/******************************************************************************
*
* 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
This file drives SBC decoding.
@ingroup codec_internal
*/
/**
@addtogroup codec_internal
@{
*/
#include <stdio.h>
#include "oi_bitstream.h"
#include "oi_codec_sbc_private.h"
OI_CHAR* const OI_Codec_Copyright =
"Copyright 2002-2007 Open Interface North America, Inc. All rights "
"reserved";
INLINE OI_STATUS internal_DecoderReset(OI_CODEC_SBC_DECODER_CONTEXT* context,
uint32_t* decoderData,
uint32_t decoderDataBytes,
OI_BYTE maxChannels, OI_BYTE pcmStride,
OI_BOOL enhanced) {
OI_UINT i;
OI_STATUS status;
for (i = 0; i < sizeof(*context); i++) {
((char*)context)[i] = 0;
}
#ifdef SBC_ENHANCED
context->enhancedEnabled = enhanced ? TRUE : FALSE;
#else
context->enhancedEnabled = FALSE;
if (enhanced) {
return OI_STATUS_INVALID_PARAMETERS;
}
#endif
status = OI_CODEC_SBC_Alloc(&context->common, decoderData, decoderDataBytes,
maxChannels, pcmStride);
if (!OI_SUCCESS(status)) {
return status;
}
context->common.codecInfo = OI_Codec_Copyright;
context->common.maxBitneed = 0;
context->limitFrameFormat = FALSE;
OI_SBC_ExpandFrameFields(&context->common.frameInfo);
/*PLATFORM_DECODER_RESET(context);*/
return OI_OK;
}
/**
* Read the SBC header up to but not including the joint stereo mask. The
* syncword has already been examined, and the enhanced mode flag set, by
* FindSyncword.
*/
INLINE void OI_SBC_ReadHeader(OI_CODEC_SBC_COMMON_CONTEXT* common,
const OI_BYTE* data) {
OI_CODEC_SBC_FRAME_INFO* frame = &common->frameInfo;
uint8_t d1;
OI_ASSERT(data[0] == OI_SBC_SYNCWORD || data[0] == OI_SBC_ENHANCED_SYNCWORD);
/* Avoid filling out all these strucutures if we already remember the values
* from last time. Just in case we get a stream corresponding to data[1] ==
* 0, DecoderReset is responsible for ensuring the lookup table entries have
* already been populated
*/
d1 = data[1];
if (d1 != frame->cachedInfo) {
frame->freqIndex = (d1 & (BIT7 | BIT6)) >> 6;
frame->frequency = freq_values[frame->freqIndex];
frame->blocks = (d1 & (BIT5 | BIT4)) >> 4;
frame->nrof_blocks = block_values[frame->blocks];
frame->mode = (d1 & (BIT3 | BIT2)) >> 2;
frame->nrof_channels = channel_values[frame->mode];
frame->alloc = (d1 & BIT1) >> 1;
frame->subbands = (d1 & BIT0);
frame->nrof_subbands = band_values[frame->subbands];
frame->cachedInfo = d1;
}
/*
* For decode, the bit allocator needs to know the bitpool value
*/
frame->bitpool = data[2];
frame->crc = data[3];
}
#define LOW(x) ((x)&0xf)
#define HIGH(x) ((x) >> 4)
/*
* Read scalefactor values and prepare the bitstream for OI_SBC_ReadSamples
*/
PRIVATE void OI_SBC_ReadScalefactors(OI_CODEC_SBC_COMMON_CONTEXT* common,
const OI_BYTE* b, OI_BITSTREAM* bs) {
OI_UINT i = common->frameInfo.nrof_subbands * common->frameInfo.nrof_channels;
int8_t* scale_factor = common->scale_factor;
OI_UINT f;
if (common->frameInfo.nrof_subbands == 8 ||
common->frameInfo.mode != SBC_JOINT_STEREO) {
if (common->frameInfo.mode == SBC_JOINT_STEREO) {
common->frameInfo.join = *b++;
} else {
common->frameInfo.join = 0;
}
i /= 2;
do {
*scale_factor++ = HIGH(f = *b++);
*scale_factor++ = LOW(f);
} while (--i);
/*
* In this case we know that the scale factors end on a byte boundary so all
* we need to do
* is initialize the bitstream.
*/
OI_BITSTREAM_ReadInit(bs, b);
} else {
OI_ASSERT(common->frameInfo.nrof_subbands == 4 &&
common->frameInfo.mode == SBC_JOINT_STEREO);
common->frameInfo.join = HIGH(f = *b++);
i = (i - 1) / 2;
do {
*scale_factor++ = LOW(f);
*scale_factor++ = HIGH(f = *b++);
} while (--i);
*scale_factor++ = LOW(f);
/*
* In 4-subband joint stereo mode, the joint stereo information ends on a
* half-byte
* boundary, so it's necessary to use the bitstream abstraction to read it,
* since
* OI_SBC_ReadSamples will need to pick up in mid-byte.
*/
OI_BITSTREAM_ReadInit(bs, b);
*scale_factor++ = OI_BITSTREAM_ReadUINT4Aligned(bs);
}
}
/** Read quantized subband samples from the input bitstream and expand them. */
PRIVATE void OI_SBC_ReadSamples(OI_CODEC_SBC_DECODER_CONTEXT* context,
OI_BITSTREAM* global_bs) {
OI_CODEC_SBC_COMMON_CONTEXT* common = &context->common;
OI_UINT nrof_blocks = common->frameInfo.nrof_blocks;
int32_t* RESTRICT s = common->subdata;
uint8_t* ptr = global_bs->ptr.w;
uint32_t value = global_bs->value;
OI_UINT bitPtr = global_bs->bitPtr;
const OI_UINT iter_count =
common->frameInfo.nrof_channels * common->frameInfo.nrof_subbands / 4;
do {
OI_UINT i;
for (i = 0; i < iter_count; ++i) {
uint32_t sf_by4 = ((uint32_t*)common->scale_factor)[i];
uint32_t bits_by4 = common->bits.uint32[i];
OI_UINT n;
for (n = 0; n < 4; ++n) {
int32_t dequant;
OI_UINT bits;
OI_INT sf;
if (OI_CPU_BYTE_ORDER == OI_LITTLE_ENDIAN_BYTE_ORDER) {
bits = bits_by4 & 0xFF;
bits_by4 >>= 8;
sf = sf_by4 & 0xFF;
sf_by4 >>= 8;
} else {
bits = (bits_by4 >> 24) & 0xFF;
bits_by4 <<= 8;
sf = (sf_by4 >> 24) & 0xFF;
sf_by4 <<= 8;
}
if (bits) {
uint32_t raw;
OI_BITSTREAM_READUINT(raw, bits, ptr, value, bitPtr);
dequant = OI_SBC_Dequant(raw, sf, bits);
} else {
dequant = 0;
}
*s++ = dequant;
}
}
} while (--nrof_blocks);
}
/**
@}
*/