1 files changed, 166 insertions, 0 deletions

diff --git a/apps/codecs/libpcm/ms_adpcm.c b/apps/codecs/libpcm/ms_adpcm.c
new file mode 100644
index 0000000000..899ecc2045
--- /dev/null
+++ b/apps/codecs/libpcm/ms_adpcm.c
@@ -0,0 +1,166 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2010 Yoshihisa Uchida
+ *
+ * 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 "codeclib.h"
+#include "pcm_common.h"
+
+/*
+ * Microsoft ADPCM
+ *
+ * References
+ * [1] Microsoft, New Multimedia Data Types and Data Techniques Revision 3.0, 1994
+ * [2] MulitimediaWiki, Microsoft ADPCM, 2006
+ * (http://wiki.multimedia.cx/index.php?title=Microsoft_ADPCM)
+ * [3] ffmpeg source code, libavcodec/adpcm.c
+ */
+
+#define ADPCM_NUM_COEFF 7
+
+static int16_t dec_coeff[2][2];
+static uint16_t delta[2];
+static int16_t sample[2][2];
+
+static struct pcm_format *fmt;
+
+static const int16_t adaptation_table[] ICONST_ATTR = {
+    230, 230, 230, 230, 307, 409, 512, 614,
+    768, 614, 512, 409, 307, 230, 230, 230
+};
+
+static bool set_format(struct pcm_format *format)
+{
+    fmt = format;
+
+    if (fmt->bitspersample != 4)
+    {
+        DEBUGF("CODEC_ERROR: microsoft adpcm must be 4 bitspersample: %d\n",
+                             fmt->bitspersample);
+        return false;
+    }
+
+    fmt->chunksize = fmt->blockalign;
+
+    return true;
+}
+
+static struct pcm_pos *get_seek_pos(long seek_time,
+                                    uint8_t *(*read_buffer)(size_t *realsize))
+{
+    static struct pcm_pos newpos;
+    uint32_t newblock = ((uint64_t)seek_time * ci->id3->frequency)
+                              / (1000LL * fmt->samplesperblock);
+
+    (void)read_buffer;
+    newpos.pos     = newblock * fmt->blockalign;
+    newpos.samples = newblock * fmt->samplesperblock;
+    return &newpos;
+}
+
+static int16_t create_pcmdata(int ch, uint8_t nibble)
+{
+    int32_t pcmdata;
+
+    pcmdata = (sample[ch][0] * dec_coeff[ch][0] +
+               sample[ch][1] * dec_coeff[ch][1]) / 256;
+    pcmdata += (delta[ch] * (nibble - ((nibble & 0x8) << 1)));
+
+    CLIP(pcmdata, -32768, 32767);
+  
+    sample[ch][1] = sample[ch][0];
+    sample[ch][0] = pcmdata;
+
+    delta[ch] = (adaptation_table[nibble] * delta[ch]) >> 8;
+    if (delta[ch] < 16)
+        delta[ch] = 16;
+
+    return (int16_t)pcmdata;
+}
+
+static int decode(const uint8_t *inbuf, size_t inbufsize,
+                  int32_t *outbuf, int *outbufcount)
+{
+    int ch;
+    size_t nsamples = 0;
+    int size = fmt->samplesperblock;
+
+    /* read block header */
+    for (ch = 0; ch < fmt->channels; ch++)
+    {
+        if (*inbuf >= ADPCM_NUM_COEFF)
+        {
+            DEBUGF("CODEC_ERROR: microsoft adpcm illegal initial coeff=%d > 7\n",
+                                 *inbuf);
+            return CODEC_ERROR;
+        }
+        dec_coeff[ch][0] = fmt->coeffs[*inbuf][0];
+        dec_coeff[ch][1] = fmt->coeffs[*inbuf][1];
+        inbuf++;
+    }
+
+    for (ch = 0; ch < fmt->channels; ch++)
+    {
+        delta[ch] = inbuf[0] | (SE(inbuf[1]) << 8);
+        inbuf += 2;
+    }
+
+    for (ch = 0; ch < fmt->channels; ch++)
+    {
+        sample[ch][0] = inbuf[0] | (SE(inbuf[1]) << 8);
+        inbuf += 2;
+    }
+
+    for (ch = 0; ch < fmt->channels; ch++)
+    {
+        sample[ch][1] = inbuf[0] | (SE(inbuf[1]) << 8);
+        inbuf += 2;
+    }
+
+    inbufsize -= 7 * fmt->channels;
+    ch = fmt->channels - 1;
+
+    while (size-- > 0)
+    {
+        *outbuf++ = create_pcmdata(0,  *inbuf >> 4 ) << 13;
+        *outbuf++ = create_pcmdata(ch, *inbuf & 0xf) << 13;
+        nsamples += 2;
+
+        inbuf++;
+        inbufsize--;
+        if (inbufsize <= 0)
+            break;
+    }
+
+    if (fmt->channels == 2)
+        nsamples >>= 1;
+    *outbufcount = nsamples;
+
+    return CODEC_OK;
+}
+
+static const struct pcm_codec codec = {
+                                          set_format,
+                                          get_seek_pos,
+                                          decode,
+                                      };
+
+const struct pcm_codec *get_ms_adpcm_codec(void)
+{
+    return &codec;
+}