add channel re-ordering tables (b0d818ec) · Commits · IVAS Codec Public Collaboration / IVAS Codec

lib_util/ambi_cenvert.c

+77 −2

Original line number	Diff line number	Diff line
		@@ -54,6 +54,10 @@

		#define AMBI_MAX_CHANNELS 16

		/* --------------------------------
		normalization conversion tables
		-------------------------------- */

		static const float N3D_SN3D[AMBI_MAX_CHANNELS] = { 1.0f,
		SQRT_3, SQRT_3, SQRT_3,
		SQRT_5, SQRT_5, SQRT_5, SQRT_5, SQRT_5,
		@@ -77,6 +81,40 @@ static const float SN3D_MAXN[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_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 };

		/* ----------------------------
		channel re-ordering tables
		---------------------------- */

		static const int16_t REORDER_FM_ACN[AMBI_MAX_CHANNELS] = { 0,
		2, 3, 1,
		8, 6, 4, 5, 7,
		15, 13, 11, 9, 10, 12, 14
		};

		static const int16_t REORDER_SID_ACN[AMBI_MAX_CHANNELS] = { 0,
		2, 3, 1,
		5, 7, 8, 6, 4,
		10, 12, 14, 15, 13, 11, 9
		};

		static const int16_t REORDER_ACN_FM[AMBI_MAX_CHANNELS] = { 0,
		3, 1, 2,
		6, 7, 5, 8, 4,
		12, 13, 11, 14, 10, 15, 9
		};

		static const int16_t REORDER_ACN_SID[AMBI_MAX_CHANNELS] = { 0,
		3, 1, 2,
		8, 4, 7, 5, 6,
		15, 9, 14, 10, 13, 11, 12
		};


		/* ----------------------------------
		API functions for the conversion
		---------------------------------- */


		int16_t convert_ambi_format( float in[][L_FRAME48k], float out[][L_FRAME48k], int16_t order, AMBI_FMT in_format, AMBI_FMT out_format )
		{
		assert( order <= 3 );
		@@ -143,7 +181,9 @@ int16_t renormalize_channels( float in[][L_FRAME48k], float out[][L_FRAME48k], i
		{
		int16_t n_chan = ( order + 1 ) * ( order + 1 );
		int16_t i_chan, i;
		float *conversion_table;
		const 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 )
		{
		@@ -180,7 +220,6 @@ int16_t renormalize_channels( float in[][L_FRAME48k], float out[][L_FRAME48k], i
		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];
		@@ -196,6 +235,42 @@ int16_t renormalize_channels( float in[][L_FRAME48k], float out[][L_FRAME48k], i
		int16_t reorder_channels( float in[][L_FRAME48k], float out[][L_FRAME48k], int16_t order, AMBI_CHANNEL_ORDER in_format, AMBI_CHANNEL_ORDER out_format )
		{
		int16_t nchan = ( order + 1 ) * ( order + 1 );
		int16_t *idx_table;

		if ( in_format == AMBI_CHANNEL_ORDER_ACN )
		{
		if ( out_format == AMBI_CHANNEL_ORDER_FM )
		{
		idx_table = REORDER_ACN_FM;
		}
		if ( out_format == AMBI_CHANNEL_ORDER_SID )
		{
		idx_table = REORDER_ACN_SID;
		}
		else
		{
		assert( 0 && "Unsupported conversion" );
		}
		}
		else if ( out_format == AMBI_CHANNEL_ORDER_ACN )
		{
		if ( in_format == AMBI_CHANNEL_ORDER_FM )
		{
		idx_table = REORDER_ACN_FM;
		}
		if ( in_format == AMBI_CHANNEL_ORDER_SID )
		{
		idx_table = REORDER_ACN_SID;
		}
		else
		{
		assert( 0 && "Unsupported conversion" );
		}
		}
		else
		{
		assert( 0 && "Conversion only supported to and from ACN-SN3D" );
		}

		return 0;
		}