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Diffstat (limited to 'apps/codecs/libpcm/linear_pcm.c')
| -rw-r--r-- | apps/codecs/libpcm/linear_pcm.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/apps/codecs/libpcm/linear_pcm.c b/apps/codecs/libpcm/linear_pcm.c new file mode 100644 index 0000000..2c766bd --- /dev/null +++ b/apps/codecs/libpcm/linear_pcm.c @@ -0,0 +1,163 @@ +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2005 Dave Chapman + * 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" + +/* + * Linear PCM + */ + +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) + { + DEBUGF("CODEC_ERROR: pcm with more than 32 bitspersample " + "is unsupported\n"); + return false; + } + + if (fmt->totalsamples == 0) + { + fmt->bytespersample = (((fmt->bitspersample - 1)/8 + 1)*fmt->channels); + fmt->totalsamples = fmt->numbytes/fmt->bytespersample; + } + + /* chunksize is computed so that one chunk is about 1/50s. + * this make 4096 for 44.1kHz 16bits stereo. + * It also has to be a multiple of blockalign */ + fmt->chunksize = (1 + fmt->avgbytespersec / (50*fmt->blockalign))*fmt->blockalign; + + return true; +} + +static uint32_t get_seek_pos(long seek_time) +{ + uint32_t newpos; + + /* use avgbytespersec to round to the closest blockalign multiple, + add firstblockposn. 64-bit casts to avoid overflows. */ + newpos = (((uint64_t)fmt->avgbytespersec*(seek_time - 1)) + / (1000LL*fmt->blockalign))*fmt->blockalign; + return newpos; +} + +static int decode(const uint8_t *inbuf, size_t inbufsize, + int32_t *outbuf, int *outbufsize) +{ + uint32_t i; + + if (fmt->bitspersample > 24) + { + for (i = 0; i < inbufsize; i += 4) + { + if (fmt->is_little_endian) + { + if (fmt->is_signed) + outbuf[i/4] = (inbuf[i]>>3)|(inbuf[i+1]<<5)|(inbuf[i+2]<<13)|(SE(inbuf[i+3])<<21); + else + outbuf[i/4] = (inbuf[i]>>3)|(inbuf[i+1]<<5)|(inbuf[i+2]<<13)|(SFT(inbuf[i+3])<<21); + } + else + { + if (fmt->is_signed) + outbuf[i/4] = (inbuf[i+3]>>3)|(inbuf[i+2]<<5)|(inbuf[i+1]<<13)|(SE(inbuf[i])<<21); + else + outbuf[i/4] = (inbuf[i+3]>>3)|(inbuf[i+2]<<5)|(inbuf[i+1]<<13)|(SFT(inbuf[i])<<21); + } + } + *outbufsize = inbufsize >> 2; + } + else if (fmt->bitspersample > 16) + { + for (i = 0; i < inbufsize; i += 3) + { + if (fmt->is_little_endian) + { + if (fmt->is_signed) + outbuf[i/3] = (inbuf[i]<<5)|(inbuf[i+1]<<13)|(SE(inbuf[i+2])<<21); + else + outbuf[i/3] = (inbuf[i]<<5)|(inbuf[i+1]<<13)|(SFT(inbuf[i+2])<<21); + } + else + { + if (fmt->is_signed) + outbuf[i/3] = (inbuf[i+2]<<5)|(inbuf[i+1]<<13)|(SE(inbuf[i])<<21); + else + outbuf[i/3] = (inbuf[i+2]<<5)|(inbuf[i+1]<<13)|(SFT(inbuf[i])<<21); + } + } + *outbufsize = inbufsize/3; + } + else if (fmt->bitspersample > 8) + { + for (i = 0; i < inbufsize; i += 2) + { + if (fmt->is_little_endian) + { + if (fmt->is_signed) + outbuf[i/2] = (inbuf[i]<<13)|(SE(inbuf[i+1])<<21); + else + outbuf[i/2] = (inbuf[i]<<13)|(SFT(inbuf[i+1])<<21); + } + else + { + if (fmt->is_signed) + outbuf[i/2] = (inbuf[i+1]<<13)|(SE(inbuf[i])<<21); + else + outbuf[i/2] = (inbuf[i+1]<<13)|(SFT(inbuf[i])<<21); + } + } + *outbufsize = inbufsize >> 1; + } + else + { + for (i = 0; i < inbufsize; i++) { + if (fmt->is_signed) + outbuf[i] = SE(inbuf[i])<<21; + else + outbuf[i] = SFT(inbuf[i])<<21; + } + *outbufsize = inbufsize; + } + + 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_linear_pcm_codec(void) +{ + return &codec; +} |