Reunification of xine-lib and xine-output. Some code cleanups.

CVS patchset: 21
CVS date: 2001/04/24 20:53:00

1 files changed, 67 insertions, 0 deletions

diff --git a/src/audio_out/resample.c b/src/audio_out/resample.c
new file mode 100644
index 000000000..9f464b276
--- /dev/null
+++ b/src/audio_out/resample.c
@@ -0,0 +1,67 @@
+/* 
+ * Copyright (C) 2000 the xine project
+ * 
+ * This file is part of xine, a unix video player.
+ * 
+ * xine 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.
+ * 
+ * xine 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
+ *
+ * $Id: resample.c,v 1.1 2001/04/24 20:53:00 f1rmb Exp $
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <inttypes.h>
+
+/* contributed by paul flinders */
+
+void audio_out_resample_stereo(int16_t* input_samples, uint32_t in_samples, 
+			       int16_t* output_samples, uint32_t out_samples)
+{
+  int osample;
+  /* 16+16 fixed point math */
+  uint32_t isample = 0;
+  uint32_t istep = (in_samples << 16)/out_samples;
+
+#ifdef VERBOSE
+  printf ("Audio : resample %d samples to %d\n",
+          in_samples, out_samples);
+#endif
+
+  for (osample = 0; osample < out_samples - 1; osample++) {
+    int  s1;
+    int  s2;
+    int16_t  os;
+    uint32_t t = isample&0xffff;
+    
+    /* don't "optimize" the (isample >> 16)*2 to (isample >> 15) */
+    s1 = input_samples[(isample >> 16)*2];
+    s2 = input_samples[(isample >> 16)*2+2];
+    
+    os = (s1 * (0x10000-t)+ s2 * t) >> 16;
+    output_samples[osample * 2] = os;
+
+    s1 = input_samples[(isample >> 16)*2+1];
+    s2 = input_samples[(isample >> 16)*2+3];
+    
+    os = (s1 * (0x10000-t)+ s2 * t) >> 16;
+    output_samples[(osample * 2 )+1] = os;
+    isample += istep;
+  }
+  output_samples[out_samples*2-2] = input_samples[in_samples*2-2];
+  output_samples[out_samples*2-1] = input_samples[in_samples*2-1];
+}
+