Sweden-Number/dlls/mf/session.c

/*
 * Copyright 2017 Nikolay Sivov
 *
 * 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
 */

#include <stdarg.h>

#define COBJMACROS

#include "windef.h"
#include "winbase.h"
#include "mfidl.h"
#include "mfapi.h"
#include "mferror.h"

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

WINE_DEFAULT_DEBUG_CHANNEL(mfplat);

enum session_command
{
    SESSION_CMD_CLEAR_TOPOLOGIES,
    SESSION_CMD_CLOSE,
};

struct session_op
{
    IUnknown IUnknown_iface;
    LONG refcount;
    enum session_command command;
};

struct queued_topology
{
    struct list entry;
    IMFTopology *topology;
};

enum session_state
{
    SESSION_STATE_STOPPED = 0,
    SESSION_STATE_CLOSED,
    SESSION_STATE_SHUT_DOWN,
};

struct media_session
{
    IMFMediaSession IMFMediaSession_iface;
    IMFGetService IMFGetService_iface;
    IMFRateSupport IMFRateSupport_iface;
    IMFRateControl IMFRateControl_iface;
    IMFAsyncCallback commands_callback;
    LONG refcount;
    IMFMediaEventQueue *event_queue;
    IMFPresentationClock *clock;
    struct list topologies;
    enum session_state state;
    CRITICAL_SECTION cs;
};

struct clock_sink
{
    struct list entry;
    IMFClockStateSink *state_sink;
};

enum clock_command
{
    CLOCK_CMD_START = 0,
    CLOCK_CMD_STOP,
    CLOCK_CMD_PAUSE,
    CLOCK_CMD_SET_RATE,
    CLOCK_CMD_MAX,
};

enum clock_notification
{
    CLOCK_NOTIFY_START,
    CLOCK_NOTIFY_STOP,
    CLOCK_NOTIFY_PAUSE,
    CLOCK_NOTIFY_RESTART,
    CLOCK_NOTIFY_SET_RATE,
};

struct clock_state_change_param
{
    union
    {
        LONGLONG offset;
        float rate;
    } u;
};

struct sink_notification
{
    IUnknown IUnknown_iface;
    LONG refcount;
    MFTIME system_time;
    struct clock_state_change_param param;
    enum clock_notification notification;
    IMFClockStateSink *sink;
};

struct presentation_clock
{
    IMFPresentationClock IMFPresentationClock_iface;
    IMFRateControl IMFRateControl_iface;
    IMFTimer IMFTimer_iface;
    IMFShutdown IMFShutdown_iface;
    IMFAsyncCallback IMFAsyncCallback_iface;
    LONG refcount;
    IMFPresentationTimeSource *time_source;
    IMFClockStateSink *time_source_sink;
    MFCLOCK_STATE state;
    struct list sinks;
    float rate;
    CRITICAL_SECTION cs;
};

static inline struct media_session *impl_from_IMFMediaSession(IMFMediaSession *iface)
{
    return CONTAINING_RECORD(iface, struct media_session, IMFMediaSession_iface);
}

static struct media_session *impl_from_commands_callback_IMFAsyncCallback(IMFAsyncCallback *iface)
{
    return CONTAINING_RECORD(iface, struct media_session, commands_callback);
}

static struct media_session *impl_from_IMFGetService(IMFGetService *iface)
{
    return CONTAINING_RECORD(iface, struct media_session, IMFGetService_iface);
}

static struct media_session *impl_session_from_IMFRateSupport(IMFRateSupport *iface)
{
    return CONTAINING_RECORD(iface, struct media_session, IMFRateSupport_iface);
}

static struct media_session *impl_session_from_IMFRateControl(IMFRateControl *iface)
{
    return CONTAINING_RECORD(iface, struct media_session, IMFRateControl_iface);
}

static struct session_op *impl_op_from_IUnknown(IUnknown *iface)
{
    return CONTAINING_RECORD(iface, struct session_op, IUnknown_iface);
}

static struct presentation_clock *impl_from_IMFPresentationClock(IMFPresentationClock *iface)
{
    return CONTAINING_RECORD(iface, struct presentation_clock, IMFPresentationClock_iface);
}

static struct presentation_clock *impl_from_IMFRateControl(IMFRateControl *iface)
{
    return CONTAINING_RECORD(iface, struct presentation_clock, IMFRateControl_iface);
}

static struct presentation_clock *impl_from_IMFTimer(IMFTimer *iface)
{
    return CONTAINING_RECORD(iface, struct presentation_clock, IMFTimer_iface);
}

static struct presentation_clock *impl_from_IMFShutdown(IMFShutdown *iface)
{
    return CONTAINING_RECORD(iface, struct presentation_clock, IMFShutdown_iface);
}

static struct presentation_clock *impl_from_IMFAsyncCallback(IMFAsyncCallback *iface)
{
    return CONTAINING_RECORD(iface, struct presentation_clock, IMFAsyncCallback_iface);
}

static struct sink_notification *impl_from_IUnknown(IUnknown *iface)
{
    return CONTAINING_RECORD(iface, struct sink_notification, IUnknown_iface);
}

static HRESULT WINAPI session_op_QueryInterface(IUnknown *iface, REFIID riid, void **obj)
{
    if (IsEqualIID(riid, &IID_IUnknown))
    {
        *obj = iface;
        IUnknown_AddRef(iface);
        return S_OK;
    }

    *obj = NULL;
    return E_NOINTERFACE;
}

static ULONG WINAPI session_op_AddRef(IUnknown *iface)
{
    struct session_op *op = impl_op_from_IUnknown(iface);
    ULONG refcount = InterlockedIncrement(&op->refcount);

    TRACE("%p, refcount %u.\n", iface, refcount);

    return refcount;
}

static ULONG WINAPI session_op_Release(IUnknown *iface)
{
    struct session_op *op = impl_op_from_IUnknown(iface);
    ULONG refcount = InterlockedDecrement(&op->refcount);

