/******************************************************************************
*
* Copyright (C) 1999-2012 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.
*
******************************************************************************/
/******************************************************************************
*
* contains code for encoder flow and initalization of encoder
*
******************************************************************************/
#include <string.h>
#include "sbc_encoder.h"
#include "sbc_enc_func_declare.h"
SINT16 EncMaxShiftCounter;
/*************************************************************************************************
* SBC encoder scramble code
* Purpose: to tie the SBC code with BTE/mobile stack code,
* especially for the case when the SBC is ported into a third-party Multimedia chip
*
* Algorithm:
* init process: all counters reset to 0,
* calculate base_index: (6 + s16NumOfChannels*s16NumOfSubBands/2)
* scramble side: the init process happens every time SBC_Encoder_Init() is called.
* descramble side: it would be nice to know if he "init" process has happened.
* alter the SBC SYNC word 0x9C (1001 1100) to 0x8C (1000 1100).
*
* scramble process:
* The CRC byte:
* Every SBC frame has a frame header.
* The 1st byte is the sync word and the following 2 bytes are about the stream format.
* They are supposed to be "constant" within a "song"
* The 4th byte is the CRC byte. The CRC byte is bound to be random.
* Derive 2 items from the CRC byte; one is the "use" bit, the other is the "index".
*
* SBC keeps 2 sets of "use" & "index"; derived the current and the previous frame.
*
* The "use" bit is any bit in SBC_PRTC_USE_MASK is set.
* If set, SBC uses the "index" from the current frame.
* If not set, SBC uses the "index" from the previous frame or 0.
*
* index = (CRC & 0x3) + ((CRC & 0x30) >> 2) // 8 is the max index
*
* if(index > 0)
* {
* p = &u8frame[base_index];
* if((index&1)&&(u16PacketLength > (base_index+index*2)))
* {
* // odd index: swap 2 bytes
* tmp = p[index];
* p[index] = p[index*2];
* p[index*2] = tmp;
* }
* else
* {
* // even index: shift by 3
* tmp = (p[index] >> 5) + (p[index] << 3);
* p[index] = tmp;
* }
* }
* //else index is 0. The frame stays unaltered
*
*/
#define SBC_PRTC_CRC_IDX 3
#define SBC_PRTC_USE_MASK 0x64
#define SBC_PRTC_SYNC_MASK 0x10
#define SBC_PRTC_CIDX 0
#define SBC_PRTC_LIDX 1
typedef struct
{
UINT8 use;
UINT8 idx;
} tSBC_FR_CB;
typedef struct
{
tSBC_FR_CB fr[2];
UINT8 init;
UINT8 index;
UINT8 base;
} tSBC_PRTC_CB;
tSBC_PRTC_CB sbc_prtc_cb;
#define SBC_PRTC_IDX(sc) (((sc) & 0x3) + (((sc) & 0x30) >> 2))
#define SBC_PRTC_CHK_INIT(ar) {if(sbc_prtc_cb.init == 0){sbc_prtc_cb.init=1; ar[0] &= ~SBC_PRTC_SYNC_MASK;}}
#define SBC_PRTC_C2L() {p_last=&sbc_prtc_cb.fr[SBC_PRTC_LIDX]; p_cur=&sbc_prtc_cb.fr[SBC_PRTC_CIDX]; \
p_last->idx = p_cur->idx; p_last->use = p_cur->use;}
