/******************************************************************************
*
* Copyright 2014 The Android Open Source Project
* Copyright 2006 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
@ingroup codec_internal
*/
/**@addtogroup codec_internal */
/**@{*/
#include "oi_bitstream.h"
#include "oi_codec_sbc_private.h"
#define SPECIALIZE_READ_SAMPLES_JOINT
/**
* Scans through a buffer looking for a codec syncword. If the decoder has been
* set for enhanced operation using OI_CODEC_SBC_DecoderReset(), it will search
* for both a standard and an enhanced syncword.
*/
PRIVATE OI_STATUS FindSyncword(OI_CODEC_SBC_DECODER_CONTEXT* context,
const OI_BYTE** frameData,
uint32_t* frameBytes) {
#ifdef SBC_ENHANCED
OI_BYTE search1 = OI_SBC_SYNCWORD;
OI_BYTE search2 = OI_SBC_ENHANCED_SYNCWORD;
#endif // SBC_ENHANCED
if (*frameBytes == 0) {
return OI_CODEC_SBC_NOT_ENOUGH_HEADER_DATA;
}
#ifdef SBC_ENHANCED
if (context->limitFrameFormat && context->enhancedEnabled) {
/* If the context is restricted, only search for specified SYNCWORD */
search1 = search2;
} else if (context->enhancedEnabled == FALSE) {
/* If enhanced is not enabled, only search for classic SBC SYNCWORD*/
search2 = search1;
}
while (*frameBytes && (**frameData != search1) && (**frameData != search2)) {
(*frameBytes)--;
(*frameData)++;
}
if (*frameBytes) {
/* Syncword found, *frameData points to it, and *frameBytes correctly
* reflects the number of bytes available to read, including the
* syncword. */
context->common.frameInfo.enhanced =
(**frameData == OI_SBC_ENHANCED_SYNCWORD);
return OI_OK;
} else {
/* No syncword was found anywhere in the provided input data.
* *frameData points past the end of the original input, and
* *frameBytes is 0. */
return OI_CODEC_SBC_NO_SYNCWORD;
}
#else // SBC_ENHANCED
while (*frameBytes && (**frameData != OI_SBC_SYNCWORD)) {
(*frameBytes)--;
(*frameData)++;
}
if (*frameBytes) {
/* Syncword found, *frameData points to it, and *frameBytes correctly
* reflects the number of bytes available to read, including the
* syncword. */
context->common.frameInfo.enhanced = FALSE;
return OI_OK;
} else {
/* No syncword was found anywhere in the provided input data.
* *frameData points past the end of the original input, and
* *frameBytes is 0. */
return OI_CODEC_SBC_NO_SYNCWORD;
}
#endif // SBC_ENHANCED
}
static OI_STATUS DecodeBody(OI_CODEC_SBC_DECODER_CONTEXT* context,
const OI_BYTE* bodyData, int16_t* pcmData,
uint32_t* pcmBytes, OI_BOOL allowPartial) {
OI_BITSTREAM bs;
OI_UINT frameSamples = context->common.frameInfo.nrof_blocks *
context->common.frameInfo.nrof_subbands;
OI_UINT decode_block_count;
/*
* Based on the header data, make sure that there is enough room to write the
* output samples.
