/****************************************************************************** * * Copyright (C) 2002-2012 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. * ******************************************************************************/ /****************************************************************************** * * Utility functions to help build and parse SBC Codec Information Element * and Media Payload. * ******************************************************************************/ #include "bt_target.h" #if (A2D_SBC_INCLUDED == TRUE) #include #include "a2d_api.h" #include "a2d_int.h" #include "a2d_sbc.h" /************************************************************************************************* * SBC descramble 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] >> 3) + (p[index] << 5); * p[index] = tmp; * } * } * //else index is 0. The frame stays unaltered * */ #define A2D_SBC_SYNC_WORD 0x9C #define A2D_SBC_CRC_IDX 3 #define A2D_SBC_USE_MASK 0x64 #define A2D_SBC_SYNC_MASK 0x10 #define A2D_SBC_CIDX 0 #define A2D_SBC_LIDX 1 #define A2D_SBC_CH_M_BITS 0xC /* channel mode bits: 0: mono; 1 ch */ #define A2D_SBC_SUBBAND_BIT 0x1 /* num of subband bit: 0:4; 1: 8 */ #define A2D_SBC_GET_IDX(sc) (((sc) & 0x3) + (((sc) & 0x30) >> 2)) typedef struct { UINT8 use; UINT8 idx; } tA2D_SBC_FR_CB; typedef struct { tA2D_SBC_FR_CB fr[2]; UINT8 index; UINT8 base; } tA2D_SBC_DS_CB; static tA2D_SBC_DS_CB a2d_sbc_ds_cb; /*int a2d_count = 0;*/ /****************************************************************************** ** ** Function A2D_SbcChkFrInit ** ** Description check if need to init the descramble control block. ** ** Returns nothing. ******************************************************************************/ void A2D_SbcChkFrInit(UINT8 *p_pkt) { UINT8 fmt; UINT8 num_chnl = 1; UINT8 num_subband = 4; if((p_pkt[0] & A2D_SBC_SYNC_MASK) == 0) { a2d_cb.use_desc = TRUE; fmt = p_pkt[1]; p_pkt[0] |= A2D_SBC_SYNC_MASK; memset(&a2d_sbc_ds_cb, 0, sizeof(tA2D_SBC_DS_CB)); if(fmt & A2D_SBC_CH_M_BITS) num_chnl = 2; if(fmt & A2D_SBC_SUBBAND_BIT) num_subband = 8; a2d_sbc_ds_cb.base = 6 + num_chnl*num_subband/2; /*printf("base: %d\n", a2d_sbc_ds_cb.base); a2d_count = 0;*/ } } /****************************************************************************** ** ** Function A2D_SbcDescramble ** ** Description descramble the packet. ** ** Returns nothing. ******************************************************************************/ void A2D_SbcDescramble(UINT8 *p_pkt, UINT16 len) { tA2D_SBC_FR_CB *p_cur, *p_last; UINT32 idx, tmp, tmp2; if(a2d_cb.use_desc) { /* c2l */ p_last = &a2d_sbc_ds_cb.fr[A2D_SBC_LIDX]; p_cur = &a2d_sbc_ds_cb.fr[A2D_SBC_CIDX]; p_last->idx = p_cur->idx; p_last->use = p_cur->use; /* getc */ p_cur->use = p_pkt[A2D_SBC_CRC_IDX] & A2D_SBC_USE_MASK; p_cur->idx = A2D_SBC_GET_IDX(p_pkt[A2D_SBC_CRC_IDX]); a2d_sbc_ds_cb.index = (p_cur->use)?A2D_SBC_CIDX:A2D_SBC_LIDX; /* printf("%05d: ar[%02d]: x%02x, msk: x%02x, use: %s, idx: %02d, ", a2d_count++, A2D_SBC_CRC_IDX, p_pkt[A2D_SBC_CRC_IDX], A2D_SBC_USE_MASK, (p_cur->use)?"cur":"lst", p_cur->idx); */ /* descramble */ idx = a2d_sbc_ds_cb.fr[a2d_sbc_ds_cb.index].idx; if(idx > 0) { p_pkt = &p_pkt[a2d_sbc_ds_cb.base]; if((idx&1) && (len > (a2d_sbc_ds_cb.base+(idx<<1)))) { tmp2 = (idx<<1); tmp = p_pkt[idx]; p_pkt[idx] = p_pkt[tmp2]; p_pkt[tmp2] = tmp; /* printf("tmp2: %02d, len: %d, idx: %d\n", tmp2, len, a2d_sbc_ds_cb.fr[a2d_sbc_ds_cb.index].idx); */ } else { tmp2 = p_pkt[idx]; tmp = (tmp2>>3)+(tmp2<<5); p_pkt[idx] = (UINT8)tmp; /* printf("tmp: x%02x, len: %d, idx: %d(cmp:%d)\n", (UINT8)tmp2, len, a2d_sbc_ds_cb.fr[a2d_sbc_ds_cb.index].idx, (a2d_sbc_ds_cb.base+(idx<<1))); */ } } /* else { printf("!!!!