#define SBC_PRTC_GETC(ar) {p_cur->use = ar[SBC_PRTC_CRC_IDX] & SBC_PRTC_USE_MASK; \
p_cur->idx = SBC_PRTC_IDX(ar[SBC_PRTC_CRC_IDX]);}
#define SBC_PRTC_CHK_CRC(ar) {SBC_PRTC_C2L();SBC_PRTC_GETC(ar);sbc_prtc_cb.index = (p_cur->use)?SBC_PRTC_CIDX:SBC_PRTC_LIDX;}
#define SBC_PRTC_SCRMB(ar) {idx = sbc_prtc_cb.fr[sbc_prtc_cb.index].idx; \
if(idx > 0){if((idx&1)&&(pstrEncParams->u16PacketLength > (sbc_prtc_cb.base+(idx<<1)))) {tmp2=idx<<1; tmp=ar[idx];ar[idx]=ar[tmp2];ar[tmp2]=tmp;} \
else{tmp2=ar[idx]; tmp=(tmp2>>5)+(tmp2<<3);ar[idx]=(UINT8)tmp;}}}
#if (SBC_JOINT_STE_INCLUDED == TRUE)
SINT32 s32LRDiff[SBC_MAX_NUM_OF_BLOCKS] = {0};
SINT32 s32LRSum[SBC_MAX_NUM_OF_BLOCKS] = {0};
#endif
void SBC_Encoder(SBC_ENC_PARAMS *pstrEncParams)
{
SINT32 s32Ch; /* counter for ch*/
SINT32 s32Sb; /* counter for sub-band*/
UINT32 u32Count, maxBit = 0; /* loop count*/
SINT32 s32MaxValue; /* temp variable to store max value */
SINT16 *ps16ScfL;
SINT32 *SbBuffer;
SINT32 s32Blk; /* counter for block*/
SINT32 s32NumOfBlocks = pstrEncParams->s16NumOfBlocks;
#if (SBC_JOINT_STE_INCLUDED == TRUE)
SINT32 s32MaxValue2;
UINT32 u32CountSum,u32CountDiff;
SINT32 *pSum, *pDiff;
#endif
UINT8 *pu8;
tSBC_FR_CB *p_cur, *p_last;
UINT32 idx, tmp, tmp2;
register SINT32 s32NumOfSubBands = pstrEncParams->s16NumOfSubBands;
pstrEncParams->pu8NextPacket = pstrEncParams->pu8Packet;
#if (SBC_NO_PCM_CPY_OPTION == TRUE)
pstrEncParams->ps16NextPcmBuffer = pstrEncParams->ps16PcmBuffer;
#else
pstrEncParams->ps16NextPcmBuffer = pstrEncParams->as16PcmBuffer;
#endif
do
{
/* SBC ananlysis filter*/
if (s32NumOfSubBands == 4)
SbcAnalysisFilter4(pstrEncParams);
else
SbcAnalysisFilter8(pstrEncParams);
/* compute the scale factor, and save the max */
ps16ScfL = pstrEncParams->as16ScaleFactor;
s32Ch=pstrEncParams->s16NumOfChannels*s32NumOfSubBands;
pstrEncParams->ps16NextPcmBuffer+=s32Ch*s32NumOfBlocks; /* in case of multible sbc frame to encode update the pcm pointer */
for (s32Sb=0; s32Sb<s32Ch; s32Sb++)
{
SbBuffer=pstrEncParams->s32SbBuffer+s32Sb;
s32MaxValue=0;
for (s32Blk=s32NumOfBlocks;s32Blk>0;s32Blk--)
{
if (s32MaxValue<abs32(*SbBuffer))
s32MaxValue=abs32(*SbBuffer);
SbBuffer+=s32Ch;
}
u32Count = (s32MaxValue > 0x800000) ? 9 : 0;
for ( ; u32Count < 15; u32Count++)
{
if (s32MaxValue <= (SINT32)(0x8000 << u32Count))
break;
}
*ps16ScfL++ = (SINT16)u32Count;
if (u32Count > maxBit)
maxBit = u32Count;
}
/* In case of JS processing,check whether to use JS */
#if (SBC_JOINT_STE_INCLUDED == TRUE)
if (pstrEncParams->s16ChannelMode == SBC_JOINT_STEREO)
{
/* Calculate sum and differance scale factors for making JS decision */
ps16ScfL = pstrEncParams->as16ScaleFactor ;
/* calculate the scale factor of Joint stereo max sum and diff */
for (s32Sb = 0; s32Sb < s32NumOfSubBands-1; s32Sb++)
{
SbBuffer=pstrEncParams->s32SbBuffer+s32Sb;
s32MaxValue2=0;
s32MaxValue=0;
pSum = s32LRSum;
pDiff = s32LRDiff;
for (s32Blk=0;s32Blk<s32NumOfBlocks;s32Blk++)
