restructure lfeplc_lev_dur main loop (1e92c06d) · Commits · IVAS Codec Public Collaboration / IVAS Codec

lib_dec/ivas_lfe_plc.c

+72 −1

Original line number	Diff line number	Diff line
		@@ -64,7 +64,7 @@
		#define EPS_STOP 1e-5
		#endif


		#if 0
		#ifndef NONE_BE_FIX_816_LFE_PLC_FLOAT
		/------------------------------------------------------------------------------------------
		* Static function declarations
		@@ -290,6 +290,77 @@ static int16_t lfeplc_lev_dur(

		return ( flag );
		}
		#else
		/---------------------------------------------------------------------
		* lfeplc_lev_dur()
		*
		* Wiener-Levinson-Durbin algorithm to compute LP parameters from the autocorrelations
		* of input signal
		---------------------------------------------------------------------/

		/! r: stability flag /
		static int16_t lfeplc_lev_dur(
		float a_out, / o : LP coefficients (a[0] = 1.0) */
		const float r, / i : vector of autocorrelations */
		const int16_t m /* i : order of LP filter */
		)
		{
		int16_t i, j, l;
		float buf[TCXLTP_LTP_ORDER];
		float rc; / reflection coefficients 0,...,m-1 */
		float s, at, err;
		float a[LFE_PLC_LPCORD + 1] = { 0.0f };

		set_f( a_out, 0.f, LFE_PLC_LPCORD + 1);
		rc = &buf[0];
		a[0] = 1.f;
		err = r[0];
		a_out[0] = a[0];
		rc[0] = ( -r[1] ) / r[0];
		s = r[1];
		a[1] = rc[0];
		a_out[1] = a[1];
		err += rc[0] * s;
		s += r[2] * a[1];
		rc[1] = ( -s ) / err;

		i = 2;
		while ( i < m )
		{
		for ( j = 1; j <= i / 2; j++ )
		{
		l = i - j;
		at = a[j] + rc[i - 1] * a[l];
		a[l] += rc[i - 1] * a[j];
		a[j] = at;
		}

		a[i] = rc[i - 1];
		err += rc[i - 1] * s;
		s = 0.f;
		i++;
		for ( j = 0; j < i; j++ )
		{
		s += r[i - j] * a[j];
		}
		rc[i - 1] = ( -s ) / err;
		if ( fabsf( rc[i - 1] ) > 0.99945f )
		{
		return 1;
		}
		else
		{
		for ( j = 0; j <= m; j++ )
		{
		a_out[j] = a[j];
		}
		}
		}

		return 0;
		}

		#endif

		#ifndef NONE_BE_FIX_816_LFE_PLC_FLOAT
		/-------------------------------------------------------------------