From dee3799f82bcc4de6833f3045b0a7663a68606a7 Mon Sep 17 00:00:00 2001
From: "Reece H. Dunn" <msclrhd@gmail.com>
Date: Tue, 24 Jan 2017 07:24:29 +0000
Subject: [PATCH] issue #172: flush audio on cancel requests.

This is a partial fix for an audio regression. The other part of
the fix requires a change in pcaudiolib to reopen the audio device
on flush requests for affected audio drivers/devices.
---
 src/libespeak-ng/fifo.c   | 4 ++++
 src/libespeak-ng/speech.c | 9 +++++++++
 src/libespeak-ng/speech.h | 2 ++
 3 files changed, 15 insertions(+)

diff --git a/src/libespeak-ng/fifo.c b/src/libespeak-ng/fifo.c
index 33177434..43f0d453 100644
--- a/src/libespeak-ng/fifo.c
+++ b/src/libespeak-ng/fifo.c
@@ -254,6 +254,10 @@ static espeak_ng_STATUS close_stream()
 			status = a_status;
 
 		if (a_stop_is_required) {
+			// cancel the audio early, to be more responsive when using eSpeak NG
+			// for audio.
+			cancel_audio();
+
 			// acknowledge the stop request
 			if((a_status = pthread_mutex_lock(&my_mutex)) != ENS_OK)
 				return a_status;
diff --git a/src/libespeak-ng/speech.c b/src/libespeak-ng/speech.c
index 4dda6764..bde25f1c 100644
--- a/src/libespeak-ng/speech.c
+++ b/src/libespeak-ng/speech.c
@@ -81,6 +81,15 @@ int (*phoneme_callback)(const char *) = NULL;
 char path_home[N_PATH_HOME]; // this is the espeak-ng-data directory
 extern int saved_parameters[N_SPEECH_PARAM]; // Parameters saved on synthesis start
 
+void cancel_audio(void)
+{
+#ifdef HAVE_PCAUDIOLIB_AUDIO_H
+	if ((my_mode & ENOUTPUT_MODE_SPEAK_AUDIO) == ENOUTPUT_MODE_SPEAK_AUDIO) {
+		audio_object_flush(my_audio);
+	}
+#endif
+}
+
 static int dispatch_audio(short *outbuf, int length, espeak_EVENT *event)
 {
 	int a_wave_can_be_played = 1;
diff --git a/src/libespeak-ng/speech.h b/src/libespeak-ng/speech.h
index b5a50d30..cc14e20c 100644
--- a/src/libespeak-ng/speech.h
+++ b/src/libespeak-ng/speech.h
@@ -65,6 +65,8 @@ typedef struct {
 } MNEM_TAB;
 int LookupMnem(MNEM_TAB *table, const char *string);
 
+void cancel_audio(void);
+
 extern char path_home[N_PATH_HOME];    // this is the espeak-ng-data directory
 
 extern ESPEAK_NG_API void strncpy0(char *to, const char *from, int size);