esp-idf/components/bt/host/bluedroid/external/sbc/decoder/srce/bitstream-decode.c
2019-06-30 16:39:00 +08:00

96 lines
2.5 KiB
C

/******************************************************************************
*
* Copyright (C) 2014 The Android Open Source Project
* Copyright 2003 - 2004 Open Interface North America, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************/
/**********************************************************************************
$Revision: #1 $
***********************************************************************************/
/**
@file
Functions for manipulating input bitstreams.
@ingroup codec_internal
*/
/**
@addtogroup codec_internal
@{
*/
#include "common/bt_target.h"
#include "oi_stddefs.h"
#include "oi_bitstream.h"
#include "oi_assert.h"
#if (defined(SBC_DEC_INCLUDED) && SBC_DEC_INCLUDED == TRUE)
PRIVATE void OI_BITSTREAM_ReadInit(OI_BITSTREAM *bs,
const OI_BYTE *buffer)
{
bs->value = ((OI_INT32)buffer[0] << 16) | ((OI_INT32)buffer[1] << 8) | (buffer[2]);
bs->ptr.r = buffer + 3;
bs->bitPtr = 8;
}
PRIVATE OI_UINT32 OI_BITSTREAM_ReadUINT(OI_BITSTREAM *bs, OI_UINT bits)
{
OI_UINT32 result;
OI_BITSTREAM_READUINT(result, bits, bs->ptr.r, bs->value, bs->bitPtr);
return result;
}
PRIVATE OI_UINT8 OI_BITSTREAM_ReadUINT4Aligned(OI_BITSTREAM *bs)
{
OI_UINT32 result;
OI_ASSERT(bs->bitPtr < 16);
OI_ASSERT(bs->bitPtr % 4 == 0);
if (bs->bitPtr == 8) {
result = bs->value << 8;
bs->bitPtr = 12;
} else {
result = bs->value << 12;
bs->value = (bs->value << 8) | *bs->ptr.r++;
bs->bitPtr = 8;
}
result >>= 28;
OI_ASSERT(result < (1u << 4));
return (OI_UINT8)result;
}
PRIVATE OI_UINT8 OI_BITSTREAM_ReadUINT8Aligned(OI_BITSTREAM *bs)
{
OI_UINT32 result;
OI_ASSERT(bs->bitPtr == 8);
result = bs->value >> 16;
bs->value = (bs->value << 8) | *bs->ptr.r++;
return (OI_UINT8)result;
}
/**
@}
*/
#endif /* #if (defined(SBC_DEC_INCLUDED) && SBC_DEC_INCLUDED == TRUE) */