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Diffstat (limited to 'apps/codecs/libpcm/ieee_float.c')
-rw-r--r--apps/codecs/libpcm/ieee_float.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/apps/codecs/libpcm/ieee_float.c b/apps/codecs/libpcm/ieee_float.c
new file mode 100644
index 0000000000..a5c50e845e
--- /dev/null
+++ b/apps/codecs/libpcm/ieee_float.c
@@ -0,0 +1,147 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Copyright (C) 2009 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"
+
+/*
+ * IEEE float
+ */
+
+static struct pcm_format *fmt;
+
+static bool set_format(struct pcm_format *format, const unsigned char *fmtpos)
+{
+ fmt = format;
+
+ (void)fmtpos;
+
+ if (fmt->bitspersample != 32 && fmt->bitspersample != 64)
+ {
+ DEBUGF("CODEC_ERROR: ieee float must be 32 or 64 bitspersample %d\n", fmt->bitspersample);
+ return false;
+ }
+
+ fmt->bytespersample = fmt->bitspersample >> 3;
+ fmt->blockalign = fmt->bytespersample;
+
+ /* chunksize is computed so that one chunk is about 1/50s. */
+ fmt->chunksize = (ci->id3->frequency * fmt->channels / 50) * fmt->blockalign;
+
+ return true;
+}
+
+static uint32_t get_seek_pos(long seek_time)
+{
+ uint32_t newpos;
+
+ newpos = ((uint64_t)(seek_time * ci->id3->frequency * fmt->channels / 1000LL))*fmt->blockalign;
+ return newpos;
+}
+
+static int decode(const uint8_t *inbuf, size_t inbufsize,
+ int32_t *outbuf, int *outbufsize)
+{
+ uint32_t i;
+ int32_t pcm;
+ int16_t exp;
+ int sgn;
+
+ if (fmt->bitspersample == 32)
+ {
+ for (i = 0; i < inbufsize; i += 4)
+ {
+ if (fmt->is_little_endian)
+ {
+ pcm = (inbuf[0]<<5)|(inbuf[1]<<13)|((inbuf[2]|0x80)<<21);
+ exp = ((inbuf[2]>>7)|((inbuf[3]&0x7f)<<1)) - 127;
+ sgn = inbuf[3] & 0x80;
+ }
+ else
+ {
+ pcm = (inbuf[3]<<5)|(inbuf[2]<<13)|((inbuf[1]|0x80)<<21);
+ exp = ((inbuf[1]>>7)|((inbuf[0]&0x7f)<<1)) - 127;
+ sgn = inbuf[0] & 0x80;
+ }
+ if (exp > -29 && exp < 0)
+ {
+ pcm >>= -exp;
+ if (sgn)
+ pcm = -pcm;
+ }
+ else if (exp < -28)
+ pcm = 0;
+ else
+ pcm = (sgn)?-(1<<28):(1<<28)-1;
+
+ outbuf[i/4] = pcm;
+ inbuf += 4;
+ }
+ *outbufsize = inbufsize >> 2;
+ }
+ else
+ {
+ for (i = 0; i < inbufsize; i += 8)
+ {
+ if (fmt->is_little_endian)
+ {
+ pcm = inbuf[3]|(inbuf[4]<<8)|(inbuf[5]<<16)|(((inbuf[6]&0x0f)|0x10)<<24);
+ exp = (((inbuf[6]&0xf0)>>4)|((inbuf[7]&0x7f)<<4)) - 1023;
+ sgn = inbuf[7] & 0x80;
+ }
+ else
+ {
+ pcm = inbuf[4]|(inbuf[3]<<8)|(inbuf[2]<<16)|(((inbuf[1]&0x0f)|0x10)<<24);
+ exp = (((inbuf[1]&0xf0)>>4)|((inbuf[0]&0x7f)<<4)) - 1023;
+ sgn = inbuf[0] & 0x80;
+ }
+ if (exp > -29 && exp < 0)
+ {
+ pcm >>= -exp;
+ if (sgn)
+ pcm = -pcm;
+ }
+ else if (exp < -28)
+ pcm = 0;
+ else
+ pcm = (sgn)?-(1<<28):(1<<28)-1;
+
+ outbuf[i/8] = pcm;
+ inbuf += 8;
+ }
+ *outbufsize = inbufsize >> 3;
+ }
+
+ if (fmt->channels == 2)
+ *outbufsize >>= 1;
+
+ return CODEC_OK;
+}
+
+static const struct pcm_codec codec = {
+ set_format,
+ get_seek_pos,
+ decode,
+ };
+
+const struct pcm_codec *get_ieee_float_codec(void)
+{
+ return &codec;
+}