/****************************************************************************** * * 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 "common/bt_target.h" #include "oi_codec_sbc_private.h" #include "oi_bitstream.h" #include #if (defined(SBC_DEC_INCLUDED) && SBC_DEC_INCLUDED == TRUE) 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, OI_UINT32 *decoderData, OI_UINT32 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; OI_UINT8 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; OI_INT8 *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; OI_INT32 *RESTRICT s = common->subdata; OI_UINT8 *ptr = global_bs->ptr.w; OI_UINT32 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) { OI_UINT32 sf_by4 = ((OI_UINT32 *)common->scale_factor)[i]; OI_UINT32 bits_by4 = common->bits.uint32[i]; OI_UINT n; for (n = 0; n < 4; ++n) { OI_INT32 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) { OI_UINT32 raw; OI_BITSTREAM_READUINT(raw, bits, ptr, value, bitPtr); dequant = OI_SBC_Dequant(raw, sf, bits); } else { dequant = 0; } *s++ = dequant; } } } while (--nrof_blocks); } /** @} */ #endif /* #if (defined(SBC_DEC_INCLUDED) && SBC_DEC_INCLUDED == TRUE) */