    TRACE("%p, refcount %u.\n", iface, refcount);

    if (!refcount)
    {
        heap_free(op);
    }

    return refcount;
}

static IUnknownVtbl session_op_vtbl =
{
    session_op_QueryInterface,
    session_op_AddRef,
    session_op_Release,
};

static HRESULT create_session_op(enum session_command command, IUnknown **ret)
{
    struct session_op *op;

    if (!(op = heap_alloc(sizeof(*op))))
        return E_OUTOFMEMORY;

    op->IUnknown_iface.lpVtbl = &session_op_vtbl;
    op->refcount = 1;
    op->command = command;

    *ret = &op->IUnknown_iface;

    return S_OK;
}

static void session_clear_topologies(struct media_session *session)
{
    struct queued_topology *ptr, *next;

    LIST_FOR_EACH_ENTRY_SAFE(ptr, next, &session->topologies, struct queued_topology, entry)
    {
        list_remove(&ptr->entry);
        IMFTopology_Release(ptr->topology);
        heap_free(ptr);
    }
}

static HRESULT WINAPI mfsession_QueryInterface(IMFMediaSession *iface, REFIID riid, void **out)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);

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

    if (IsEqualIID(riid, &IID_IMFMediaSession) ||
            IsEqualIID(riid, &IID_IMFMediaEventGenerator) ||
            IsEqualIID(riid, &IID_IUnknown))
    {
        *out = &session->IMFMediaSession_iface;
        IMFMediaSession_AddRef(iface);
        return S_OK;
    }
    else if (IsEqualIID(riid, &IID_IMFGetService))
    {
        *out = &session->IMFGetService_iface;
        IMFMediaSession_AddRef(iface);
        return S_OK;
    }

    WARN("Unsupported %s.\n", debugstr_guid(riid));
    *out = NULL;
    return E_NOINTERFACE;
}

static ULONG WINAPI mfsession_AddRef(IMFMediaSession *iface)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);
    ULONG refcount = InterlockedIncrement(&session->refcount);

    TRACE("(%p) refcount=%u\n", iface, refcount);

    return refcount;
}

static ULONG WINAPI mfsession_Release(IMFMediaSession *iface)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);
    ULONG refcount = InterlockedDecrement(&session->refcount);

    TRACE("(%p) refcount=%u\n", iface, refcount);

    if (!refcount)
    {
        session_clear_topologies(session);
        if (session->event_queue)
            IMFMediaEventQueue_Release(session->event_queue);
        if (session->clock)
            IMFPresentationClock_Release(session->clock);
        DeleteCriticalSection(&session->cs);
        heap_free(session);
    }

    return refcount;
}

static HRESULT WINAPI mfsession_GetEvent(IMFMediaSession *iface, DWORD flags, IMFMediaEvent **event)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);

    TRACE("(%p)->(%#x, %p)\n", iface, flags, event);

    return IMFMediaEventQueue_GetEvent(session->event_queue, flags, event);
}

static HRESULT WINAPI mfsession_BeginGetEvent(IMFMediaSession *iface, IMFAsyncCallback *callback, IUnknown *state)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);

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

    return IMFMediaEventQueue_BeginGetEvent(session->event_queue, callback, state);
}

static HRESULT WINAPI mfsession_EndGetEvent(IMFMediaSession *iface, IMFAsyncResult *result, IMFMediaEvent **event)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);

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

    return IMFMediaEventQueue_EndGetEvent(session->event_queue, result, event);
}

static HRESULT WINAPI mfsession_QueueEvent(IMFMediaSession *iface, MediaEventType event_type, REFGUID ext_type,
        HRESULT hr, const PROPVARIANT *value)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);

    TRACE("(%p)->(%d, %s, %#x, %p)\n", iface, event_type, debugstr_guid(ext_type), hr, value);

    return IMFMediaEventQueue_QueueEventParamVar(session->event_queue, event_type, ext_type, hr, value);
}

static HRESULT WINAPI mfsession_SetTopology(IMFMediaSession *iface, DWORD flags, IMFTopology *topology)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);
    struct queued_topology *queued_topology;

    FIXME("%p, %#x, %p.\n", iface, flags, topology);

    if (!(queued_topology = heap_alloc(sizeof(*queued_topology))))
        return E_OUTOFMEMORY;

    queued_topology->topology = topology;
    IMFTopology_AddRef(queued_topology->topology);

    EnterCriticalSection(&session->cs);
    list_add_tail(&session->topologies, &queued_topology->entry);
    LeaveCriticalSection(&session->cs);

    return S_OK;
}

static HRESULT session_submit_command(struct media_session *session, IUnknown *op)
{
    HRESULT hr;

    EnterCriticalSection(&session->cs);
    if (session->state == SESSION_STATE_SHUT_DOWN)
        hr = MF_E_SHUTDOWN;
    else
        hr = MFPutWorkItem(MFASYNC_CALLBACK_QUEUE_STANDARD, &session->commands_callback, op);
    LeaveCriticalSection(&session->cs);

    return hr;
}

static HRESULT WINAPI mfsession_ClearTopologies(IMFMediaSession *iface)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);
    IUnknown *op;
    HRESULT hr;

    TRACE("%p.\n", iface);

    if (FAILED(hr = create_session_op(SESSION_CMD_CLEAR_TOPOLOGIES, &op)))
        return hr;

    hr = session_submit_command(session, op);
    IUnknown_Release(op);

    return hr;
}

static HRESULT WINAPI mfsession_Start(IMFMediaSession *iface, const GUID *format, const PROPVARIANT *start)
{
    FIXME("(%p)->(%s, %p)\n", iface, debugstr_guid(format), start);

    return E_NOTIMPL;
}

static HRESULT WINAPI mfsession_Pause(IMFMediaSession *iface)
{
    FIXME("(%p)\n", iface);

    return E_NOTIMPL;
}

static HRESULT WINAPI mfsession_Stop(IMFMediaSession *iface)
{
    FIXME("(%p)\n", iface);

    return E_NOTIMPL;
}

static HRESULT WINAPI mfsession_Close(IMFMediaSession *iface)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);
    IUnknown *op;
    HRESULT hr;

