FreeCalypso > hg > gsm-codec-lib
view libtwamr/g_adapt.c @ 388:550d3594c878
libtwamr: integrate lsp.c
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Mon, 06 May 2024 06:43:22 +0000 |
parents | 2a265be82195 |
children |
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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 : g_adapt.c * Purpose : gain adaptation for MR795 gain quantization * ******************************************************************************** */ /* ******************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ******************************************************************************** */ #include "namespace.h" #include "g_adapt.h" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" #include "basic_op.h" #include "oper_32b.h" #include "no_count.h" #include "cnst.h" #include "gmed_n.h" /* ******************************************************************************** * LOCAL VARIABLES AND TABLES ******************************************************************************** */ #define LTP_GAIN_THR1 2721 /* 2721 Q13 = 0.3322 ~= 1.0 / (10*log10(2)) */ #define LTP_GAIN_THR2 5443 /* 5443 Q13 = 0.6644 ~= 2.0 / (10*log10(2)) */ /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ /************************************************************************* * * Function: gain_adapt_reset * Purpose: Initializes state memory to zero * ************************************************************************** */ void gain_adapt_reset (GainAdaptState *st) { Word16 i; st->onset = 0; st->prev_alpha = 0; st->prev_gc = 0; for (i = 0; i < LTPG_MEM_SIZE; i++) { st->ltpg_mem[i] = 0; } } /************************************************************************* * * Function: gain_adapt() * Purpose: calculate pitch/codebook gain adaptation factor alpha * (and update the adaptor state) * ************************************************************************** */ void gain_adapt( GainAdaptState *st, /* i : state struct */ Word16 ltpg, /* i : ltp coding gain (log2()), Q13 */ Word16 gain_cod, /* i : code gain, Q1 */ Word16 *alpha /* o : gain adaptation factor, Q15 */ ) { Word16 adapt; /* adaptdation status; 0, 1, or 2 */ Word16 result; /* alpha factor, Q13 */ Word16 filt; /* median-filtered LTP coding gain, Q13 */ Word16 tmp, i; /* basic adaptation */ test (); if (sub (ltpg, LTP_GAIN_THR1) <= 0) { adapt = 0; move16 (); } else { test (); if (sub (ltpg, LTP_GAIN_THR2) <= 0) { adapt = 1; move16 (); } else { adapt = 2; move16 (); } } /* * // onset indicator * if ((cbGain > onFact * cbGainMem[0]) && (cbGain > 100.0)) * onset = 8; * else * if (onset) * onset--; */ /* tmp = cbGain / onFact; onFact = 2.0; 200 Q1 = 100.0 */ tmp = shr_r (gain_cod, 1); test (); test (); if ((sub (tmp, st->prev_gc) > 0) && sub(gain_cod, 200) > 0) { st->onset = 8; move16 (); } else { test (); if (st->onset != 0) { st->onset = sub (st->onset, 1); move16 (); } } /* * // if onset, increase adaptor state * if (onset && (gainAdapt < 2)) gainAdapt++; */ test(); test (); if ((st->onset != 0) && (sub (adapt, 2) < 0)) { adapt = add (adapt, 1); } st->ltpg_mem[0] = ltpg; move16 (); filt = gmed_n (st->ltpg_mem, 5); move16 (); /* function result */ test (); if (adapt == 0) { test (); if (sub (filt, 5443) > 0) /* 5443 Q13 = 0.66443... */ { result = 0; move16 (); } else { test (); if (filt < 0) { result = 16384; move16 (); /* 16384 Q15 = 0.5 */ } else { /* result = 0.5 - 0.75257499*filt */ /* result (Q15) = 16384 - 24660 * (filt << 2) */ filt = shl (filt, 2); /* Q15 */ result = sub (16384, mult (24660, filt)); } } } else { result = 0; move16 (); } /* * if (prevAlpha == 0.0) result = 0.5 * (result + prevAlpha); */ test (); if (st->prev_alpha == 0) { result = shr (result, 1); } /* store the result */ *alpha = result; move16 (); /* update adapter state memory */ st->prev_alpha = result; move16 (); st->prev_gc = gain_cod; move16 (); for (i = LTPG_MEM_SIZE-1; i > 0; i--) { st->ltpg_mem[i] = st->ltpg_mem[i-1]; move16 (); } /* mem[0] is just present for convenience in calling the gmed_n[5] * function above. The memory depth is really LTPG_MEM_SIZE-1. */ }