*/
if (*pcmBytes <
(sizeof(int16_t) * frameSamples * context->common.pcmStride) &&
!allowPartial) {
/* If we're not allowing partial decodes, we need room for the entire
* codec frame */
TRACE(("-OI_CODEC_SBC_Decode: OI_CODEC_SBC_NOT_ENOUGH_AUDIO_DATA"));
return OI_CODEC_SBC_NOT_ENOUGH_AUDIO_DATA;
} else if (*pcmBytes < sizeof(int16_t) *
context->common.frameInfo.nrof_subbands *
context->common.pcmStride) {
/* Even if we're allowing partials, we can still only decode on a frame
* boundary */
return OI_CODEC_SBC_NOT_ENOUGH_AUDIO_DATA;
}
if (context->bufferedBlocks == 0) {
TRACE(("Reading scalefactors"));
OI_SBC_ReadScalefactors(&context->common, bodyData, &bs);
TRACE(("Computing bit allocation"));
OI_SBC_ComputeBitAllocation(&context->common);
TRACE(("Reading samples"));
if (context->common.frameInfo.mode == SBC_JOINT_STEREO) {
OI_SBC_ReadSamplesJoint(context, &bs);
} else {
OI_SBC_ReadSamples(context, &bs);
}
context->bufferedBlocks = context->common.frameInfo.nrof_blocks;
}
if (allowPartial) {
decode_block_count = *pcmBytes / sizeof(int16_t) /
context->common.pcmStride /
context->common.frameInfo.nrof_subbands;
if (decode_block_count > context->bufferedBlocks) {
decode_block_count = context->bufferedBlocks;
}
} else {
decode_block_count = context->common.frameInfo.nrof_blocks;
}
TRACE(("Synthesizing frame"));
{
OI_UINT start_block =
context->common.frameInfo.nrof_blocks - context->bufferedBlocks;
OI_SBC_SynthFrame(context, pcmData, start_block, decode_block_count);
}
OI_ASSERT(context->bufferedBlocks >= decode_block_count);
context->bufferedBlocks -= decode_block_count;
frameSamples = decode_block_count * context->common.frameInfo.nrof_subbands;
/*
* When decoding mono into a stride-2 array, copy pcm data to second channel
*/
if (context->common.frameInfo.nrof_channels == 1 &&
context->common.pcmStride == 2) {
OI_UINT i;
for (i = 0; i < frameSamples; ++i) {
pcmData[2 * i + 1] = pcmData[2 * i];
}
}
/*
* Return number of pcm bytes generated by the decode operation.
*/
*pcmBytes = frameSamples * sizeof(int16_t) * context->common.pcmStride;
if (context->bufferedBlocks > 0) {
return OI_CODEC_SBC_PARTIAL_DECODE;
} else {
return OI_OK;
}
}
PRIVATE OI_STATUS internal_DecodeRaw(OI_CODEC_SBC_DECODER_CONTEXT* context,
uint8_t bitpool, const OI_BYTE** frameData,
uint32_t* frameBytes, int16_t* pcmData,
uint32_t* pcmBytes) {
OI_STATUS status;
OI_UINT bodyLen;
TRACE(("+OI_CODEC_SBC_DecodeRaw"));
if (context->bufferedBlocks == 0) {
/*
* The bitallocator needs to know the bitpool value.
*/
context->common.frameInfo.bitpool = bitpool;
/*
* Compute the frame length and check we have enough frame data to proceed
*/
bodyLen = OI_CODEC_SBC_CalculateFramelen(&context->common.frameInfo) -
SBC_HEADER_LEN;
if (*frameBytes < bodyLen) {
TRACE(("-OI_CODEC_SBC_Decode: OI_CODEC_SBC_NOT_ENOUGH_BODY_DATA"));
return OI_CODEC_SBC_NOT_ENOUGH_BODY_DATA;
}
} else {
bodyLen = 0;
}
/*
* Decode the SBC data. Pass TRUE to DecodeBody to allow partial decoding of
* tones.
*/
status = DecodeBody(context, *frameData, pcmData, pcmBytes, TRUE);
if (OI_SUCCESS(status) || status == OI_CODEC_SBC_PARTIAL_DECODE) {
*frameData += bodyLen;
*frameBytes -= bodyLen;
}
TRACE(("-OI_CODEC_SBC_DecodeRaw: %d", status));
return status;
}
OI_STATUS OI_CODEC_SBC_DecoderReset(OI_CODEC_SBC_DECODER_CONTEXT* context,
uint32_t* decoderData,
uint32_t decoderDataBytes,
uint8_t maxChannels, uint8_t pcmStride,
OI_BOOL enhanced) {
return internal_DecoderReset(context, decoderData, decoderDataBytes,
maxChannels, pcmStride, enhanced);
}
OI_STATUS OI_CODEC_SBC_DecodeFrame(OI_CODEC_SBC_DECODER_CONTEXT* context,
const OI_BYTE** frameData,
uint32_t* frameBytes, int16_t* pcmData,
uint32_t* pcmBytes) {
OI_STATUS status;
OI_UINT framelen;
uint8_t crc;
TRACE(("+OI_CODEC_SBC_DecodeFrame"));
TRACE(("Finding syncword"));
status = FindSyncword(context, frameData, frameBytes);
if (!OI_SUCCESS(status)) {
return status;
}
/* Make sure enough data remains to read the header. */
if (*frameBytes < SBC_HEADER_LEN) {
TRACE(("-OI_CODEC_SBC_DecodeFrame: OI_CODEC_SBC_NOT_ENOUGH_HEADER_DATA"));
return OI_CODEC_SBC_NOT_ENOUGH_HEADER_DATA;
}
TRACE(("Reading Header"));
OI_SBC_ReadHeader(&context->common, *frameData);
/*
* Some implementations load the decoder into RAM and use overlays for 4 vs 8
* subbands. We need
* to ensure that the SBC parameters for this frame are compatible with the
* restrictions imposed
* by the loaded overlays.
