1 files changed, 100 insertions, 0 deletions

diff --git a/firmware/asm/generic/pcm-mixer.c b/firmware/asm/generic/pcm-mixer.c
new file mode 100644
index 0000000000..93841be70d
--- /dev/null
+++ b/firmware/asm/generic/pcm-mixer.c
@@ -0,0 +1,100 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2011 by Michael Sevakis
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "dsp-util.h" /* for clip_sample_16 */
+/* Mix channels' samples and apply gain factors */
+static FORCE_INLINE void mix_samples(uint32_t *out,
+                                     int16_t *src0,
+                                     int32_t src0_amp,
+                                     int16_t *src1,
+                                     int32_t src1_amp,
+                                     size_t size)
+{
+    if (src0_amp == MIX_AMP_UNITY && src1_amp == MIX_AMP_UNITY)
+    {
+        /* Both are unity amplitude */
+        do
+        {
+            int32_t l = *src0++ + *src1++;
+            int32_t h = *src0++ + *src1++;
+            *out++ = (uint16_t)clip_sample_16(l) | (clip_sample_16(h) << 16);
+        }
+        while ((size -= 4) > 0);
+    }
+    else if (src0_amp != MIX_AMP_UNITY && src1_amp != MIX_AMP_UNITY)
+    {
+        /* Neither are unity amplitude */
+        do
+        {
+            int32_t l = (*src0++ * src0_amp >> 16) + (*src1++ * src1_amp >> 16);
+            int32_t h = (*src0++ * src0_amp >> 16) + (*src1++ * src1_amp >> 16);
+            *out++ = (uint16_t)clip_sample_16(l) | (clip_sample_16(h) << 16);
+        }
+        while ((size -= 4) > 0);
+    }
+    else
+    {
+        /* One is unity amplitude */
+        if (src0_amp != MIX_AMP_UNITY)
+        {
+            /* Keep unity in src0, amp0 */
+            int16_t *src_tmp = src0;
+            src0 = src1;
+            src1 = src_tmp;
+            src1_amp = src0_amp;
+            src0_amp = MIX_AMP_UNITY;
+        }
+
+        do
+        {
+            int32_t l = *src0++ + (*src1++ * src1_amp >> 16);
+            int32_t h = *src0++ + (*src1++ * src1_amp >> 16);
+            *out++ = (uint16_t)clip_sample_16(l) | (clip_sample_16(h) << 16);
+        }
+        while ((size -= 4) > 0);
+    }
+}
+
+/* Write channel's samples and apply gain factor */
+static FORCE_INLINE void write_samples(uint32_t *out,
+                                       int16_t *src,
+                                       int32_t amp,
+                                       size_t size)
+{
+    if (LIKELY(amp == MIX_AMP_UNITY))
+    {
+        /* Channel is unity amplitude */
+        memcpy(out, src, size);
+    }
+    else
+    {
+        /* Channel needs amplitude cut */
+        do
+        {
+            int32_t l = *src++ * amp >> 16;
+            int32_t h = *src++ * amp & 0xffff0000;
+            *out++ = (uint16_t)l | h;
+        }
+        while ((size -= 4) > 0);
+    }     
+}
+
+#endif