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

    if (FAILED(hr = create_session_op(SESSION_CMD_CLOSE, &op)))
        return hr;

    hr = session_submit_command(session, op);
    IUnknown_Release(op);

    return hr;
}

static HRESULT WINAPI mfsession_Shutdown(IMFMediaSession *iface)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);
    HRESULT hr = S_OK;

    FIXME("(%p)\n", iface);

    EnterCriticalSection(&session->cs);
    if (session->state == SESSION_STATE_SHUT_DOWN)
        hr = MF_E_SHUTDOWN;
    else
    {
        session->state = SESSION_STATE_SHUT_DOWN;
        IMFMediaEventQueue_Shutdown(session->event_queue);
    }
    LeaveCriticalSection(&session->cs);

    return hr;
}

static HRESULT WINAPI mfsession_GetClock(IMFMediaSession *iface, IMFClock **clock)
{
    struct media_session *session = impl_from_IMFMediaSession(iface);

    TRACE("%p, %p.\n", iface, clock);

    *clock = (IMFClock *)session->clock;
    IMFClock_AddRef(*clock);

    return S_OK;
}

static HRESULT WINAPI mfsession_GetSessionCapabilities(IMFMediaSession *iface, DWORD *caps)
{
    FIXME("(%p)->(%p)\n", iface, caps);

    return E_NOTIMPL;
}

static HRESULT WINAPI mfsession_GetFullTopology(IMFMediaSession *iface, DWORD flags, TOPOID id, IMFTopology **topology)
{
    FIXME("(%p)->(%#x, %s, %p)\n", iface, flags, wine_dbgstr_longlong(id), topology);

    return E_NOTIMPL;
}

static const IMFMediaSessionVtbl mfmediasessionvtbl =
{
    mfsession_QueryInterface,
    mfsession_AddRef,
    mfsession_Release,
    mfsession_GetEvent,
    mfsession_BeginGetEvent,
    mfsession_EndGetEvent,
    mfsession_QueueEvent,
    mfsession_SetTopology,
    mfsession_ClearTopologies,
    mfsession_Start,
    mfsession_Pause,
    mfsession_Stop,
    mfsession_Close,
    mfsession_Shutdown,
    mfsession_GetClock,
    mfsession_GetSessionCapabilities,
    mfsession_GetFullTopology,
};

static HRESULT WINAPI session_get_service_QueryInterface(IMFGetService *iface, REFIID riid, void **obj)
{
    struct media_session *session = impl_from_IMFGetService(iface);
    return IMFMediaSession_QueryInterface(&session->IMFMediaSession_iface, riid, obj);
}

static ULONG WINAPI session_get_service_AddRef(IMFGetService *iface)
{
    struct media_session *session = impl_from_IMFGetService(iface);
    return IMFMediaSession_AddRef(&session->IMFMediaSession_iface);
}

static ULONG WINAPI session_get_service_Release(IMFGetService *iface)
{
    struct media_session *session = impl_from_IMFGetService(iface);
    return IMFMediaSession_Release(&session->IMFMediaSession_iface);
}

static HRESULT WINAPI session_get_service_GetService(IMFGetService *iface, REFGUID service, REFIID riid, void **obj)
{
    struct media_session *session = impl_from_IMFGetService(iface);

    TRACE("%p, %s, %s, %p.\n", iface, debugstr_guid(service), debugstr_guid(riid), obj);

    *obj = NULL;

    if (IsEqualGUID(service, &MF_RATE_CONTROL_SERVICE))
    {
        if (IsEqualIID(riid, &IID_IMFRateSupport))
        {
            *obj = &session->IMFRateSupport_iface;
        }
        else if (IsEqualIID(riid, &IID_IMFRateControl))
        {
            *obj = &session->IMFRateControl_iface;
        }

        if (*obj)
            IUnknown_AddRef((IUnknown *)*obj);

        return *obj ? S_OK : E_NOINTERFACE;
    }
    else
        FIXME("Unsupported service %s.\n", debugstr_guid(service));

    return E_NOTIMPL;
}

static const IMFGetServiceVtbl session_get_service_vtbl =
{
    session_get_service_QueryInterface,
    session_get_service_AddRef,
    session_get_service_Release,
    session_get_service_GetService,
};

static HRESULT WINAPI session_commands_callback_QueryInterface(IMFAsyncCallback *iface, REFIID riid, void **obj)
{
    if (IsEqualIID(riid, &IID_IMFAsyncCallback) ||
            IsEqualIID(riid, &IID_IUnknown))
    {
        *obj = iface;
        IMFAsyncCallback_AddRef(iface);
        return S_OK;
    }

    WARN("Unsupported %s.\n", debugstr_guid(riid));
    *obj = NULL;
    return E_NOINTERFACE;
}

static ULONG WINAPI session_commands_callback_AddRef(IMFAsyncCallback *iface)
{
    struct media_session *session = impl_from_commands_callback_IMFAsyncCallback(iface);
    return IMFMediaSession_AddRef(&session->IMFMediaSession_iface);
}

static ULONG WINAPI session_commands_callback_Release(IMFAsyncCallback *iface)
{
    struct media_session *session = impl_from_commands_callback_IMFAsyncCallback(iface);
    return IMFMediaSession_Release(&session->IMFMediaSession_iface);
}

static HRESULT WINAPI session_commands_callback_GetParameters(IMFAsyncCallback *iface, DWORD *flags, DWORD *queue)
{
    return E_NOTIMPL;
}

static HRESULT WINAPI session_commands_callback_Invoke(IMFAsyncCallback *iface, IMFAsyncResult *result)
{
    struct session_op *op = impl_op_from_IUnknown(IMFAsyncResult_GetStateNoAddRef(result));
    struct media_session *session = impl_from_commands_callback_IMFAsyncCallback(iface);

    switch (op->command)
    {
        case SESSION_CMD_CLEAR_TOPOLOGIES:
            EnterCriticalSection(&session->cs);
            session_clear_topologies(session);
            LeaveCriticalSection(&session->cs);