{
*pSum=(*SbBuffer+*(SbBuffer+s32NumOfSubBands))>>1;
if (abs32(*pSum)>s32MaxValue)
s32MaxValue=abs32(*pSum);
pSum++;
*pDiff=(*SbBuffer-*(SbBuffer+s32NumOfSubBands))>>1;
if (abs32(*pDiff)>s32MaxValue2)
s32MaxValue2=abs32(*pDiff);
pDiff++;
SbBuffer+=s32Ch;
}
u32Count = (s32MaxValue > 0x800000) ? 9 : 0;
for ( ; u32Count < 15; u32Count++)
{
if (s32MaxValue <= (SINT32)(0x8000 << u32Count))
break;
}
u32CountSum=u32Count;
u32Count = (s32MaxValue2 > 0x800000) ? 9 : 0;
for ( ; u32Count < 15; u32Count++)
{
if (s32MaxValue2 <= (SINT32)(0x8000 << u32Count))
break;
}
u32CountDiff=u32Count;
if ( (*ps16ScfL + *(ps16ScfL+s32NumOfSubBands)) > (SINT16)(u32CountSum + u32CountDiff) )
{
if (u32CountSum > maxBit)
maxBit = u32CountSum;
if (u32CountDiff > maxBit)
maxBit = u32CountDiff;
*ps16ScfL = (SINT16)u32CountSum;
*(ps16ScfL+s32NumOfSubBands) = (SINT16)u32CountDiff;
SbBuffer=pstrEncParams->s32SbBuffer+s32Sb;
pSum = s32LRSum;
pDiff = s32LRDiff;
for (s32Blk = 0; s32Blk < s32NumOfBlocks; s32Blk++)
{
*SbBuffer = *pSum;
*(SbBuffer+s32NumOfSubBands) = *pDiff;
SbBuffer += s32NumOfSubBands<<1;
pSum++;
pDiff++;
}
pstrEncParams->as16Join[s32Sb] = 1;
}
else
{
pstrEncParams->as16Join[s32Sb] = 0;
}
ps16ScfL++;
}
pstrEncParams->as16Join[s32Sb] = 0;
}
#endif
pstrEncParams->s16MaxBitNeed = (SINT16)maxBit;
/* bit allocation */
if ((pstrEncParams->s16ChannelMode == SBC_STEREO) || (pstrEncParams->s16ChannelMode == SBC_JOINT_STEREO))
sbc_enc_bit_alloc_ste(pstrEncParams);
else
sbc_enc_bit_alloc_mono(pstrEncParams);
/* save the beginning of the frame. pu8NextPacket is modified in EncPacking() */
pu8 = pstrEncParams->pu8NextPacket;
/* Quantize the encoded audio */
EncPacking(pstrEncParams);
/* scramble the code */
SBC_PRTC_CHK_INIT(pu8);
SBC_PRTC_CHK_CRC(pu8);
#if 0
if(pstrEncParams->u16PacketLength > ((sbc_prtc_cb.fr[sbc_prtc_cb.index].idx * 2) + sbc_prtc_cb.base))
printf("len: %d, idx: %d\n", pstrEncParams->u16PacketLength, sbc_prtc_cb.fr[sbc_prtc_cb.index].idx);
else
printf("len: %d, idx: %d!!!!\n", pstrEncParams->u16PacketLength, sbc_prtc_cb.fr[sbc_prtc_cb.index].idx);
#endif
SBC_PRTC_SCRMB((&pu8[sbc_prtc_cb.base]));
}
while(--(pstrEncParams->u8NumPacketToEncode));
pstrEncParams->u8NumPacketToEncode = 1; /* default is one for retrocompatibility purpose */
}
/****************************************************************************
* InitSbcAnalysisFilt - Initalizes the input data to 0
*
* RETURNS : N/A
*/
void SBC_Encoder_Init(SBC_ENC_PARAMS *pstrEncParams)
{
UINT16 s16SamplingFreq; /*temp variable to store smpling freq*/
SINT16 s16Bitpool; /*to store bit pool value*/
SINT16 s16BitRate; /*to store bitrate*/
SINT16 s16FrameLen; /*to store frame length*/
UINT16 HeaderParams;
pstrEncParams->u8NumPacketToEncode = 1; /* default is one for retrocompatibility purpose */
/* Required number of channels */
if (pstrEncParams->s16ChannelMode == SBC_MONO)
pstrEncParams->s16NumOfChannels = 1;
else
