[PATCH 0/2] MR574: mf: Improve session pause / restart handling.

[Paul Gofman (＠gofman)]

Patch 1.

The tests on Windows show that when the timer callback is queued behind the clock time it is queued and executed quite soon with 0-15ms delay which corresponds to default timer granularity. The timeout tolerance in the test is quite bigger to avoid a flaky test. Wine currently may execute the callback right away or delay it indefinitely depending on the time difference and current system time.

Patch 2.
It turns out when the session is paused and then restarted and all the samples were delivered to sample grabber before restart, nothing is going to request the samples again when the session is restarted. I am attaching a test in a patch which hopefully confirms how that should work. I am not including that in the patches as the test involves delays (to make sure all the async events settle at certain points) and inherently flaky. Also, _ 
IMFStreamSink_GetEvent(stream, ...) in the test crashes on Win7 for some unknown reason.

[0001-mf-tests-Add-test-for-pausing-and-restarting-sample-.patch](/uploads/58c1738d48b3392e7ec430a0757210d0/0001-mf-tests-Add-test-for-pausing-and-restarting-sample-.patch)

[PATCH 1/2] mf: Handle timer time behind clock time in present_clock_schedule_timer().

[Paul Gofman]

From: Paul Gofman

---
 dlls/mf/clock.c    |  5 ++++-
 dlls/mf/tests/mf.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/dlls/mf/clock.c b/dlls/mf/clock.c
index e9877533a5a..aef4366c6d9 100644
--- a/dlls/mf/clock.c
+++ b/dlls/mf/clock.c
@@ -819,7 +819,10 @@ static HRESULT present_clock_schedule_timer(struct presentation_clock *clock, DW
             WARN("Failed to get clock time, hr %#lx.\n", hr);
             return hr;
         }
-        time -= clocktime;
+        if (time > clocktime)
+            time -= clocktime;
+        else
+            time = 0;
     }

frequency = clock->frequency / 1000;
diff --git a/dlls/mf/tests/mf.c b/dlls/mf/tests/mf.c
index 6621a0f0674..2dda77c339b 100644
--- a/dlls/mf/tests/mf.c
+++ b/dlls/mf/tests/mf.c
@@ -1428,8 +1428,14 @@ static const struct test_stream_sink test_stream_sink = {.IMFStreamSink_iface.lp
 struct test_callback
 {
     IMFAsyncCallback IMFAsyncCallback_iface;
+    HANDLE event;
 };

+static struct test_callback *test_callback_from_IMFAsyncCallback(IMFAsyncCallback *iface)
+{
+    return CONTAINING_RECORD(iface, struct test_callback, IMFAsyncCallback_iface);
+}
+
 static HRESULT WINAPI testcallback_QueryInterface(IMFAsyncCallback *iface, REFIID riid, void **obj)
 {
     if (IsEqualIID(riid, &IID_IMFAsyncCallback) ||
@@ -1462,8 +1468,12 @@ static HRESULT WINAPI testcallback_GetParameters(IMFAsyncCallback *iface, DWORD

static HRESULT WINAPI testcallback_Invoke(IMFAsyncCallback *iface, IMFAsyncResult *result)
 {
+    struct test_callback *test = test_callback_from_IMFAsyncCallback(iface);
     ok(result != NULL, "Unexpected result object.\n");

+    if (test->event)
+        SetEvent(test->event);
+
     return E_NOTIMPL;
 }

@@ -1479,6 +1489,7 @@ static const IMFAsyncCallbackVtbl testcallbackvtbl =
 static void init_test_callback(struct test_callback *callback)
 {
     callback->IMFAsyncCallback_iface.lpVtbl = &testcallbackvtbl;
+    callback->event = NULL;
 }

static void test_session_events(IMFMediaSession *session)
@@ -2865,15 +2876,19 @@ static void test_presentation_clock(void)
     };
     IMFClockStateSink test_sink = { &test_clock_sink_vtbl };
     IMFPresentationTimeSource *time_source;
+    struct test_callback timer_callback;
     MFCLOCK_PROPERTIES props, props2;
     IMFRateControl *rate_control;
     IMFPresentationClock *clock;
+    IUnknown *timer_cancel_key;
     MFSHUTDOWN_STATUS status;
     IMFShutdown *shutdown;
     MFTIME systime, time;
     LONGLONG clock_time;
     MFCLOCK_STATE state;
+    IMFTimer *timer;
     unsigned int i;
+    DWORD t1, t2;
     DWORD value;
     float rate;
     HRESULT hr;
@@ -3097,6 +3112,33 @@ static void test_presentation_clock(void)

IMFRateControl_Release(rate_control);

