[PATCH v3 2/3] mf: Generate missing MEStreamSinkPaused event in the sample grabber.

[Nikolay Sivov]

On 5/31/21 1:11 PM, Giovanni Mascellani wrote:
> The following behaviors from Windows are implemented:
>  * Transitions from STOPPED to PAUSED are forbidden;
>  * Sample requests are only emitted for transitions from STOPPED to
>    RUNNING (i.e., not when transitioning from PAUSED);
>  * Transition events are emitted again when transitioning from a
>    state to the same state, except when such state is PAUSED.
>
Ideally we'd be fixing such issues separately. Anyway, this looks much
closer to how it should work. One difference now is that user
OnClockPause() callback is called every time, when it should only be
called when event was fired.

> 1146     struct sample_grabber *grabber =
> impl_from_IMFClockStateSink(iface);
> 1147     HRESULT hr;
> 1148
> 1149     TRACE("%p, %s, %s.\n", iface, debugstr_time(systime),
> debugstr_time(offset));
> 1150
> 1151     hr = sample_grabber_set_state(grabber, SINK_STATE_RUNNING);
> 1152     if (FAILED(hr))
> 1153         return hr;
> 1154
> 1155     return
> IMFSampleGrabberSinkCallback_OnClockStart(sample_grabber_get_callback(grabber),
> systime, offset);
This could be nicer, without additional error paths. Maybe by invoking
callback from the helper.