mirror of
https://github.com/TorqueGameEngines/Torque3D.git
synced 2026-03-21 05:10:53 +00:00
a745fc3757
added libraries: opus flac libsndfile updated: libvorbis libogg openal - Everything works as expected for now. Bare in mind libsndfile needed the check for whether or not it could find the xiph libraries removed in order for this to work.
101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
/*
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* Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
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* Universitaet Berlin. See the accompanying file "COPYRIGHT" for
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* details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
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*/
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#include <stdio.h>
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#include <assert.h>
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#include "gsm610_priv.h"
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/* 4.2.0 .. 4.2.3 PREPROCESSING SECTION
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*
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* After A-law to linear conversion (or directly from the
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* Ato D converter) the following scaling is assumed for
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* input to the RPE-LTP algorithm:
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*
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* in: 0.1.....................12
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* S.v.v.v.v.v.v.v.v.v.v.v.v.*.*.*
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*
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* Where S is the sign bit, v a valid bit, and * a "don't care" bit.
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* The original signal is called sop[..]
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*
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* out: 0.1................... 12
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* S.S.v.v.v.v.v.v.v.v.v.v.v.v.0.0
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*/
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void Gsm_Preprocess (
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struct gsm_state * S,
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int16_t * s,
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int16_t * so) /* [0..159] IN/OUT */
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{
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int16_t z1 = S->z1 ;
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int32_t L_z2 = S->L_z2 ;
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int16_t mp = S->mp ;
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int16_t s1 ;
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int32_t L_s2 ;
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int32_t L_temp ;
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int16_t msp, lsp ;
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int16_t SO ;
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register int k = 160 ;
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while (k--)
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{
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/* 4.2.1 Downscaling of the input signal */
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SO = arith_shift_left (SASR_W (*s, 3), 2) ;
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s++ ;
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assert (SO >= -0x4000) ; /* downscaled by */
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assert (SO <= 0x3FFC) ; /* previous routine. */
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/* 4.2.2 Offset compensation
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*
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* This part implements a high-pass filter and requires extended
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* arithmetic precision for the recursive part of this filter.
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* The input of this procedure is the array so[0...159] and the
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* output the array sof[ 0...159 ].
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*/
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/* Compute the non-recursive part */
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s1 = SO - z1 ; /* s1 = gsm_sub (*so, z1) ; */
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z1 = SO ;
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assert (s1 != MIN_WORD) ;
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/* Compute the recursive part */
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L_s2 = s1 ;
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L_s2 = arith_shift_left (L_s2, 15) ;
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/* Execution of a 31 bv 16 bits multiplication */
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msp = SASR_L (L_z2, 15) ;
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lsp = L_z2 - arith_shift_left ((int32_t) msp, 15) ; /* gsm_L_sub (L_z2,(msp<<15)) ; */
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L_s2 += GSM_MULT_R (lsp, 32735) ;
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L_temp = (int32_t) msp * 32735 ; /* GSM_L_MULT (msp,32735) >> 1 ;*/
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L_z2 = GSM_L_ADD (L_temp, L_s2) ;
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/* Compute sof[k] with rounding */
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L_temp = GSM_L_ADD (L_z2, 16384) ;
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/* 4.2.3 Preemphasis */
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msp = GSM_MULT_R (mp, -28180) ;
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mp = SASR_L (L_temp, 15) ;
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*so++ = GSM_ADD (mp, msp) ;
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}
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S->z1 = z1 ;
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S->L_z2 = L_z2 ;
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S->mp = mp ;
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}
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