            IMFMediaEventQueue_QueueEventParamVar(session->event_queue, MESessionTopologiesCleared, &GUID_NULL,
                    S_OK, NULL);
            break;
        case SESSION_CMD_CLOSE:
            EnterCriticalSection(&session->cs);
            if (session->state != SESSION_STATE_CLOSED)
            {
                /* FIXME: actually do something to presentation objects */
                session->state = SESSION_STATE_CLOSED;
                IMFMediaEventQueue_QueueEventParamVar(session->event_queue, MESessionClosed, &GUID_NULL, S_OK, NULL);
            }
            LeaveCriticalSection(&session->cs);
            break;
        default:
            ;
    }

    return S_OK;
}

static const IMFAsyncCallbackVtbl session_commands_callback_vtbl =
{
    session_commands_callback_QueryInterface,
    session_commands_callback_AddRef,
    session_commands_callback_Release,
    session_commands_callback_GetParameters,
    session_commands_callback_Invoke,
};

static HRESULT WINAPI session_rate_support_QueryInterface(IMFRateSupport *iface, REFIID riid, void **obj)
{
    struct media_session *session = impl_session_from_IMFRateSupport(iface);
    return IMFMediaSession_QueryInterface(&session->IMFMediaSession_iface, riid, obj);
}

static ULONG WINAPI session_rate_support_AddRef(IMFRateSupport *iface)
{
    struct media_session *session = impl_session_from_IMFRateSupport(iface);
    return IMFMediaSession_AddRef(&session->IMFMediaSession_iface);
}

static ULONG WINAPI session_rate_support_Release(IMFRateSupport *iface)
{
    struct media_session *session = impl_session_from_IMFRateSupport(iface);
    return IMFMediaSession_Release(&session->IMFMediaSession_iface);
}

static HRESULT WINAPI session_rate_support_GetSlowestRate(IMFRateSupport *iface, MFRATE_DIRECTION direction,
        BOOL thin, float *rate)
{
    FIXME("%p, %d, %d, %p.\n", iface, direction, thin, rate);

    return E_NOTIMPL;
}

static HRESULT WINAPI session_rate_support_GetFastestRate(IMFRateSupport *iface, MFRATE_DIRECTION direction,
        BOOL thin, float *rate)
{
    FIXME("%p, %d, %d, %p.\n", iface, direction, thin, rate);

    return E_NOTIMPL;
}

static HRESULT WINAPI session_rate_support_IsSupported(IMFRateSupport *iface, BOOL thin, float rate,
        float *nearest_supported_rate)
{
    FIXME("%p, %d, %f, %p.\n", iface, thin, rate, nearest_supported_rate);

    return E_NOTIMPL;
}

static const IMFRateSupportVtbl session_rate_support_vtbl =
{
    session_rate_support_QueryInterface,
    session_rate_support_AddRef,
    session_rate_support_Release,
    session_rate_support_GetSlowestRate,
    session_rate_support_GetFastestRate,
    session_rate_support_IsSupported,
};

static HRESULT WINAPI session_rate_control_QueryInterface(IMFRateControl *iface, REFIID riid, void **obj)
{
    struct media_session *session = impl_session_from_IMFRateControl(iface);
    return IMFMediaSession_QueryInterface(&session->IMFMediaSession_iface, riid, obj);
}

static ULONG WINAPI session_rate_control_AddRef(IMFRateControl *iface)
{
    struct media_session *session = impl_session_from_IMFRateControl(iface);
    return IMFMediaSession_AddRef(&session->IMFMediaSession_iface);
}

static ULONG WINAPI session_rate_control_Release(IMFRateControl *iface)
{
    struct media_session *session = impl_session_from_IMFRateControl(iface);
    return IMFMediaSession_Release(&session->IMFMediaSession_iface);
}

static HRESULT WINAPI session_rate_control_SetRate(IMFRateControl *iface, BOOL thin, float rate)
{
    FIXME("%p, %d, %f.\n", iface, thin, rate);

    return E_NOTIMPL;
}

static HRESULT WINAPI session_rate_control_GetRate(IMFRateControl *iface, BOOL *thin, float *rate)
{
    FIXME("%p, %p, %p.\n", iface, thin, rate);

    return E_NOTIMPL;
}

static const IMFRateControlVtbl session_rate_control_vtbl =
{
    session_rate_control_QueryInterface,
    session_rate_control_AddRef,
    session_rate_control_Release,
    session_rate_control_SetRate,
    session_rate_control_GetRate,
};

/***********************************************************************
 *      MFCreateMediaSession (mf.@)
 */
HRESULT WINAPI MFCreateMediaSession(IMFAttributes *config, IMFMediaSession **session)
{
    struct media_session *object;
    HRESULT hr;

    TRACE("(%p, %p)\n", config, session);

    if (config)
        FIXME("session configuration ignored\n");

    object = heap_alloc_zero(sizeof(*object));
    if (!object)
        return E_OUTOFMEMORY;

    object->IMFMediaSession_iface.lpVtbl = &mfmediasessionvtbl;
    object->IMFGetService_iface.lpVtbl = &session_get_service_vtbl;
    object->IMFRateSupport_iface.lpVtbl = &session_rate_support_vtbl;
    object->IMFRateControl_iface.lpVtbl = &session_rate_control_vtbl;
    object->commands_callback.lpVtbl = &session_commands_callback_vtbl;
    object->refcount = 1;
    list_init(&object->topologies);
    InitializeCriticalSection(&object->cs);

    if (FAILED(hr = MFCreateEventQueue(&object->event_queue)))
        goto failed;

    if (FAILED(hr = MFCreatePresentationClock(&object->clock)))
        goto failed;

    *session = &object->IMFMediaSession_iface;

    return S_OK;

failed:
    IMFMediaSession_Release(&object->IMFMediaSession_iface);
    return hr;
}

static HRESULT WINAPI present_clock_QueryInterface(IMFPresentationClock *iface, REFIID riid, void **out)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);

