1 files changed, 233 insertions, 0 deletions

diff --git a/apps/codecs/libpcm/swf_adpcm.c b/apps/codecs/libpcm/swf_adpcm.c
new file mode 100644
index 0000000000..456e1cdd4c
--- /dev/null
+++ b/apps/codecs/libpcm/swf_adpcm.c
@@ -0,0 +1,233 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   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"
+#include "ima_adpcm_common.h"
+
+/*
+ * Adobe SWF ADPCM
+ *
+ * References
+ * [1] Adobe, SWF File Format Specification Version 10, 2008
+ * [2] Jack Jansen, adpcm.c in adpcm.zip
+ * [3] ffmpeg source code, libavcodec/adpcm.c
+ */
+
+/* step index table when bitspersample is 3.
+ * (when bitspersample is 2, 4, 5, step index table uses the table
+ * which is defined ima_adpcm_common.c.)
+ */
+static const int index_table[4] ICONST_ATTR = {
+    -1, -1, 2, 4,
+};
+
+static int validity_bits = 8;
+static bool first_block = true;
+static int blockbits = 0;
+static int lastbytebits = 0;
+static bool after_seek = false;
+
+static struct pcm_format *fmt;
+
+static bool set_format(struct pcm_format *format)
+{
+    fmt = format;
+
+    if (fmt->bitspersample < 2 || fmt->bitspersample > 5)
+    {
+        DEBUGF("CODEC_ERROR: swf adpcm must be 2, 3, 4 or 5 bitspersample: %d\n",
+                             fmt->bitspersample);
+        return false;
+    }
+
+    if (fmt->samplesperblock == 0)
+        fmt->samplesperblock = (((fmt->blockalign << 3) - 2) / fmt->channels - 22)
+                                                             / fmt->bitspersample + 1;
+
+    blockbits = ((fmt->samplesperblock - 1) * fmt->bitspersample + 22) * fmt->channels;
+
+    /*
+     * chunksize = about 93 [ms] data (frequency:44.1kHz, 4096 [sample/block])
+     * chunksize changes depending upon the position of block.
+     */
+    fmt->chunksize = (blockbits + 9) >> 3;
+
+    /* initialize for ima adpcm common functions */
+    if (fmt->bitspersample == 3)
+        init_ima_adpcm_decoder(fmt->bitspersample, index_table);
+    else
+        init_ima_adpcm_decoder(fmt->bitspersample, NULL);
+
+   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 chunkbits = blockbits;
+    uint32_t seekbits = (((uint64_t)seek_time * ci->id3->frequency)
+                                       / (1000LL * fmt->samplesperblock)) * blockbits + 2;
+
+    (void)read_buffer;
+
+    newpos.pos     = seekbits >> 3;
+    newpos.samples = (((uint64_t)seek_time * ci->id3->frequency)
+                                           / (1000LL * fmt->samplesperblock))
+                                           * fmt->samplesperblock;
+
+    if (newpos.pos == 0)
+    {
+        first_block = true;
+        lastbytebits = 0;
+    }
+    else
+    {
+        first_block = false;
+        lastbytebits = seekbits & 0x07;
+        if (lastbytebits != 0)
+            chunkbits -= (8 - lastbytebits);
+    }
+
+    /* calculates next read bytes */
+    fmt->chunksize = (chunkbits >> 3) + (((chunkbits & 0x07) > 0)?1:0)
+                                      + ((lastbytebits > 0)?1:0);
+
+    after_seek = true;
+    return &newpos;
+}
+
+static uint8_t get_data(const uint8_t **buf, int bit)
+{
+    uint8_t res = 0;
+    uint8_t mask = (1 << bit) - 1;
+
+    if (validity_bits >= bit)
+    {
+        validity_bits -= bit;
+        return (**buf >> validity_bits) & mask;
+    }
+
+    if (validity_bits > 0)
+        res = **buf << (bit - validity_bits);
+
+    validity_bits += 8 - bit;
+    res = (res | (*(++(*buf)) >> validity_bits)) & mask;
+    return res;
+}
+
+static int decode(const uint8_t *inbuf, size_t inbufsize,
+                  int32_t *outbuf, int *outbufcount)
+{
+    int ch;
+    int adpcm_code_size;
+    int count = fmt->samplesperblock;
+    int32_t init_pcmdata[2];
+    int8_t init_index[2];
+    static uint8_t lastbyte = 0;
+
+    (void)inbufsize;
+
+    validity_bits = 8;
+
+    /* read block header */
+    ch = fmt->channels - 1;
+    if (first_block)
+    {
+        adpcm_code_size = get_data(&inbuf, 2) + 2;
+        if (fmt->bitspersample != adpcm_code_size)
+        {
+            DEBUGF("CODEC_ERROR: swf adpcm different adpcm code size=%d != %d\n",
+                                 adpcm_code_size, fmt->bitspersample);
+            return CODEC_ERROR;
+        }
+        init_pcmdata[0] = (get_data(&inbuf, 8) << 8) | get_data(&inbuf, 8);
+
+        lastbytebits = 0;
+        first_block = false;
+    }
+    else
+    {
+        if (after_seek && lastbytebits > 0)
+        {
+            lastbyte = *inbuf++;
+            after_seek = false;
+        }
+        if (lastbytebits > 0)
+            init_pcmdata[0] = ((lastbyte << (8 + lastbytebits)) |
+                              (get_data(&inbuf, 8) << lastbytebits) |
+                              get_data(&inbuf, lastbytebits)) & 65535;
+        else
+            init_pcmdata[0] = (get_data(&inbuf, 8) << 8) | get_data(&inbuf, 8);
+    }
+    after_seek = false;
+
+    init_index[0] = get_data(&inbuf, 6);
+    if (init_pcmdata[0] > 32767)
+        init_pcmdata[0] -= 65536;
+
+    if (ch > 0)
+    {
+        init_pcmdata[1] = (get_data(&inbuf, 8) << 8) | get_data(&inbuf, 8);
+        init_index[1] = get_data(&inbuf, 6);
+        if (init_pcmdata[1] > 32767)
+            init_pcmdata[1] -= 65536;
+    }
+
+    *outbuf++ = init_pcmdata[0] << 13;
+    if (ch > 0)
+        *outbuf++ = init_pcmdata[1] << 13;
+
+    set_decode_parameters(fmt->channels, init_pcmdata, init_index);
+
+    /* read block data */
+    while (--count > 0)
+    {
+        *outbuf++ = create_pcmdata(0, get_data(&inbuf, fmt->bitspersample)) << 13;
+        if (ch > 0)
+            *outbuf++ = create_pcmdata(ch, get_data(&inbuf, fmt->bitspersample)) << 13;
+    }
+
+    *outbufcount = fmt->samplesperblock;
+
+    lastbyte = *inbuf;
+    lastbytebits = (8 - validity_bits) & 0x07;
+
+    /* calculates next read bytes */
+    fmt->chunksize = (blockbits - validity_bits + 7) >> 3;
+
+    return CODEC_OK;
+}
+
+static const struct pcm_codec codec = {
+                                          set_format,
+                                          get_seek_pos,
+                                          decode,
+                                      };
+
+const struct pcm_codec *get_swf_adpcm_codec(void)
+{
+    first_block = true;
+    lastbytebits = 0;
+    after_seek = false;
+
+    return &codec;
+}