diff options
Diffstat (limited to 'apps/codecs/libpcm/ieee_float.c')
-rw-r--r-- | apps/codecs/libpcm/ieee_float.c | 147 |
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; +} |