Commit 7cf0c276 authored by Dominik Weckbecker's avatar Dominik Weckbecker 💬
Browse files

add more conversion tables

parent f612094a

lib_util/ambi_cenvert.c

+65 −2
Original line number Diff line number Diff line
@@ -42,6 +42,16 @@ 
#define INV_SQRT_5 0.4472135f

#define INV_SQRT_7 0.3779644f



#define TWO_OVER_SQRT_3 1.1547005f

#define SQRT_8_OVER_5   1.2649110f

#define SQRT_3_OVER_5   0.7745966f

#define SQRT_45_OVER_32 1.1858541f



#define INV_TWO_OVER_SQRT_3 0.8660254f

#define INV_SQRT_8_OVER_5   0.7905694f

#define INV_SQRT_3_OVER_5   1.2909944f

#define INV_SQRT_45_OVER_32 0.8432740f



#define AMBI_MAX_CHANNELS 16



static const float N3D_SN3D[AMBI_MAX_CHANNELS] = { 1.0f,
@@ -56,7 +66,16 @@ static const float SN3D_N3D[AMBI_MAX_CHANNELS] = { 1.0f, 
                                                   INV_SQRT_7, INV_SQRT_7, INV_SQRT_7, INV_SQRT_7, INV_SQRT_7, INV_SQRT_7, INV_SQRT_7 

};



static const float MAXN_SN3D[AMBI_MAX_CHANNELS] = { 1.0f,

                                                    1.0f, 1.0f, 1.0f,

                                                    TWO_OVER_SQRT_3, TWO_OVER_SQRT_3, 1, TWO_OVER_SQRT_3, TWO_OVER_SQRT_3,

                                                    SQRT_8_OVER_5, SQRT_3_OVER_5, SQRT_45_OVER_32, 1, SQRT_45_OVER_32, SQRT_3_OVER_5, SQRT_8_OVER_5 

};



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

                                                    1.0f, 1.0f, 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_SQRT_3_OVER_5, INV_SQRT_45_OVER_32, 1.0f, INV_SQRT_45_OVER_32, INV_SQRT_3_OVER_5, INV_SQRT_8_OVER_5 };



int16_t convert_ambi_format( float in[][L_FRAME48k], float out[][L_FRAME48k], int16_t order, AMBI_FMT in_format, AMBI_FMT out_format )

{
@@ -122,10 +141,54 @@ int16_t convert_ambi_format( float in[][L_FRAME48k], float out[][L_FRAME48k], in 


int16_t renormalize_channels( float in[][L_FRAME48k], float out[][L_FRAME48k], int16_t order, AMBI_CHANNEL_NORM in_format, AMBI_CHANNEL_NORM out_format )

{

    int16_t nchan = ( order + 1 ) * ( order + 1 );

    int16_t n_chan = ( order + 1 ) * ( order + 1 );

    int16_t i_chan, i;

    float *conversion_table;



	/* conversion factors are aplpied on the channels assuming that they are still/already in ACN order */

	if ( in_format == AMBI_NORM_SN3D )

    {

		if ( out_format == AMBI_NORM_N3D )

		{

			conversion_table = SN3D_N3D;

		}

        if ( out_format == AMBI_NORM_MAXN )

        {

            conversion_table = SN3D_MAXN;

        }

        else

        {

            assert( 0 && "Unsupported conversion" );

        }

	}

	else if ( out_format == AMBI_NORM_SN3D )

	{

        if ( in_format == AMBI_NORM_N3D )

        {

            conversion_table = N3D_SN3D;

        }

        if ( in_format == AMBI_NORM_MAXN )

        {

            conversion_table = MAXN_SN3D;

        }

        else

        {

            assert( 0 && "Unsupported conversion" );

        }

	}

    else

    {

        assert( 0 && "Conversion only supported to and from ACN-SN3D" );

    }



	/* conversion factors are aplpied on the channels assuming that they are still/already in ACN order */

	for (i_chan = 0; i_chan < n_chan; i_chan++)

	{

		float conversion_factor = conversion_table[i_chan];

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

		{

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

		}

	}



    return 0;

}