    TRACE("%p, %s, %p.\n", iface, debugstr_guid(riid), out);

    if (IsEqualIID(riid, &IID_IMFPresentationClock) ||
            IsEqualIID(riid, &IID_IMFClock) ||
            IsEqualIID(riid, &IID_IUnknown))
    {
        *out = &clock->IMFPresentationClock_iface;
    }
    else if (IsEqualIID(riid, &IID_IMFRateControl))
    {
        *out = &clock->IMFRateControl_iface;
    }
    else if (IsEqualIID(riid, &IID_IMFTimer))
    {
        *out = &clock->IMFTimer_iface;
    }
    else if (IsEqualIID(riid, &IID_IMFShutdown))
    {
        *out = &clock->IMFShutdown_iface;
    }
    else
    {
        WARN("Unsupported %s.\n", debugstr_guid(riid));
        *out = NULL;
        return E_NOINTERFACE;
    }

    IUnknown_AddRef((IUnknown *)*out);
    return S_OK;
}

static ULONG WINAPI present_clock_AddRef(IMFPresentationClock *iface)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    ULONG refcount = InterlockedIncrement(&clock->refcount);

    TRACE("%p, refcount %u.\n", iface, refcount);

    return refcount;
}

static ULONG WINAPI present_clock_Release(IMFPresentationClock *iface)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    ULONG refcount = InterlockedDecrement(&clock->refcount);
    struct clock_sink *sink, *sink2;

    TRACE("%p, refcount %u.\n", iface, refcount);

    if (!refcount)
    {
        if (clock->time_source)
            IMFPresentationTimeSource_Release(clock->time_source);
        if (clock->time_source_sink)
            IMFClockStateSink_Release(clock->time_source_sink);
        LIST_FOR_EACH_ENTRY_SAFE(sink, sink2, &clock->sinks, struct clock_sink, entry)
        {
            list_remove(&sink->entry);
            IMFClockStateSink_Release(sink->state_sink);
            heap_free(sink);
        }
        DeleteCriticalSection(&clock->cs);
        heap_free(clock);
    }

    return refcount;
}

static HRESULT WINAPI present_clock_GetClockCharacteristics(IMFPresentationClock *iface, DWORD *flags)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    HRESULT hr = MF_E_CLOCK_NO_TIME_SOURCE;

    TRACE("%p, %p.\n", iface, flags);

    EnterCriticalSection(&clock->cs);
    if (clock->time_source)
        hr = IMFPresentationTimeSource_GetClockCharacteristics(clock->time_source, flags);
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_GetCorrelatedTime(IMFPresentationClock *iface, DWORD reserved,
        LONGLONG *clock_time, MFTIME *system_time)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    HRESULT hr = MF_E_CLOCK_NO_TIME_SOURCE;

    TRACE("%p, %#x, %p, %p.\n", iface, reserved, clock_time, system_time);

    EnterCriticalSection(&clock->cs);
    if (clock->time_source)
        hr = IMFPresentationTimeSource_GetCorrelatedTime(clock->time_source, reserved, clock_time, system_time);
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_GetContinuityKey(IMFPresentationClock *iface, DWORD *key)
{
    TRACE("%p, %p.\n", iface, key);

    *key = 0;

    return S_OK;
}

static HRESULT WINAPI present_clock_GetState(IMFPresentationClock *iface, DWORD reserved, MFCLOCK_STATE *state)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);

    TRACE("%p, %#x, %p.\n", iface, reserved, state);

    EnterCriticalSection(&clock->cs);
    *state = clock->state;
    LeaveCriticalSection(&clock->cs);

    return S_OK;
}

static HRESULT WINAPI present_clock_GetProperties(IMFPresentationClock *iface, MFCLOCK_PROPERTIES *props)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    HRESULT hr = MF_E_CLOCK_NO_TIME_SOURCE;

    TRACE("%p, %p.\n", iface, props);

    EnterCriticalSection(&clock->cs);
    if (clock->time_source)
        hr = IMFPresentationTimeSource_GetProperties(clock->time_source, props);
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_SetTimeSource(IMFPresentationClock *iface,
        IMFPresentationTimeSource *time_source)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    HRESULT hr;

    TRACE("%p, %p.\n", iface, time_source);

    EnterCriticalSection(&clock->cs);
    if (clock->time_source)
        IMFPresentationTimeSource_Release(clock->time_source);
    if (clock->time_source_sink)
        IMFClockStateSink_Release(clock->time_source_sink);
    clock->time_source = NULL;
    clock->time_source_sink = NULL;

    hr = IMFPresentationTimeSource_QueryInterface(time_source, &IID_IMFClockStateSink, (void **)&clock->time_source_sink);
    if (SUCCEEDED(hr))
    {
        clock->time_source = time_source;
        IMFPresentationTimeSource_AddRef(clock->time_source);
    }

    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_GetTimeSource(IMFPresentationClock *iface,
        IMFPresentationTimeSource **time_source)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    HRESULT hr = S_OK;

    TRACE("%p, %p.\n", iface, time_source);

    if (!time_source)
        return E_INVALIDARG;

    EnterCriticalSection(&clock->cs);
    if (clock->time_source)
    {
        *time_source = clock->time_source;
        IMFPresentationTimeSource_AddRef(*time_source);
    }
    else
        hr = MF_E_CLOCK_NO_TIME_SOURCE;
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_GetTime(IMFPresentationClock *iface, MFTIME *time)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    HRESULT hr = MF_E_CLOCK_NO_TIME_SOURCE;
    MFTIME systime;

    TRACE("%p, %p.\n", iface, time);

    if (!time)
        return E_POINTER;

    EnterCriticalSection(&clock->cs);
    if (clock->time_source)
        hr = IMFPresentationTimeSource_GetCorrelatedTime(clock->time_source, 0, time, &systime);
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_AddClockStateSink(IMFPresentationClock *iface, IMFClockStateSink *state_sink)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    struct clock_sink *sink, *cur;
    HRESULT hr = S_OK;

