diff options
Diffstat (limited to 'silk/fixed/burg_modified_FIX.c')
-rw-r--r-- | silk/fixed/burg_modified_FIX.c | 218 |
1 files changed, 109 insertions, 109 deletions
diff --git a/silk/fixed/burg_modified_FIX.c b/silk/fixed/burg_modified_FIX.c index 4878553b..7d072a46 100644 --- a/silk/fixed/burg_modified_FIX.c +++ b/silk/fixed/burg_modified_FIX.c @@ -34,7 +34,7 @@ POSSIBILITY OF SUCH DAMAGE. #include "tuning_parameters.h" #include "pitch.h" -#define MAX_FRAME_SIZE 384 /* subfr_length * nb_subfr = ( 0.005 * 16000 + 16 ) * 4 = 384 */ +/* This code implements the method from https://www.opus-codec.org/docs/vos_fastburg.pdf */ #define QA 25 #define N_BITS_HEAD_ROOM 2 @@ -54,45 +54,44 @@ void silk_burg_modified_c( int arch /* I Run-time architecture */ ) { - opus_int k, n, s, lz, rshifts, reached_max_gain; + opus_int k, n, s, lz, rshifts, rshifts_extra, reached_max_gain; opus_int32 C0, num, nrg, rc_Q31, invGain_Q30, Atmp_QA, Atmp1, tmp1, tmp2, x1, x2; const opus_int16 *x_ptr; - opus_int32 C_first_row[ SILK_MAX_ORDER_LPC ]; - opus_int32 C_last_row[ SILK_MAX_ORDER_LPC ]; - opus_int32 Af_QA[ SILK_MAX_ORDER_LPC ]; - opus_int32 CAf[ SILK_MAX_ORDER_LPC + 1 ]; - opus_int32 CAb[ SILK_MAX_ORDER_LPC + 1 ]; - opus_int32 xcorr[ SILK_MAX_ORDER_LPC ]; - opus_int64 C0_64; - - silk_assert( subfr_length * nb_subfr <= MAX_FRAME_SIZE ); + opus_int32 Af_QA[ SILK_MAX_ORDER_LPC ]; + opus_int32 g[ SILK_MAX_ORDER_LPC + 1 ]; + opus_int32 c[ SILK_MAX_ORDER_LPC + 1 ]; /* Compute autocorrelations, added over subframes */ - C0_64 = silk_inner_prod16_aligned_64( x, x, subfr_length*nb_subfr, arch ); - lz = silk_CLZ64(C0_64); - rshifts = 32 + 1 + N_BITS_HEAD_ROOM - lz; - if (rshifts > MAX_RSHIFTS) rshifts = MAX_RSHIFTS; - if (rshifts < MIN_RSHIFTS) rshifts = MIN_RSHIFTS; - - if (rshifts > 0) { - C0 = (opus_int32)silk_RSHIFT64(C0_64, rshifts ); + silk_sum_sqr_shift( &C0, &rshifts, x, nb_subfr * subfr_length ); + if( rshifts > MAX_RSHIFTS ) { + C0 = silk_LSHIFT32( C0, rshifts - MAX_RSHIFTS ); + silk_assert( C0 > 0 ); + rshifts = MAX_RSHIFTS; } else { - C0 = silk_LSHIFT32((opus_int32)C0_64, -rshifts ); + lz = silk_CLZ32( C0 ) - 1; + rshifts_extra = N_BITS_HEAD_ROOM - lz; + if( rshifts_extra > 0 ) { + rshifts_extra = silk_min( rshifts_extra, MAX_RSHIFTS - rshifts ); + C0 = silk_RSHIFT32( C0, rshifts_extra ); + } else { + rshifts_extra = silk_max( rshifts_extra, MIN_RSHIFTS - rshifts ); + C0 = silk_LSHIFT32( C0, -rshifts_extra ); + } + rshifts += rshifts_extra; } - - CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ) + 1; /* Q(-rshifts) */ - silk_memset( C_first_row, 0, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) ); + silk_memset( c, 0, (D+1) * sizeof( opus_int32 ) ); if( rshifts > 0 ) { for( s = 0; s < nb_subfr; s++ ) { x_ptr = x + s * subfr_length; for( n = 1; n < D + 1; n++ ) { - C_first_row[ n - 1 ] += (opus_int32)silk_RSHIFT64( + c[ n ] += (opus_int32)silk_RSHIFT64( silk_inner_prod16_aligned_64( x_ptr, x_ptr + n, subfr_length - n, arch ), rshifts ); } } } else { for( s = 0; s < nb_subfr; s++ ) { int i; + opus_int32 xcorr[ SILK_MAX_ORDER_LPC ]; opus_int32 d; x_ptr = x + s * subfr_length; celt_pitch_xcorr(x_ptr, x_ptr + 1, xcorr, subfr_length - D, D, arch ); @@ -102,23 +101,50 @@ void silk_burg_modified_c( xcorr[ n - 1 ] += d; } for( n = 1; n < D + 1; n++ ) { - C_first_row[ n - 1 ] += silk_LSHIFT32( xcorr[ n - 1 ], -rshifts ); + c[ n ] += silk_LSHIFT32( xcorr[ n - 1 ], -rshifts ); } } } - silk_memcpy( C_last_row, C_first_row, SILK_MAX_ORDER_LPC * sizeof( opus_int32 ) ); - /* Initialize */ - CAb[ 0 ] = CAf[ 0 ] = C0 + silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ) + 1; /* Q(-rshifts) */ + /* Multiply all correlations by 2 */ + rshifts++; - invGain_Q30 = (opus_int32)1 << 30; + /* Initialize */ + c[ 0 ] = C0 + silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ) + 1; /* Q(-rshifts) */ + g[ 0 ] = c[ 0 ]; /* Q(-rshifts) */ + tmp1 = 0; + if( rshifts > -N_BITS_HEAD_ROOM ) { + for( s = 0; s < nb_subfr; s++ ) { + x_ptr = x + s * subfr_length; + x1 = x_ptr[ 0 ]; + x2 = x_ptr[ subfr_length - 1 ]; + tmp1 = silk_SMLAWB( tmp1, silk_LSHIFT32( x1, 16 - rshifts ), x1 ); /* Q(-rshifts) */ + tmp1 = silk_SMLAWB( tmp1, silk_LSHIFT32( x2, 16 - rshifts ), x2 ); /* Q(-rshifts) */ + } + } else { + for( s = 0; s < nb_subfr; s++ ) { + x_ptr = x + s * subfr_length; + x1 = x_ptr[ 0 ]; + x2 = x_ptr[ subfr_length - 1 ]; + tmp1 = silk_MLA( tmp1, silk_LSHIFT32( x1, -rshifts ), x1 ); /* Q(-rshifts) */ + tmp1 = silk_MLA( tmp1, silk_LSHIFT32( x2, -rshifts ), x2 ); /* Q(-rshifts) */ + } + } + g[ 0 ] -= tmp1; + g[ 1 ] = c[ 1 ]; + silk_assert( g[ 1 ] < g[ 0 ] && g[ 1 ] > -g[ 0 ] ); + rc_Q31 = -silk_DIV32_varQ( g[ 1 ], g[ 0 ], 31 ); + Af_QA[ 0 ] = silk_RSHIFT32( rc_Q31, 31 - QA ); /* QA */ + invGain_Q30 = SILK_FIX_CONST( 1, 30 ) - silk_SMMUL( rc_Q31, rc_Q31 ); reached_max_gain = 0; - for( n = 0; n < D; n++ ) { - /* Update first row of correlation matrix (without first element) */ - /* Update last row of correlation matrix (without last element, stored in reversed order) */ - /* Update C * Af */ - /* Update C * flipud(Af) (stored in reversed order) */ - if( rshifts > -2 ) { + for( n = 1; n < D; n++ ) { + for( k = 0; k < (n >> 1) + 1; k++ ) { + tmp1 = g[ k ]; + tmp2 = g[ n - k ]; + g[ k ] = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 ); /* Q(-rshifts) */ + g[ n - k ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 ); /* Q(-rshifts) */ + } + if( rshifts > -N_BITS_HEAD_ROOM ) { for( s = 0; s < nb_subfr; s++ ) { x_ptr = x + s * subfr_length; x1 = -silk_LSHIFT32( (opus_int32)x_ptr[ n ], 16 - rshifts ); /* Q(16-rshifts) */ @@ -126,29 +152,29 @@ void silk_burg_modified_c( tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ], QA - 16 ); /* Q(QA-16) */ tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], QA - 16 ); /* Q(QA-16) */ for( k = 0; k < n; k++ ) { - C_first_row[ k ] = silk_SMLAWB( C_first_row[ k ], x1, x_ptr[ n - k - 1 ] ); /* Q( -rshifts ) */ - C_last_row[ k ] = silk_SMLAWB( C_last_row[ k ], x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts ) */ + c[ k + 1 ] = silk_SMLAWB( silk_SMLAWB( c[ k + 1 ], x1, x_ptr[ n - k - 1 ] ), /* Q( -rshifts ) */ + x2, x_ptr[ subfr_length - n + k ] ); Atmp_QA = Af_QA[ k ]; tmp1 = silk_SMLAWB( tmp1, Atmp_QA, x_ptr[ n - k - 1 ] ); /* Q(QA-16) */ tmp2 = silk_SMLAWB( tmp2, Atmp_QA, x_ptr[ subfr_length - n + k ] ); /* Q(QA-16) */ } - tmp1 = silk_LSHIFT32( -tmp1, 32 - QA - rshifts ); /* Q(16-rshifts) */ + tmp1 = silk_LSHIFT32( -tmp1, 32 - QA - rshifts ); /* Q(16-rshifts) */ tmp2 = silk_LSHIFT32( -tmp2, 32 - QA - rshifts ); /* Q(16-rshifts) */ for( k = 0; k <= n; k++ ) { - CAf[ k ] = silk_SMLAWB( CAf[ k ], tmp1, x_ptr[ n - k ] ); /* Q( -rshift ) */ - CAb[ k ] = silk_SMLAWB( CAb[ k ], tmp2, x_ptr[ subfr_length - n + k - 1 ] ); /* Q( -rshift ) */ + g[ k ] = silk_SMLAWB( silk_SMLAWB( g[ k ], tmp1, x_ptr[ n - k ] ), /* Q( -rshift ) */ + tmp2, x_ptr[ subfr_length - n + k - 1 ] ); } } } else { for( s = 0; s < nb_subfr; s++ ) { x_ptr = x + s * subfr_length; - x1 = -silk_LSHIFT32( (opus_int32)x_ptr[ n ], -rshifts ); /* Q( -rshifts ) */ + x1 = -silk_LSHIFT32( (opus_int32)x_ptr[ n ], -rshifts ); /* Q( -rshifts ) */ x2 = -silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], -rshifts ); /* Q( -rshifts ) */ tmp1 = silk_LSHIFT32( (opus_int32)x_ptr[ n ], 17 ); /* Q17 */ tmp2 = silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n - 1 ], 17 ); /* Q17 */ for( k = 0; k < n; k++ ) { - C_first_row[ k ] = silk_MLA( C_first_row[ k ], x1, x_ptr[ n - k - 1 ] ); /* Q( -rshifts ) */ - C_last_row[ k ] = silk_MLA( C_last_row[ k ], x2, x_ptr[ subfr_length - n + k ] ); /* Q( -rshifts ) */ + c[ k + 1 ] = silk_MLA( silk_MLA( c[ k + 1 ], x1, x_ptr[ n - k - 1 ] ), /* Q( -rshifts ) */ + x2, x_ptr[ subfr_length - n + k ] ); Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 17 ); /* Q17 */ tmp1 = silk_MLA( tmp1, x_ptr[ n - k - 1 ], Atmp1 ); /* Q17 */ tmp2 = silk_MLA( tmp2, x_ptr[ subfr_length - n + k ], Atmp1 ); /* Q17 */ @@ -156,53 +182,47 @@ void silk_burg_modified_c( tmp1 = -tmp1; /* Q17 */ tmp2 = -tmp2; /* Q17 */ for( k = 0; k <= n; k++ ) { - CAf[ k ] = silk_SMLAWW( CAf[ k ], tmp1, - silk_LSHIFT32( (opus_int32)x_ptr[ n - k ], -rshifts - 1 ) ); /* Q( -rshift ) */ - CAb[ k ] = silk_SMLAWW( CAb[ k ], tmp2, - silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n + k - 1 ], -rshifts - 1 ) ); /* Q( -rshift ) */ + g[ k ] = silk_SMLAWW( silk_SMLAWW( g[ k ], /* Q( -rshift ) */ + tmp1, silk_LSHIFT32( (opus_int32)x_ptr[ n - k ], -rshifts - 1 ) ), + tmp2, silk_LSHIFT32( (opus_int32)x_ptr[ subfr_length - n + k - 1 ], -rshifts - 1 ) ); } } } /* Calculate nominator and denominator for the next order reflection (parcor) coefficient */ - tmp1 = C_first_row[ n ]; /* Q( -rshifts ) */ - tmp2 = C_last_row[ n ]; /* Q( -rshifts ) */ + tmp1 = c[ n + 1 ]; /* Q( -rshifts ) */ num = 0; /* Q( -rshifts ) */ - nrg = silk_ADD32( CAb[ 0 ], CAf[ 0 ] ); /* Q( 1-rshifts ) */ + nrg = g[ 0 ]; /* Q( -rshifts ) */ for( k = 0; k < n; k++ ) { Atmp_QA = Af_QA[ k ]; lz = silk_CLZ32( silk_abs( Atmp_QA ) ) - 1; lz = silk_min( 32 - QA, lz ); Atmp1 = silk_LSHIFT32( Atmp_QA, lz ); /* Q( QA + lz ) */ - - tmp1 = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( C_last_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ - tmp2 = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( C_first_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ - num = silk_ADD_LSHIFT32( num, silk_SMMUL( CAb[ n - k ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ - nrg = silk_ADD_LSHIFT32( nrg, silk_SMMUL( silk_ADD32( CAb[ k + 1 ], CAf[ k + 1 ] ), - Atmp1 ), 32 - QA - lz ); /* Q( 1-rshifts ) */ + tmp1 = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( c[ n - k ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ + num = silk_ADD_LSHIFT32( num, silk_SMMUL( g[ n - k ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ + nrg = silk_ADD_LSHIFT32( nrg, silk_SMMUL( g[ k + 1 ], Atmp1 ), 32 - QA - lz ); /* Q( -rshifts ) */ } - CAf[ n + 1 ] = tmp1; /* Q( -rshifts ) */ - CAb[ n + 1 ] = tmp2; /* Q( -rshifts ) */ - num = silk_ADD32( num, tmp2 ); /* Q( -rshifts ) */ - num = silk_LSHIFT32( -num, 1 ); /* Q( 1-rshifts ) */ + g[ n + 1 ] = tmp1; /* Q( -rshifts ) */ + num = silk_ADD32( num, tmp1 ); /* Q( -rshifts ) */ + silk_assert( nrg > 0 ); /* Calculate the next order reflection (parcor) coefficient */ if( silk_abs( num ) < nrg ) { - rc_Q31 = silk_DIV32_varQ( num, nrg, 31 ); + rc_Q31 = -silk_DIV32_varQ( num, nrg, 31 ); } else { - rc_Q31 = ( num > 0 ) ? silk_int32_MAX : silk_int32_MIN; + rc_Q31 = ( num > 0 ) ? silk_int32_MIN : silk_int32_MAX; } /* Update inverse prediction gain */ - tmp1 = ( (opus_int32)1 << 30 ) - silk_SMMUL( rc_Q31, rc_Q31 ); + tmp1 = SILK_FIX_CONST( 1, 30 ) - silk_SMMUL( rc_Q31, rc_Q31 ); tmp1 = silk_LSHIFT( silk_SMMUL( invGain_Q30, tmp1 ), 2 ); if( tmp1 <= minInvGain_Q30 ) { /* Max prediction gain exceeded; set reflection coefficient such that max prediction gain is exactly hit */ - tmp2 = ( (opus_int32)1 << 30 ) - silk_DIV32_varQ( minInvGain_Q30, invGain_Q30, 30 ); /* Q30 */ - rc_Q31 = silk_SQRT_APPROX( tmp2 ); /* Q15 */ + tmp2 = SILK_FIX_CONST( 1, 30 ) - silk_DIV32_varQ( minInvGain_Q30, invGain_Q30, 30 ); /* Q30 */ + rc_Q31 = silk_SQRT_APPROX( tmp2 ); /* Q15 */ /* Newton-Raphson iteration */ - rc_Q31 = silk_RSHIFT32( rc_Q31 + silk_DIV32( tmp2, rc_Q31 ), 1 ); /* Q15 */ - rc_Q31 = silk_LSHIFT32( rc_Q31, 16 ); /* Q31 */ + rc_Q31 = silk_RSHIFT32( rc_Q31 + silk_DIV32( tmp2, rc_Q31 ), 1 ); /* Q15 */ + rc_Q31 = silk_LSHIFT32( rc_Q31, 16 ); /* Q31 */ if( num < 0 ) { /* Ensure adjusted reflection coefficients has the original sign */ rc_Q31 = -rc_Q31; @@ -215,12 +235,12 @@ void silk_burg_modified_c( /* Update the AR coefficients */ for( k = 0; k < (n + 1) >> 1; k++ ) { - tmp1 = Af_QA[ k ]; /* QA */ - tmp2 = Af_QA[ n - k - 