vad1.cpp

实现3GPP的GSM中AMR语音的CODECS。

    return 0;
}


/*
------------------------------------------------------------------------------
 FUNCTION NAME: vad1_exit
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    state -- pointer to type vadState1 --  State struct

 Outputs:
    None

 Returns:
    None

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

    The memory used for state memory is freed

------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 vad1.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE


------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void vad1_exit(vadState1 **state)
{
    if (state == NULL || *state == NULL)
        return;

    /* deallocate memory */
    oscl_free(*state);
    *state = NULL;

    return;
}


/*
------------------------------------------------------------------------------
 FUNCTION NAME: vad_complex_detection_update
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    best_corr_hp -- Word16 -- best Corr
    state -- pointer to type vadState1 --  State struct

 Outputs:
    state -- pointer to type vadState1 --  State struct

 Returns:
    None

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 Purpose      : update vad->bestCorr_hp  complex signal feature state
------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 vad1.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE


------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void vad_complex_detection_update(
    vadState1 *st,       /* i/o : State struct */
    Word16 best_corr_hp) /* i   : best Corr    */
{
    st->best_corr_hp = best_corr_hp;
}



/*
------------------------------------------------------------------------------
 FUNCTION NAME: vad_tone_detection
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    st -- pointer to type vadState1 --  State struct
    t0 -- Word32 -- autocorrelation maxima
    t1 -- Word32 -- energy

 Outputs:
    st -- pointer to type vadState1 --  State struct
    pOverflow -- pointer to type Flag -- overflow indicator

 Returns:
    None

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 Purpose      : Set tone flag if pitch gain is high. This is used to detect
                signaling tones and other signals with high pitch gain.
 Inputs       : tone: flags indicating presence of a tone
 Outputs      : tone: flags indicating presence of a tone
------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 vad1.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE


------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void vad_tone_detection(
    vadState1 *st,    /* i/o : State struct                       */
    Word32 t0,        /* i   : autocorrelation maxima             */
    Word32 t1,        /* i   : energy                             */
    Flag  *pOverflow  /* o : Flag set when overflow occurs        */
)
{
    Word16 temp;
    /*
       if (t0 > TONE_THR * t1)
       set tone flag
       */
    temp = pv_round(t1, pOverflow);

    if ((temp > 0) && (L_msu(t0, temp, TONE_THR, pOverflow) > 0))
    {
        st->tone |= 0x4000;
    }
}


/*
------------------------------------------------------------------------------
 FUNCTION NAME: vad_tone_detection_update
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    one_lag_per_frame -- Word16 -- 1 if one open-loop lag is calculated per
                                   each frame, otherwise 0
    st -- pointer to type vadState1 --  State struct

 Outputs:
    st -- pointer to type vadState1 --  State struct
    pOverflow -- pointer to type Flag -- overflow indicator

 Returns:
    None

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 Purpose      : Update the tone flag register. Tone flags are shifted right
                by one bit. This function should be called from the speech
                encoder before call to Vad_tone_detection() function.

------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 vad1.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE


------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void vad_tone_detection_update(
    vadState1 *st,              /* i/o : State struct           */
    Word16 one_lag_per_frame,   /* i   : 1 if one open-loop lag */
    /*       is calculated per each */
    /*       frame, otherwise 0     */
    Flag *pOverflow             /* o   : Flags overflow         */
)
{
    /* Shift tone flags right by one bit */
    st->tone = shr(st->tone, 1, pOverflow);

    /* If open-loop lag is calculated only once in each frame, do extra update
       and assume that the other tone flag of the frame is one. */
    if (one_lag_per_frame != 0)
    {
        st->tone = shr(st->tone, 1, pOverflow);
        st->tone |= 0x2000;
    }
}


/*
------------------------------------------------------------------------------
 FUNCTION NAME: vad_pitch_detection
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    T_op -- array of type Word16 -- speech encoder open loop lags
    st -- pointer to type vadState1 --  State struct

 Outputs:
    st -- pointer to type vadState1 --  State struct
    pOverflow -- pointer to type Flag -- overflow indicator

 Returns:
    None

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 Purpose      : Test whether signal contains pitch or other periodic
                component.
 Return value : Boolean voiced / unvoiced decision in state variable

------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 vad1.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE


------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void vad_pitch_detection(
    vadState1 *st,    /* i/o : State struct                  */
    Word16 T_op[],    /* i   : speech encoder open loop lags */
    Flag  *pOverflow  /* o : Flag set when overflow occurs   */
)
{
    Word16 lagcount;
    Word16 i;
    Word16 temp;

    lagcount = 0;

    for (i = 0; i < 2; i++)
    {
        temp = sub(st->oldlag, T_op[i], pOverflow);
        temp = abs_s(temp);

        if (temp < LTHRESH)
        {
            lagcount = add(lagcount, 1, pOverflow);
        }

        /* Save the current LTP lag */
        st->oldlag = T_op[i];
    }

    /* Make pitch decision.
       Save flag of the pitch detection to the variable pitch.
       */
    st->pitch = shr(st->pitch, 1, pOverflow);

    temp =
        add(
            st->oldlag_count,
            lagcount,
            pOverflow);

    if (temp >= NTHRESH)
    {
        st->pitch |= 0x4000;
    }

    /* Update oldlagcount */
    st->oldlag_count = lagcount