\n"); } */ } } /****************************************************************************** ** ** Function A2D_BldSbcInfo ** ** Description This function is called by an application to build ** the SBC Media Codec Capabilities byte sequence ** beginning from the LOSC octet. ** Input Parameters: ** media_type: Indicates Audio, or Multimedia. ** ** p_ie: The SBC Codec Information Element information. ** ** Output Parameters: ** p_result: the resulting codec info byte sequence. ** ** Returns A2D_SUCCESS if function execution succeeded. ** Error status code, otherwise. ******************************************************************************/ tA2D_STATUS A2D_BldSbcInfo(UINT8 media_type, tA2D_SBC_CIE *p_ie, UINT8 *p_result) { tA2D_STATUS status; if( p_ie == NULL || p_result == NULL || (p_ie->samp_freq & ~A2D_SBC_IE_SAMP_FREQ_MSK) || (p_ie->ch_mode & ~A2D_SBC_IE_CH_MD_MSK) || (p_ie->block_len & ~A2D_SBC_IE_BLOCKS_MSK) || (p_ie->num_subbands & ~A2D_SBC_IE_SUBBAND_MSK) || (p_ie->alloc_mthd & ~A2D_SBC_IE_ALLOC_MD_MSK) || (p_ie->max_bitpool < p_ie->min_bitpool) || (p_ie->max_bitpool < A2D_SBC_IE_MIN_BITPOOL) || (p_ie->max_bitpool > A2D_SBC_IE_MAX_BITPOOL) || (p_ie->min_bitpool < A2D_SBC_IE_MIN_BITPOOL) || (p_ie->min_bitpool > A2D_SBC_IE_MAX_BITPOOL) ) { /* if any unused bit is set */ status = A2D_INVALID_PARAMS; } else { status = A2D_SUCCESS; *p_result++ = A2D_SBC_INFO_LEN; *p_result++ = media_type; *p_result++ = A2D_MEDIA_CT_SBC; /* Media Codec Specific Information Element */ *p_result++ = p_ie->samp_freq | p_ie->ch_mode; *p_result++ = p_ie->block_len | p_ie->num_subbands | p_ie->alloc_mthd; *p_result++ = p_ie->min_bitpool; *p_result = p_ie->max_bitpool; } return status; } /****************************************************************************** ** ** Function A2D_ParsSbcInfo ** ** Description This function is called by an application to parse ** the SBC Media Codec Capabilities byte sequence ** beginning from the LOSC octet. ** Input Parameters: ** p_info: the byte sequence to parse. ** ** for_caps: TRUE, if the byte sequence is for get capabilities response. ** ** Output Parameters: ** p_ie: The SBC Codec Information Element information. ** ** Returns A2D_SUCCESS if function execution succeeded. ** Error status code, otherwise. ******************************************************************************/ tA2D_STATUS A2D_ParsSbcInfo(tA2D_SBC_CIE *p_ie, UINT8 *p_info, BOOLEAN for_caps) { tA2D_STATUS status; UINT8 losc; UINT8 mt; if( p_ie == NULL || p_info == NULL) status = A2D_INVALID_PARAMS; else { losc = *p_info++; mt = *p_info++; /* If the function is called for the wrong Media Type or Media Codec Type */ if(losc != A2D_SBC_INFO_LEN || *p_info != A2D_MEDIA_CT_SBC) status = A2D_WRONG_CODEC; else { p_info++; p_ie->samp_freq = *p_info & A2D_SBC_IE_SAMP_FREQ_MSK; p_ie->ch_mode = *p_info & A2D_SBC_IE_CH_MD_MSK; p_info++; p_ie->block_len = *p_info & A2D_SBC_IE_BLOCKS_MSK; p_ie->num_subbands = *p_info & A2D_SBC_IE_SUBBAND_MSK; p_ie->alloc_mthd = *p_info & A2D_SBC_IE_ALLOC_MD_MSK; p_info++; p_ie->min_bitpool = *p_info++; p_ie->max_bitpool = *p_info; status = A2D_SUCCESS; if(p_ie->min_bitpool < A2D_SBC_IE_MIN_BITPOOL || p_ie->min_bitpool > A2D_SBC_IE_MAX_BITPOOL ) status = A2D_BAD_MIN_BITPOOL; if(p_ie->max_bitpool < A2D_SBC_IE_MIN_BITPOOL || p_ie->max_bitpool > A2D_SBC_IE_MAX_BITPOOL || p_ie->max_bitpool < p_ie->min_bitpool) status = A2D_BAD_MAX_BITPOOL; if(for_caps == FALSE) { if(A2D_BitsSet(p_ie->samp_freq) != A2D_SET_ONE_BIT) status = A2D_BAD_SAMP_FREQ; if(A2D_BitsSet(p_ie->ch_mode) != A2D_SET_ONE_BIT) status = A2D_BAD_CH_MODE; if(A2D_BitsSet(p_ie->block_len) != A2D_SET_ONE_BIT) status = A2D_BAD_BLOCK_LEN; if(A2D_BitsSet(p_ie->num_subbands) != A2D_SET_ONE_BIT) status = A2D_BAD_SUBBANDS; if(A2D_BitsSet(p_ie->alloc_mthd) != A2D_SET_ONE_BIT) status = A2D_BAD_ALLOC_MTHD; } } } return status; } /****************************************************************************** ** ** Function A2D_BldSbcMplHdr ** ** Description This function is called by an application to parse ** the SBC Media Payload header. ** Input Parameters: ** frag: 1, if fragmented. 0, otherwise. ** ** start: 1, if the starting packet of a fragmented frame. ** ** last: 1, if the last packet of a fragmented frame. ** ** num: If frag is 1, this is the number of remaining fragments ** (including this fragment) of this frame. ** If frag is 0, this is the number of frames in this packet. ** ** Output Parameters: ** p_dst: the resulting media payload header byte sequence. ** ** Returns void. ******************************************************************************/ void A2D_BldSbcMplHdr(UINT8 *p_dst, BOOLEAN frag, BOOLEAN start, BOOLEAN last, UINT8 num) { if(p_dst) { *p_dst = 0; if(frag) *p_dst |= A2D_SBC_HDR_F_MSK; if(start) *p_dst |= A2D_SBC_HDR_S_MSK; if(last) *p_dst |= A2D_SBC_HDR_L_MSK; *p_dst |= (A2D_SBC_HDR_NUM_MSK & num); } } /****************************************************************************** ** ** Function A2D_ParsSbcMplHdr ** ** Description This function is called by an application to parse ** the SBC Media Payload header. ** Input Parameters: ** p_src: the byte sequence to parse.. ** ** Output Parameters: ** frag: 1, if fragmented. 0, otherwise. ** ** start: 1, if the starting packet of a fragmented frame. ** ** last: 1, if the last packet of a fragmented frame. ** ** num: If frag is 1, this is the number of remaining fragments ** (including this fragment) of this frame. ** If frag is 0, this is the number of frames in this packet. ** ** Returns void. ******************************************************************************/ void A2D_ParsSbcMplHdr(UINT8 *p_src, BOOLEAN *p_frag, BOOLEAN *p_start, BOOLEAN *p_last, UINT8 *p_num) { if(p_src && p_frag && p_start && p_last && p_num) { *p_frag = (*p_src & A2D_SBC_HDR_F_MSK) ? TRUE: FALSE; *p_start= (*p_src & A2D_SBC_HDR_S_MSK) ? TRUE: FALSE; *p_last = (*p_src & A2D_SBC_HDR_L_MSK) ? TRUE: FALSE; *p_num = (*p_src & A2D_SBC_HDR_NUM_MSK); } } #endif /* A2D_SBC_INCLUDED == TRUE */