view libgsmefr/d_homing.c @ 242:f081a6850fb5

libgsmfrp: new refined implementation The previous implementation exhibited the following defects, which are now fixed: 1) The last received valid SID was cached forever for the purpose of handling future invalid SIDs - we could have received some valid SID ages ago, then lots of speech or NO_DATA, and if we then get an invalid SID, we would resurrect the last valid SID from ancient history - a bad design. In our new design, we handle invalid SID based on the current state, much like BFI. 2) GSM 06.11 spec says clearly that after the second lost SID (received BFI=1 && TAF=1 in CN state) we need to gradually decrease the output level, rather than jump directly to emitting silence frames - we previously failed to implement such logic. 3) Per GSM 06.12 section 5.2, Xmaxc should be the same in all 4 subframes in a SID frame. What should we do if we receive an otherwise valid SID frame with different Xmaxc? Our previous approach would replicate this Xmaxc oddity in every subsequent generated CN frame, which is rather bad. In our new design, the very first CN frame (which can be seen as a transformation of the SID frame itself) retains the original 4 distinct Xmaxc, but all subsequent CN frames are based on the Xmaxc from the last subframe of the most recent SID.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 09 May 2023 05:16:31 +0000
parents eefef9f6d533
children
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/**************************************************************************
 *
 *   File Name:  d_homing.c
 *
 *   Purpose:
 *      This file contains the following functions:
 *
 *      decoder_homing_frame_test()  checks if a frame of input speech
 *                                   parameters matches the Decoder Homing
 *                                   Frame pattern.
 *
 *      decoder_reset()              called by reset_dec() to reset all of
 *                                   the state variables for the decoder
 *
 *      reset_dec()                  calls functions to reset the state
 *                                   variables for the decoder, and for
 *                                   the receive DTX and Comfort Noise.
 *
 **************************************************************************/

#include "gsm_efr.h"
#include "typedef.h"
#include "namespace.h"
#include "cnst.h"
#include "dtx.h"
#include "codec.h"
#include "memops.h"
#include "dec_state.h"
#include "d_homing.h"
#include "q_plsf5_tab.h"

#define PRM_NO    57

/***************************************************************************
 *
 *   FUNCTION NAME:  decoder_homing_frame_test
 *
 *   PURPOSE:
 *      Checks if a frame of input speech parameters matches the Decoder
 *      Homing Frame pattern, which is:
 *
 *      parameter    decimal value    hexidecimal value
 *      ---------    -------------    -----------------
 *      LPC 1        4                0x0004
 *      LPC 2        47               0x002F
 *      LPC 3        180              0x00B4
 *      LPC 4        144              0x0090
 *      LPC 5        62               0x003E
 *      LTP-LAG 1    342              0x0156
 *      LTP-GAIN 1   11               0x000B
 *      PULSE1_1     0                0x0000
 *      PULSE1_2     1                0x0001
 *      PULSE1_3     15               0x000F
 *      PULSE1_4     1                0x0001
 *      PULSE1_5     13               0x000D
 *      PULSE1_6     0                0x0000
 *      PULSE1_7     3                0x0003
 *      PULSE1_8     0                0x0000
 *      PULSE1_9     3                0x0003
 *      PULSE1_10    0                0x0000
 *      FCB-GAIN 1   3                0x0003
 *      LTP-LAG 2    54               0x0036
 *      LTP-GAIN 2   1                0x0001
 *      PULSE2_1     8                0x0008
 *      PULSE2_2     8                0x0008
 *      PULSE2_3     5                0x0005
 *      PULSE2_4     8                0x0008
 *      PULSE2_5     1                0x0001
 *      PULSE2_6     0                0x0000
 *      PULSE2_7     0                0x0000
 *      PULSE2_8     1                0x0001
 *      PULSE2_9     1                0x0001
 *      PULSE2_10    0                0x0000
 *      FCB-GAIN 2   0                0x0000
 *      LTP-LAG 3    342              0x0156
 *      LTP-GAIN 3   0                0x0000
 *      PULSE3_1     0                0x0000
 *      PULSE3_2     0                0x0000
 *      PULSE3_3     0                0x0000
 *      PULSE3_4     0                0x0000
 *      PULSE3_5     0                0x0000
 *      PULSE3_6     0                0x0000
 *      PULSE3_7     0                0x0000
 *      PULSE3_8     0                0x0000
 *      PULSE3_9     0                0x0000
 *      PULSE3_10    0                0x0000
 *      FCB-GAIN 3   0                0x0000
 *      LTP-LAG 4    54               0x0036
 *      LTP-GAIN 4   11               0x000B
 *      PULSE4_1     0                0x0000
 *      PULSE4_2     0                0x0000
 *      PULSE4_3     0                0x0000
 *      PULSE4_4     0                0x0000
 *      PULSE4_5     0                0x0000
 *      PULSE4_6     0                0x0000
 *      PULSE4_7     0                0x0000
 *      PULSE4_8     0                0x0000
 *      PULSE4_9     0                0x0000
 *      PULSE4_10    0                0x0000
 *      FCB-GAIN 4   0                0x0000
 *
 *   INPUT:
 *      parm[]  one frame of speech parameters in parallel format
 *
 *      nbr_of_params
 *              the number of consecutive parameters in parm[] to match
 *
 *   OUTPUT:
 *      None
 *
 *   RETURN:
 *      0       input frame does not match the Decoder Homing Frame pattern.
 *      1       input frame matches the Decoder Homing Frame pattern.
 *
 **************************************************************************/