*/
if (context->limitFrameFormat &&
(context->common.frameInfo.subbands != context->restrictSubbands)) {
ERROR(("SBC parameters incompatible with loaded overlay"));
return OI_STATUS_INVALID_PARAMETERS;
}
if (context->common.frameInfo.nrof_channels > context->common.maxChannels) {
ERROR(
("SBC parameters incompatible with number of channels specified during "
"reset"));
return OI_STATUS_INVALID_PARAMETERS;
}
if (context->common.pcmStride < 1 || context->common.pcmStride > 2) {
ERROR(("PCM stride not set correctly during reset"));
return OI_STATUS_INVALID_PARAMETERS;
}
/*
* At this point a header has been read. However, it's possible that we found
* a false syncword,
* so the header data might be invalid. Make sure we have enough bytes to read
* in the
* CRC-protected header, but don't require we have the whole frame. That way,
* if it turns out
* that we're acting on bogus header data, we don't stall the decoding process
* by waiting for
* data that we don't actually need.
*/
framelen = OI_CODEC_SBC_CalculateFramelen(&context->common.frameInfo);
if (*frameBytes < framelen) {
TRACE(("-OI_CODEC_SBC_DecodeFrame: OI_CODEC_SBC_NOT_ENOUGH_BODY_DATA"));
return OI_CODEC_SBC_NOT_ENOUGH_BODY_DATA;
}
TRACE(("Calculating checksum"));
crc = OI_SBC_CalculateChecksum(&context->common.frameInfo, *frameData);
if (crc != context->common.frameInfo.crc) {
TRACE(("CRC Mismatch: calc=%02x read=%02x\n", crc,
context->common.frameInfo.crc));
TRACE(("-OI_CODEC_SBC_DecodeFrame: OI_CODEC_SBC_CHECKSUM_MISMATCH"));
return OI_CODEC_SBC_CHECKSUM_MISMATCH;
}
#ifdef OI_DEBUG
/*
* Make sure the bitpool values are sane.
*/
if ((context->common.frameInfo.bitpool < SBC_MIN_BITPOOL) &&
!context->common.frameInfo.enhanced) {
ERROR(("Bitpool too small: %d (must be >= 2)",
context->common.frameInfo.bitpool));
return OI_STATUS_INVALID_PARAMETERS;
}
if (context->common.frameInfo.bitpool >
OI_SBC_MaxBitpool(&context->common.frameInfo)) {
ERROR(("Bitpool too large: %d (must be <= %ld)",
context->common.frameInfo.bitpool,
OI_SBC_MaxBitpool(&context->common.frameInfo)));
return OI_STATUS_INVALID_PARAMETERS;
}
#endif
/*
* Now decode the SBC data. Partial decode is not yet implemented for an SBC
* stream, so pass FALSE to decode body to have it enforce the old rule that
* you have to decode a whole packet at a time.
