Tristan Matthews | 0a329cc | 2013-07-17 13:20:14 -0400 | [diff] [blame] | 1 | |
| 2 | /****************************************************************** |
| 3 | |
| 4 | iLBC Speech Coder ANSI-C Source Code |
| 5 | |
| 6 | filter.h |
| 7 | |
| 8 | Copyright (C) The Internet Society (2004). |
| 9 | All Rights Reserved. |
| 10 | |
| 11 | ******************************************************************/ |
| 12 | |
| 13 | |
| 14 | |
| 15 | |
| 16 | |
| 17 | |
| 18 | #ifndef __iLBC_FILTER_H |
| 19 | #define __iLBC_FILTER_H |
| 20 | |
| 21 | void AllPoleFilter( |
| 22 | float *InOut, /* (i/o) on entrance InOut[-orderCoef] to |
| 23 | InOut[-1] contain the state of the |
| 24 | filter (delayed samples). InOut[0] to |
| 25 | InOut[lengthInOut-1] contain the filter |
| 26 | input, on en exit InOut[-orderCoef] to |
| 27 | InOut[-1] is unchanged and InOut[0] to |
| 28 | InOut[lengthInOut-1] contain filtered |
| 29 | samples */ |
| 30 | float *Coef,/* (i) filter coefficients, Coef[0] is assumed |
| 31 | to be 1.0 */ |
| 32 | int lengthInOut,/* (i) number of input/output samples */ |
| 33 | int orderCoef /* (i) number of filter coefficients */ |
| 34 | ); |
| 35 | |
| 36 | void AllZeroFilter( |
| 37 | float *In, /* (i) In[0] to In[lengthInOut-1] contain |
| 38 | filter input samples */ |
| 39 | float *Coef,/* (i) filter coefficients (Coef[0] is assumed |
| 40 | to be 1.0) */ |
| 41 | int lengthInOut,/* (i) number of input/output samples */ |
| 42 | int orderCoef, /* (i) number of filter coefficients */ |
| 43 | float *Out /* (i/o) on entrance Out[-orderCoef] to Out[-1] |
| 44 | contain the filter state, on exit Out[0] |
| 45 | to Out[lengthInOut-1] contain filtered |
| 46 | samples */ |
| 47 | ); |
| 48 | |
| 49 | void ZeroPoleFilter( |
| 50 | float *In, /* (i) In[0] to In[lengthInOut-1] contain filter |
| 51 | input samples In[-orderCoef] to In[-1] |
| 52 | contain state of all-zero section */ |
| 53 | float *ZeroCoef,/* (i) filter coefficients for all-zero |
| 54 | section (ZeroCoef[0] is assumed to |
| 55 | be 1.0) */ |
| 56 | float *PoleCoef,/* (i) filter coefficients for all-pole section |
| 57 | (ZeroCoef[0] is assumed to be 1.0) */ |
| 58 | int lengthInOut,/* (i) number of input/output samples */ |
| 59 | int orderCoef, /* (i) number of filter coefficients */ |
| 60 | float *Out /* (i/o) on entrance Out[-orderCoef] to Out[-1] |
| 61 | contain state of all-pole section. On |
| 62 | exit Out[0] to Out[lengthInOut-1] |
| 63 | contain filtered samples */ |
| 64 | ); |
| 65 | |
| 66 | |
| 67 | |
| 68 | |
| 69 | |
| 70 | |
| 71 | void DownSample ( |
| 72 | float *In, /* (i) input samples */ |
| 73 | float *Coef, /* (i) filter coefficients */ |
| 74 | int lengthIn, /* (i) number of input samples */ |
| 75 | float *state, /* (i) filter state */ |
| 76 | float *Out /* (o) downsampled output */ |
| 77 | ); |
| 78 | |
| 79 | #endif |
| 80 | |