Adding a null output plugin.

git-svn-id: https://svn.musicpd.org/mpd/trunk@6393 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/audioOutputs/audioOutput_null.c

@@ -0,0 +1,129 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
+ * This project's homepage is: http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "../audioOutput.h"
+
+#include <stdlib.h>
+#include <limits.h>
+#include <sys/time.h>
+
+typedef struct _NullData {
+	uint64_t nextPlay;
+	int rate;
+} NullData;
+
+static NullData *newNullData(void)
+{
+	NullData *ret;
+
+	ret = xmalloc(sizeof(NullData));
+	ret->nextPlay = 0;
+	ret->rate = 0;
+
+	return ret;
+}
+
+static void freeNullData(NullData *nd)
+{
+	free(nd);
+}
+
+static uint64_t null_getTime(void)
+{
+	struct timeval tv;
+
+	gettimeofday(&tv, NULL);
+
+	return ((uint64_t)tv.tv_sec * 1000000) + tv.tv_usec;
+}
+
+static int null_initDriver(AudioOutput *audioOutput, ConfigParam *param)
+{
+	NullData *nd;
+
+	nd = newNullData();
+	audioOutput->data = nd;
+
+	return 0;
+}
+
+static void null_finishDriver(AudioOutput *audioOutput)
+{
+	freeNullData((NullData *)audioOutput->data);
+}
+
+static int null_openDevice(AudioOutput *audioOutput)
+{
+	NullData *nd;
+	AudioFormat *af;
+
+	nd = audioOutput->data;
+	af = &audioOutput->outAudioFormat;
+	nd->rate = af->sampleRate * (af->bits / CHAR_BIT) * af->channels;
+	audioOutput->open = 1;
+
+	return 0;
+}
+
+static void null_dropBufferedAudio(AudioOutput *audioOutput)
+{
+	NullData *nd;
+
+	nd = audioOutput->data;
+	nd->nextPlay = 0;
+}
+
+static void null_closeDevice(AudioOutput *audioOutput)
+{
+	NullData *nd;
+
+	nd = audioOutput->data;
+	nd->nextPlay = 0;
+	nd->rate = 0;
+	audioOutput->open = 0;
+}
+
+static int null_playAudio(AudioOutput *audioOutput, char *playChunk, int size)
+{
+	NullData *nd;
+	uint64_t now;
+
+	nd = audioOutput->data;
+	now = null_getTime();
+
+	if (nd->nextPlay == 0)
+		nd->nextPlay = now;
+	else if (nd->nextPlay > now)
+		my_usleep(nd->nextPlay - now);
+
+	nd->nextPlay += ((uint64_t)size * 1000000) / nd->rate;
+
+	return 0;
+}
+
+AudioOutputPlugin nullPlugin = {
+	"null",
+	NULL,
+	null_initDriver,
+	null_finishDriver,
+	null_openDevice,
+	null_playAudio,
+	null_dropBufferedAudio,
+	null_closeDevice,
+	NULL,
+};