Commit fdcaee46 authored by Dominik Weckbecker's avatar Dominik Weckbecker 💬
Browse files

do not scale down channels in format conversions

parent b5db8f0f

lib_util/ambi_convert.c

+1 −18
Original line number Diff line number Diff line
@@ -73,9 +73,6 @@ static const float N3D_SN3D[AMBI_MAX_CHANNELS] = { 1.0f, 
                                                   INV_SQRT_5_, INV_SQRT_5_, INV_SQRT_5_, INV_SQRT_5_, INV_SQRT_5_,

                                                   INV_SQRT_7_, INV_SQRT_7_, INV_SQRT_7_, INV_SQRT_7_, INV_SQRT_7_, INV_SQRT_7_, INV_SQRT_7_ };



static const float N3D_SN3D_SCALING_FACTOR = 1.0f;

static const float SN3D_N3D_SCALING_FACTOR = INV_SQRT_7_;





static const float SN3D_MAXN[AMBI_MAX_CHANNELS] = { 1.0f,

                                                    1.0f, 1.0f, 1.0f,
@@ -87,10 +84,6 @@ static const float MAXN_SN3D[AMBI_MAX_CHANNELS] = { 1.0f, 
                                                    INV_TWO_OVER_SQRT_3_, INV_TWO_OVER_SQRT_3_, 1.0f, INV_TWO_OVER_SQRT_3_, INV_TWO_OVER_SQRT_3_,

                                                    INV_SQRT_8_OVER_5_, INV_THREE_OVER_SQRT_5_, INV_SQRT_45_OVER_32_, 1.0f, INV_SQRT_45_OVER_32_, INV_THREE_OVER_SQRT_5_, INV_SQRT_8_OVER_5_ };



static const float MAXN_SN3D_SCALING_FACTOR = 1.0f;

static const float SN3D_MAXN_SCALING_FACTOR = INV_THREE_OVER_SQRT_5_;





static const float SN3D_FM[AMBI_MAX_CHANNELS] = { INV_SQRT_2,

                                                  1.0f, 1.0f, 1.0f,

                                                  TWO_OVER_SQRT_3_, TWO_OVER_SQRT_3_, 1.0f, TWO_OVER_SQRT_3_, TWO_OVER_SQRT_3_,
@@ -101,10 +94,6 @@ static const float FM_SN3D[AMBI_MAX_CHANNELS] = { SQRT_2_, 
                                                  INV_TWO_OVER_SQRT_3_, INV_TWO_OVER_SQRT_3_, 1.0f, INV_TWO_OVER_SQRT_3_, INV_TWO_OVER_SQRT_3_,

                                                  INV_SQRT_8_OVER_5_, INV_THREE_OVER_SQRT_5_, INV_SQRT_45_OVER_32_, 1.0f, INV_SQRT_45_OVER_32_, INV_THREE_OVER_SQRT_5_, INV_SQRT_8_OVER_5_ };



static const float FM_SN3D_SCALING_FACTOR = INV_SQRT_2;

static const float SN3D_FM_SCALING_FACTOR = INV_THREE_OVER_SQRT_5_;





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

    channel re-ordering tables

   ---------------------------- */
@@ -236,17 +225,14 @@ int16_t renormalize_channels( float *in[], float *out[], int16_t order, AMBI_CHA 
        if ( out_format == AMBI_NORM_N3D )

        {

            conversion_table = SN3D_N3D;

            sf = SN3D_N3D_SCALING_FACTOR;

        }

        else if ( out_format == AMBI_NORM_MAXN )

        {

            conversion_table = SN3D_MAXN;

            sf = SN3D_MAXN_SCALING_FACTOR;

        }

        else if ( out_format == AMBI_NORM_FM )

        {

            conversion_table = SN3D_FM;

            sf = SN3D_FM_SCALING_FACTOR;

        }

        else

        {
@@ -258,17 +244,14 @@ int16_t renormalize_channels( float *in[], float *out[], int16_t order, AMBI_CHA 
        if ( in_format == AMBI_NORM_N3D )

        {

            conversion_table = N3D_SN3D;

            sf = N3D_SN3D_SCALING_FACTOR;

        }

        else if ( in_format == AMBI_NORM_MAXN )

        {

            conversion_table = MAXN_SN3D;

            sf = MAXN_SN3D_SCALING_FACTOR;

        }

        else if ( in_format == AMBI_NORM_FM )

        {

            conversion_table = FM_SN3D;

            sf = FM_SN3D_SCALING_FACTOR;

        }

        else

        {
@@ -286,7 +269,7 @@ int16_t renormalize_channels( float *in[], float *out[], int16_t order, AMBI_CHA 
        float conversion_factor = conversion_table[i_chan];

        for ( i = 0; i < L_FRAME48k; i++ )

        {

            out[i_chan][i] = sf * in[i_chan][i] * conversion_factor;

            out[i_chan][i] = in[i_chan][i] * conversion_factor;

        }

    }