+
+    hr = IMFPresentationClock_QueryInterface(clock, &IID_IMFTimer, (void **)&timer);
+    ok(hr == S_OK, "got hr %#lx.\n", hr);
+
+    hr = IMFPresentationClock_Start(clock, 200000);
+    ok(hr == S_OK, "got hr %#lx.\n", hr);
+
+    hr = IMFPresentationClock_GetCorrelatedTime(clock, 0, &time, &systime);
+    ok(hr == S_OK, "got hr %#lx.\n", hr);
+
+    init_test_callback(&timer_callback);
+    timer_callback.event = CreateEventW(NULL, FALSE, FALSE, NULL);
+    hr = IMFTimer_SetTimer(timer, 0, 100000,
+            &timer_callback.IMFAsyncCallback_iface, NULL, &timer_cancel_key);
+    ok(hr == S_OK, "got hr %#lx.\n", hr);
+
+    t1 = GetTickCount();
+    ok(WaitForSingleObject(timer_callback.event, INFINITE) == WAIT_OBJECT_0, "WaitForSingleObject failed.\n");
+    t2 = GetTickCount();
+
+    ok(t2 - t1 < 200, "unexpected time difference %lu.\n", t2 - t1);
+
+    CloseHandle(timer_callback.event);
+    IUnknown_Release(timer_cancel_key);
+    IMFTimer_Release(timer);
+
+
     hr = IMFPresentationClock_QueryInterface(clock, &IID_IMFShutdown, (void **)&shutdown);
     ok(hr == S_OK, "Failed to get shutdown interface, hr %#lx.\n", hr);

[PATCH 2/2] mf/samplegrabber: Request a sample when going from paused to running state.

[Paul Gofman]

From: Paul Gofman

---
 dlls/mf/samplegrabber.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/dlls/mf/samplegrabber.c b/dlls/mf/samplegrabber.c
index 2d9f8109aca..a8791b698c7 100644
--- a/dlls/mf/samplegrabber.c
+++ b/dlls/mf/samplegrabber.c
@@ -85,6 +85,7 @@ struct sample_grabber
     UINT64 sample_time_offset;
     enum sink_state state;
     CRITICAL_SECTION cs;
+    BOOL received_sample_while_paused;
 };

static IMFSampleGrabberSinkCallback *sample_grabber_get_callback(const struct sample_grabber *sink)
@@ -422,6 +423,8 @@ static HRESULT WINAPI sample_grabber_stream_ProcessSample(IMFStreamSink *iface,

EnterCriticalSection(&grabber->cs);

+    grabber->received_sample_while_paused = FALSE;
+
     if (grabber->is_shut_down)
         hr = MF_E_STREAMSINK_REMOVED;
     else if (grabber->state == SINK_STATE_RUNNING)
@@ -442,6 +445,10 @@ static HRESULT WINAPI sample_grabber_stream_ProcessSample(IMFStreamSink *iface,
                 hr = stream_queue_sample(grabber, sample);
         }
     }
+    else if (grabber->state == SINK_STATE_PAUSED)
+    {
+        grabber->received_sample_while_paused = TRUE;
+    }

LeaveCriticalSection(&grabber->cs);

@@ -1136,6 +1143,12 @@ static HRESULT sample_grabber_set_state(struct sample_grabber *grabber, enum sin
                 for (i = 0; i < 4; ++i)
                     sample_grabber_stream_request_sample(grabber);
             }
+            else if (state == SINK_STATE_RUNNING && grabber->state == SINK_STATE_PAUSED
+                    && grabber->received_sample_while_paused)
+            {
+                grabber->received_sample_while_paused = FALSE;
+                sample_grabber_stream_request_sample(grabber);
+            }
             do_callback = state != grabber->state || state != SINK_STATE_PAUSED;
             if (do_callback)
                 IMFStreamSink_QueueEvent(&grabber->IMFStreamSink_iface, events[state], &GUID_NULL, S_OK, NULL);

[Nikolay Sivov (＠nsivov)]

Nikolay Sivov (@nsivov) commented about dlls/mf/samplegrabber.c:
>              for (i = 0; i < 4; ++i)
>                  sample_grabber_stream_request_sample(grabber);
>          }
> -
>        else if (state == SINK_STATE_RUNNING && grabber->state == SINK_STATE_PAUSED
> -
>                && grabber->received_sample_while_paused)
> -
>        {
> -
>            grabber->received_sample_while_paused = FALSE;
> -
>            sample_grabber_stream_request_sample(grabber);
> -
>        }

This is inaccurate, it can't use binary flag. With a test you attached, if you send same sample twice while sink is paused you'll get two requests on restart. But it does not accumulate indefinitely, same limit of 4 requests applies here as well. I think we should use a counter instead, reset it to 4 on stop, and increment up to 4 if sample is received when paused. When transitioning back to running, we'll need to issue that number of requests. It will be essentially same path for both start and restart state changes.