD reason, void *reserved)
{
    switch (reason)
    {
    case DLL_PROCESS_ATTACH:
        g_timer_q = CreateTimerQueue();
        if(!g_timer_q)
            return FALSE;
        break;

    case DLL_PROCESS_DETACH:
        if (!reserved)
        {
            OSSDevice *iter, *iter2;

            DeleteCriticalSection(&g_sessions_lock);

            LIST_FOR_EACH_ENTRY_SAFE(iter, iter2, &g_devices, OSSDevice, entry){
                HeapFree(GetProcessHeap(), 0, iter);
            }
        }
        break;
    }
    return TRUE;
}

/* From <dlls/mmdevapi/mmdevapi.h> */
enum DriverPriority {
    Priority_Unavailable = 0,
    Priority_Low,
    Priority_Neutral,
    Priority_Preferred
};

int WINAPI AUDDRV_GetPriority(void)
{
    int mixer_fd;
    oss_sysinfo sysinfo;

    /* Attempt to determine if we are running on OSS or ALSA's OSS
     * compatibility layer. There is no official way to do that, so just check
     * for validity as best as possible, without rejecting valid OSS
     * implementations. */

    mixer_fd = open("/dev/mixer", O_RDONLY, 0);
    if(mixer_fd < 0){
        TRACE("Priority_Unavailable: open failed\n");
        return Priority_Unavailable;
    }

    sysinfo.version[0] = 0xFF;
    sysinfo.versionnum = ~0;
    if(ioctl(mixer_fd, SNDCTL_SYSINFO, &sysinfo) < 0){
        TRACE("Priority_Unavailable: ioctl failed\n");
        close(mixer_fd);
        return Priority_Unavailable;
    }

    close(mixer_fd);

    if(sysinfo.version[0] < '4' || sysinfo.version[0] > '9'){
        TRACE("Priority_Low: sysinfo.version[0]: %x\n", sysinfo.version[0]);
        return Priority_Low;
    }
    if(sysinfo.versionnum & 0x80000000){
        TRACE("Priority_Low: sysinfo.versionnum: %x\n", sysinfo.versionnum);
        return Priority_Low;
    }

    TRACE("Priority_Preferred: Seems like valid OSS!\n");

    return Priority_Preferred;
}

static void set_device_guid(EDataFlow flow, HKEY drv_key, const WCHAR *key_name,
        GUID *guid)
{
    HKEY key;
    BOOL opened = FALSE;
    LONG lr;

    if(!drv_key){
        lr = RegCreateKeyExW(HKEY_CURRENT_USER, drv_key_devicesW, 0, NULL, 0, KEY_WRITE,
                    NULL, &drv_key, NULL);
        if(lr != ERROR_SUCCESS){
            ERR("RegCreateKeyEx(drv_key) failed: %u\n", lr);
            return;
        }
        opened = TRUE;
    }

    lr = RegCreateKeyExW(drv_key, key_name, 0, NULL, 0, KEY_WRITE,
                NULL, &key, NULL);
    if(lr != ERROR_SUCCESS){
        ERR("RegCreateKeyEx(%s) failed: %u\n", wine_dbgstr_w(key_name), lr);
        goto exit;
    }

    lr = RegSetValueExW(key, guidW, 0, REG_BINARY, (BYTE*)guid,
                sizeof(GUID));
    if(lr != ERROR_SUCCESS)
        ERR("RegSetValueEx(%s\\guid) failed: %u\n", wine_dbgstr_w(key_name), lr);

    RegCloseKey(key);
exit:
    if(opened)
        RegCloseKey(drv_key);
}

static void get_device_guid(EDataFlow flow, const char *device, GUID *guid)
{
    HKEY key = NULL, dev_key;
    DWORD type, size = sizeof(*guid);
    WCHAR key_name[256];

    if(flow == eCapture)
        key_name[0] = '1';
    else
        key_name[0] = '0';
    key_name[1] = ',';
    MultiByteToWideChar(CP_UNIXCP, 0, device, -1, key_name + 2,
            (sizeof(key_name) / sizeof(*key_name)) - 2);

    if(RegOpenKeyExW(HKEY_CURRENT_USER, drv_key_devicesW, 0, KEY_WRITE|KEY_READ, &key) == ERROR_SUCCESS){
        if(RegOpenKeyExW(key, key_name, 0, KEY_READ, &dev_key) == ERROR_SUCCESS){
            if(RegQueryValueExW(dev_key, guidW, 0, &type,
                        (BYTE*)guid, &size) == ERROR_SUCCESS){
                if(type == REG_BINARY){
                    RegCloseKey(dev_key);
                    RegCloseKey(key);
                    return;
                }
                ERR("Invalid type for device %s GUID: %u; ignoring and overwriting\n",
                        wine_dbgstr_w(key_name), type);
            }
            RegCloseKey(dev_key);
        }
    }

    CoCreateGuid(guid);

    set_device_guid(flow, key, key_name, guid);

    if(key)
        RegCloseKey(key);
}

static const char *oss_clean_devnode(const char *devnode)
{
    static char ret[OSS_DEVNODE_SIZE];

    const char *dot, *slash;
    size_t len;

    dot = strrchr(devnode, '.');
    if(!dot)
        return devnode;

    slash = strrchr(devnode, '/');
    if(slash && dot < slash)
        return devnode;

    len = dot - devnode;

    memcpy(ret, devnode, len);
    ret[len] = '\0';

    return ret;
}

static UINT get_default_index(EDataFlow flow)
{
    int fd = -1, err;
    UINT i;
    oss_audioinfo ai;
    const char *devnode;
    OSSDevice *dev_item;

    if(flow == eRender)
        fd = open("/dev/dsp", O_WRONLY | O_NONBLOCK);
    else
        fd = open("/dev/dsp", O_RDONLY | O_NONBLOCK);

    if(fd < 0){
        WARN("Couldn't open default device!\n");
        return 0;
    }

    ai.dev = -1;
    if((err = ioctl(fd, SNDCTL_ENGINEINFO, &ai)) < 0){
        WARN("SNDCTL_ENGINEINFO failed: %d (%s)\n", err, strerror(errno));
        close(fd);
        return 0;
    }

    close(fd);

    TRACE("Default devnode: %s\n", ai.devnode);
    devnode = oss_clean_devnode(ai.devnode);
    i = 0;
    LIST_FOR_EACH_ENTRY(dev_item, &g_devices, OSSDevice, entry){
        if(dev_item->flow == flow){
            if(!strcmp(devnode, dev_item->devnode))
                return i;
            ++i;
        }
    }

    WARN("Couldn't find default device! Choosing first.\n");
    return 0;
}

HRESULT WINAPI AUDDRV_GetEndpointIDs(EDataFlow flow, WCHAR ***ids, GUID **guids,
        UINT *num, UINT *def_index)
{
    int i, mixer_fd;
    oss_sysinfo sysinfo;
    static int print_once = 0;

    static const WCHAR outW[] = {'O','u','t',':',' ',0};
    static const WCHAR inW[] = {'I','n',':',' ',0};

    TRACE("%d %p %p %p %p\n", flow, ids, guids, num, def_index);

    mixer_fd = open("/dev/mixer", O_RDONLY, 0);
    if(mixer_fd < 0){
        ERR("OSS /dev/mixer doesn't seem to exist\n");
        return AUDCLNT_E_SERVICE_NOT_RUNNING;
    }

    if(ioctl(mixer_fd, SNDCTL_SYSINFO, &sysinfo) < 0){
        close(mixer_fd);

        if(errno == EINVAL){
            ERR("OSS version too old, need at least OSSv4\n");
            return AUDCLNT_E_SERVICE_NOT_RUNNING;
        }

        ERR("Error getting SNDCTL_SYSINFO: %d (%s)\n", errno, strerror(errno));
        return E_FAIL;
    }

    if(!print_once){
        TRACE("OSS sysinfo:\n");
        TRACE("product: %s\n", sysinfo.product);
        TRACE("version: %s\n", sysinfo.version);
        TRACE("versionnum: %x\n", sysinfo.versionnum);
        TRACE("numaudios: %d\n", sysinfo.numaudios);
        TRACE("nummixers: %d\n", sysinfo.nummixers);
        TRACE("numcards: %d\n", sysinfo.numcards);
        TRACE("numaudioengines: %d\n", sysinfo.numaudioengines);
        print_once = 1;
    }

    if(sysinfo.numaudios <= 0){
        WARN("No audio devices!\n");
        close(mixer_fd);
        return AUDCLNT_E_SERVICE_NOT_RUNNING;
    }

    *ids = HeapAlloc(GetProcessHeap(), 0, sysinfo.numaudios * sizeof(WCHAR *));
    *guids = HeapAlloc(GetProcessHeap(), 0, sysinfo.numaudios * sizeof(GUID));

    *num = 0;
    for(i = 0; i < sysinfo.numaudios; ++i){
        oss_audioinfo ai = {0};
        const char *devnode;
        OSSDevice *dev_item;
        int fd;

        ai.dev = i;
        if(ioctl(mixer_fd, SNDCTL_AUDIOINFO, &ai) < 0){
            WARN("Error getting AUDIOINFO for dev %d: %d (%s)\n", i, errno,
                    strerror(errno));
            continue;
        }

        devnode = oss_clean_devnode(ai.devnode);

        /* check for duplicates */
        LIST_FOR_EACH_ENTRY(dev_item, &g_devices, OSSDevice, entry){
            if(dev_item->flow == flow && !strcmp(devnode, dev_item->devnode))
                break;
        }
        if(&dev_item->entry != &g_devices)
            continue;

        if(flow == eRender)
            fd = open(devnode, O_WRONLY | O_NONBLOCK, 0);
        else
            fd = open(devnode, O_RDONLY | O_NONBLOCK, 0);
        if(fd < 0){
            WARN("Opening device \"%s\" failed, pretending it doesn't exist: %d (%s)\n",
                    devnode, errno, strerror(errno));
            continue;
        }
        close(fd);

        if((flow == eCapture && (ai.caps & PCM_CAP_INPUT)) ||
                (flow == eRender && (ai.caps & PCM_CAP_OUTPUT))){
            size_t len, prefix_len;
            const WCHAR *prefix;

            dev_item = HeapAlloc(GetProcessHeap(), 0, sizeof(*dev_item));

            dev_item->flow = flow;
            get_device_guid(flow, devnode, &dev_item->guid);
            strcpy(dev_item->devnode, devnode);

