Commit ebe904dc authored by sagnowski's avatar sagnowski
Browse files

Simplify strong limiting logic

parent 2ad7a310

lib_com/options.h

+1 −0
Original line number Diff line number Diff line
@@ -156,6 +156,7 @@ 
#define FIX_890_ARRAY_SIZE                              /* Nokia: issue #890: mismatch in 2D array size declaration and use */

#define BE_FIX_887_GCC_WARNING_ARRAY_SIZE               /* VoiceAge: Issue 887: change array size definition to avoid warning with gcc 11.4.0 */

#define FIX_247_EXTERNAL_RENDERER_COMMAND_LINE          /* VA: issue 247: harmonize command-line options names of external renderer with the decoder */

#define BE_893_SIMPLIFY_STRONG_LIMITING_LOGIC



/* #################### End BE switches ################################## */

lib_rend/ivas_limiter.c

+45 −1
Original line number Diff line number Diff line
@@ -51,9 +51,37 @@ static int16_t detect_strong_saturations( 
    const int16_t BER_detect,       /* i  : BER detect flag                 */

    int16_t *strong_saturation_cnt, /* i/o: counter of strong saturations   */

    const float max_val,            /* i  : maximum absolute value          */

#ifdef BE_893_SIMPLIFY_STRONG_LIMITING_LOGIC

    const float *frame_gain /* i  : frame gain value                */

#else

    float *frame_gain /* i/o: frame gain value                */

#endif

)

{

#ifdef BE_893_SIMPLIFY_STRONG_LIMITING_LOGIC

    if ( BER_detect )

    {

        *strong_saturation_cnt = 50;

    }

    else if ( max_val > 3 * IVAS_LIMITER_THRESHOLD && *strong_saturation_cnt > 0 )

    {

        /* strong_saturation_cnt stays unchanged.

         * `if` condition still needs to be checked to avoid reaching the final `else` clause*/

    }

    else if ( max_val > 10 * IVAS_LIMITER_THRESHOLD )

    {

        *strong_saturation_cnt += 20;

        *strong_saturation_cnt = min( *strong_saturation_cnt, 50 );

    }

    else

    {

        ( *strong_saturation_cnt )--;

        *strong_saturation_cnt = max( *strong_saturation_cnt, 0 );

        return 0;

    }



    return *frame_gain < 0.3f;

#else

    int16_t apply_strong_limiting;



    apply_strong_limiting = 0;
@@ -92,6 +120,7 @@ static int16_t detect_strong_saturations( 
    }



    return apply_strong_limiting;

#endif

}



/*-------------------------------------------------------------------*
@@ -328,12 +357,27 @@ void limiter_process( 
        apply_strong_limiting = detect_strong_saturations( BER_detect, strong_saturation_cnt, max_val, &frame_gain );

    }



#ifdef BE_893_SIMPLIFY_STRONG_LIMITING_LOGIC

    /* Apply strong limiting? */

    if ( apply_strong_limiting )

    {

        frame_gain /= 3.0f;

    }

    /* ...otherwise limit gain reduction to 20dB. Any peaks that require gain reduction

     * higher than this are most likely due to bit errors during decoding and should have

     * been handled by the strong limiting mechanism */

    else if ( frame_gain < 0.1f )

    {

        frame_gain = 0.1f;

    }

#else

    /* Limit gain reduction to 20dB. Any peaks that require gain reduction

     * higher than this are most likely due to bit errors during decoding */

    if ( frame_gain < 0.1f && !apply_strong_limiting )

    {

        frame_gain = 0.1f;

    }

#endif



    if ( apply_limiting )

    {