*/
status = DecodeBody(context, *frameData + SBC_HEADER_LEN, pcmData, pcmBytes,
FALSE);
if (OI_SUCCESS(status)) {
*frameData += framelen;
*frameBytes -= framelen;
}
TRACE(("-OI_CODEC_SBC_DecodeFrame: %d", status));
return status;
}
OI_STATUS OI_CODEC_SBC_SkipFrame(OI_CODEC_SBC_DECODER_CONTEXT* context,
const OI_BYTE** frameData,
uint32_t* frameBytes) {
OI_STATUS status;
OI_UINT framelen;
OI_UINT headerlen;
uint8_t crc;
status = FindSyncword(context, frameData, frameBytes);
if (!OI_SUCCESS(status)) {
return status;
}
if (*frameBytes < SBC_HEADER_LEN) {
return OI_CODEC_SBC_NOT_ENOUGH_HEADER_DATA;
}
OI_SBC_ReadHeader(&context->common, *frameData);
framelen =
OI_SBC_CalculateFrameAndHeaderlen(&context->common.frameInfo, &headerlen);
if (*frameBytes < headerlen) {
return OI_CODEC_SBC_NOT_ENOUGH_HEADER_DATA;
}
crc = OI_SBC_CalculateChecksum(&context->common.frameInfo, *frameData);
if (crc != context->common.frameInfo.crc) {
return OI_CODEC_SBC_CHECKSUM_MISMATCH;
}
if (*frameBytes < framelen) {
return OI_CODEC_SBC_NOT_ENOUGH_BODY_DATA;
}
context->bufferedBlocks = 0;
*frameData += framelen;
*frameBytes -= framelen;
return OI_OK;
}
uint8_t OI_CODEC_SBC_FrameCount(OI_BYTE* frameData, uint32_t frameBytes) {
uint8_t mode;
uint8_t blocks;
uint8_t subbands;
uint8_t frameCount = 0;
OI_UINT frameLen;
while (frameBytes) {
while (frameBytes && ((frameData[0] & 0xFE) != 0x9C)) {
frameData++;
frameBytes--;
}
if (frameBytes < SBC_HEADER_LEN) {
return frameCount;
}
/* Extract and translate required fields from Header */
subbands = mode = blocks = frameData[1];
;
mode = (mode & (BIT3 | BIT2)) >> 2;
blocks = block_values[(blocks & (BIT5 | BIT4)) >> 4];
subbands = band_values[(subbands & BIT0)];
/* Inline logic to avoid corrupting context */
frameLen = blocks * frameData[2];
switch (mode) {
case SBC_JOINT_STEREO:
frameLen += subbands + (8 * subbands);
break;
case SBC_DUAL_CHANNEL:
frameLen *= 2;
/* fall through */
default:
if (mode == SBC_MONO) {
frameLen += 4 * subbands;
} else {
frameLen += 8 * subbands;
}
}
frameCount++;
frameLen = SBC_HEADER_LEN + (frameLen + 7) / 8;
if (frameBytes > frameLen) {
frameBytes -= frameLen;
frameData += frameLen;
} else {
frameBytes = 0;
}
}
return frameCount;
}
/** Read quantized subband samples from the input bitstream and expand them. */
#ifdef SPECIALIZE_READ_SAMPLES_JOINT
PRIVATE void OI_SBC_ReadSamplesJoint4(OI_CODEC_SBC_DECODER_CONTEXT* context,
OI_BITSTREAM* global_bs) {
#define NROF_SUBBANDS 4
#include "readsamplesjoint.inc"
#undef NROF_SUBBANDS
}
PRIVATE void OI_SBC_ReadSamplesJoint8(OI_CODEC_SBC_DECODER_CONTEXT* context,
OI_BITSTREAM* global_bs) {
#define NROF_SUBBANDS 8
#include "readsamplesjoint.inc"
#undef NROF_SUBBANDS
}
typedef void (*READ_SAMPLES)(OI_CODEC_SBC_DECODER_CONTEXT* context,
OI_BITSTREAM* global_bs);
static const READ_SAMPLES SpecializedReadSamples[] = {OI_SBC_ReadSamplesJoint4,
OI_SBC_ReadSamplesJoint8};
#endif /* SPECIALIZE_READ_SAMPLES_JOINT */
PRIVATE void OI_SBC_ReadSamplesJoint(OI_CODEC_SBC_DECODER_CONTEXT* context,
OI_BITSTREAM* global_bs) {
OI_CODEC_SBC_COMMON_CONTEXT* common = &context->common;
OI_UINT nrof_subbands = common->frameInfo.nrof_subbands;
#ifdef SPECIALIZE_READ_SAMPLES_JOINT
OI_ASSERT((nrof_subbands >> 3u) <= 1u);
SpecializedReadSamples[nrof_subbands >> 3](context, global_bs);
#else
#define NROF_SUBBANDS nrof_subbands
#include "readsamplesjoint.inc"
#undef NROF_SUBBANDS
#endif /* SPECIALIZE_READ_SAMPLES_JOINT */
}
/**@}*/