            (*guids)[*num] = dev_item->guid;

            len = MultiByteToWideChar(CP_UNIXCP, 0, ai.name, -1, NULL, 0);
            if(flow == eRender){
                prefix = outW;
                prefix_len = (sizeof(outW) / sizeof(*outW)) - 1;
                len += prefix_len;
            }else{
                prefix = inW;
                prefix_len = (sizeof(inW) / sizeof(*inW)) - 1;
                len += prefix_len;
            }
            (*ids)[*num] = HeapAlloc(GetProcessHeap(), 0,
                    len * sizeof(WCHAR));
            if(!(*ids)[*num]){
                for(i = 0; i < *num; ++i)
                    HeapFree(GetProcessHeap(), 0, (*ids)[i]);
                HeapFree(GetProcessHeap(), 0, *ids);
                HeapFree(GetProcessHeap(), 0, *guids);
                HeapFree(GetProcessHeap(), 0, dev_item);
                close(mixer_fd);
                return E_OUTOFMEMORY;
            }
            memcpy((*ids)[*num], prefix, prefix_len * sizeof(WCHAR));
            MultiByteToWideChar(CP_UNIXCP, 0, ai.name, -1,
                    (*ids)[*num] + prefix_len, len - prefix_len);

            list_add_tail(&g_devices, &dev_item->entry);

            (*num)++;
        }
    }

    close(mixer_fd);

    *def_index = get_default_index(flow);

    return S_OK;
}

static const OSSDevice *get_ossdevice_from_guid(const GUID *guid)
{
    OSSDevice *dev_item;
    LIST_FOR_EACH_ENTRY(dev_item, &g_devices, OSSDevice, entry)
        if(IsEqualGUID(guid, &dev_item->guid))
            return dev_item;
    return NULL;
}

HRESULT WINAPI AUDDRV_GetAudioEndpoint(GUID *guid, IMMDevice *dev,
        IAudioClient **out)
{
    ACImpl *This;
    const OSSDevice *oss_dev;

    TRACE("%s %p %p\n", debugstr_guid(guid), dev, out);

    oss_dev = get_ossdevice_from_guid(guid);
    if(!oss_dev){
        WARN("Unknown GUID: %s\n", debugstr_guid(guid));
        return AUDCLNT_E_DEVICE_INVALIDATED;
    }

    This = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(ACImpl));
    if(!This)
        return E_OUTOFMEMORY;

    if(oss_dev->flow == eRender)
        This->fd = open(oss_dev->devnode, O_WRONLY | O_NONBLOCK, 0);
    else if(oss_dev->flow == eCapture)
        This->fd = open(oss_dev->devnode, O_RDONLY | O_NONBLOCK, 0);
    else{
        HeapFree(GetProcessHeap(), 0, This);
        return E_INVALIDARG;
    }
    if(This->fd < 0){
        WARN("Unable to open device %s: %d (%s)\n", oss_dev->devnode, errno,
                strerror(errno));
        HeapFree(GetProcessHeap(), 0, This);
        return AUDCLNT_E_DEVICE_INVALIDATED;
    }

    This->dataflow = oss_dev->flow;

    This->ai.dev = -1;
    if(ioctl(This->fd, SNDCTL_ENGINEINFO, &This->ai) < 0){
        WARN("Unable to get audio info for device %s: %d (%s)\n", oss_dev->devnode,
                errno, strerror(errno));
        close(This->fd);
        HeapFree(GetProcessHeap(), 0, This);
        return E_FAIL;
    }

    strcpy(This->devnode, oss_dev->devnode);

    TRACE("OSS audioinfo:\n");
    TRACE("devnode: %s\n", This->ai.devnode);
    TRACE("name: %s\n", This->ai.name);
    TRACE("busy: %x\n", This->ai.busy);
    TRACE("caps: %x\n", This->ai.caps);
    TRACE("iformats: %x\n", This->ai.iformats);
    TRACE("oformats: %x\n", This->ai.oformats);
    TRACE("enabled: %d\n", This->ai.enabled);
    TRACE("min_rate: %d\n", This->ai.min_rate);
    TRACE("max_rate: %d\n", This->ai.max_rate);
    TRACE("min_channels: %d\n", This->ai.min_channels);
    TRACE("max_channels: %d\n", This->ai.max_channels);

    This->IAudioClient_iface.lpVtbl = &AudioClient_Vtbl;
    This->IAudioRenderClient_iface.lpVtbl = &AudioRenderClient_Vtbl;
    This->IAudioCaptureClient_iface.lpVtbl = &AudioCaptureClient_Vtbl;
    This->IAudioClock_iface.lpVtbl = &AudioClock_Vtbl;
    This->IAudioClock2_iface.lpVtbl = &AudioClock2_Vtbl;
    This->IAudioStreamVolume_iface.lpVtbl = &AudioStreamVolume_Vtbl;

    InitializeCriticalSection(&This->lock);
    This->lock.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": ACImpl.lock");

    This->parent = dev;
    IMMDevice_AddRef(This->parent);

    IAudioClient_AddRef(&This->IAudioClient_iface);

    *out = &This->IAudioClient_iface;

    return S_OK;
}

static HRESULT WINAPI AudioClient_QueryInterface(IAudioClient *iface,
        REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;
    if(IsEqualIID(riid, &IID_IUnknown) || IsEqualIID(riid, &IID_IAudioClient))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }
    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI AudioClient_AddRef(IAudioClient *iface)
{
    ACImpl *This = impl_from_IAudioClient(iface);
    ULONG ref;
    ref = InterlockedIncrement(&This->ref);
    TRACE("(%p) Refcount now %u\n", This, ref);
    return ref;
}

static ULONG WINAPI AudioClient_Release(IAudioClient *iface)
{
    ACImpl *This = impl_from_IAudioClient(iface);
    ULONG ref;
    ref = InterlockedDecrement(&This->ref);
    TRACE("(%p) Refcount now %u\n", This, ref);
    if(!ref){
        IAudioClient_Stop(iface);
        IMMDevice_Release(This->parent);
        This->lock.DebugInfo->Spare[0] = 0;
        DeleteCriticalSection(&This->lock);
        close(This->fd);
        if(This->initted){
            EnterCriticalSection(&g_sessions_lock);
            list_remove(&This->entry);
            LeaveCriticalSection(&g_sessions_lock);
        }
        HeapFree(GetProcessHeap(), 0, This->vols);
        HeapFree(GetProcessHeap(), 0, This->local_buffer);
        HeapFree(GetProcessHeap(), 0, This->tmp_buffer);
        CoTaskMemFree(This->fmt);
        HeapFree(GetProcessHeap(), 0, This);
    }
    return ref;
}

static void dump_fmt(const WAVEFORMATEX *fmt)
{
    TRACE("wFormatTag: 0x%x (", fmt->wFormatTag);
    switch(fmt->wFormatTag){
    case WAVE_FORMAT_PCM:
        TRACE("WAVE_FORMAT_PCM");
        break;
    case WAVE_FORMAT_IEEE_FLOAT:
        TRACE("WAVE_FORMAT_IEEE_FLOAT");
        break;
    case WAVE_FORMAT_EXTENSIBLE:
        TRACE("WAVE_FORMAT_EXTENSIBLE");
        break;
    default:
        TRACE("Unknown");
        break;
    }
    TRACE(")\n");

    TRACE("nChannels: %u\n", fmt->nChannels);
    TRACE("nSamplesPerSec: %u\n", fmt->nSamplesPerSec);
    TRACE("nAvgBytesPerSec: %u\n", fmt->nAvgBytesPerSec);
    TRACE("nBlockAlign: %u\n", fmt->nBlockAlign);
    TRACE("wBitsPerSample: %u\n", fmt->wBitsPerSample);
    TRACE("cbSize: %u\n", fmt->cbSize);

    if(fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE){
        WAVEFORMATEXTENSIBLE *fmtex = (void*)fmt;
        TRACE("dwChannelMask: %08x\n", fmtex->dwChannelMask);
        TRACE("Samples: %04x\n", fmtex->Samples.wReserved);
        TRACE("SubFormat: %s\n", wine_dbgstr_guid(&fmtex->SubFormat));
    }
}

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 int get_oss_format(const WAVEFORMATEX *fmt)
{
    WAVEFORMATEXTENSIBLE *fmtex = (WAVEFORMATEXTENSIBLE*)fmt;

    if(fmt->wFormatTag == WAVE_FORMAT_PCM ||
            (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
             IsEqualGUID(&fmtex->SubFormat, &KSDATAFORMAT_SUBTYPE_PCM))){
        switch(fmt->wBitsPerSample){
        case 8:
            return AFMT_U8;
        case 16:
            return AFMT_S16_LE;
        case 24:
            return AFMT_S24_LE;
        case 32:
            return AFMT_S32_LE;
        }
        return -1;
    }

#ifdef AFMT_FLOAT
    if(fmt->wFormatTag == WAVE_FORMAT_IEEE_FLOAT ||
            (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
             IsEqualGUID(&fmtex->SubFormat, &KSDATAFORMAT_SUBTYPE_IEEE_FLOAT))){
        if(fmt->wBitsPerSample != 32)
            return -1;

        return AFMT_FLOAT;
    }
#endif

    return -1;
}

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

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

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

    memcpy(ret, fmt, size);

