[PATCH v4 2/5] mf: Drop transform node input events when unpausing at a specific position.

[Conor McCarthy]

From: Conor McCarthy

The start position is empty when starting at the current position from
the paused state, but if it is not empty, this is a seek operation.
Behaviour in Windows is to send MFT_MESSAGE_COMMAND_FLUSH before calling
Start() on the source. Other reset actions should probably be done then
also.
---
 dlls/mf/session.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/dlls/mf/session.c b/dlls/mf/session.c
index e595cadd185..0103d7a65df 100644
--- a/dlls/mf/session.c
+++ b/dlls/mf/session.c
@@ -1061,7 +1061,7 @@ static void session_handle_start_error(struct media_session *session, HRESULT hr
     session_command_complete_with_event(session, MESessionStarted, hr, NULL);
 }

-static void session_reset_transforms(struct media_session *session)
+static void session_reset_transforms(struct media_session *session, BOOL drop)
 {
     struct topo_node *topo_node;
     UINT i;
@@ -1075,6 +1075,8 @@ static void session_reset_transforms(struct media_session *session)
         {
             struct transform_stream *stream = &topo_node->u.transform.inputs[i];
             stream->draining = FALSE;
+            if (drop)
+                transform_stream_drop_events(stream);
         }
     }
 }
@@ -1082,6 +1084,7 @@ static void session_reset_transforms(struct media_session *session)
 static void session_start(struct media_session *session, const GUID *time_format, const PROPVARIANT *start_position)
 {
     struct media_source *source;
+    BOOL unpause_seek;
     MFTIME duration;
     HRESULT hr;

@@ -1109,6 +1112,11 @@ static void session_start(struct media_session *session, const GUID *time_format
                 return;
             }

+            unpause_seek = start_position->vt == VT_I8;
+            if (unpause_seek)
+                session_flush_nodes(session);
+            session_reset_transforms(session, unpause_seek);
+
             LIST_FOR_EACH_ENTRY(source, &session->presentation.sources, struct media_source, entry)
             {
                 if (FAILED(hr = IMFMediaSource_Start(source->source, source->pd, &GUID_NULL, start_position)))
@@ -1119,8 +1127,6 @@ static void session_start(struct media_session *session, const GUID *time_format
                 }
             }

-            session_reset_transforms(session);
-
             session->state = SESSION_STATE_STARTING_SOURCES;
             break;
         case SESSION_STATE_STARTED: