/******************************************************************************
*
* Copyright (C) 2003-2012 Broadcom Corporation
*
* 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.
*
******************************************************************************/
/******************************************************************************
*
* This file contains the down sampling utility to convert PCM samples in
* 16k/32k/48k/44.1k/22050/11025 sampling rate into 8K/16bits samples
* required for SCO channel format. One API function isprovided and only
* possible to be used when transmitting SCO data is sent via HCI
* interface.
*
******************************************************************************/
#include <string.h>
#include "bta_api.h"
#include "bta_sys.h"
#if (BTM_SCO_HCI_INCLUDED == TRUE)
#ifndef BTA_DM_SCO_DEBUG
#define BTA_DM_SCO_DEBUG false
#endif
/*****************************************************************************
* Constants
****************************************************************************/
#define BTA_DM_PCM_OVERLAP_SIZE 48
#define BTA_DM_PCM_SMPL_RATE_44100 44100
#define BTA_DM_PCM_SMPL_RATE_22050 22050
#define BTA_DM_PCM_SMPL_RATE_11025 11025
/*****************************************************************************
* Data types for PCM Resampling utility
****************************************************************************/
typedef int32_t (*PCONVERT_TO_BT_FILTERED)(uint8_t* pSrc, void* pDst,
uint32_t dwSrcSamples,
uint32_t dwSrcSps,
int32_t* pLastCurPos,
uint8_t* pOverlapArea);
typedef int32_t (*PCONVERT_TO_BT_NOFILTER)(void* pSrc, void* pDst,
uint32_t dwSrcSamples,
uint32_t dwSrcSps);
typedef struct {
uint8_t overlap_area[BTA_DM_PCM_OVERLAP_SIZE * 4];
uint32_t cur_pos; /* current position */
uint32_t src_sps; /* samples per second (source audio data) */
PCONVERT_TO_BT_FILTERED filter; /* the action function to do the
conversion 44100, 22050, 11025*/
PCONVERT_TO_BT_NOFILTER nofilter; /* the action function to do
the conversion 48000, 32000, 16000*/
uint32_t bits; /* number of bits per pcm sample */
uint32_t n_channels; /* number of channels (i.e. mono(1), stereo(2)...) */
uint32_t sample_size;
uint32_t can_be_filtered;
uint32_t divisor;
} tBTA_DM_PCM_RESAMPLE_CB;
tBTA_DM_PCM_RESAMPLE_CB bta_dm_pcm_cb;
/*****************************************************************************
* Macro Definition
****************************************************************************/
#define CHECK_SATURATION16(x) \
do { \
if ((x) > 32767) \
(x) = 32767; \
else if ((x) < -32768) \
(x) = -32768; \
} while (0)
////////////////////////////////////////////////////////////////////////////////
//
#define CONVERT_44100_TO_BLUETOOTH(pStart, pEnd) \
do { \
int32_t out1, out2, out3, out4, out5; \
SRC_TYPE* pS = (SRC_TYPE*)(pStart); \
SRC_TYPE* pSEnd = (SRC_TYPE*)(pEnd); \
\
while (pS < pSEnd) { \
CurrentPos -= 8000; \
\
if (CurrentPos >= 0) { \
pS += SRC_CHANNELS; \
continue; \
} \
CurrentPos += dwSrcSps; \
\
out1 = (SRC_SAMPLE(0) * 1587) + \
((SRC_SAMPLE(1) + SRC_SAMPLE(-1)) * 1522) + \
((SRC_SAMPLE(2) + SRC_SAMPLE(-2)) * 1337) + \
((SRC_SAMPLE(3) + SRC_SAMPLE(-3)) * 1058); \
\
out1 = out1 / 30000; \
\
out2 = ((SRC_SAMPLE(4) + SRC_SAMPLE(-4)) * 725) + \
((SRC_SAMPLE(5) + SRC_SAMPLE(-5)) * 384) + \
((SRC_SAMPLE(6) + SRC_SAMPLE(-6)) * 79); \
\
out2 = out2 / 30000; \
\
out3 = ((SRC_SAMPLE(7) + SRC_SAMPLE(-7)) * 156) + \
((SRC_SAMPLE(8) + SRC_SAMPLE(-8)) * 298) + \
((SRC_SAMPLE(9) + SRC_SAMPLE(-9)) * 345); \
\
out3 = out3 / 30000; \
\
out4 = ((SRC_SAMPLE(10) + SRC_SAMPLE(-10)) * 306) + \
((SRC_SAMPLE(11) + SRC_SAMPLE(-11)) * 207) + \
((SRC_SAMPLE(12) + SRC_SAMPLE(-12)) * 78); \
\
out4 = out4 / 30000; \
\
out5 = out1 + out2 - out3 - out4; \
\
CHECK_SATURATION16(out5); \
*psBtOut++ = (int16_t)out5; \
\
pS += SRC_CHANNELS; \
} \
} while (0)
////////////////////////////////////////////////////////////////////////////////
//
#define CONVERT_22050_TO_BLUETOOTH(pStart, pEnd) \
do { \
int32_t out1, out2, out3, out4, out5; \
SRC_TYPE* pS = (SRC_TYPE*)(pStart); \
SRC_TYPE* pSEnd = (SRC_TYPE*)(pEnd); \
\
while (pS < pSEnd) { \
CurrentPos -= 8000; \
\
if (CurrentPos >= 0) { \
pS += SRC_CHANNELS; \
continue; \
} \
CurrentPos += dwSrcSps; \
\
out1 = (SRC_SAMPLE(0) * 2993) + \
((SRC_SAMPLE(1) + SRC_SAMPLE(-1)) * 2568) + \
((SRC_SAMPLE(2) + SRC_SAMPLE(-2)) * 1509) + \
((SRC_SAMPLE(3) + SRC_SAMPLE(-3)) * 331); \
\
out1 = out1 / 30000; \
\
out2 = ((SRC_SAMPLE(4) + SRC_SAMPLE(-4)) * 454) + \
((SRC_SAMPLE(5) + SRC_SAMPLE(-5)) * 620) + \
((SRC_SAMPLE(6) + SRC_SAMPLE(-6)) * 305); \
\
out2 = out2 / 30000; \
\
out3 = ((SRC_SAMPLE(7) + SRC_SAMPLE(-7)) * 127) + \
((SRC_SAMPLE(8) + SRC_SAMPLE(-8)) * 350) + \
((SRC_SAMPLE(9) + SRC_SAMPLE(-9)) * 265) + \
((SRC_SAMPLE(10) + SRC_SAMPLE(-10)) * 6); \
\
out3 = out3 / 30000; \
\
out4 = ((SRC_SAMPLE(11) + SRC_SAMPLE(-11)) * 201); \
\
out4 = out4 / 30000; \
\
out5 = out1 - out2 + out3 - out4; \
\
CHECK_SATURATION16(out5); \
*psBtOut++ = (int16_t)out5; \
\
pS += SRC_CHANNELS; \
} \
} while (0)
////////////////////////////////////////////////////////////////////////////////
//
#define CONVERT_11025_TO_BLUETOOTH(pStart, pEnd) \
do { \
int32_t out1; \
SRC_TYPE* pS = (SRC_TYPE*)(pStart); \
SRC_TYPE* pSEnd = (SRC_TYPE*)(pEnd); \
\
while (pS < pSEnd) { \
CurrentPos -= 8000; \
\
if (CurrentPos >= 0) { \
pS += SRC_CHANNELS; \
continue; \
} \
CurrentPos += dwSrcSps; \
\
out1 = (SRC_SAMPLE(0) * 6349) + \
((SRC_SAMPLE(1) + SRC_SAMPLE(-1)) * 2874) - \
((SRC_SAMPLE(2) + SRC_SAMPLE(-2)) * 1148) - \
((SRC_SAMPLE(3) + SRC_SAMPLE(-3)) * 287) + \
((SRC_SAMPLE(4) + SRC_SAMPLE(-4)) * 675) - \
((SRC_SAMPLE(5) + SRC_SAMPLE(-5)) * 258) - \
((SRC_SAMPLE(6) + SRC_SAMPLE(-6)) * 206) + \
((SRC_SAMPLE(7) + SRC_SAMPLE(-7)) * 266); \
\
out1 = out1 / 30000; \
\
CHECK_SATURATION16(out1); \
*psBtOut++ = (int16_t)out1; \
\
pS += SRC_CHANNELS; \
} \
} while (0)
////////////////////////////////////////////////////////////////////////////////
//
#undef SRC_CHANNELS
#undef SRC_SAMPLE
#undef SRC_TYPE
#define SRC_TYPE uint8_t
#define SRC_CHANNELS 1
#define SRC_SAMPLE(x) ((pS[x] - 0x80) << 8)
/*****************************************************************************
* Local Function
****************************************************************************/
int32_t Convert_8M_ToBT_Filtered(uint8_t* pSrc, void* pDst,
uint32_t dwSrcSamples, uint32_t dwSrcSps,
int32_t* pLastCurPos, uint8_t* pOverlapArea) {
int32_t CurrentPos = *pLastCurPos;
SRC_TYPE *pIn, *pInEnd;
SRC_TYPE *pOv, *pOvEnd;
int16_t* psBtOut = (int16_t*)pDst;
#if (BTA_DM_SCO_DEBUG == TRUE)
APPL_TRACE_DEBUG("Convert_8M_ToBT_Filtered, CurrentPos %d\n", CurrentPos);
#endif
memcpy(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 2), pSrc,
BTA_DM_PCM_OVERLAP_SIZE * 2);
pOv = (SRC_TYPE*)(pOverlapArea + BTA_DM_PCM_OVERLAP_SIZE);
pOvEnd = (SRC_TYPE*)(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 3));
pIn = (SRC_TYPE*)(pSrc + BTA_DM_PCM_OVERLAP_SIZE);
pInEnd = (SRC_TYPE*)(pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
BTA_DM_PCM_OVERLAP_SIZE);
if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_44100) {
CONVERT_44100_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_44100_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_22050) {
CONVERT_22050_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_22050_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_11025) {
CONVERT_11025_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_11025_TO_BLUETOOTH(pIn, pInEnd);
}
memcpy(pOverlapArea, pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
(BTA_DM_PCM_OVERLAP_SIZE * 2),
BTA_DM_PCM_OVERLAP_SIZE * 2);
*pLastCurPos = CurrentPos;
return (psBtOut - (int16_t*)pDst);
}
int32_t Convert_8M_ToBT_NoFilter(void* pSrc, void* pDst, uint32_t dwSrcSamples,
uint32_t dwSrcSps) {
int32_t CurrentPos;
uint8_t* pbSrc = (uint8_t*)pSrc;
int16_t* psDst = (int16_t*)pDst;
int16_t sWorker;
// start at dwSpsSrc / 2, decrement by 8000
//
CurrentPos = (dwSrcSps >> 1);
while (dwSrcSamples--) {
CurrentPos -= 8000;
if (CurrentPos >= 0)
pbSrc++;
else {
sWorker = *pbSrc++;
sWorker -= 0x80;
sWorker <<= 8;
*psDst++ = sWorker;
CurrentPos += dwSrcSps;
}
}
return (psDst - (int16_t*)pDst);
}
////////////////////////////////////////////////////////////////////////////////
//
#undef SRC_CHANNELS
#undef SRC_SAMPLE
#undef SRC_TYPE
#define SRC_TYPE int16_t
#define SRC_CHANNELS 1
#define SRC_SAMPLE(x) pS[x]
int32_t Convert_16M_ToBT_Filtered(uint8_t* pSrc, void* pDst,
uint32_t dwSrcSamples, uint32_t dwSrcSps,
int32_t* pLastCurPos, uint8_t* pOverlapArea) {
int32_t CurrentPos = *pLastCurPos;
SRC_TYPE *pIn, *pInEnd;
SRC_TYPE *pOv, *pOvEnd;
int16_t* psBtOut = (int16_t*)pDst;
memcpy(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 2), pSrc,
BTA_DM_PCM_OVERLAP_SIZE * 2);
pOv = (SRC_TYPE*)(pOverlapArea + BTA_DM_PCM_OVERLAP_SIZE);
pOvEnd = (SRC_TYPE*)(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 3));
pIn = (SRC_TYPE*)(pSrc + BTA_DM_PCM_OVERLAP_SIZE);
pInEnd = (SRC_TYPE*)(pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
BTA_DM_PCM_OVERLAP_SIZE);
if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_44100) {
CONVERT_44100_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_44100_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_22050) {
CONVERT_22050_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_22050_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_11025) {
CONVERT_11025_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_11025_TO_BLUETOOTH(pIn, pInEnd);
}
memcpy(pOverlapArea, pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
(BTA_DM_PCM_OVERLAP_SIZE * 2),
BTA_DM_PCM_OVERLAP_SIZE * 2);
*pLastCurPos = CurrentPos;
return (psBtOut - (int16_t*)pDst);
}
int32_t Convert_16M_ToBT_NoFilter(void* pSrc, void* pDst, uint32_t dwSrcSamples,
uint32_t dwSrcSps) {
int32_t CurrentPos;
int16_t* psSrc = (int16_t*)pSrc;
int16_t* psDst = (int16_t*)pDst;
// start at dwSpsSrc / 2, decrement by 8000
//
CurrentPos = (dwSrcSps >> 1);
while (dwSrcSamples--) {
CurrentPos -= 8000;
if (CurrentPos >= 0)
psSrc++;
else {
*psDst++ = *psSrc++;
CurrentPos += dwSrcSps;
}
}
return (psDst - (int16_t*)pDst);
}
////////////////////////////////////////////////////////////////////////////////
//
#undef SRC_CHANNELS
#undef SRC_SAMPLE
#undef SRC_TYPE
#define SRC_TYPE uint8_t
#define SRC_CHANNELS 2
#define SRC_SAMPLE(x) \
((((pS[x * 2] - 0x80) << 8) + ((pS[(x * 2) + 1] - 0x80) << 8)) >> 1)
int32_t Convert_8S_ToBT_Filtered(uint8_t* pSrc, void* pDst,
uint32_t dwSrcSamples, uint32_t dwSrcSps,
int32_t* pLastCurPos, uint8_t* pOverlapArea) {
int32_t CurrentPos = *pLastCurPos;
SRC_TYPE *pIn, *pInEnd;
SRC_TYPE *pOv, *pOvEnd;
int16_t* psBtOut = (int16_t*)pDst;
#if (BTA_DM_SCO_DEBUG == TRUE)
APPL_TRACE_DEBUG(
"Convert_8S_ToBT_Filtered CurrentPos %d, SRC_TYPE %d, SRC_CHANNELS %d, \
dwSrcSamples %d, dwSrcSps %d",
CurrentPos, sizeof(SRC_TYPE), SRC_CHANNELS, dwSrcSamples, dwSrcSps);
#endif
memcpy(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 2), pSrc,
BTA_DM_PCM_OVERLAP_SIZE * 2);
pOv = (SRC_TYPE*)(pOverlapArea + BTA_DM_PCM_OVERLAP_SIZE);
pOvEnd = (SRC_TYPE*)(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 3));
pIn = (SRC_TYPE*)(pSrc + BTA_DM_PCM_OVERLAP_SIZE);
pInEnd = (SRC_TYPE*)(pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
BTA_DM_PCM_OVERLAP_SIZE);
if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_44100) {
CONVERT_44100_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_44100_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_22050) {
CONVERT_22050_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_22050_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_11025) {
CONVERT_11025_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_11025_TO_BLUETOOTH(pIn, pInEnd);
}
memcpy(pOverlapArea, pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
(BTA_DM_PCM_OVERLAP_SIZE * 2),
BTA_DM_PCM_OVERLAP_SIZE * 2);
*pLastCurPos = CurrentPos;
return (psBtOut - (int16_t*)pDst);
}
int32_t Convert_8S_ToBT_NoFilter(void* pSrc, void* pDst, uint32_t dwSrcSamples,
uint32_t dwSrcSps) {
int32_t CurrentPos;
uint8_t* pbSrc = (uint8_t*)pSrc;
int16_t* psDst = (int16_t*)pDst;
int16_t sWorker, sWorker2;
// start at dwSpsSrc / 2, decrement by 8000
//
CurrentPos = (dwSrcSps >> 1);
while (dwSrcSamples--) {
CurrentPos -= 8000;
if (CurrentPos >= 0)
pbSrc += 2;
else {
sWorker = *(unsigned char*)pbSrc;
sWorker -= 0x80;
sWorker <<= 8;
pbSrc++;
sWorker2 = *(unsigned char*)pbSrc;
sWorker2 -= 0x80;
sWorker2 <<= 8;
pbSrc++;
sWorker += sWorker2;
sWorker >>= 1;
*psDst++ = sWorker;
CurrentPos += dwSrcSps;
}
}
return (psDst - (int16_t*)pDst);
}
////////////////////////////////////////////////////////////////////////////////
//
#undef SRC_CHANNELS
#undef SRC_SAMPLE
#undef SRC_TYPE
#define SRC_TYPE int16_t
#define SRC_CHANNELS 2
#define SRC_SAMPLE(x) ((pS[x * 2] + pS[(x * 2) + 1]) >> 1)
int32_t Convert_16S_ToBT_Filtered(uint8_t* pSrc, void* pDst,
uint32_t dwSrcSamples, uint32_t dwSrcSps,
int32_t* pLastCurPos, uint8_t* pOverlapArea) {
int32_t CurrentPos = *pLastCurPos;
SRC_TYPE *pIn, *pInEnd;
SRC_TYPE *pOv, *pOvEnd;
int16_t* psBtOut = (int16_t*)pDst;
memcpy(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 2), pSrc,
BTA_DM_PCM_OVERLAP_SIZE * 2);
pOv = (SRC_TYPE*)(pOverlapArea + BTA_DM_PCM_OVERLAP_SIZE);
pOvEnd = (SRC_TYPE*)(pOverlapArea + (BTA_DM_PCM_OVERLAP_SIZE * 3));
pIn = (SRC_TYPE*)(pSrc + BTA_DM_PCM_OVERLAP_SIZE);
pInEnd = (SRC_TYPE*)(pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
BTA_DM_PCM_OVERLAP_SIZE);
if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_44100) {
CONVERT_44100_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_44100_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_22050) {
CONVERT_22050_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_22050_TO_BLUETOOTH(pIn, pInEnd);
} else if (dwSrcSps == BTA_DM_PCM_SMPL_RATE_11025) {
CONVERT_11025_TO_BLUETOOTH(pOv, pOvEnd);
CONVERT_11025_TO_BLUETOOTH(pIn, pInEnd);
}
memcpy(pOverlapArea, pSrc + (dwSrcSamples * SRC_CHANNELS * sizeof(SRC_TYPE)) -
(BTA_DM_PCM_OVERLAP_SIZE * 2),
BTA_DM_PCM_OVERLAP_SIZE * 2);
*pLastCurPos = CurrentPos;
return (psBtOut - (int16_t*)pDst);
}
int32_t Convert_16S_ToBT_NoFilter(void* pSrc, void* pDst, uint32_t dwSrcSamples,
uint32_t dwSrcSps) {
int32_t CurrentPos;
int16_t* psSrc = (int16_t*)pSrc;
int16_t* psDst = (int16_t*)pDst;
int16_t sWorker;
// start at dwSpsSrc / 2, decrement by 8000
//
CurrentPos = (dwSrcSps >> 1);
while (dwSrcSamples--) {
CurrentPos -= 8000;
if (CurrentPos >= 0)
psSrc += 2;
else {
/* CR 82894, to avoid overflow, divide before add */
sWorker = ((*psSrc) >> 1);
psSrc++;
sWorker += ((*psSrc) >> 1);
psSrc++;
*psDst++ = sWorker;
CurrentPos += dwSrcSps;
}
}
return (psDst - (int16_t*)pDst);
}
/*******************************************************************************
*
* Function BTA_DmPcmInitSamples
*
* Description initialize the down sample converter.
*
* src_sps: original samples per second (source audio data)
* (ex. 44100, 48000)
* bits: number of bits per pcm sample (16)
* n_channels: number of channels (i.e. mono(1), stereo(2)...)