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

    return ret;
}

static HRESULT setup_oss_device(AUDCLNT_SHAREMODE mode, int fd,
        const WAVEFORMATEX *fmt, WAVEFORMATEX **out)
{
    int tmp, oss_format;
    double tenth;
    HRESULT ret = S_OK;
    WAVEFORMATEX *closest = NULL;

    tmp = oss_format = get_oss_format(fmt);
    if(oss_format < 0)
        return AUDCLNT_E_UNSUPPORTED_FORMAT;
    if(ioctl(fd, SNDCTL_DSP_SETFMT, &tmp) < 0){
        WARN("SETFMT failed: %d (%s)\n", errno, strerror(errno));
        return E_FAIL;
    }
    if(tmp != oss_format){
        TRACE("Format unsupported by this OSS version: %x\n", oss_format);
        return AUDCLNT_E_UNSUPPORTED_FORMAT;
    }

    if(fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
            (fmt->nAvgBytesPerSec == 0 ||
             fmt->nBlockAlign == 0 ||
             ((WAVEFORMATEXTENSIBLE*)fmt)->Samples.wValidBitsPerSample > fmt->wBitsPerSample))
        return E_INVALIDARG;

    if(fmt->nChannels == 0)
        return AUDCLNT_E_UNSUPPORTED_FORMAT;

    closest = clone_format(fmt);
    if(!closest)
        return E_OUTOFMEMORY;

    tmp = fmt->nSamplesPerSec;
    if(ioctl(fd, SNDCTL_DSP_SPEED, &tmp) < 0){
        WARN("SPEED failed: %d (%s)\n", errno, strerror(errno));
        CoTaskMemFree(closest);
        return E_FAIL;
    }
    tenth = fmt->nSamplesPerSec * 0.1;
    if(tmp > fmt->nSamplesPerSec + tenth || tmp < fmt->nSamplesPerSec - tenth){
        ret = S_FALSE;
        closest->nSamplesPerSec = tmp;
    }

    tmp = fmt->nChannels;
    if(ioctl(fd, SNDCTL_DSP_CHANNELS, &tmp) < 0){
        WARN("CHANNELS failed: %d (%s)\n", errno, strerror(errno));
        CoTaskMemFree(closest);
        return E_FAIL;
    }
    if(tmp != fmt->nChannels){
        ret = S_FALSE;
        closest->nChannels = tmp;
    }

    if(closest->wFormatTag == WAVE_FORMAT_EXTENSIBLE)
        ((WAVEFORMATEXTENSIBLE*)closest)->dwChannelMask = get_channel_mask(closest->nChannels);

    if(fmt->nBlockAlign != fmt->nChannels * fmt->wBitsPerSample / 8 ||
            fmt->nAvgBytesPerSec != fmt->nBlockAlign * fmt->nSamplesPerSec ||
            (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
             ((WAVEFORMATEXTENSIBLE*)fmt)->Samples.wValidBitsPerSample < fmt->wBitsPerSample))
        ret = S_FALSE;

    if(mode == AUDCLNT_SHAREMODE_EXCLUSIVE &&
            fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE){
        if(((WAVEFORMATEXTENSIBLE*)fmt)->dwChannelMask == 0 ||
                ((WAVEFORMATEXTENSIBLE*)fmt)->dwChannelMask & SPEAKER_RESERVED)
            ret = S_FALSE;
    }

    if(ret == S_FALSE && !out)
        ret = AUDCLNT_E_UNSUPPORTED_FORMAT;

    if(ret == S_FALSE && out){
        closest->nBlockAlign =
            closest->nChannels * closest->wBitsPerSample / 8;
        closest->nAvgBytesPerSec =
            closest->nBlockAlign * closest->nSamplesPerSec;
        if(closest->wFormatTag == WAVE_FORMAT_EXTENSIBLE)
            ((WAVEFORMATEXTENSIBLE*)closest)->Samples.wValidBitsPerSample = closest->wBitsPerSample;
        *out = closest;
    } else
        CoTaskMemFree(closest);

    TRACE("returning: %08x\n", ret);
    return ret;
}

static void session_init_vols(AudioSession *session, UINT channels)
{
    if(session->channel_count < channels){
        UINT i;

        if(session->channel_vols)
            session->channel_vols = HeapReAlloc(GetProcessHeap(), 0,
                    session->channel_vols, sizeof(float) * channels);
        else
            session->channel_vols = HeapAlloc(GetProcessHeap(), 0,
                    sizeof(float) * channels);
        if(!session->channel_vols)
            return;

        for(i = session->channel_count; i < channels; ++i)
            session->channel_vols[i] = 1.f;

        session->channel_count = channels;
    }
}

static AudioSession *create_session(const GUID *guid, IMMDevice *device,
        UINT num_channels)
{
    AudioSession *ret;

    ret = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(AudioSession));
    if(!ret)
        return NULL;

    memcpy(&ret->guid, guid, sizeof(GUID));

    ret->device = device;

    list_init(&ret->clients);

    list_add_head(&g_sessions, &ret->entry);

    InitializeCriticalSection(&ret->lock);
    ret->lock.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": AudioSession.lock");

    session_init_vols(ret, num_channels);

    ret->master_vol = 1.f;

    return ret;
}

/* if channels == 0, then this will return or create a session with
 * matching dataflow and GUID. otherwise, channels must also match */
static HRESULT get_audio_session(const GUID *sessionguid,
        IMMDevice *device, UINT channels, AudioSession **out)
{
    AudioSession *session;

    if(!sessionguid || IsEqualGUID(sessionguid, &GUID_NULL)){
        *out = create_session(&GUID_NULL, device, channels);
        if(!*out)
            return E_OUTOFMEMORY;

        return S_OK;
    }

    *out = NULL;
    LIST_FOR_EACH_ENTRY(session, &g_sessions, AudioSession, entry){
        if(session->device == device &&
                IsEqualGUID(sessionguid, &session->guid)){
            session_init_vols(session, channels);
            *out = session;
            break;
        }
    }

    if(!*out){
        *out = create_session(sessionguid, device, channels);
        if(!*out)
            return E_OUTOFMEMORY;
    }

    return S_OK;
}

static HRESULT WINAPI AudioClient_Initialize(IAudioClient *iface,
        AUDCLNT_SHAREMODE mode, DWORD flags, REFERENCE_TIME duration,
        REFERENCE_TIME period, const WAVEFORMATEX *fmt,
        const GUID *sessionguid)
{
    ACImpl *This = impl_from_IAudioClient(iface);
    int i;
    HRESULT hr;

    TRACE("(%p)->(%x, %x, %s, %s, %p, %s)\n", This, mode, flags,
          wine_dbgstr_longlong(duration), wine_dbgstr_longlong(period), fmt, debugstr_guid(sessionguid));

    if(!fmt)
        return E_POINTER;

    dump_fmt(fmt);

    if(mode != AUDCLNT_SHAREMODE_SHARED && mode != AUDCLNT_SHAREMODE_EXCLUSIVE)
        return AUDCLNT_E_NOT_INITIALIZED;

    if(flags & ~(AUDCLNT_STREAMFLAGS_CROSSPROCESS |
                AUDCLNT_STREAMFLAGS_LOOPBACK |
                AUDCLNT_STREAMFLAGS_EVENTCALLBACK |
                AUDCLNT_STREAMFLAGS_NOPERSIST |
                AUDCLNT_STREAMFLAGS_RATEADJUST |
                AUDCLNT_SESSIONFLAGS_EXPIREWHENUNOWNED |
                AUDCLNT_SESSIONFLAGS_DISPLAY_HIDE |
                AUDCLNT_SESSIONFLAGS_DISPLAY_HIDEWHENEXPIRED)){
        TRACE("Unknown flags: %08x\n", flags);
        return E_INVALIDARG;
    }

    if(mode == AUDCLNT_SHAREMODE_SHARED){
        period = DefaultPeriod;
        if( duration < 3 * period)
            duration = 3 * period;
    }else{
        if(!period)
            period = DefaultPeriod; /* not minimum */
        if(period < MinimumPeriod || period > 5000000)
            return AUDCLNT_E_INVALID_DEVICE_PERIOD;
        if(duration > 20000000) /* the smaller the period, the lower this limit */
            return AUDCLNT_E_BUFFER_SIZE_ERROR;
        if(flags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK){
            if(duration != period)
                return AUDCLNT_E_BUFDURATION_PERIOD_NOT_EQUAL;
            FIXME("EXCLUSIVE mode with EVENTCALLBACK\n");
            return AUDCLNT_E_DEVICE_IN_USE;
        }else{
            if( duration < 8 * period)
                duration = 8 * period; /* may grow above 2s */
        }
    }

    EnterCriticalSection(&This->lock);

    if(This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_ALREADY_INITIALIZED;
    }

    hr = setup_oss_device(mode, This->fd, fmt, NULL);
    if(FAILED(hr)){
        LeaveCriticalSection(&This->lock);
        return hr;
    }

    This->fmt = clone_format(fmt);
    if(!This->fmt){
        LeaveCriticalSection(&This->lock);
        return E_OUTOFMEMORY;
    }

    This->period_us = period / 10;
    This->period_frames = MulDiv(fmt->nSamplesPerSec, period, 10000000);

    This->bufsize_frames = MulDiv(duration, fmt->nSamplesPerSec, 10000000);
    This->local_buffer = HeapAlloc(GetProcessHeap(), 0,
            This->bufsize_frames * fmt->nBlockAlign);
    if(!This->local_buffer){
        CoTaskMemFree(This->fmt);
        This->fmt = NULL;
        LeaveCriticalSection(&This->lock);
        return E_OUTOFMEMORY;
    }

    This->vols = HeapAlloc(GetProcessHeap(), 0, fmt->nChannels * sizeof(float));
    if(!This->vols){
        CoTaskMemFree(This->fmt);
        This->fmt = NULL;
        LeaveCriticalSection(&This->lock);
        return E_OUTOFMEMORY;
    }

    for(i = 0; i < fmt->nChannels; ++i)
        This->vols[i] = 1.f;

    This->share = mode;
    This->flags = flags;
    This->oss_bufsize_bytes = 0;

    EnterCriticalSection(&g_sessions_lock);

    hr = get_audio_session(sessionguid, This->parent, fmt->nChannels,
            &This->session);
    if(FAILED(hr)){
        LeaveCriticalSection(&g_sessions_lock);
        HeapFree(GetProcessHeap(), 0, This->vols);
        This->vols = NULL;
        CoTaskMemFree(This->fmt);
        This->fmt = NULL;
        LeaveCriticalSection(&This->lock);
        return hr;
    }

    list_add_tail(&This->session->clients, &This->entry);

    LeaveCriticalSection(&g_sessions_lock);

    This->initted = TRUE;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioClient_GetBufferSize(IAudioClient *iface,
        UINT32 *frames)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)->(%p)\n", This, frames);

    if(!frames)
        return E_POINTER;

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    *frames = This->bufsize_frames;

    TRACE("buffer size: %u\n", *frames);

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioClient_GetStreamLatency(IAudioClient *iface,
        REFERENCE_TIME *latency)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)->(%p)\n", This, latency);

    if(!latency)
        return E_POINTER;

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    /* pretend we process audio in Period chunks, so max latency includes
     * the period time.  Some native machines add .6666ms in shared mode. */
    *latency = This->period_us * 10 + 6666;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioClient_GetCurrentPadding(IAudioClient *iface,
        UINT32 *numpad)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)->(%p)\n", This, numpad);

    if(!numpad)
        return E_POINTER;

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    *numpad = This->held_frames;

    TRACE("padding: %u\n", *numpad);

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioClient_IsFormatSupported(IAudioClient *iface,
        AUDCLNT_SHAREMODE mode, const WAVEFORMATEX *pwfx,
        WAVEFORMATEX **outpwfx)
{
    ACImpl *This = impl_from_IAudioClient(iface);
    int fd = -1;
    HRESULT ret;

