// 22 -> 8 resampler
void WebRtcSpl_Resample22khzTo8khz(const int16_t* in, int16_t* out,
WebRtcSpl_State22khzTo8khz* state, int32_t* tmpmem)
{
int k;
// process two blocks of 10/SUB_BLOCKS_22_8 ms (to reduce temp buffer size)
for (k = 0; k < SUB_BLOCKS_22_8; k++)
{
///// 22 --> 22 lowpass /////
// int16_t in[220/SUB_BLOCKS_22_8]
// int32_t out[220/SUB_BLOCKS_22_8]
/////
WebRtcSpl_LPBy2ShortToInt(in, 220 / SUB_BLOCKS_22_8, tmpmem + 16, state->S_22_22);
///// 22 --> 16 /////
// int32_t in[220/SUB_BLOCKS_22_8]
// int32_t out[160/SUB_BLOCKS_22_8]
/////
// copy state to and from input array
tmpmem[8] = state->S_22_16[0];
tmpmem[9] = state->S_22_16[1];
tmpmem[10] = state->S_22_16[2];
tmpmem[11] = state->S_22_16[3];
tmpmem[12] = state->S_22_16[4];
tmpmem[13] = state->S_22_16[5];
tmpmem[14] = state->S_22_16[6];
tmpmem[15] = state->S_22_16[7];
state->S_22_16[0] = tmpmem[220 / SUB_BLOCKS_22_8 + 8];
state->S_22_16[1] = tmpmem[220 / SUB_BLOCKS_22_8 + 9];
state->S_22_16[2] = tmpmem[220 / SUB_BLOCKS_22_8 + 10];
state->S_22_16[3] = tmpmem[220 / SUB_BLOCKS_22_8 + 11];
state->S_22_16[4] = tmpmem[220 / SUB_BLOCKS_22_8 + 12];
state->S_22_16[5] = tmpmem[220 / SUB_BLOCKS_22_8 + 13];
state->S_22_16[6] = tmpmem[220 / SUB_BLOCKS_22_8 + 14];
state->S_22_16[7] = tmpmem[220 / SUB_BLOCKS_22_8 + 15];
WebRtcSpl_Resample44khzTo32khz(tmpmem + 8, tmpmem, 20 / SUB_BLOCKS_22_8);
///// 16 --> 8 /////
// int32_t in[160/SUB_BLOCKS_22_8]
// int32_t out[80/SUB_BLOCKS_22_8]
/////
WebRtcSpl_DownBy2IntToShort(tmpmem, 160 / SUB_BLOCKS_22_8, out, state->S_16_8);
// move input/output pointers 10/SUB_BLOCKS_22_8 ms seconds ahead
in += 220 / SUB_BLOCKS_22_8;
out += 80 / SUB_BLOCKS_22_8;
}
}
// 48 -> 16 resampler
void WebRtcSpl_Resample48khzTo16khz(const WebRtc_Word16* in, WebRtc_Word16* out,
WebRtcSpl_State48khzTo16khz* state, WebRtc_Word32* tmpmem)
{
///// 48 --> 48(LP) /////
// WebRtc_Word16 in[480]
// WebRtc_Word32 out[480]
/////
WebRtcSpl_LPBy2ShortToInt(in, 480, tmpmem + 16, state->S_48_48);
///// 48 --> 32 /////
// WebRtc_Word32 in[480]
// WebRtc_Word32 out[320]
/////
// copy state to and from input array
memcpy(tmpmem + 8, state->S_48_32, 8 * sizeof(WebRtc_Word32));
memcpy(state->S_48_32, tmpmem + 488, 8 * sizeof(WebRtc_Word32));
WebRtcSpl_Resample48khzTo32khz(tmpmem + 8, tmpmem, 160);
///// 32 --> 16 /////
// WebRtc_Word32 in[320]
// WebRtc_Word16 out[160]
/////
WebRtcSpl_DownBy2IntToShort(tmpmem, 320, out, state->S_32_16);
}