*
* Returns none
*
******************************************************************************/
void BTA_DmPcmInitSamples(uint32_t src_sps, uint32_t bits,
uint32_t n_channels) {
tBTA_DM_PCM_RESAMPLE_CB* p_cb = &bta_dm_pcm_cb;
p_cb->cur_pos = src_sps / 2;
p_cb->src_sps = src_sps;
p_cb->bits = bits;
p_cb->n_channels = n_channels;
p_cb->sample_size = 2;
p_cb->divisor = 2;
memset(p_cb->overlap_area, 0, sizeof(p_cb->overlap_area));
if ((src_sps == BTA_DM_PCM_SMPL_RATE_44100) ||
(src_sps == BTA_DM_PCM_SMPL_RATE_22050) ||
(src_sps == BTA_DM_PCM_SMPL_RATE_11025))
p_cb->can_be_filtered = 1;
else
p_cb->can_be_filtered = 0;
#if (BTA_DM_SCO_DEBUG == TRUE)
APPL_TRACE_DEBUG("bta_dm_pcm_init_samples: n_channels = %d bits = %d",
n_channels, bits);
#endif
if (n_channels == 1) {
/* mono */
if (bits == 8) {
p_cb->filter = (PCONVERT_TO_BT_FILTERED)Convert_8M_ToBT_Filtered;
p_cb->nofilter = (PCONVERT_TO_BT_NOFILTER)Convert_8M_ToBT_NoFilter;
p_cb->divisor = 1;
} else {
p_cb->filter = (PCONVERT_TO_BT_FILTERED)Convert_16M_ToBT_Filtered;
p_cb->nofilter = (PCONVERT_TO_BT_NOFILTER)Convert_16M_ToBT_NoFilter;
}
} else {
/* stereo */
if (bits == 8) {
p_cb->filter = (PCONVERT_TO_BT_FILTERED)Convert_8S_ToBT_Filtered;
p_cb->nofilter = (PCONVERT_TO_BT_NOFILTER)Convert_8S_ToBT_NoFilter;
} else {
p_cb->filter = (PCONVERT_TO_BT_FILTERED)Convert_16S_ToBT_Filtered;
p_cb->nofilter = (PCONVERT_TO_BT_NOFILTER)Convert_16S_ToBT_NoFilter;
p_cb->divisor = 4;
}
}
#if (BTA_DM_SCO_DEBUG == TRUE)
APPL_TRACE_DEBUG("bta_pcm_init_dwn_sample: cur_pos %d, src_sps %d",
p_cb->cur_pos, p_cb->src_sps);
APPL_TRACE_DEBUG(
"bta_pcm_init_dwn_sample: bits %d, n_channels %d, sample_size %d, ",
p_cb->bits, p_cb->n_channels, p_cb->sample_size);
APPL_TRACE_DEBUG(
"bta_pcm_init_dwn_sample: can_be_filtered %d, n_channels: %d, \
divisor %d",
p_cb->can_be_filtered, p_cb->n_channels, p_cb->divisor);
#endif
}
/*******************************************************************************
* Function BTA_DmPcmResample
*
* Description Down sampling utility to convert higher sampling rate into
* 8K/16bits PCM samples.
*
* Parameters p_src: pointer to the buffer where the original sampling PCM
* are stored.
* in_bytes: Length of the input PCM sample buffer in byte.
* p_dst: pointer to the buffer which is to be used to
* store the converted PCM samples.
*
*
* Returns int32_t: number of samples converted.
*
******************************************************************************/
int32_t BTA_DmPcmResample(void* p_src, uint32_t in_bytes, void* p_dst) {
uint32_t out_sample;
#if (BTA_DM_SCO_DEBUG == TRUE)
APPL_TRACE_DEBUG("bta_pcm_resample : insamples %d",
(in_bytes / bta_dm_pcm_cb.divisor));
#endif
if (bta_dm_pcm_cb.can_be_filtered) {
out_sample = (*bta_dm_pcm_cb.filter)(
p_src, p_dst, (in_bytes / bta_dm_pcm_cb.divisor), bta_dm_pcm_cb.src_sps,
(int32_t*)&bta_dm_pcm_cb.cur_pos, bta_dm_pcm_cb.overlap_area);
} else {
out_sample = (*bta_dm_pcm_cb.nofilter)(p_src, p_dst,
(in_bytes / bta_dm_pcm_cb.divisor),
bta_dm_pcm_cb.src_sps);
}
#if (BTA_DM_SCO_DEBUG == TRUE)
APPL_TRACE_DEBUG("bta_pcm_resample : outsamples %d", out_sample);
#endif
return (out_sample * bta_dm_pcm_cb.sample_size);
}
#endif