Mercurial > hg > audiostuff
view spandsp-0.0.3/spandsp-0.0.3/src/bitstream.c @ 5:f762bf195c4b
import spandsp-0.0.3
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 16:00:21 +0200 |
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/* * SpanDSP - a series of DSP components for telephony * * bitstream.c - Bitstream composition and decomposition routines. * * Written by Steve Underwood <steveu@coppice.org> * * Copyright (C) 2006 Steve Underwood * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id: bitstream.c,v 1.6 2006/11/30 15:41:47 steveu Exp $ */ /*! \file */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include <inttypes.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include "spandsp/telephony.h" #include "spandsp/logging.h" #include "spandsp/bitstream.h" void bitstream_put(bitstream_state_t *s, uint8_t **c, unsigned int value, int bits) { value &= ((1 << bits) - 1); if (s->residue + bits <= 32) { s->bitstream |= (value << s->residue); s->residue += bits; } while (s->residue >= 8) { s->residue -= 8; *(*c)++ = (uint8_t)(s->bitstream & 0xFF); s->bitstream >>= 8; } } /*- End of function --------------------------------------------------------*/ void bitstream_flush(bitstream_state_t *s, uint8_t **c) { if (s->residue > 0) { *(*c)++ = (uint8_t)((s->bitstream << (8 - s->residue)) & 0xFF); s->residue = 0; } } /*- End of function --------------------------------------------------------*/ unsigned int bitstream_get(bitstream_state_t *s, const uint8_t **c, int bits) { unsigned int x; while (s->residue < bits) { x = (unsigned int) *(*c)++; s->bitstream |= (x << s->residue); s->residue += 8; } s->residue -= bits; x = s->bitstream & ((1 << bits) - 1); s->bitstream >>= bits; return x; } /*- End of function --------------------------------------------------------*/ void bitstream_put2(bitstream_state_t *s, uint8_t **c, unsigned int value, int bits) { value &= ((1 << bits) - 1); if (s->residue + bits <= 32) { s->bitstream = (s->bitstream << bits) | value; s->residue += bits; } while (s->residue >= 8) { s->residue -= 8; *(*c)++ = (uint8_t) ((s->bitstream >> s->residue) & 0xFF); } } /*- End of function --------------------------------------------------------*/ void bitstream_flush2(bitstream_state_t *s, uint8_t **c) { if (s->residue > 0) { *(*c)++ = (uint8_t) ((s->bitstream << (8 - s->residue)) & 0xFF); s->residue = 0; } } /*- End of function --------------------------------------------------------*/ unsigned int bitstream_get2(bitstream_state_t *s, const uint8_t **c, int bits) { unsigned int x; while (s->residue < bits) { x = (unsigned int) *(*c)++; s->bitstream = (s->bitstream << 8) | x; s->residue += 8; } s->residue -= bits; x = (s->bitstream >> s->residue) & ((1 << bits) - 1); return x; } /*- End of function --------------------------------------------------------*/ bitstream_state_t *bitstream_init(bitstream_state_t *s) { if (s) memset(s, 0, sizeof(*s)); return s; } /*- End of function --------------------------------------------------------*/ /*- End of file ------------------------------------------------------------*/