    TRACE("(%p)->(%x, %p, %p)\n", This, mode, pwfx, outpwfx);

    if(!pwfx || (mode == AUDCLNT_SHAREMODE_SHARED && !outpwfx))
        return E_POINTER;

    if(mode != AUDCLNT_SHAREMODE_SHARED && mode != AUDCLNT_SHAREMODE_EXCLUSIVE)
        return E_INVALIDARG;

    if(pwfx->wFormatTag == WAVE_FORMAT_EXTENSIBLE &&
            pwfx->cbSize < sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX))
        return E_INVALIDARG;

    dump_fmt(pwfx);

    if(outpwfx){
        *outpwfx = NULL;
        if(mode != AUDCLNT_SHAREMODE_SHARED)
            outpwfx = NULL;
    }

    if(This->dataflow == eRender)
        fd = open(This->devnode, O_WRONLY | O_NONBLOCK, 0);
    else if(This->dataflow == eCapture)
        fd = open(This->devnode, O_RDONLY | O_NONBLOCK, 0);

    if(fd < 0){
        WARN("Unable to open device %s: %d (%s)\n", This->devnode, errno,
                strerror(errno));
        return AUDCLNT_E_DEVICE_INVALIDATED;
    }

    ret = setup_oss_device(mode, fd, pwfx, outpwfx);

    close(fd);

    return ret;
}

static HRESULT WINAPI AudioClient_GetMixFormat(IAudioClient *iface,
        WAVEFORMATEX **pwfx)
{
    ACImpl *This = impl_from_IAudioClient(iface);
    WAVEFORMATEXTENSIBLE *fmt;
    int formats;

    TRACE("(%p)->(%p)\n", This, pwfx);

    if(!pwfx)
        return E_POINTER;
    *pwfx = NULL;

    if(This->dataflow == eRender)
        formats = This->ai.oformats;
    else if(This->dataflow == eCapture)
        formats = This->ai.iformats;
    else
        return E_UNEXPECTED;

    fmt = CoTaskMemAlloc(sizeof(WAVEFORMATEXTENSIBLE));
    if(!fmt)
        return E_OUTOFMEMORY;

    fmt->Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
    if(formats & AFMT_S16_LE){
        fmt->Format.wBitsPerSample = 16;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
#ifdef AFMT_FLOAT
    }else if(formats & AFMT_FLOAT){
        fmt->Format.wBitsPerSample = 32;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_IEEE_FLOAT;
#endif
    }else if(formats & AFMT_U8){
        fmt->Format.wBitsPerSample = 8;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
    }else if(formats & AFMT_S32_LE){
        fmt->Format.wBitsPerSample = 32;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
    }else if(formats & AFMT_S24_LE){
        fmt->Format.wBitsPerSample = 24;
        fmt->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
    }else{
        WARN("Didn't recognize any available OSS formats: %x\n", formats);
        CoTaskMemFree(fmt);
        return E_FAIL;
    }

    /* some OSS drivers are buggy, so set reasonable defaults if
     * the reported values seem wacky */
    fmt->Format.nChannels = max(This->ai.max_channels, This->ai.min_channels);
    if(fmt->Format.nChannels == 0 || fmt->Format.nChannels > 8)
        fmt->Format.nChannels = 2;

    if(This->ai.max_rate == 0)
        fmt->Format.nSamplesPerSec = 44100;
    else
        fmt->Format.nSamplesPerSec = min(This->ai.max_rate, 44100);
    if(fmt->Format.nSamplesPerSec < This->ai.min_rate)
        fmt->Format.nSamplesPerSec = This->ai.min_rate;

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

    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);

    *pwfx = (WAVEFORMATEX*)fmt;
    dump_fmt(*pwfx);

    return S_OK;
}

static HRESULT WINAPI AudioClient_GetDevicePeriod(IAudioClient *iface,
        REFERENCE_TIME *defperiod, REFERENCE_TIME *minperiod)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)->(%p, %p)\n", This, defperiod, minperiod);

    if(!defperiod && !minperiod)
        return E_POINTER;

    if(defperiod)
        *defperiod = DefaultPeriod;
    if(minperiod)
        *minperiod = MinimumPeriod;

    return S_OK;
}

static void oss_silence_buffer(ACImpl *This, BYTE *buf, UINT32 frames)
{
    if(This->fmt->wBitsPerSample == 8)
        memset(buf, 128, frames * This->fmt->nBlockAlign);
    else
        memset(buf, 0, frames * This->fmt->nBlockAlign);
}

static void oss_write_data(ACImpl *This)
{
    ssize_t written_bytes;
    UINT32 written_frames, in_oss_frames, write_limit, max_period;
    size_t to_write_frames, to_write_bytes;
    audio_buf_info bi;
    BYTE *buf =
        This->local_buffer + (This->lcl_offs_frames * This->fmt->nBlockAlign);

    if(This->held_frames == 0)
        return;

    if(This->lcl_offs_frames + This->held_frames > This->bufsize_frames)
        to_write_frames = This->bufsize_frames - This->lcl_offs_frames;
    else
        to_write_frames = This->held_frames;

    if(ioctl(This->fd, SNDCTL_DSP_GETOSPACE, &bi) < 0){
        WARN("GETOSPACE failed: %d (%s)\n", errno, strerror(errno));
        return;
    }

    max_period = max(bi.fragsize / This->fmt->nBlockAlign, This->period_frames);

    if(bi.bytes > This->oss_bufsize_bytes){
        TRACE("New buffer size (%u) is larger than old buffer size (%u)\n",
                bi.bytes, This->oss_bufsize_bytes);
        This->oss_bufsize_bytes = bi.bytes;
        in_oss_frames = 0;
    }else if(This->oss_bufsize_bytes - bi.bytes <= bi.fragsize)
        in_oss_frames = 0;
    else
        in_oss_frames = (This->oss_bufsize_bytes - bi.bytes) / This->fmt->nBlockAlign;

    write_limit = 0;
    while(write_limit + in_oss_frames < max_period * 3)
        write_limit += max_period;
    if(write_limit == 0)
        return;

    to_write_frames = min(to_write_frames, write_limit);
    to_write_bytes = to_write_frames * This->fmt->nBlockAlign;

    if(This->session->mute)
        oss_silence_buffer(This, buf, to_write_frames);

    written_bytes = write(This->fd, buf, to_write_bytes);
    if(written_bytes < 0){
        /* EAGAIN is OSS buffer full, log that too */
        WARN("write failed: %d (%s)\n", errno, strerror(errno));
        return;
    }
    written_frames = written_bytes / This->fmt->nBlockAlign;

    This->lcl_offs_frames += written_frames;
    This->lcl_offs_frames %= This->bufsize_frames;
    This->held_frames -= written_frames;

    if(written_frames < to_write_frames){
        /* OSS buffer probably full */
        return;
    }

    if(This->held_frames && written_frames < write_limit){
        /* wrapped and have some data back at the start to write */

        to_write_frames = min(write_limit - written_frames, This->held_frames);
        to_write_bytes = to_write_frames * This->fmt->nBlockAlign;

        if(This->session->mute)
            oss_silence_buffer(This, This->local_buffer, to_write_frames);

        written_bytes = write(This->fd, This->local_buffer, to_write_bytes);
        if(written_bytes < 0){
            WARN("write failed: %d (%s)\n", errno, strerror(errno));
            return;
        }
        written_frames = written_bytes / This->fmt->nBlockAlign;

        This->lcl_offs_frames += written_frames;
        This->lcl_offs_frames %= This->bufsize_frames;
        This->held_frames -= written_frames;
    }
}

static void oss_read_data(ACImpl *This)
{
    UINT64 pos, readable;
    audio_buf_info bi;
    ssize_t nread;

    if(ioctl(This->fd, SNDCTL_DSP_GETISPACE, &bi) < 0){
        WARN("GETISPACE failed: %d (%s)\n", errno, strerror(errno));
        return;
    }

    pos = (This->held_frames + This->lcl_offs_frames) % This->bufsize_frames;
    readable = (This->bufsize_frames - pos) * This->fmt->nBlockAlign;

    if(bi.bytes < readable)
        readable = bi.bytes;

    nread = read(This->fd, This->local_buffer + pos * This->fmt->nBlockAlign,
            readable);
    if(nread < 0){
        WARN("read failed: %d (%s)\n", errno, strerror(errno));
        return;
    }

    This->held_frames += nread / This->fmt->nBlockAlign;

    if(This->held_frames > This->bufsize_frames){
        WARN("Overflow of unread data\n");
        This->lcl_offs_frames += This->held_frames;
        This->lcl_offs_frames %= This->bufsize_frames;
        This->held_frames = This->bufsize_frames;
    }
}

static void CALLBACK oss_period_callback(void *user, BOOLEAN timer)
{
    ACImpl *This = user;

    EnterCriticalSection(&This->lock);

    if(This->playing){
        if(This->dataflow == eRender && This->held_frames)
            oss_write_data(This);
        else if(This->dataflow == eCapture)
            oss_read_data(This);
    }

    LeaveCriticalSection(&This->lock);

    if(This->event)
        SetEvent(This->event);
}

static HRESULT WINAPI AudioClient_Start(IAudioClient *iface)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)\n", This);

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    if((This->flags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK) && !This->event){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_EVENTHANDLE_NOT_SET;
    }

    if(This->playing){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_STOPPED;
    }

    if(!CreateTimerQueueTimer(&This->timer, g_timer_q,
                oss_period_callback, This, 0, This->period_us / 1000,
                WT_EXECUTEINTIMERTHREAD))
        ERR("Unable to create period timer: %u\n", GetLastError());

    This->playing = TRUE;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioClient_Stop(IAudioClient *iface)
{
    ACImpl *This = impl_from_IAudioClient(iface);
    HANDLE event;
    DWORD wait;

    TRACE("(%p)\n", This);

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    if(!This->playing){
        LeaveCriticalSection(&This->lock);
        return S_FALSE;
    }

    event = CreateEventW(NULL, TRUE, FALSE, NULL);
    wait = !DeleteTimerQueueTimer(g_timer_q, This->timer, event);
    if(wait)
        WARN("DeleteTimerQueueTimer error %u\n", GetLastError());
    wait = wait && GetLastError() == ERROR_IO_PENDING;

    This->playing = FALSE;

    LeaveCriticalSection(&This->lock);

    if(event && wait)
        WaitForSingleObject(event, INFINITE);
    CloseHandle(event);

    return S_OK;
}

static HRESULT WINAPI AudioClient_Reset(IAudioClient *iface)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)\n", This);

