INLINE OI_INT32 OI_SBC_Dequant(OI_UINT32 raw, OI_UINT scale_factor, OI_UINT bits)
{
OI_UINT32 d;
OI_INT32 result;
OI_ASSERT(scale_factor <= 15);
OI_ASSERT(bits <= 16);
if (bits <= 1) {
return 0;
}
d = (raw * 2) + 1;
d *= dequant_long_scaled[bits];
result = d - SBC_DEQUANT_LONG_SCALED_OFFSET;
#ifdef DEBUG_DEQUANTIZATION
{
OI_INT32 integerized_float_result;
float float_result;
float_result = dequant_float(raw, scale_factor, bits);
integerized_float_result = (OI_INT32)floor(0.5f+float_result * (1 << 15));
/* This detects overflow */
OI_ASSERT(((result >= 0) && (integerized_float_result >= 0)) ||
((result <= 0) && (integerized_float_result <= 0)));
}
#endif
return result >> (15 - scale_factor);
}
/* BK4BTSTACK_CHANGE START */
INLINE void OI_SBC_ReadHeader_mSBC(OI_CODEC_SBC_COMMON_CONTEXT *common, const OI_BYTE *data){
OI_CODEC_SBC_FRAME_INFO *frame = &common->frameInfo;
OI_ASSERT(data[0] == OI_mSBC_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
*/
frame->reserved_for_future_use[0] = data[1];
frame->reserved_for_future_use[1] = data[2];
frame->freqIndex = 0;
frame->frequency = 16000;
frame->blocks = 4; // ?
frame->nrof_blocks = 15;
frame->mode = 0;
frame->nrof_channels = 1;
frame->alloc = SBC_LOUDNESS;
frame->subbands = 1;
frame->nrof_subbands = 8;
frame->bitpool = 26;
frame->crc = data[3];
frame->cachedInfo = 0;
}
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;
}
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;
}
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;
}
INLINE OI_INT32 OI_SBC_Dequant_Unscaled(OI_UINT32 raw, OI_UINT scale_factor, OI_UINT bits)
{
OI_UINT32 d;
OI_INT32 result;
OI_ASSERT(scale_factor <= 15);
OI_ASSERT(bits <= 16);
if (bits <= 1) {
return 0;
}
if (bits == 16) {
result = (raw << 16) + raw - 0x7fff7fff;
return SCALE(result, 24 - scale_factor);
}
d = (raw * 2) + 1;
d *= dequant_long_unscaled[bits];
result = d - 0x80000000;
return SCALE(result, 24 - scale_factor);
}
INLINE float dequant_float(OI_UINT32 raw, OI_UINT scale_factor, OI_UINT bits)
{
float result = (1 << (scale_factor+1)) * ((raw * 2.0f + 1.0f) / ((1 << bits) - 1.0f) - 1.0f);
result /= SBC_DEQUANT_SCALING_FACTOR;
/* Unless the encoder screwed up, all correct dequantized values should
* satisfy this inequality. Non-compliant encoders which generate quantized
* values with all 1-bits set can, theoretically, trigger this assert. This
* is unlikely, however, and only an issue in debug mode.
*/
OI_ASSERT(fabs(result) < 32768 * 1.6);
return result;
}
static OI_STATUS DecodeBody(OI_CODEC_SBC_DECODER_CONTEXT *context,
const OI_BYTE *bodyData,
OI_INT16 *pcmData,
OI_UINT32 *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(OI_INT16) * 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 (OI_INT16) * 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(OI_INT16) / 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(OI_INT16) * context->common.pcmStride;
if (context->bufferedBlocks > 0) {
return OI_CODEC_SBC_PARTIAL_DECODE;
} else {
return OI_OK;
}
}