pstrEncParams->s16NumOfChannels = 2;
/* Bit pool calculation */
if (pstrEncParams->s16SamplingFreq == SBC_sf16000)
s16SamplingFreq = 16000;
else if (pstrEncParams->s16SamplingFreq == SBC_sf32000)
s16SamplingFreq = 32000;
else if (pstrEncParams->s16SamplingFreq == SBC_sf44100)
s16SamplingFreq = 44100;
else
s16SamplingFreq = 48000;
if ( (pstrEncParams->s16ChannelMode == SBC_JOINT_STEREO)
|| (pstrEncParams->s16ChannelMode == SBC_STEREO) )
{
s16Bitpool = (SINT16)( (pstrEncParams->u16BitRate *
pstrEncParams->s16NumOfSubBands * 1000 / s16SamplingFreq)
-( (32 + (4 * pstrEncParams->s16NumOfSubBands *
pstrEncParams->s16NumOfChannels)
+ ( (pstrEncParams->s16ChannelMode - 2) *
pstrEncParams->s16NumOfSubBands ) )
/ pstrEncParams->s16NumOfBlocks) );
s16FrameLen = 4 + (4*pstrEncParams->s16NumOfSubBands*
pstrEncParams->s16NumOfChannels)/8
+ ( ((pstrEncParams->s16ChannelMode - 2) *
pstrEncParams->s16NumOfSubBands)
+ (pstrEncParams->s16NumOfBlocks * s16Bitpool) ) / 8;
s16BitRate = (8 * s16FrameLen * s16SamplingFreq)
/ (pstrEncParams->s16NumOfSubBands *
pstrEncParams->s16NumOfBlocks * 1000);
if (s16BitRate > pstrEncParams->u16BitRate)
s16Bitpool--;
if(pstrEncParams->s16NumOfSubBands == 8)
pstrEncParams->s16BitPool = (s16Bitpool > 255) ? 255 : s16Bitpool;
else
pstrEncParams->s16BitPool = (s16Bitpool > 128) ? 128 : s16Bitpool;
}
else
{
s16Bitpool = (SINT16)( ((pstrEncParams->s16NumOfSubBands *
pstrEncParams->u16BitRate * 1000)
/ (s16SamplingFreq * pstrEncParams->s16NumOfChannels))
-( ( (32 / pstrEncParams->s16NumOfChannels) +
(4 * pstrEncParams->s16NumOfSubBands) )
/ pstrEncParams->s16NumOfBlocks ) );
pstrEncParams->s16BitPool = (s16Bitpool >
(16 * pstrEncParams->s16NumOfSubBands))
? (16*pstrEncParams->s16NumOfSubBands) : s16Bitpool;
}
if (pstrEncParams->s16BitPool < 0)
pstrEncParams->s16BitPool = 0;
/* sampling freq */
HeaderParams = ((pstrEncParams->s16SamplingFreq & 3)<< 6);
/* number of blocks*/
HeaderParams |= (((pstrEncParams->s16NumOfBlocks -4) & 12) << 2);
/* channel mode: mono, dual...*/
HeaderParams |= ((pstrEncParams->s16ChannelMode & 3)<< 2);
/* Loudness or SNR */
HeaderParams |= ((pstrEncParams->s16AllocationMethod & 1)<< 1);
HeaderParams |= ((pstrEncParams->s16NumOfSubBands >> 3) & 1); /*4 or 8*/
pstrEncParams->FrameHeader=HeaderParams;
if (pstrEncParams->s16NumOfSubBands==4)
{
if (pstrEncParams->s16NumOfChannels==1)
EncMaxShiftCounter=((ENC_VX_BUFFER_SIZE-4*10)>>2)<<2;
else
EncMaxShiftCounter=((ENC_VX_BUFFER_SIZE-4*10*2)>>3)<<2;
}
else
{
if (pstrEncParams->s16NumOfChannels==1)
EncMaxShiftCounter=((ENC_VX_BUFFER_SIZE-8*10)>>3)<<3;
else
EncMaxShiftCounter=((ENC_VX_BUFFER_SIZE-8*10*2)>>4)<<3;
}
APPL_TRACE_EVENT2("SBC_Encoder_Init : bitrate %d, bitpool %d",
pstrEncParams->u16BitRate, pstrEncParams->s16BitPool);
SbcAnalysisInit();
memset(&sbc_prtc_cb, 0, sizeof(tSBC_PRTC_CB));
sbc_prtc_cb.base = 6 + pstrEncParams->s16NumOfChannels*pstrEncParams->s16NumOfSubBands/2;
}