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    if(This->playing){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_STOPPED;
    }

    if(This->getbuf_last){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_BUFFER_OPERATION_PENDING;
    }

    if(This->dataflow == eRender){
        This->written_frames = 0;
        This->last_pos_frames = 0;
    }else{
        This->written_frames += This->held_frames;
    }
    This->held_frames = 0;
    This->lcl_offs_frames = 0;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioClient_SetEventHandle(IAudioClient *iface,
        HANDLE event)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)->(%p)\n", This, event);

    if(!event)
        return E_INVALIDARG;

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    if(!(This->flags & AUDCLNT_STREAMFLAGS_EVENTCALLBACK)){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_EVENTHANDLE_NOT_EXPECTED;
    }

    if (This->event){
        LeaveCriticalSection(&This->lock);
        FIXME("called twice\n");
        return HRESULT_FROM_WIN32(ERROR_INVALID_NAME);
    }

    This->event = event;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioClient_GetService(IAudioClient *iface, REFIID riid,
        void **ppv)
{
    ACImpl *This = impl_from_IAudioClient(iface);

    TRACE("(%p)->(%s, %p)\n", This, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    EnterCriticalSection(&This->lock);

    if(!This->initted){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_NOT_INITIALIZED;
    }

    if(IsEqualIID(riid, &IID_IAudioRenderClient)){
        if(This->dataflow != eRender){
            LeaveCriticalSection(&This->lock);
            return AUDCLNT_E_WRONG_ENDPOINT_TYPE;
        }
        IAudioRenderClient_AddRef(&This->IAudioRenderClient_iface);
        *ppv = &This->IAudioRenderClient_iface;
    }else if(IsEqualIID(riid, &IID_IAudioCaptureClient)){
        if(This->dataflow != eCapture){
            LeaveCriticalSection(&This->lock);
            return AUDCLNT_E_WRONG_ENDPOINT_TYPE;
        }
        IAudioCaptureClient_AddRef(&This->IAudioCaptureClient_iface);
        *ppv = &This->IAudioCaptureClient_iface;
    }else if(IsEqualIID(riid, &IID_IAudioClock)){
        IAudioClock_AddRef(&This->IAudioClock_iface);
        *ppv = &This->IAudioClock_iface;
    }else if(IsEqualIID(riid, &IID_IAudioStreamVolume)){
        IAudioStreamVolume_AddRef(&This->IAudioStreamVolume_iface);
        *ppv = &This->IAudioStreamVolume_iface;
    }else if(IsEqualIID(riid, &IID_IAudioSessionControl)){
        if(!This->session_wrapper){
            This->session_wrapper = AudioSessionWrapper_Create(This);
            if(!This->session_wrapper){
                LeaveCriticalSection(&This->lock);
                return E_OUTOFMEMORY;
            }
        }else
            IAudioSessionControl2_AddRef(&This->session_wrapper->IAudioSessionControl2_iface);

        *ppv = &This->session_wrapper->IAudioSessionControl2_iface;
    }else if(IsEqualIID(riid, &IID_IChannelAudioVolume)){
        if(!This->session_wrapper){
            This->session_wrapper = AudioSessionWrapper_Create(This);
            if(!This->session_wrapper){
                LeaveCriticalSection(&This->lock);
                return E_OUTOFMEMORY;
            }
        }else
            IChannelAudioVolume_AddRef(&This->session_wrapper->IChannelAudioVolume_iface);

        *ppv = &This->session_wrapper->IChannelAudioVolume_iface;
    }else if(IsEqualIID(riid, &IID_ISimpleAudioVolume)){
        if(!This->session_wrapper){
            This->session_wrapper = AudioSessionWrapper_Create(This);
            if(!This->session_wrapper){
                LeaveCriticalSection(&This->lock);
                return E_OUTOFMEMORY;
            }
        }else
            ISimpleAudioVolume_AddRef(&This->session_wrapper->ISimpleAudioVolume_iface);

        *ppv = &This->session_wrapper->ISimpleAudioVolume_iface;
    }

    if(*ppv){
        LeaveCriticalSection(&This->lock);
        return S_OK;
    }

    LeaveCriticalSection(&This->lock);

    FIXME("stub %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static const IAudioClientVtbl AudioClient_Vtbl =
{
    AudioClient_QueryInterface,
    AudioClient_AddRef,
    AudioClient_Release,
    AudioClient_Initialize,
    AudioClient_GetBufferSize,
    AudioClient_GetStreamLatency,
    AudioClient_GetCurrentPadding,
    AudioClient_IsFormatSupported,
    AudioClient_GetMixFormat,
    AudioClient_GetDevicePeriod,
    AudioClient_Start,
    AudioClient_Stop,
    AudioClient_Reset,
    AudioClient_SetEventHandle,
    AudioClient_GetService
};

static HRESULT WINAPI AudioRenderClient_QueryInterface(
        IAudioRenderClient *iface, REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) ||
            IsEqualIID(riid, &IID_IAudioRenderClient))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI AudioRenderClient_AddRef(IAudioRenderClient *iface)
{
    ACImpl *This = impl_from_IAudioRenderClient(iface);
    return AudioClient_AddRef(&This->IAudioClient_iface);
}

static ULONG WINAPI AudioRenderClient_Release(IAudioRenderClient *iface)
{
    ACImpl *This = impl_from_IAudioRenderClient(iface);
    return AudioClient_Release(&This->IAudioClient_iface);
}

static HRESULT WINAPI AudioRenderClient_GetBuffer(IAudioRenderClient *iface,
        UINT32 frames, BYTE **data)
{
    ACImpl *This = impl_from_IAudioRenderClient(iface);
    UINT32 write_pos;

    TRACE("(%p)->(%u, %p)\n", This, frames, data);

    if(!data)
        return E_POINTER;

    *data = NULL;

    EnterCriticalSection(&This->lock);

    if(This->getbuf_last){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_OUT_OF_ORDER;
    }

    if(!frames){
        LeaveCriticalSection(&This->lock);
        return S_OK;
    }

    if(This->held_frames + frames > This->bufsize_frames){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_BUFFER_TOO_LARGE;
    }

    write_pos =
        (This->lcl_offs_frames + This->held_frames) % This->bufsize_frames;
    if(write_pos + frames > This->bufsize_frames){
        if(This->tmp_buffer_frames < frames){
            HeapFree(GetProcessHeap(), 0, This->tmp_buffer);
            This->tmp_buffer = HeapAlloc(GetProcessHeap(), 0,
                    frames * This->fmt->nBlockAlign);
            if(!This->tmp_buffer){
                LeaveCriticalSection(&This->lock);
                return E_OUTOFMEMORY;
            }
            This->tmp_buffer_frames = frames;
        }
        *data = This->tmp_buffer;
        This->getbuf_last = -frames;
    }else{
        *data = This->local_buffer + write_pos * This->fmt->nBlockAlign;
        This->getbuf_last = frames;
    }

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static void oss_wrap_buffer(ACImpl *This, BYTE *buffer, UINT32 written_frames)
{
    UINT32 write_offs_frames =
        (This->lcl_offs_frames + This->held_frames) % This->bufsize_frames;
    UINT32 write_offs_bytes = write_offs_frames * This->fmt->nBlockAlign;
    UINT32 chunk_frames = This->bufsize_frames - write_offs_frames;
    UINT32 chunk_bytes = chunk_frames * This->fmt->nBlockAlign;
    UINT32 written_bytes = written_frames * This->fmt->nBlockAlign;

    if(written_bytes <= chunk_bytes){
        memcpy(This->local_buffer + write_offs_bytes, buffer, written_bytes);
    }else{
        memcpy(This->local_buffer + write_offs_bytes, buffer, chunk_bytes);
        memcpy(This->local_buffer, buffer + chunk_bytes,
                written_bytes - chunk_bytes);
    }
}

static HRESULT WINAPI AudioRenderClient_ReleaseBuffer(
        IAudioRenderClient *iface, UINT32 written_frames, DWORD flags)
{
    ACImpl *This = impl_from_IAudioRenderClient(iface);
    BYTE *buffer;

    TRACE("(%p)->(%u, %x)\n", This, written_frames, flags);

    EnterCriticalSection(&This->lock);

    if(!written_frames){
        This->getbuf_last = 0;
        LeaveCriticalSection(&This->lock);
        return S_OK;
    }

    if(!This->getbuf_last){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_OUT_OF_ORDER;
    }

    if(written_frames > (This->getbuf_last >= 0 ? This->getbuf_last : -This->getbuf_last)){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_INVALID_SIZE;
    }

    if(This->getbuf_last >= 0)
        buffer = This->local_buffer + This->fmt->nBlockAlign *
          ((This->lcl_offs_frames + This->held_frames) % This->bufsize_frames);
    else
        buffer = This->tmp_buffer;

    if(flags & AUDCLNT_BUFFERFLAGS_SILENT)
        oss_silence_buffer(This, buffer, written_frames);

    if(This->getbuf_last < 0)
        oss_wrap_buffer(This, buffer, written_frames);

    This->held_frames += written_frames;
    This->written_frames += written_frames;
    This->getbuf_last = 0;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static const IAudioRenderClientVtbl AudioRenderClient_Vtbl = {
    AudioRenderClient_QueryInterface,
    AudioRenderClient_AddRef,
    AudioRenderClient_Release,
    AudioRenderClient_GetBuffer,
    AudioRenderClient_ReleaseBuffer
};

static HRESULT WINAPI AudioCaptureClient_QueryInterface(
        IAudioCaptureClient *iface, REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) ||
            IsEqualIID(riid, &IID_IAudioCaptureClient))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI AudioCaptureClient_AddRef(IAudioCaptureClient *iface)
{
    ACImpl *This = impl_from_IAudioCaptureClient(iface);
    return IAudioClient_AddRef(&This->IAudioClient_iface);
}

static ULONG WINAPI AudioCaptureClient_Release(IAudioCaptureClient *iface)
{
    ACImpl *This = impl_from_IAudioCaptureClient(iface);
    return IAudioClient_Release(&This->IAudioClient_iface);
}

static HRESULT WINAPI AudioCaptureClient_GetBuffer(IAudioCaptureClient *iface,
        BYTE **data, UINT32 *frames, DWORD *flags, UINT64 *devpos,
        UINT64 *qpcpos)
{
    ACImpl *This = impl_from_IAudioCaptureClient(iface);

