From f40bfc9267b13b54e6379dfe7539447662879d24 Mon Sep 17 00:00:00 2001
From: Sean Bartell <wingedtachikoma@gmail.com>
Date: Sat, 25 Jun 2011 21:32:25 -0400
Subject: Add codecs to librbcodec.
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Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97
Reviewed-on: http://gerrit.rockbox.org/137
Reviewed-by: Nils Wallménius <nils@rockbox.org>
Tested-by: Nils Wallménius <nils@rockbox.org>
---
 lib/rbcodec/codecs/libpcm/qt_ima_adpcm.c | 138 +++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100644 lib/rbcodec/codecs/libpcm/qt_ima_adpcm.c

(limited to 'lib/rbcodec/codecs/libpcm/qt_ima_adpcm.c')

diff --git a/lib/rbcodec/codecs/libpcm/qt_ima_adpcm.c b/lib/rbcodec/codecs/libpcm/qt_ima_adpcm.c
new file mode 100644
index 0000000000..d7b3360eb3
--- /dev/null
+++ b/lib/rbcodec/codecs/libpcm/qt_ima_adpcm.c
@@ -0,0 +1,138 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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 "ima_adpcm_common.h"
+#include "support_formats.h"
+
+/*
+ * Apple QuickTime IMA ADPCM
+ *
+ * References
+ * [1] Multimedia Wiki, Apple QuickTime IMA ADPCM
+ *     URL:http://wiki.multimedia.cx/index.php?title=Apple_QuickTime_IMA_ADPCM
+ * [2] Apple Inc., Technical Note TN1081 Understanding the Differences Between
+ *     Apple and Windows IMA-ADPCM Compressed Sound Files, 1996
+ * [3] ffmpeg source code, libavcodec/adpcm.c
+ */
+
+static struct pcm_format *fmt;
+
+static bool set_format(struct pcm_format *format)
+{
+    fmt = format;
+
+    if (fmt->bitspersample != 4)
+    {
+        DEBUGF("CODEC_ERROR: quicktime ima adpcm must be 4 bitspersample: %d\n",
+                             fmt->bitspersample);
+        return false;
+    }
+
+    fmt->blockalign = 34 * fmt->channels;
+    fmt->samplesperblock = 64;
+
+    /* chunksize = about 1/50[s] data */
+    fmt->chunksize = (ci->id3->frequency / (50 * fmt->samplesperblock))
+                                         * fmt->blockalign;
+
+    init_ima_adpcm_decoder(4, NULL);
+    return true;
+}
+
+static struct pcm_pos *get_seek_pos(uint32_t seek_val, int seek_mode,
+                                    uint8_t *(*read_buffer)(size_t *realsize))
+{
+    static struct pcm_pos newpos;
+    uint32_t newblock = (seek_mode == PCM_SEEK_TIME) ?
+                        ((uint64_t)seek_val * ci->id3->frequency / 1000LL)
+                                            / fmt->samplesperblock :
+                        seek_val / fmt->blockalign;
+
+    (void)read_buffer;
+    newpos.pos     = newblock * fmt->blockalign;
+    newpos.samples = newblock * fmt->samplesperblock;
+    return &newpos;
+}
+
+static int decode(const uint8_t *inbuf, size_t inbufsize,
+                  int32_t *outbuf, int *outbufcount)
+{
+    int ch;
+    size_t nsamples = 0;
+    int block_size;
+    int32_t *pcmbuf;
+    int32_t init_pcmdata;
+    int8_t init_index;
+
+    while (inbufsize > 0)
+    {
+        for (ch = 0; ch < fmt->channels; ch++)
+        {
+            /* read block header */
+            init_pcmdata = (inbuf[0] << 8)|(inbuf[1] & 0x80);
+            if (init_pcmdata > 32767)
+                init_pcmdata -= 65536;
+
+            init_index = inbuf[1] & 0x7f;
+            if (init_index > 88)
+            {
+                DEBUGF("CODEC_ERROR: quicktime ima adpcm illegal step index=%d > 88\n",
+                                     init_index);
+                return CODEC_ERROR;
+            }
+
+            inbuf += 2;
+            inbufsize -= 2;
+
+            set_decode_parameters(1, &init_pcmdata, &init_index);
+
+            /* read block data */
+            pcmbuf = outbuf + ch;
+            for (block_size = 32; block_size > 0 && inbufsize > 0; block_size--, inbufsize--)
+            {
+                *pcmbuf = create_pcmdata_size4(ch, *inbuf     ) << IMA_ADPCM_INC_DEPTH;
+                pcmbuf += fmt->channels;
+                *pcmbuf = create_pcmdata_size4(ch, *inbuf >> 4) << IMA_ADPCM_INC_DEPTH;
+                pcmbuf += fmt->channels;
+                nsamples += 2;
+                inbuf++;
+            }
+        }
+        outbuf += 64 * fmt->channels;
+    }
+
+    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_qt_ima_adpcm_codec(void)
+{
+    return &codec;
+}
-- 
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