Word16 decoder_homing_frame_test (const Word16 parm[], Word16 nbr_of_params)
{
    static const Word16 dhf_mask[PRM_NO] =
    {
        0x0004,                 /* LPC 1 */
        0x002f,                 /* LPC 2 */
        0x00b4,                 /* LPC 3 */
        0x0090,                 /* LPC 4 */
        0x003e,                 /* LPC 5 */

        0x0156,                 /* LTP-LAG 1 */
        0x000b,                 /* LTP-GAIN 1 */
        0x0000,                 /* PULSE 1_1 */
        0x0001,                 /* PULSE 1_2 */
        0x000f,                 /* PULSE 1_3 */
        0x0001,                 /* PULSE 1_4 */
        0x000d,                 /* PULSE 1_5 */
        0x0000,                 /* PULSE 1_6 */
        0x0003,                 /* PULSE 1_7 */
        0x0000,                 /* PULSE 1_8 */
        0x0003,                 /* PULSE 1_9 */
        0x0000,                 /* PULSE 1_10 */
        0x0003,                 /* FCB-GAIN 1 */

        0x0036,                 /* LTP-LAG 2 */
        0x0001,                 /* LTP-GAIN 2 */
        0x0008,                 /* PULSE 2_1 */
        0x0008,                 /* PULSE 2_2 */
        0x0005,                 /* PULSE 2_3 */
        0x0008,                 /* PULSE 2_4 */
        0x0001,                 /* PULSE 2_5 */
        0x0000,                 /* PULSE 2_6 */
        0x0000,                 /* PULSE 2_7 */
        0x0001,                 /* PULSE 2_8 */
        0x0001,                 /* PULSE 2_9 */
        0x0000,                 /* PULSE 2_10 */
        0x0000,                 /* FCB-GAIN 2 */

        0x0156,                 /* LTP-LAG 3 */
        0x0000,                 /* LTP-GAIN 3 */
        0x0000,                 /* PULSE 3_1 */
        0x0000,                 /* PULSE 3_2 */
        0x0000,                 /* PULSE 3_3 */
        0x0000,                 /* PULSE 3_4 */
        0x0000,                 /* PULSE 3_5 */
        0x0000,                 /* PULSE 3_6 */
        0x0000,                 /* PULSE 3_7 */
        0x0000,                 /* PULSE 3_8 */
        0x0000,                 /* PULSE 3_9 */
        0x0000,                 /* PULSE 3_10 */
        0x0000,                 /* FCB-GAIN 3 */