    TRACE("%p, %p.\n", iface, state_sink);

    if (!state_sink)
        return E_INVALIDARG;

    sink = heap_alloc(sizeof(*sink));
    if (!sink)
        return E_OUTOFMEMORY;

    sink->state_sink = state_sink;
    IMFClockStateSink_AddRef(sink->state_sink);

    EnterCriticalSection(&clock->cs);
    LIST_FOR_EACH_ENTRY(cur, &clock->sinks, struct clock_sink, entry)
    {
        if (cur->state_sink == state_sink)
        {
            hr = E_INVALIDARG;
            break;
        }
    }
    if (SUCCEEDED(hr))
        list_add_tail(&clock->sinks, &sink->entry);
    LeaveCriticalSection(&clock->cs);

    if (FAILED(hr))
    {
        IMFClockStateSink_Release(sink->state_sink);
        heap_free(sink);
    }

    return hr;
}

static HRESULT WINAPI present_clock_RemoveClockStateSink(IMFPresentationClock *iface,
        IMFClockStateSink *state_sink)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    struct clock_sink *sink;

    TRACE("%p, %p.\n", iface, state_sink);

    if (!state_sink)
        return E_INVALIDARG;

    EnterCriticalSection(&clock->cs);
    LIST_FOR_EACH_ENTRY(sink, &clock->sinks, struct clock_sink, entry)
    {
        if (sink->state_sink == state_sink)
        {
            IMFClockStateSink_Release(sink->state_sink);
            list_remove(&sink->entry);
            heap_free(sink);
            break;
        }
    }
    LeaveCriticalSection(&clock->cs);

    return S_OK;
}

static HRESULT WINAPI sink_notification_QueryInterface(IUnknown *iface, REFIID riid, void **out)
{
    if (IsEqualIID(riid, &IID_IUnknown))
    {
        *out = iface;
        IUnknown_AddRef(iface);
        return S_OK;
    }

    WARN("Unsupported %s.\n", debugstr_guid(riid));
    *out = NULL;
    return E_NOINTERFACE;
}

static ULONG WINAPI sink_notification_AddRef(IUnknown *iface)
{
    struct sink_notification *notification = impl_from_IUnknown(iface);
    ULONG refcount = InterlockedIncrement(&notification->refcount);

    TRACE("%p, refcount %u.\n", iface, refcount);

    return refcount;
}

static ULONG WINAPI sink_notification_Release(IUnknown *iface)
{
    struct sink_notification *notification = impl_from_IUnknown(iface);
    ULONG refcount = InterlockedDecrement(&notification->refcount);

    TRACE("%p, refcount %u.\n", iface, refcount);

    if (!refcount)
    {
        IMFClockStateSink_Release(notification->sink);
        heap_free(notification);
    }

    return refcount;
}

static const IUnknownVtbl sinknotificationvtbl =
{
    sink_notification_QueryInterface,
    sink_notification_AddRef,
    sink_notification_Release,
};

static HRESULT create_sink_notification(MFTIME system_time, struct clock_state_change_param param,
        enum clock_notification notification, IMFClockStateSink *sink, IUnknown **out)
{
    struct sink_notification *object;

    object = heap_alloc(sizeof(*object));
    if (!object)
        return E_OUTOFMEMORY;

    object->IUnknown_iface.lpVtbl = &sinknotificationvtbl;
    object->refcount = 1;
    object->system_time = system_time;
    object->param = param;
    object->notification = notification;
    object->sink = sink;
    IMFClockStateSink_AddRef(object->sink);

    *out = &object->IUnknown_iface;

    return S_OK;
}

static HRESULT clock_call_state_change(MFTIME system_time, struct clock_state_change_param param,
        enum clock_notification notification, IMFClockStateSink *sink)
{
    HRESULT hr = S_OK;

    switch (notification)
    {
        case CLOCK_NOTIFY_START:
            hr = IMFClockStateSink_OnClockStart(sink, system_time, param.u.offset);
            break;
        case CLOCK_NOTIFY_STOP:
            hr = IMFClockStateSink_OnClockStop(sink, system_time);
            break;
        case CLOCK_NOTIFY_PAUSE:
            hr = IMFClockStateSink_OnClockPause(sink, system_time);
            break;
        case CLOCK_NOTIFY_RESTART:
            hr = IMFClockStateSink_OnClockRestart(sink, system_time);
            break;
        case CLOCK_NOTIFY_SET_RATE:
            /* System time source does not allow 0.0 rate, presentation clock allows it without raising errors. */
            IMFClockStateSink_OnClockSetRate(sink, system_time, param.u.rate);
            break;
        default:
            ;
    }

    return hr;
}

static HRESULT clock_change_state(struct presentation_clock *clock, enum clock_command command,
        struct clock_state_change_param param)
{
    static const BYTE state_change_is_allowed[MFCLOCK_STATE_PAUSED+1][CLOCK_CMD_MAX] =
    {   /*              S  S* P, R  */
        /* INVALID */ { 1, 1, 1, 1 },
        /* RUNNING */ { 1, 1, 1, 1 },
        /* STOPPED */ { 1, 1, 0, 1 },
        /* PAUSED  */ { 1, 1, 0, 1 },
    };
    static const MFCLOCK_STATE states[CLOCK_CMD_MAX] =
    {
        /* CLOCK_CMD_START    */ MFCLOCK_STATE_RUNNING,
        /* CLOCK_CMD_STOP     */ MFCLOCK_STATE_STOPPED,
        /* CLOCK_CMD_PAUSE    */ MFCLOCK_STATE_PAUSED,
        /* CLOCK_CMD_SET_RATE */ 0, /* Unused */
    };
    enum clock_notification notification;
    struct clock_sink *sink;
    IUnknown *notify_object;
    IMFAsyncResult *result;
    MFTIME system_time;
    HRESULT hr;

    if (command != CLOCK_CMD_SET_RATE && clock->state == states[command] && clock->state != MFCLOCK_STATE_RUNNING)
        return MF_E_CLOCK_STATE_ALREADY_SET;

