1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/silk/stereo_MS_to_LR.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,85 @@
1.4 +/***********************************************************************
1.5 +Copyright (c) 2006-2011, Skype Limited. All rights reserved.
1.6 +Redistribution and use in source and binary forms, with or without
1.7 +modification, are permitted provided that the following conditions
1.8 +are met:
1.9 +- Redistributions of source code must retain the above copyright notice,
1.10 +this list of conditions and the following disclaimer.
1.11 +- Redistributions in binary form must reproduce the above copyright
1.12 +notice, this list of conditions and the following disclaimer in the
1.13 +documentation and/or other materials provided with the distribution.
1.14 +- Neither the name of Internet Society, IETF or IETF Trust, nor the
1.15 +names of specific contributors, may be used to endorse or promote
1.16 +products derived from this software without specific prior written
1.17 +permission.
1.18 +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.19 +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.20 +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.21 +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
1.22 +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.23 +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.24 +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.25 +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.26 +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.27 +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.28 +POSSIBILITY OF SUCH DAMAGE.
1.29 +***********************************************************************/
1.30 +
1.31 +#ifdef HAVE_CONFIG_H
1.32 +#include "config.h"
1.33 +#endif
1.34 +
1.35 +#include "main.h"
1.36 +
1.37 +/* Convert adaptive Mid/Side representation to Left/Right stereo signal */
1.38 +void silk_stereo_MS_to_LR(
1.39 + stereo_dec_state *state, /* I/O State */
1.40 + opus_int16 x1[], /* I/O Left input signal, becomes mid signal */
1.41 + opus_int16 x2[], /* I/O Right input signal, becomes side signal */
1.42 + const opus_int32 pred_Q13[], /* I Predictors */
1.43 + opus_int fs_kHz, /* I Samples rate (kHz) */
1.44 + opus_int frame_length /* I Number of samples */
1.45 +)
1.46 +{
1.47 + opus_int n, denom_Q16, delta0_Q13, delta1_Q13;
1.48 + opus_int32 sum, diff, pred0_Q13, pred1_Q13;
1.49 +
1.50 + /* Buffering */
1.51 + silk_memcpy( x1, state->sMid, 2 * sizeof( opus_int16 ) );
1.52 + silk_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) );
1.53 + silk_memcpy( state->sMid, &x1[ frame_length ], 2 * sizeof( opus_int16 ) );
1.54 + silk_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) );
1.55 +
1.56 + /* Interpolate predictors and add prediction to side channel */
1.57 + pred0_Q13 = state->pred_prev_Q13[ 0 ];
1.58 + pred1_Q13 = state->pred_prev_Q13[ 1 ];
1.59 + denom_Q16 = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz );
1.60 + delta0_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 );
1.61 + delta1_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 );
1.62 + for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) {
1.63 + pred0_Q13 += delta0_Q13;
1.64 + pred1_Q13 += delta1_Q13;
1.65 + sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */
1.66 + sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */
1.67 + sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */
1.68 + x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
1.69 + }
1.70 + pred0_Q13 = pred_Q13[ 0 ];
1.71 + pred1_Q13 = pred_Q13[ 1 ];
1.72 + for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) {
1.73 + sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */
1.74 + sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */
1.75 + sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */
1.76 + x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
1.77 + }
1.78 + state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ];
1.79 + state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ];
1.80 +
1.81 + /* Convert to left/right signals */
1.82 + for( n = 0; n < frame_length; n++ ) {
1.83 + sum = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ];
1.84 + diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ];
1.85 + x1[ n + 1 ] = (opus_int16)silk_SAT16( sum );
1.86 + x2[ n + 1 ] = (opus_int16)silk_SAT16( diff );
1.87 + }
1.88 +}