    TRACE("(%p)->(%p, %p, %p, %p, %p)\n", This, data, frames, flags,
            devpos, qpcpos);

    if(!data || !frames || !flags)
        return E_POINTER;

    EnterCriticalSection(&This->lock);

    if(This->getbuf_last){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_OUT_OF_ORDER;
    }

    if(This->held_frames < This->period_frames){
        *frames = 0;
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_S_BUFFER_EMPTY;
    }

    *flags = 0;

    *frames = This->period_frames;

    if(This->lcl_offs_frames + *frames > This->bufsize_frames){
        UINT32 chunk_bytes, offs_bytes, frames_bytes;
        if(This->tmp_buffer_frames < *frames){
            HeapFree(GetProcessHeap(), 0, This->tmp_buffer);
            This->tmp_buffer = HeapAlloc(GetProcessHeap(), 0,
                    *frames * This->fmt->nBlockAlign);
            if(!This->tmp_buffer){
                LeaveCriticalSection(&This->lock);
                return E_OUTOFMEMORY;
            }
            This->tmp_buffer_frames = *frames;
        }

        *data = This->tmp_buffer;
        chunk_bytes = (This->bufsize_frames - This->lcl_offs_frames) *
            This->fmt->nBlockAlign;
        offs_bytes = This->lcl_offs_frames * This->fmt->nBlockAlign;
        frames_bytes = *frames * This->fmt->nBlockAlign;
        memcpy(This->tmp_buffer, This->local_buffer + offs_bytes, chunk_bytes);
        memcpy(This->tmp_buffer + chunk_bytes, This->local_buffer,
                frames_bytes - chunk_bytes);
    }else
        *data = This->local_buffer +
            This->lcl_offs_frames * This->fmt->nBlockAlign;

    This->getbuf_last = *frames;

    if(devpos)
       *devpos = This->written_frames;
    if(qpcpos){
        LARGE_INTEGER stamp, freq;
        QueryPerformanceCounter(&stamp);
        QueryPerformanceFrequency(&freq);
        *qpcpos = (stamp.QuadPart * (INT64)10000000) / freq.QuadPart;
    }

    LeaveCriticalSection(&This->lock);

    return *frames ? S_OK : AUDCLNT_S_BUFFER_EMPTY;
}

static HRESULT WINAPI AudioCaptureClient_ReleaseBuffer(
        IAudioCaptureClient *iface, UINT32 done)
{
    ACImpl *This = impl_from_IAudioCaptureClient(iface);

    TRACE("(%p)->(%u)\n", This, done);

    EnterCriticalSection(&This->lock);

    if(!done){
        This->getbuf_last = 0;
        LeaveCriticalSection(&This->lock);
        return S_OK;
    }

    if(!This->getbuf_last){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_OUT_OF_ORDER;
    }

    if(This->getbuf_last != done){
        LeaveCriticalSection(&This->lock);
        return AUDCLNT_E_INVALID_SIZE;
    }

    This->written_frames += done;
    This->held_frames -= done;
    This->lcl_offs_frames += done;
    This->lcl_offs_frames %= This->bufsize_frames;
    This->getbuf_last = 0;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioCaptureClient_GetNextPacketSize(
        IAudioCaptureClient *iface, UINT32 *frames)
{
    ACImpl *This = impl_from_IAudioCaptureClient(iface);

    TRACE("(%p)->(%p)\n", This, frames);

    if(!frames)
        return E_POINTER;

    EnterCriticalSection(&This->lock);

    *frames = This->held_frames < This->period_frames ? 0 : This->period_frames;

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static const IAudioCaptureClientVtbl AudioCaptureClient_Vtbl =
{
    AudioCaptureClient_QueryInterface,
    AudioCaptureClient_AddRef,
    AudioCaptureClient_Release,
    AudioCaptureClient_GetBuffer,
    AudioCaptureClient_ReleaseBuffer,
    AudioCaptureClient_GetNextPacketSize
};

static HRESULT WINAPI AudioClock_QueryInterface(IAudioClock *iface,
        REFIID riid, void **ppv)
{
    ACImpl *This = impl_from_IAudioClock(iface);

    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) || IsEqualIID(riid, &IID_IAudioClock))
        *ppv = iface;
    else if(IsEqualIID(riid, &IID_IAudioClock2))
        *ppv = &This->IAudioClock2_iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI AudioClock_AddRef(IAudioClock *iface)
{
    ACImpl *This = impl_from_IAudioClock(iface);
    return IAudioClient_AddRef(&This->IAudioClient_iface);
}

static ULONG WINAPI AudioClock_Release(IAudioClock *iface)
{
    ACImpl *This = impl_from_IAudioClock(iface);
    return IAudioClient_Release(&This->IAudioClient_iface);
}

static HRESULT WINAPI AudioClock_GetFrequency(IAudioClock *iface, UINT64 *freq)
{
    ACImpl *This = impl_from_IAudioClock(iface);

    TRACE("(%p)->(%p)\n", This, freq);

    *freq = This->fmt->nSamplesPerSec;

    return S_OK;
}

static HRESULT WINAPI AudioClock_GetPosition(IAudioClock *iface, UINT64 *pos,
        UINT64 *qpctime)
{
    ACImpl *This = impl_from_IAudioClock(iface);
    int delay;

    TRACE("(%p)->(%p, %p)\n", This, pos, qpctime);

    if(!pos)
        return E_POINTER;

    EnterCriticalSection(&This->lock);

    if(This->dataflow == eRender){
        if(!This->playing || !This->held_frames ||
                ioctl(This->fd, SNDCTL_DSP_GETODELAY, &delay) < 0)
            delay = 0;
        else
            delay /= This->fmt->nBlockAlign;
        if(This->held_frames + delay >= This->written_frames)
            *pos = This->last_pos_frames;
        else{
            *pos = This->written_frames - This->held_frames - delay;
            if(*pos < This->last_pos_frames)
                *pos = This->last_pos_frames;
        }
    }else if(This->dataflow == eCapture){
        audio_buf_info bi;
        UINT32 held;

        if(ioctl(This->fd, SNDCTL_DSP_GETISPACE, &bi) < 0){
            TRACE("GETISPACE failed: %d (%s)\n", errno, strerror(errno));
            held = 0;
        }else{
            if(bi.bytes <= bi.fragsize)
                held = 0;
            else
                held = bi.bytes / This->fmt->nBlockAlign;
        }

        *pos = This->written_frames + held;
    }

    This->last_pos_frames = *pos;

    LeaveCriticalSection(&This->lock);

    if(qpctime){
        LARGE_INTEGER stamp, freq;
        QueryPerformanceCounter(&stamp);
        QueryPerformanceFrequency(&freq);
        *qpctime = (stamp.QuadPart * (INT64)10000000) / freq.QuadPart;
    }

    return S_OK;
}

static HRESULT WINAPI AudioClock_GetCharacteristics(IAudioClock *iface,
        DWORD *chars)
{
    ACImpl *This = impl_from_IAudioClock(iface);

    TRACE("(%p)->(%p)\n", This, chars);

    if(!chars)
        return E_POINTER;

    *chars = AUDIOCLOCK_CHARACTERISTIC_FIXED_FREQ;

    return S_OK;
}

static const IAudioClockVtbl AudioClock_Vtbl =
{
    AudioClock_QueryInterface,
    AudioClock_AddRef,
    AudioClock_Release,
    AudioClock_GetFrequency,
    AudioClock_GetPosition,
    AudioClock_GetCharacteristics
};

static HRESULT WINAPI AudioClock2_QueryInterface(IAudioClock2 *iface,
        REFIID riid, void **ppv)
{
    ACImpl *This = impl_from_IAudioClock2(iface);
    return IAudioClock_QueryInterface(&This->IAudioClock_iface, riid, ppv);
}

static ULONG WINAPI AudioClock2_AddRef(IAudioClock2 *iface)
{
    ACImpl *This = impl_from_IAudioClock2(iface);
    return IAudioClient_AddRef(&This->IAudioClient_iface);
}

static ULONG WINAPI AudioClock2_Release(IAudioClock2 *iface)
{
    ACImpl *This = impl_from_IAudioClock2(iface);
    return IAudioClient_Release(&This->IAudioClient_iface);
}

static HRESULT WINAPI AudioClock2_GetDevicePosition(IAudioClock2 *iface,
        UINT64 *pos, UINT64 *qpctime)
{
    ACImpl *This = impl_from_IAudioClock2(iface);

    FIXME("(%p)->(%p, %p)\n", This, pos, qpctime);

    return E_NOTIMPL;
}

static const IAudioClock2Vtbl AudioClock2_Vtbl =
{
    AudioClock2_QueryInterface,
    AudioClock2_AddRef,
    AudioClock2_Release,
    AudioClock2_GetDevicePosition
};

static AudioSessionWrapper *AudioSessionWrapper_Create(ACImpl *client)
{
    AudioSessionWrapper *ret;

    ret = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY,
            sizeof(AudioSessionWrapper));
    if(!ret)
        return NULL;

    ret->IAudioSessionControl2_iface.lpVtbl = &AudioSessionControl2_Vtbl;
    ret->ISimpleAudioVolume_iface.lpVtbl = &SimpleAudioVolume_Vtbl;
    ret->IChannelAudioVolume_iface.lpVtbl = &ChannelAudioVolume_Vtbl;

    ret->ref = 1;

    ret->client = client;
    if(client){
        ret->session = client->session;
        AudioClient_AddRef(&client->IAudioClient_iface);
    }

    return ret;
}

static HRESULT WINAPI AudioSessionControl_QueryInterface(
        IAudioSessionControl2 *iface, REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) ||
            IsEqualIID(riid, &IID_IAudioSessionControl) ||
            IsEqualIID(riid, &IID_IAudioSessionControl2))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI AudioSessionControl_AddRef(IAudioSessionControl2 *iface)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);
    ULONG ref;
    ref = InterlockedIncrement(&This->ref);
    TRACE("(%p) Refcount now %u\n", This, ref);
    return ref;
}

static ULONG WINAPI AudioSessionControl_Release(IAudioSessionControl2 *iface)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);
    ULONG ref;
    ref = InterlockedDecrement(&This->ref);
    TRACE("(%p) Refcount now %u\n", This, ref);
    if(!ref){
        if(This->client){
            EnterCriticalSection(&This->client->lock);
            This->client->session_wrapper = NULL;
            LeaveCriticalSection(&This->client->lock);
            AudioClient_Release(&This->client->IAudioClient_iface);
        }
        HeapFree(GetProcessHeap(), 0, This);
    }
    return ref;
}

static HRESULT WINAPI AudioSessionControl_GetState(IAudioSessionControl2 *iface,
        AudioSessionState *state)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);
    ACImpl *client;