    if (!state_change_is_allowed[clock->state][command])
        return MF_E_INVALIDREQUEST;

    system_time = MFGetSystemTime();

    switch (command)
    {
        case CLOCK_CMD_START:
            if (clock->state == MFCLOCK_STATE_PAUSED && param.u.offset == PRESENTATION_CURRENT_POSITION)
                notification = CLOCK_NOTIFY_RESTART;
            else
                notification = CLOCK_NOTIFY_START;
            break;
        case CLOCK_CMD_STOP:
            notification = CLOCK_NOTIFY_STOP;
            break;
        case CLOCK_CMD_PAUSE:
            notification = CLOCK_NOTIFY_PAUSE;
            break;
        case CLOCK_CMD_SET_RATE:
            notification = CLOCK_NOTIFY_SET_RATE;
            break;
        default:
            ;
    }

    if (FAILED(hr = clock_call_state_change(system_time, param, notification, clock->time_source_sink)))
        return hr;

    clock->state = states[command];

    LIST_FOR_EACH_ENTRY(sink, &clock->sinks, struct clock_sink, entry)
    {
        if (SUCCEEDED(create_sink_notification(system_time, param, notification, sink->state_sink, &notify_object)))
        {
            hr = MFCreateAsyncResult(notify_object, &clock->IMFAsyncCallback_iface, NULL, &result);
            IUnknown_Release(notify_object);
            if (SUCCEEDED(hr))
            {
                MFPutWorkItemEx(MFASYNC_CALLBACK_QUEUE_STANDARD, result);
                IMFAsyncResult_Release(result);
            }
        }
    }

    return S_OK;
}

static HRESULT WINAPI present_clock_Start(IMFPresentationClock *iface, LONGLONG start_offset)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    struct clock_state_change_param param = {{0}};
    HRESULT hr;

    TRACE("%p, %s.\n", iface, wine_dbgstr_longlong(start_offset));

    EnterCriticalSection(&clock->cs);
    param.u.offset = start_offset;
    hr = clock_change_state(clock, CLOCK_CMD_START, param);
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_Stop(IMFPresentationClock *iface)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    struct clock_state_change_param param = {{0}};
    HRESULT hr;

    TRACE("%p.\n", iface);

    EnterCriticalSection(&clock->cs);
    hr = clock_change_state(clock, CLOCK_CMD_STOP, param);
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_Pause(IMFPresentationClock *iface)
{
    struct presentation_clock *clock = impl_from_IMFPresentationClock(iface);
    struct clock_state_change_param param = {{0}};
    HRESULT hr;

    TRACE("%p.\n", iface);

    EnterCriticalSection(&clock->cs);
    hr = clock_change_state(clock, CLOCK_CMD_PAUSE, param);
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static const IMFPresentationClockVtbl presentationclockvtbl =
{
    present_clock_QueryInterface,
    present_clock_AddRef,
    present_clock_Release,
    present_clock_GetClockCharacteristics,
    present_clock_GetCorrelatedTime,
    present_clock_GetContinuityKey,
    present_clock_GetState,
    present_clock_GetProperties,
    present_clock_SetTimeSource,
    present_clock_GetTimeSource,
    present_clock_GetTime,
    present_clock_AddClockStateSink,
    present_clock_RemoveClockStateSink,
    present_clock_Start,
    present_clock_Stop,
    present_clock_Pause,
};

static HRESULT WINAPI present_clock_rate_control_QueryInterface(IMFRateControl *iface, REFIID riid, void **out)
{
    struct presentation_clock *clock = impl_from_IMFRateControl(iface);
    return IMFPresentationClock_QueryInterface(&clock->IMFPresentationClock_iface, riid, out);
}

static ULONG WINAPI present_clock_rate_control_AddRef(IMFRateControl *iface)
{
    struct presentation_clock *clock = impl_from_IMFRateControl(iface);
    return IMFPresentationClock_AddRef(&clock->IMFPresentationClock_iface);
}

static ULONG WINAPI present_clock_rate_control_Release(IMFRateControl *iface)
{
    struct presentation_clock *clock = impl_from_IMFRateControl(iface);
    return IMFPresentationClock_Release(&clock->IMFPresentationClock_iface);
}

static HRESULT WINAPI present_clock_rate_SetRate(IMFRateControl *iface, BOOL thin, float rate)
{
    struct presentation_clock *clock = impl_from_IMFRateControl(iface);
    struct clock_state_change_param param;
    HRESULT hr;

    TRACE("%p, %d, %f.\n", iface, thin, rate);

    if (thin)
        return MF_E_THINNING_UNSUPPORTED;

    EnterCriticalSection(&clock->cs);
    param.u.rate = rate;
    if (SUCCEEDED(hr = clock_change_state(clock, CLOCK_CMD_SET_RATE, param)))
        clock->rate = rate;
    LeaveCriticalSection(&clock->cs);

    return hr;
}

static HRESULT WINAPI present_clock_rate_GetRate(IMFRateControl *iface, BOOL *thin, float *rate)
{
    struct presentation_clock *clock = impl_from_IMFRateControl(iface);

    TRACE("%p, %p, %p.\n", iface, thin, rate);

    if (!rate)
        return E_INVALIDARG;

    if (thin)
        *thin = FALSE;

