FreeCalypso > hg > gsm-codec-lib
view libtwamr/agc.h @ 282:9ee8ad3d4d30
frtest: rm gsmfr-hand-test and gsmfr-max-out utils
These hack programs were never properly documented and were written
only as part of a debug chase, in pursuit of a bug that ultimately
turned out to be in our then-hacky patch to osmo-bts-sysmo,
before beginning of proper patches in Osmocom. These hack programs
need to be dropped from the present sw package because they depend
on old libgsm, and we are eliminating that dependency.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Sun, 14 Apr 2024 05:44:47 +0000 |
| parents | 54f6bc41ed10 |
| children | 6b33f3ba4289 |
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/* ***************************************************************************** * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ***************************************************************************** * * File : agc.h * Purpose : Scales the postfilter output on a subframe basis * : by automatic control of the subframe gain. * ***************************************************************************** */ #ifndef agc_h #define agc_h "$Id $" /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include "typedef.h" /* ***************************************************************************** * DEFINITION OF DATA TYPES ***************************************************************************** */ typedef struct { Word16 past_gain; } agcState; /* ***************************************************************************** * DECLARATION OF PROTOTYPES ***************************************************************************** */ /* ************************************************************************** * * Function : agc_init * Purpose : Allocates memory for agc state and initializes * state memory * Description : Stores pointer to agc status struct in *st. This pointer * has to be passed to agc in each call. * Returns : 0 on success * ************************************************************************** */ int agc_init(agcState **st); /* ************************************************************************** * * Function : agc_reset * Purpose : Reset of agc (i.e. set state memory to 1.0) * Returns : 0 on success * ************************************************************************** */ int agc_reset (agcState *st); /* ************************************************************************** * * Function : agc_exit * Purpose : The memory used for state memory is freed, * de-initialize agc * ************************************************************************** */ void agc_exit (agcState **st); /* ************************************************************************** * * Function : agc * Purpose : Scales the postfilter output on a subframe basis * Description : sig_out[n] = sig_out[n] * gain[n]; * where gain[n] is the gain at the nth sample given by * gain[n] = agc_fac * gain[n-1] + (1 - agc_fac) g_in/g_out * g_in/g_out is the square root of the ratio of energy at * the input and output of the postfilter. * ************************************************************************** */ int agc ( agcState *st, /* i/o : agc state */ Word16 *sig_in, /* i : postfilter input signal, (l_trm) */ Word16 *sig_out, /* i/o : postfilter output signal, (l_trm) */ Word16 agc_fac, /* i : AGC factor */ Word16 l_trm /* i : subframe size */ ); /* ************************************************************************** * * Function: agc2 * Purpose: Scales the excitation on a subframe basis * ************************************************************************** */ void agc2 ( Word16 *sig_in, /* i : postfilter input signal */ Word16 *sig_out, /* i/o : postfilter output signal */ Word16 l_trm /* i : subframe size */ ); #endif