1 ]; /* QA */ - Af_QA[ k ] = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 ); /* QA */ - Af_QA[ n - k - 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 ); /* QA */ + tmp1 = Af_QA[ k ]; /* QA */ + tmp2 = Af_QA[ n - k - 1 ]; /* QA */ + Af_QA[ k ] = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 ); /* QA */ + Af_QA[ n - k - 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 ); /* QA */ } - Af_QA[ n ] = silk_RSHIFT32( rc_Q31, 31 - QA ); /* QA */ + Af_QA[ n ] = silk_RSHIFT32( rc_Q31, 31 - QA ); /* QA */ if( reached_max_gain ) { /* Reached max prediction gain; set remaining coefficients to zero and exit loop */ @@ -229,47 +249,27 @@ void silk_burg_modified_c( } break; } - - /* Update C * Af and C * Ab */ - for( k = 0; k <= n + 1; k++ ) { - tmp1 = CAf[ k ]; /* Q( -rshifts ) */ - tmp2 = CAb[ n - k + 1 ]; /* Q( -rshifts ) */ - CAf[ k ] = silk_ADD_LSHIFT32( tmp1, silk_SMMUL( tmp2, rc_Q31 ), 1 ); /* Q( -rshifts ) */ - CAb[ n - k + 1 ] = silk_ADD_LSHIFT32( tmp2, silk_SMMUL( tmp1, rc_Q31 ), 1 ); /* Q( -rshifts ) */ - } } - if( reached_max_gain ) { - for( k = 0; k < D; k++ ) { - /* Scale coefficients */ - A_Q16[ k ] = -silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 ); - } - /* Subtract energy of preceding samples from C0 */ - if( rshifts > 0 ) { - for( s = 0; s < nb_subfr; s++ ) { - x_ptr = x + s * subfr_length; - C0 -= (opus_int32)silk_RSHIFT64( silk_inner_prod16_aligned_64( x_ptr, x_ptr, D, arch ), rshifts ); - } - } else { - for( s = 0; s < nb_subfr; s++ ) { - x_ptr = x + s * subfr_length; - C0 -= silk_LSHIFT32( silk_inner_prod_aligned( x_ptr, x_ptr, D, arch), -rshifts); - } + for( k = 0; k < D; k++ ) { + /* Scale coefficients */ + A_Q16[ k ] = -silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 ); + } + + /* Subtract energy of preceding samples from C0 */ + rshifts--; /* divide c0 by two */ + if( rshifts > 0 ) { + for( s = 0; s < nb_subfr; s++ ) { + x_ptr = x + s * subfr_length; + C0 -= (opus_int32)silk_RSHIFT64( silk_inner_prod16_aligned_64( x_ptr, x_ptr, D, arch ), rshifts ); } - /* Approximate residual energy */ - *res_nrg = silk_LSHIFT( silk_SMMUL( invGain_Q30, C0 ), 2 ); - *res_nrg_Q = -rshifts; } else { - /* Return residual energy */ - nrg = CAf[ 0 ]; /* Q( -rshifts ) */ - tmp1 = (opus_int32)1 << 16; /* Q16 */ - for( k = 0; k < D; k++ ) { - Atmp1 = silk_RSHIFT_ROUND( Af_QA[ k ], QA - 16 ); /* Q16 */ - nrg = silk_SMLAWW( nrg, CAf[ k + 1 ], Atmp1 ); /* Q( -rshifts ) */ - tmp1 = silk_SMLAWW( tmp1, Atmp1, Atmp1 ); /* Q16 */ - A_Q16[ k ] = -Atmp1; + for( s = 0; s < nb_subfr; s++ ) { + x_ptr = x + s * subfr_length; + C0 -= silk_LSHIFT32( silk_inner_prod_aligned( x_ptr, x_ptr, D, arch), -rshifts); } - *res_nrg = silk_SMLAWW( nrg, silk_SMMUL( SILK_FIX_CONST( FIND_LPC_COND_FAC, 32 ), C0 ), -tmp1 );/* Q( -rshifts ) */ - *res_nrg_Q = -rshifts; } + /* Approximate residual energy */ + *res_nrg = silk_LSHIFT( silk_SMMUL( invGain_Q30, C0 ), 2 ); + *res_nrg_Q = -rshifts; } |