    TRACE("(%p)->(%p)\n", This, state);

    if(!state)
        return NULL_PTR_ERR;

    EnterCriticalSection(&g_sessions_lock);

    if(list_empty(&This->session->clients)){
        *state = AudioSessionStateExpired;
        LeaveCriticalSection(&g_sessions_lock);
        return S_OK;
    }

    LIST_FOR_EACH_ENTRY(client, &This->session->clients, ACImpl, entry){
        EnterCriticalSection(&client->lock);
        if(client->playing){
            *state = AudioSessionStateActive;
            LeaveCriticalSection(&client->lock);
            LeaveCriticalSection(&g_sessions_lock);
            return S_OK;
        }
        LeaveCriticalSection(&client->lock);
    }

    LeaveCriticalSection(&g_sessions_lock);

    *state = AudioSessionStateInactive;

    return S_OK;
}

static HRESULT WINAPI AudioSessionControl_GetDisplayName(
        IAudioSessionControl2 *iface, WCHAR **name)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p) - stub\n", This, name);

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_SetDisplayName(
        IAudioSessionControl2 *iface, const WCHAR *name, const GUID *session)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p, %s) - stub\n", This, name, debugstr_guid(session));

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_GetIconPath(
        IAudioSessionControl2 *iface, WCHAR **path)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p) - stub\n", This, path);

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_SetIconPath(
        IAudioSessionControl2 *iface, const WCHAR *path, const GUID *session)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p, %s) - stub\n", This, path, debugstr_guid(session));

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_GetGroupingParam(
        IAudioSessionControl2 *iface, GUID *group)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p) - stub\n", This, group);

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_SetGroupingParam(
        IAudioSessionControl2 *iface, const GUID *group, const GUID *session)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%s, %s) - stub\n", This, debugstr_guid(group),
            debugstr_guid(session));

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_RegisterAudioSessionNotification(
        IAudioSessionControl2 *iface, IAudioSessionEvents *events)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p) - stub\n", This, events);

    return S_OK;
}

static HRESULT WINAPI AudioSessionControl_UnregisterAudioSessionNotification(
        IAudioSessionControl2 *iface, IAudioSessionEvents *events)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p) - stub\n", This, events);

    return S_OK;
}

static HRESULT WINAPI AudioSessionControl_GetSessionIdentifier(
        IAudioSessionControl2 *iface, WCHAR **id)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p) - stub\n", This, id);

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_GetSessionInstanceIdentifier(
        IAudioSessionControl2 *iface, WCHAR **id)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    FIXME("(%p)->(%p) - stub\n", This, id);

    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionControl_GetProcessId(
        IAudioSessionControl2 *iface, DWORD *pid)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    TRACE("(%p)->(%p)\n", This, pid);

    if(!pid)
        return E_POINTER;

    *pid = GetCurrentProcessId();

    return S_OK;
}

static HRESULT WINAPI AudioSessionControl_IsSystemSoundsSession(
        IAudioSessionControl2 *iface)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    TRACE("(%p)\n", This);

    return S_FALSE;
}

static HRESULT WINAPI AudioSessionControl_SetDuckingPreference(
        IAudioSessionControl2 *iface, BOOL optout)
{
    AudioSessionWrapper *This = impl_from_IAudioSessionControl2(iface);

    TRACE("(%p)->(%d)\n", This, optout);

    return S_OK;
}

static const IAudioSessionControl2Vtbl AudioSessionControl2_Vtbl =
{
    AudioSessionControl_QueryInterface,
    AudioSessionControl_AddRef,
    AudioSessionControl_Release,
    AudioSessionControl_GetState,
    AudioSessionControl_GetDisplayName,
    AudioSessionControl_SetDisplayName,
    AudioSessionControl_GetIconPath,
    AudioSessionControl_SetIconPath,
    AudioSessionControl_GetGroupingParam,
    AudioSessionControl_SetGroupingParam,
    AudioSessionControl_RegisterAudioSessionNotification,
    AudioSessionControl_UnregisterAudioSessionNotification,
    AudioSessionControl_GetSessionIdentifier,
    AudioSessionControl_GetSessionInstanceIdentifier,
    AudioSessionControl_GetProcessId,
    AudioSessionControl_IsSystemSoundsSession,
    AudioSessionControl_SetDuckingPreference
};

static HRESULT WINAPI SimpleAudioVolume_QueryInterface(
        ISimpleAudioVolume *iface, REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) ||
            IsEqualIID(riid, &IID_ISimpleAudioVolume))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI SimpleAudioVolume_AddRef(ISimpleAudioVolume *iface)
{
    AudioSessionWrapper *This = impl_from_ISimpleAudioVolume(iface);
    return AudioSessionControl_AddRef(&This->IAudioSessionControl2_iface);
}

static ULONG WINAPI SimpleAudioVolume_Release(ISimpleAudioVolume *iface)
{
    AudioSessionWrapper *This = impl_from_ISimpleAudioVolume(iface);
    return AudioSessionControl_Release(&This->IAudioSessionControl2_iface);
}

static HRESULT WINAPI SimpleAudioVolume_SetMasterVolume(
        ISimpleAudioVolume *iface, float level, const GUID *context)
{
    AudioSessionWrapper *This = impl_from_ISimpleAudioVolume(iface);
    AudioSession *session = This->session;

    TRACE("(%p)->(%f, %s)\n", session, level, wine_dbgstr_guid(context));

    if(level < 0.f || level > 1.f)
        return E_INVALIDARG;

    if(context)
        FIXME("Notifications not supported yet\n");

    EnterCriticalSection(&session->lock);

    session->master_vol = level;

    TRACE("OSS doesn't support setting volume\n");

    LeaveCriticalSection(&session->lock);

    return S_OK;
}

static HRESULT WINAPI SimpleAudioVolume_GetMasterVolume(
        ISimpleAudioVolume *iface, float *level)
{
    AudioSessionWrapper *This = impl_from_ISimpleAudioVolume(iface);
    AudioSession *session = This->session;

    TRACE("(%p)->(%p)\n", session, level);

    if(!level)
        return NULL_PTR_ERR;

    *level = session->master_vol;

    return S_OK;
}

static HRESULT WINAPI SimpleAudioVolume_SetMute(ISimpleAudioVolume *iface,
        BOOL mute, const GUID *context)
{
    AudioSessionWrapper *This = impl_from_ISimpleAudioVolume(iface);
    AudioSession *session = This->session;

    TRACE("(%p)->(%u, %p)\n", session, mute, context);

    EnterCriticalSection(&session->lock);

    session->mute = mute;

    LeaveCriticalSection(&session->lock);

    return S_OK;
}

static HRESULT WINAPI SimpleAudioVolume_GetMute(ISimpleAudioVolume *iface,
        BOOL *mute)
{
    AudioSessionWrapper *This = impl_from_ISimpleAudioVolume(iface);
    AudioSession *session = This->session;

    TRACE("(%p)->(%p)\n", session, mute);

    if(!mute)
        return NULL_PTR_ERR;

    *mute = This->session->mute;

    return S_OK;
}

static const ISimpleAudioVolumeVtbl SimpleAudioVolume_Vtbl  =
{
    SimpleAudioVolume_QueryInterface,
    SimpleAudioVolume_AddRef,
    SimpleAudioVolume_Release,
    SimpleAudioVolume_SetMasterVolume,
    SimpleAudioVolume_GetMasterVolume,
    SimpleAudioVolume_SetMute,
    SimpleAudioVolume_GetMute
};

static HRESULT WINAPI AudioStreamVolume_QueryInterface(
        IAudioStreamVolume *iface, REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) ||
            IsEqualIID(riid, &IID_IAudioStreamVolume))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI AudioStreamVolume_AddRef(IAudioStreamVolume *iface)
{
    ACImpl *This = impl_from_IAudioStreamVolume(iface);
    return IAudioClient_AddRef(&This->IAudioClient_iface);
}

static ULONG WINAPI AudioStreamVolume_Release(IAudioStreamVolume *iface)
{
    ACImpl *This = impl_from_IAudioStreamVolume(iface);
    return IAudioClient_Release(&This->IAudioClient_iface);
}

static HRESULT WINAPI AudioStreamVolume_GetChannelCount(
        IAudioStreamVolume *iface, UINT32 *out)
{
    ACImpl *This = impl_from_IAudioStreamVolume(iface);

    TRACE("(%p)->(%p)\n", This, out);

    if(!out)
        return E_POINTER;

    *out = This->fmt->nChannels;

    return S_OK;
}

static HRESULT WINAPI AudioStreamVolume_SetChannelVolume(
        IAudioStreamVolume *iface, UINT32 index, float level)
{
    ACImpl *This = impl_from_IAudioStreamVolume(iface);

    TRACE("(%p)->(%d, %f)\n", This, index, level);

    if(level < 0.f || level > 1.f)
        return E_INVALIDARG;

    if(index >= This->fmt->nChannels)
        return E_INVALIDARG;

    EnterCriticalSection(&This->lock);

    This->vols[index] = level;

    TRACE("OSS doesn't support setting volume\n");

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioStreamVolume_GetChannelVolume(
        IAudioStreamVolume *iface, UINT32 index, float *level)
{
    ACImpl *This = impl_from_IAudioStreamVolume(iface);

    TRACE("(%p)->(%d, %p)\n", This, index, level);

    if(!level)
        return E_POINTER;

    if(index >= This->fmt->nChannels)
        return E_INVALIDARG;

    *level = This->vols[index];

    return S_OK;
}

static HRESULT WINAPI AudioStreamVolume_SetAllVolumes(
        IAudioStreamVolume *iface, UINT32 count, const float *levels)
{
    ACImpl *This = impl_from_IAudioStreamVolume(iface);
    int i;

    TRACE("(%p)->(%d, %p)\n", This, count, levels);

    if(!levels)
        return E_POINTER;

    if(count != This->fmt->nChannels)
        return E_INVALIDARG;

    EnterCriticalSection(&This->lock);

    for(i = 0; i < count; ++i)
        This->vols[i] = levels[i];

    TRACE("OSS doesn't support setting volume\n");

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static HRESULT WINAPI AudioStreamVolume_GetAllVolumes(
        IAudioStreamVolume *iface, UINT32 count, float *levels)
{
    ACImpl *This = impl_from_IAudioStreamVolume(iface);
    int i;

