1 files changed, 98 insertions, 0 deletions
diff --git a/audio/filter/af_karaoke.c b/audio/filter/af_karaoke.c
new file mode 100644
index 0000000000..965eb8f40d
--- /dev/null
+++ b/audio/filter/af_karaoke.c
@@ -0,0 +1,98 @@
+/*
+ * simple voice removal filter
+ *
+ * copyright (c) 2006 Reynaldo H. Verdejo Pinochet
+ * Based on code by Alex Beregszaszi for his 'center' filter.
+ *
+ * This file is part of MPlayer.
+ *
+ * MPlayer 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.
+ *
+ * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "af.h"
+
+// Data for specific instances of this filter
+
+// Initialization and runtime control
+static int control(struct af_instance* af, int cmd, void* arg)
+{
+	switch(cmd){
+		case AF_CONTROL_REINIT:
+		af->data->rate	= ((struct mp_audio*)arg)->rate;
+		af->data->nch	= ((struct mp_audio*)arg)->nch;
+		af->data->format= AF_FORMAT_FLOAT_NE;
+		af->data->bps	= 4;
+		return af_test_output(af,(struct mp_audio*)arg);
+	}
+	return AF_UNKNOWN;
+}
+
+// Deallocate memory
+static void uninit(struct af_instance* af)
+{
+	free(af->data);
+}
+
+// Filter data through filter
+static struct mp_audio* play(struct af_instance* af, struct mp_audio* data)
+{
+	struct mp_audio*	c	= data;		 // Current working data
+	float*		a	= c->audio;	 // Audio data
+	int			len	= c->len/4;	 // Number of samples in current audio block
+	int			nch	= c->nch;	 // Number of channels
+	register int  i;
+
+	/*
+		FIXME1 add a low band pass filter to avoid suppressing
+		centered bass/drums
+		FIXME2 better calculated* attenuation factor
+	*/
+
+	for(i=0;i<len;i+=nch)
+	{
+		a[i] = (a[i] - a[i+1]) * 0.7;
+		a[i+1]=a[i];
+	}
+
+	return c;
+}
+
+// Allocate memory and set function pointers
+static int af_open(struct af_instance* af){
+	af->control	= control;
+	af->uninit	= uninit;
+	af->play	= play;
+	af->mul		= 1;
+	af->data	= calloc(1,sizeof(struct mp_audio));
+
+	if(af->data == NULL)
+		return AF_ERROR;
+
+	return AF_OK;
+}
+
+// Description of this filter
+struct af_info af_info_karaoke = {
+	"Simple karaoke/voice-removal audio filter",
+	"karaoke",
+	"Reynaldo H. Verdejo Pinochet",
+	"",
+	AF_FLAGS_NOT_REENTRANT,
+	af_open
+};