        0x0036,                 /* LTP-LAG 4 */
        0x000b,                 /* LTP-GAIN 4 */
        0x0000,                 /* PULSE 4_1 */
        0x0000,                 /* PULSE 4_2 */
        0x0000,                 /* PULSE 4_3 */
        0x0000,                 /* PULSE 4_4 */
        0x0000,                 /* PULSE 4_5 */
        0x0000,                 /* PULSE 4_6 */
        0x0000,                 /* PULSE 4_7 */
        0x0000,                 /* PULSE 4_8 */
        0x0000,                 /* PULSE 4_9 */
        0x0000,                 /* PULSE 4_10 */
        0x0000                  /* FCB-GAIN 4 */ };

    Word16 i, j;

    for (i = 0; i < nbr_of_params; i++)
    {
        j = parm[i] ^ dhf_mask[i];

        if (j)
            break;
    }

    return !j;
}

/***************************************************************************
 *
 *   FUNCTION NAME:  decoder_reset
 *
 *   PURPOSE:
 *      resets all of the state variables for the decoder
 *
 *   INPUT:
 *      None
 *
 *   OUTPUT:
 *      None
 *
 *   RETURN:
 *      None
 *
 **************************************************************************/

void decoder_reset (struct EFR_decoder_state *st)
{
    Word16 i;

    /* reset all the decoder state variables */
    /* ------------------------------------- */

    /* Variable in decoder.c: */
    Set_zero (st->synth_buf, M);

    /* Variables in dec_12k2.c: */
    Init_Decoder_12k2 (st);

    /* Variable in agc.c: */
    st->past_gain = 4096;

    /* Variables in d_gains.c: */
    for (i = 0; i < 5; i++)
    {
        st->pbuf[i] = 410;          /* Error concealment */
        st->gbuf[i] = 1;            /* Error concealment */
    }

    st->past_gain_pit = 0;          /* Error concealment */
    st->prev_gp = 4096;             /* Error concealment */
    st->past_gain_code = 0;         /* Error concealment */
    st->prev_gc = 1;                /* Error concealment */
    st->gcode0_CN = 0;              /* CNI */
    st->gain_code_old_CN = 0;       /* CNI */
    st->gain_code_new_CN = 0;       /* CNI */
    st->gain_code_muting_CN = 0;    /* CNI */

    for (i = 0; i < 4; i++)
    {
        st->past_qua_en[i] = -2381; /* past quantized energies */
    }

    st->pred[0] = 44;               /* MA prediction coeff */
    st->pred[1] = 37;               /* MA prediction coeff */
    st->pred[2] = 22;               /* MA prediction coeff */
    st->pred[3] = 12;               /* MA prediction coeff */

    /* Variables in d_plsf_5.c: */
    for (i = 0; i < M; i++)
    {
        st->past_r2_q[i] = 0;             /* Past quantized prediction error */
        st->past_lsf_q[i] = mean_lsf[i];  /* Past dequantized lsfs */
        st->lsf_p_CN[i] = mean_lsf[i];    /* CNI */
        st->lsf_new_CN[i] = mean_lsf[i];  /* CNI */
        st->lsf_old_CN[i] = mean_lsf[i];  /* CNI */
    }

    /* Variable in dec_lag6.c: */
    st->old_T0 = 40;                /* Old integer lag */

    /* Variable in preemph.c: */
    st->mem_pre = 0;                /* Filter memory */

    /* Variables in pstfilt2.c: */
    Init_Post_Filter (st);

    return;
}

/***************************************************************************
 *
 *   FUNCTION NAME:  reset_dec
 *
 *   PURPOSE:
 *      resets all of the state variables for the decoder, and for the
 *      receive DTX and Comfort Noise.
 *
 *   INPUT:
 *      None
 *
 *   OUTPUT:
 *      None
 *
 *   RETURN:
 *      None
 *
 **************************************************************************/

void EFR_decoder_reset (struct EFR_decoder_state *st)
{
    st->reset_flag_old = 1;

    decoder_reset (st); /* reset all the state variables in the speech decoder*/
    reset_rx_dtx (st);  /* reset all the receive DTX and CN state variables */

    /* Themyscira libgsmefr addition for no-data BFI handling */
    st->L_pn_seed_nodata = PN_INITIAL_SEED;

    return;
}