From aeaef855077384f4d669dc8013948a17b5ce38cc Mon Sep 17 00:00:00 2001
From: Richard Schorrig <richard.schorrig@web.de>
Date: Tue, 22 Feb 2022 21:05:41 +0100
Subject: [PATCH] WasapiOutputPlugin pause bug fix

Wasapi output plugin won't start playing after being paused

The cause is that the scope guard in the WASAPI work thread
(WasapiOutputPlugin.cxx, function WasapiOutputThread::Work(), in the
while (true) loop) is set up too 'late' in the execution. There is one
condition ("if (data_in_frames >= buffer_size_in_frames)") when it is
hit, the loop will continue without executing the scope guard. This
scope guard is responsible for emptying the buffer again, and if the
buffer is not emptied, the above mentioned condition will stay true.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1451
---
 NEWS                                          |  1 +
 .../plugins/wasapi/WasapiOutputPlugin.cxx     | 20 +++++++++----------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/NEWS b/NEWS
index daa2b77a7..cdc114954 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,7 @@ ver 0.23.6 (not yet released)
   - opus: fix "readpicture" on Opus files
 * output
   - pipewire: fix crash bug if setting volume before playback starts
+  - wasapi: fix resume after pause
 
 ver 0.23.5 (2021/12/01)
 * protocol
diff --git a/src/output/plugins/wasapi/WasapiOutputPlugin.cxx b/src/output/plugins/wasapi/WasapiOutputPlugin.cxx
index bedd9f756..992dc2e67 100644
--- a/src/output/plugins/wasapi/WasapiOutputPlugin.cxx
+++ b/src/output/plugins/wasapi/WasapiOutputPlugin.cxx
@@ -471,6 +471,16 @@ try {
 		}
 
 		UINT32 write_in_frames = buffer_size_in_frames;
+		DWORD mode = 0;
+		AtScopeExit(&) {
+			render_client->ReleaseBuffer(write_in_frames, mode);
+
+			if (!started) {
+				Start(client);
+				started = true;
+			}
+		};
+
 		if (!is_exclusive) {
 			UINT32 data_in_frames =
 				GetCurrentPaddingFrames(client);
@@ -481,7 +491,6 @@ try {
 		}
 
 		BYTE *data;
-		DWORD mode = 0;
 
 		if (HRESULT result =
 		    render_client->GetBuffer(write_in_frames, &data);
@@ -489,15 +498,6 @@ try {
 			throw MakeHResultError(result, "Failed to get buffer");
 		}
 
-		AtScopeExit(&) {
-			render_client->ReleaseBuffer(write_in_frames, mode);
-
-			if (!started) {
-				Start(client);
-				started = true;
-			}
-		};
-
 		const UINT32 write_size = write_in_frames * frame_size;
 		UINT32 new_data_size = 0;
 		new_data_size = spsc_buffer.pop(data, write_size);