    EnterCriticalSection(&clock->cs);
    *rate = clock->rate;
    LeaveCriticalSection(&clock->cs);

    return S_OK;
}

static const IMFRateControlVtbl presentclockratecontrolvtbl =
{
    present_clock_rate_control_QueryInterface,
    present_clock_rate_control_AddRef,
    present_clock_rate_control_Release,
    present_clock_rate_SetRate,
    present_clock_rate_GetRate,
};

static HRESULT WINAPI present_clock_timer_QueryInterface(IMFTimer *iface, REFIID riid, void **out)
{
    struct presentation_clock *clock = impl_from_IMFTimer(iface);
    return IMFPresentationClock_QueryInterface(&clock->IMFPresentationClock_iface, riid, out);
}

static ULONG WINAPI present_clock_timer_AddRef(IMFTimer *iface)
{
    struct presentation_clock *clock = impl_from_IMFTimer(iface);
    return IMFPresentationClock_AddRef(&clock->IMFPresentationClock_iface);
}

static ULONG WINAPI present_clock_timer_Release(IMFTimer *iface)
{
    struct presentation_clock *clock = impl_from_IMFTimer(iface);
    return IMFPresentationClock_Release(&clock->IMFPresentationClock_iface);
}

static HRESULT WINAPI present_clock_timer_SetTimer(IMFTimer *iface, DWORD flags, LONGLONG time,
        IMFAsyncCallback *callback, IUnknown *state, IUnknown **cancel_key)
{
    FIXME("%p, %#x, %s, %p, %p, %p.\n", iface, flags, wine_dbgstr_longlong(time), callback, state, cancel_key);

    return E_NOTIMPL;
}

static HRESULT WINAPI present_clock_timer_CancelTimer(IMFTimer *iface, IUnknown *cancel_key)
{
    FIXME("%p, %p.\n", iface, cancel_key);

    return E_NOTIMPL;
}

static const IMFTimerVtbl presentclocktimervtbl =
{
    present_clock_timer_QueryInterface,
    present_clock_timer_AddRef,
    present_clock_timer_Release,
    present_clock_timer_SetTimer,
    present_clock_timer_CancelTimer,
};

static HRESULT WINAPI present_clock_shutdown_QueryInterface(IMFShutdown *iface, REFIID riid, void **out)
{
    struct presentation_clock *clock = impl_from_IMFShutdown(iface);
    return IMFPresentationClock_QueryInterface(&clock->IMFPresentationClock_iface, riid, out);
}

static ULONG WINAPI present_clock_shutdown_AddRef(IMFShutdown *iface)
{
    struct presentation_clock *clock = impl_from_IMFShutdown(iface);
    return IMFPresentationClock_AddRef(&clock->IMFPresentationClock_iface);
}

static ULONG WINAPI present_clock_shutdown_Release(IMFShutdown *iface)
{
    struct presentation_clock *clock = impl_from_IMFShutdown(iface);
    return IMFPresentationClock_Release(&clock->IMFPresentationClock_iface);
}

static HRESULT WINAPI present_clock_shutdown_Shutdown(IMFShutdown *iface)
{
    FIXME("%p.\n", iface);

    return E_NOTIMPL;
}

static HRESULT WINAPI present_clock_shutdown_GetShutdownStatus(IMFShutdown *iface, MFSHUTDOWN_STATUS *status)
{
    FIXME("%p, %p.\n", iface, status);

    return E_NOTIMPL;
}

static const IMFShutdownVtbl presentclockshutdownvtbl =
{
    present_clock_shutdown_QueryInterface,
    present_clock_shutdown_AddRef,
    present_clock_shutdown_Release,
    present_clock_shutdown_Shutdown,
    present_clock_shutdown_GetShutdownStatus,
};

static HRESULT WINAPI present_clock_sink_callback_QueryInterface(IMFAsyncCallback *iface, REFIID riid, void **out)
{
    if (IsEqualIID(riid, &IID_IMFAsyncCallback) ||
            IsEqualIID(riid, &IID_IUnknown))
    {
        *out = iface;
        IMFAsyncCallback_AddRef(iface);
        return S_OK;
    }

    WARN("Unsupported %s.\n", wine_dbgstr_guid(riid));
    *out = NULL;
    return E_NOINTERFACE;
}

static ULONG WINAPI present_clock_sink_callback_AddRef(IMFAsyncCallback *iface)
{
    struct presentation_clock *clock = impl_from_IMFAsyncCallback(iface);
    return IMFPresentationClock_AddRef(&clock->IMFPresentationClock_iface);
}

static ULONG WINAPI present_clock_sink_callback_Release(IMFAsyncCallback *iface)
{
    struct presentation_clock *clock = impl_from_IMFAsyncCallback(iface);
    return IMFPresentationClock_Release(&clock->IMFPresentationClock_iface);
}

static HRESULT WINAPI present_clock_sink_callback_GetParameters(IMFAsyncCallback *iface, DWORD *flags, DWORD *queue)
{
    return E_NOTIMPL;
}

static HRESULT WINAPI present_clock_sink_callback_Invoke(IMFAsyncCallback *iface, IMFAsyncResult *result)
{
    struct sink_notification *data;
    IUnknown *object;
    HRESULT hr;

    if (FAILED(hr = IMFAsyncResult_GetObject(result, &object)))
        return hr;

    data = impl_from_IUnknown(object);

    clock_call_state_change(data->system_time, data->param, data->notification, data->sink);

    IUnknown_Release(object);

    return S_OK;
}

static const IMFAsyncCallbackVtbl presentclocksinkcallbackvtbl =
{
    present_clock_sink_callback_QueryInterface,
    present_clock_sink_callback_AddRef,
    present_clock_sink_callback_Release,
    present_clock_sink_callback_GetParameters,
    present_clock_sink_callback_Invoke,
};

/***********************************************************************
 *      MFCreatePresentationClock (mf.@)
 */
HRESULT WINAPI MFCreatePresentationClock(IMFPresentationClock **clock)
{
    struct presentation_clock *object;

    TRACE("%p.\n", clock);

    object = heap_alloc_zero(sizeof(*object));
    if (!object)
        return E_OUTOFMEMORY;

    object->IMFPresentationClock_iface.lpVtbl = &presentationclockvtbl;
    object->IMFRateControl_iface.lpVtbl = &presentclockratecontrolvtbl;
    object->IMFTimer_iface.lpVtbl = &presentclocktimervtbl;
    object->IMFShutdown_iface.lpVtbl = &presentclockshutdownvtbl;
    object->IMFAsyncCallback_iface.lpVtbl = &presentclocksinkcallbackvtbl;
    object->refcount = 1;
    list_init(&object->sinks);
    object->rate = 1.0f;
    InitializeCriticalSection(&object->cs);

    *clock = &object->IMFPresentationClock_iface;

    return S_OK;
}