    TRACE("(%p)->(%d, %p)\n", This, count, levels);

    if(!levels)
        return E_POINTER;

    if(count != This->fmt->nChannels)
        return E_INVALIDARG;

    EnterCriticalSection(&This->lock);

    for(i = 0; i < count; ++i)
        levels[i] = This->vols[i];

    LeaveCriticalSection(&This->lock);

    return S_OK;
}

static const IAudioStreamVolumeVtbl AudioStreamVolume_Vtbl =
{
    AudioStreamVolume_QueryInterface,
    AudioStreamVolume_AddRef,
    AudioStreamVolume_Release,
    AudioStreamVolume_GetChannelCount,
    AudioStreamVolume_SetChannelVolume,
    AudioStreamVolume_GetChannelVolume,
    AudioStreamVolume_SetAllVolumes,
    AudioStreamVolume_GetAllVolumes
};

static HRESULT WINAPI ChannelAudioVolume_QueryInterface(
        IChannelAudioVolume *iface, REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) ||
            IsEqualIID(riid, &IID_IChannelAudioVolume))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI ChannelAudioVolume_AddRef(IChannelAudioVolume *iface)
{
    AudioSessionWrapper *This = impl_from_IChannelAudioVolume(iface);
    return AudioSessionControl_AddRef(&This->IAudioSessionControl2_iface);
}

static ULONG WINAPI ChannelAudioVolume_Release(IChannelAudioVolume *iface)
{
    AudioSessionWrapper *This = impl_from_IChannelAudioVolume(iface);
    return AudioSessionControl_Release(&This->IAudioSessionControl2_iface);
}

static HRESULT WINAPI ChannelAudioVolume_GetChannelCount(
        IChannelAudioVolume *iface, UINT32 *out)
{
    AudioSessionWrapper *This = impl_from_IChannelAudioVolume(iface);
    AudioSession *session = This->session;

    TRACE("(%p)->(%p)\n", session, out);

    if(!out)
        return NULL_PTR_ERR;

    *out = session->channel_count;

    return S_OK;
}

static HRESULT WINAPI ChannelAudioVolume_SetChannelVolume(
        IChannelAudioVolume *iface, UINT32 index, float level,
        const GUID *context)
{
    AudioSessionWrapper *This = impl_from_IChannelAudioVolume(iface);
    AudioSession *session = This->session;

    TRACE("(%p)->(%d, %f, %s)\n", session, index, level,
            wine_dbgstr_guid(context));

    if(level < 0.f || level > 1.f)
        return E_INVALIDARG;

    if(index >= session->channel_count)
        return E_INVALIDARG;

    if(context)
        FIXME("Notifications not supported yet\n");

    EnterCriticalSection(&session->lock);

    session->channel_vols[index] = level;

    TRACE("OSS doesn't support setting volume\n");

    LeaveCriticalSection(&session->lock);

    return S_OK;
}

static HRESULT WINAPI ChannelAudioVolume_GetChannelVolume(
        IChannelAudioVolume *iface, UINT32 index, float *level)
{
    AudioSessionWrapper *This = impl_from_IChannelAudioVolume(iface);
    AudioSession *session = This->session;

    TRACE("(%p)->(%d, %p)\n", session, index, level);

    if(!level)
        return NULL_PTR_ERR;

    if(index >= session->channel_count)
        return E_INVALIDARG;

    *level = session->channel_vols[index];

    return S_OK;
}

static HRESULT WINAPI ChannelAudioVolume_SetAllVolumes(
        IChannelAudioVolume *iface, UINT32 count, const float *levels,
        const GUID *context)
{
    AudioSessionWrapper *This = impl_from_IChannelAudioVolume(iface);
    AudioSession *session = This->session;
    int i;

    TRACE("(%p)->(%d, %p, %s)\n", session, count, levels,
            wine_dbgstr_guid(context));

    if(!levels)
        return NULL_PTR_ERR;

    if(count != session->channel_count)
        return E_INVALIDARG;

    if(context)
        FIXME("Notifications not supported yet\n");

    EnterCriticalSection(&session->lock);

    for(i = 0; i < count; ++i)
        session->channel_vols[i] = levels[i];

    TRACE("OSS doesn't support setting volume\n");

    LeaveCriticalSection(&session->lock);

    return S_OK;
}

static HRESULT WINAPI ChannelAudioVolume_GetAllVolumes(
        IChannelAudioVolume *iface, UINT32 count, float *levels)
{
    AudioSessionWrapper *This = impl_from_IChannelAudioVolume(iface);
    AudioSession *session = This->session;
    int i;

    TRACE("(%p)->(%d, %p)\n", session, count, levels);

    if(!levels)
        return NULL_PTR_ERR;

    if(count != session->channel_count)
        return E_INVALIDARG;

    for(i = 0; i < count; ++i)
        levels[i] = session->channel_vols[i];

    return S_OK;
}

static const IChannelAudioVolumeVtbl ChannelAudioVolume_Vtbl =
{
    ChannelAudioVolume_QueryInterface,
    ChannelAudioVolume_AddRef,
    ChannelAudioVolume_Release,
    ChannelAudioVolume_GetChannelCount,
    ChannelAudioVolume_SetChannelVolume,
    ChannelAudioVolume_GetChannelVolume,
    ChannelAudioVolume_SetAllVolumes,
    ChannelAudioVolume_GetAllVolumes
};

static HRESULT WINAPI AudioSessionManager_QueryInterface(IAudioSessionManager2 *iface,
        REFIID riid, void **ppv)
{
    TRACE("(%p)->(%s, %p)\n", iface, debugstr_guid(riid), ppv);

    if(!ppv)
        return E_POINTER;
    *ppv = NULL;

    if(IsEqualIID(riid, &IID_IUnknown) ||
            IsEqualIID(riid, &IID_IAudioSessionManager) ||
            IsEqualIID(riid, &IID_IAudioSessionManager2))
        *ppv = iface;
    if(*ppv){
        IUnknown_AddRef((IUnknown*)*ppv);
        return S_OK;
    }

    WARN("Unknown interface %s\n", debugstr_guid(riid));
    return E_NOINTERFACE;
}

static ULONG WINAPI AudioSessionManager_AddRef(IAudioSessionManager2 *iface)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    ULONG ref;
    ref = InterlockedIncrement(&This->ref);
    TRACE("(%p) Refcount now %u\n", This, ref);
    return ref;
}

static ULONG WINAPI AudioSessionManager_Release(IAudioSessionManager2 *iface)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    ULONG ref;
    ref = InterlockedDecrement(&This->ref);
    TRACE("(%p) Refcount now %u\n", This, ref);
    if(!ref)
        HeapFree(GetProcessHeap(), 0, This);
    return ref;
}

static HRESULT WINAPI AudioSessionManager_GetAudioSessionControl(
        IAudioSessionManager2 *iface, const GUID *session_guid, DWORD flags,
        IAudioSessionControl **out)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    AudioSession *session;
    AudioSessionWrapper *wrapper;
    HRESULT hr;

    TRACE("(%p)->(%s, %x, %p)\n", This, debugstr_guid(session_guid),
            flags, out);

    hr = get_audio_session(session_guid, This->device, 0, &session);
    if(FAILED(hr))
        return hr;

    wrapper = AudioSessionWrapper_Create(NULL);
    if(!wrapper)
        return E_OUTOFMEMORY;

    wrapper->session = session;

    *out = (IAudioSessionControl*)&wrapper->IAudioSessionControl2_iface;

    return S_OK;
}

static HRESULT WINAPI AudioSessionManager_GetSimpleAudioVolume(
        IAudioSessionManager2 *iface, const GUID *session_guid, DWORD flags,
        ISimpleAudioVolume **out)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    AudioSession *session;
    AudioSessionWrapper *wrapper;
    HRESULT hr;

    TRACE("(%p)->(%s, %x, %p)\n", This, debugstr_guid(session_guid),
            flags, out);

    hr = get_audio_session(session_guid, This->device, 0, &session);
    if(FAILED(hr))
        return hr;

    wrapper = AudioSessionWrapper_Create(NULL);
    if(!wrapper)
        return E_OUTOFMEMORY;

    wrapper->session = session;

    *out = &wrapper->ISimpleAudioVolume_iface;

    return S_OK;
}

static HRESULT WINAPI AudioSessionManager_GetSessionEnumerator(
        IAudioSessionManager2 *iface, IAudioSessionEnumerator **out)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    FIXME("(%p)->(%p) - stub\n", This, out);
    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionManager_RegisterSessionNotification(
        IAudioSessionManager2 *iface, IAudioSessionNotification *notification)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    FIXME("(%p)->(%p) - stub\n", This, notification);
    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionManager_UnregisterSessionNotification(
        IAudioSessionManager2 *iface, IAudioSessionNotification *notification)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    FIXME("(%p)->(%p) - stub\n", This, notification);
    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionManager_RegisterDuckNotification(
        IAudioSessionManager2 *iface, const WCHAR *session_id,
        IAudioVolumeDuckNotification *notification)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    FIXME("(%p)->(%p) - stub\n", This, notification);
    return E_NOTIMPL;
}

static HRESULT WINAPI AudioSessionManager_UnregisterDuckNotification(
        IAudioSessionManager2 *iface,
        IAudioVolumeDuckNotification *notification)
{
    SessionMgr *This = impl_from_IAudioSessionManager2(iface);
    FIXME("(%p)->(%p) - stub\n", This, notification);
    return E_NOTIMPL;
}

static const IAudioSessionManager2Vtbl AudioSessionManager2_Vtbl =
{
    AudioSessionManager_QueryInterface,
    AudioSessionManager_AddRef,
    AudioSessionManager_Release,
    AudioSessionManager_GetAudioSessionControl,
    AudioSessionManager_GetSimpleAudioVolume,
    AudioSessionManager_GetSessionEnumerator,
    AudioSessionManager_RegisterSessionNotification,
    AudioSessionManager_UnregisterSessionNotification,
    AudioSessionManager_RegisterDuckNotification,
    AudioSessionManager_UnregisterDuckNotification
};

HRESULT WINAPI AUDDRV_GetAudioSessionManager(IMMDevice *device,
        IAudioSessionManager2 **out)
{
    SessionMgr *This;

    This = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(SessionMgr));
    if(!This)
        return E_OUTOFMEMORY;

    This->IAudioSessionManager2_iface.lpVtbl = &AudioSessionManager2_Vtbl;
    This->device = device;
    This->ref = 1;

    *out = &This->IAudioSessionManager2_iface;

    return S_OK;
}