size_t WebRtcSpl_FilterAR(const int16_t* a, size_t a_length, const int16_t* x, size_t x_length, int16_t* state, size_t state_length, int16_t* state_low, size_t state_low_length, int16_t* filtered, int16_t* filtered_low, size_t filtered_low_length) { int32_t o; int32_t oLOW; size_t i, j, stop; const int16_t* x_ptr = &x[0]; int16_t* filteredFINAL_ptr = filtered; int16_t* filteredFINAL_LOW_ptr = filtered_low; for (i = 0; i < x_length; i++) { // Calculate filtered[i] and filtered_low[i] const int16_t* a_ptr = &a[1]; int16_t* filtered_ptr = &filtered[i - 1]; int16_t* filtered_low_ptr = &filtered_low[i - 1]; int16_t* state_ptr = &state[state_length - 1]; int16_t* state_low_ptr = &state_low[state_length - 1]; o = (int32_t)(*x_ptr++) << 12; oLOW = (int32_t)0; stop = (i < a_length) ? i + 1 : a_length; for (j = 1; j < stop; j++) { o -= *a_ptr * *filtered_ptr--; oLOW -= *a_ptr++ * *filtered_low_ptr--; } for (j = i + 1; j < a_length; j++) { o -= *a_ptr * *state_ptr--; oLOW -= *a_ptr++ * *state_low_ptr--; } o += (oLOW >> 12); *filteredFINAL_ptr = (int16_t)((o + (int32_t)2048) >> 12); *filteredFINAL_LOW_ptr++ = (int16_t)(o - ((int32_t)(*filteredFINAL_ptr++) << 12)); } // Save the filter state if (x_length >= state_length) { WebRtcSpl_CopyFromEndW16(filtered, x_length, a_length - 1, state); WebRtcSpl_CopyFromEndW16(filtered_low, x_length, a_length - 1, state_low); } else { for (i = 0; i < state_length - x_length; i++) { state[i] = state[i + x_length]; state_low[i] = state_low[i + x_length]; } for (i = 0; i < x_length; i++) { state[state_length - x_length + i] = filtered[i]; state[state_length - x_length + i] = filtered_low[i]; } } return x_length; }
int WebRtcSpl_FilterAR(G_CONST WebRtc_Word16* a, int a_length, G_CONST WebRtc_Word16* x, int x_length, WebRtc_Word16* state, int state_length, WebRtc_Word16* state_low, int state_low_length, WebRtc_Word16* filtered, WebRtc_Word16* filtered_low, int filtered_low_length) { WebRtc_Word32 o; WebRtc_Word32 oLOW; int i, j, stop; G_CONST WebRtc_Word16* x_ptr = &x[0]; WebRtc_Word16* filteredFINAL_ptr = filtered; WebRtc_Word16* filteredFINAL_LOW_ptr = filtered_low; for (i = 0; i < x_length; i++) { // Calculate filtered[i] and filtered_low[i] G_CONST WebRtc_Word16* a_ptr = &a[1]; WebRtc_Word16* filtered_ptr = &filtered[i - 1]; WebRtc_Word16* filtered_low_ptr = &filtered_low[i - 1]; WebRtc_Word16* state_ptr = &state[state_length - 1]; WebRtc_Word16* state_low_ptr = &state_low[state_length - 1]; o = (WebRtc_Word32)(*x_ptr++) << 12; oLOW = (WebRtc_Word32)0; stop = (i < a_length) ? i + 1 : a_length; for (j = 1; j < stop; j++) { o -= WEBRTC_SPL_MUL_16_16(*a_ptr, *filtered_ptr--); oLOW -= WEBRTC_SPL_MUL_16_16(*a_ptr++, *filtered_low_ptr--); } for (j = i + 1; j < a_length; j++) { o -= WEBRTC_SPL_MUL_16_16(*a_ptr, *state_ptr--); oLOW -= WEBRTC_SPL_MUL_16_16(*a_ptr++, *state_low_ptr--); } o += (oLOW >> 12); *filteredFINAL_ptr = (WebRtc_Word16)((o + (WebRtc_Word32)2048) >> 12); *filteredFINAL_LOW_ptr++ = (WebRtc_Word16)(o - ((WebRtc_Word32)(*filteredFINAL_ptr++) << 12)); } // Save the filter state if (x_length >= state_length) { WebRtcSpl_CopyFromEndW16(filtered, x_length, a_length - 1, state); WebRtcSpl_CopyFromEndW16(filtered_low, x_length, a_length - 1, state_low); } else { for (i = 0; i < state_length - x_length; i++) { state[i] = state[i + x_length]; state_low[i] = state_low[i + x_length]; } for (i = 0; i < x_length; i++) { state[state_length - x_length + i] = filtered[i]; state[state_length - x_length + i] = filtered_low[i]; } } return x_length; }