209 lines
6.3 KiB
C
209 lines
6.3 KiB
C
/******************************************************************************
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*
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* Copyright 2014 The Android Open Source Project
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* Copyright 2003 - 2004 Open Interface North America, Inc. All rights
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* reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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******************************************************************************/
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/*******************************************************************************
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$Revision: #1 $
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******************************************************************************/
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/**
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@file
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This file drives SBC decoding.
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@ingroup codec_internal
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*/
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/**
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@addtogroup codec_internal
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@{
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*/
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#include <stdio.h>
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#include "oi_bitstream.h"
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#include "oi_codec_sbc_private.h"
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OI_CHAR* const OI_Codec_Copyright =
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"Copyright 2002-2007 Open Interface North America, Inc. All rights "
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"reserved";
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INLINE OI_STATUS internal_DecoderReset(OI_CODEC_SBC_DECODER_CONTEXT* context,
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uint32_t* decoderData,
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uint32_t decoderDataBytes,
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OI_BYTE maxChannels, OI_BYTE pcmStride,
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OI_BOOL enhanced) {
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OI_UINT i;
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OI_STATUS status;
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for (i = 0; i < sizeof(*context); i++) {
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((char*)context)[i] = 0;
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}
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#ifdef SBC_ENHANCED
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context->enhancedEnabled = enhanced ? TRUE : FALSE;
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#else
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context->enhancedEnabled = FALSE;
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if (enhanced) {
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return OI_STATUS_INVALID_PARAMETERS;
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}
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#endif
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status = OI_CODEC_SBC_Alloc(&context->common, decoderData, decoderDataBytes,
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maxChannels, pcmStride);
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if (!OI_SUCCESS(status)) {
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return status;
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}
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context->common.codecInfo = OI_Codec_Copyright;
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context->common.maxBitneed = 0;
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context->limitFrameFormat = FALSE;
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OI_SBC_ExpandFrameFields(&context->common.frameInfo);
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/*PLATFORM_DECODER_RESET(context);*/
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return OI_OK;
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}
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/**
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* Read the SBC header up to but not including the joint stereo mask. The
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* syncword has already been examined, and the enhanced mode flag set, by
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* FindSyncword.
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*/
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INLINE void OI_SBC_ReadHeader(OI_CODEC_SBC_COMMON_CONTEXT* common,
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const OI_BYTE* data) {
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OI_CODEC_SBC_FRAME_INFO* frame = &common->frameInfo;
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uint8_t d1;
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OI_ASSERT(data[0] == OI_SBC_SYNCWORD || data[0] == OI_SBC_ENHANCED_SYNCWORD);
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/* Avoid filling out all these strucutures if we already remember the values
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* from last time. Just in case we get a stream corresponding to data[1] ==
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* 0, DecoderReset is responsible for ensuring the lookup table entries have
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* already been populated
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*/
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d1 = data[1];
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if (d1 != frame->cachedInfo) {
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frame->freqIndex = (d1 & (BIT7 | BIT6)) >> 6;
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frame->frequency = freq_values[frame->freqIndex];
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frame->blocks = (d1 & (BIT5 | BIT4)) >> 4;
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frame->nrof_blocks = block_values[frame->blocks];
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frame->mode = (d1 & (BIT3 | BIT2)) >> 2;
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frame->nrof_channels = channel_values[frame->mode];
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frame->alloc = (d1 & BIT1) >> 1;
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frame->subbands = (d1 & BIT0);
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frame->nrof_subbands = band_values[frame->subbands];
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frame->cachedInfo = d1;
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}
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/*
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* For decode, the bit allocator needs to know the bitpool value
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*/
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frame->bitpool = data[2];
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frame->crc = data[3];
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}
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#define LOW(x) ((x)&0xf)
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#define HIGH(x) ((x) >> 4)
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/*
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* Read scalefactor values and prepare the bitstream for OI_SBC_ReadSamples
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*/
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PRIVATE void OI_SBC_ReadScalefactors(OI_CODEC_SBC_COMMON_CONTEXT* common,
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const OI_BYTE* b, OI_BITSTREAM* bs) {
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OI_UINT i = common->frameInfo.nrof_subbands * common->frameInfo.nrof_channels;
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int8_t* scale_factor = common->scale_factor;
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OI_UINT f;
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if (common->frameInfo.nrof_subbands == 8 ||
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common->frameInfo.mode != SBC_JOINT_STEREO) {
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if (common->frameInfo.mode == SBC_JOINT_STEREO) {
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common->frameInfo.join = *b++;
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} else {
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common->frameInfo.join = 0;
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}
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i /= 2;
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do {
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*scale_factor++ = HIGH(f = *b++);
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*scale_factor++ = LOW(f);
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} while (--i);
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/*
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* In this case we know that the scale factors end on a byte boundary so all
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* we need to do
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* is initialize the bitstream.
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*/
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OI_BITSTREAM_ReadInit(bs, b);
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} else {
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OI_ASSERT(common->frameInfo.nrof_subbands == 4 &&
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common->frameInfo.mode == SBC_JOINT_STEREO);
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common->frameInfo.join = HIGH(f = *b++);
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i = (i - 1) / 2;
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do {
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*scale_factor++ = LOW(f);
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*scale_factor++ = HIGH(f = *b++);
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} while (--i);
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*scale_factor++ = LOW(f);
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/*
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* In 4-subband joint stereo mode, the joint stereo information ends on a
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* half-byte
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* boundary, so it's necessary to use the bitstream abstraction to read it,
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* since
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* OI_SBC_ReadSamples will need to pick up in mid-byte.
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*/
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OI_BITSTREAM_ReadInit(bs, b);
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*scale_factor++ = OI_BITSTREAM_ReadUINT4Aligned(bs);
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}
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}
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/** Read quantized subband samples from the input bitstream and expand them. */
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PRIVATE void OI_SBC_ReadSamples(OI_CODEC_SBC_DECODER_CONTEXT* context,
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OI_BITSTREAM* global_bs) {
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OI_CODEC_SBC_COMMON_CONTEXT* common = &context->common;
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OI_UINT nrof_blocks = common->frameInfo.nrof_blocks;
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int32_t* RESTRICT s = common->subdata;
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const uint8_t* ptr = global_bs->ptr.r;
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uint32_t value = global_bs->value;
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OI_UINT bitPtr = global_bs->bitPtr;
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const OI_UINT iter_count =
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common->frameInfo.nrof_channels * common->frameInfo.nrof_subbands;
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do {
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OI_UINT n;
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for (n = 0; n < iter_count; ++n) {
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int32_t dequant;
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OI_UINT bits = common->bits.uint8[n];
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OI_INT sf = common->scale_factor[n];
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if (bits) {
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uint32_t raw;
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OI_BITSTREAM_READUINT(raw, bits, ptr, value, bitPtr);
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dequant = OI_SBC_Dequant(raw, sf, bits);
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} else {
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dequant = 0;
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}
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*s++ = dequant;
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}
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} while (--nrof_blocks);
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}
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/**
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@}
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*/
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