cannam@154: /*********************************************************************** cannam@154: Copyright (c) 2006-2011, Skype Limited. All rights reserved. cannam@154: Redistribution and use in source and binary forms, with or without cannam@154: modification, are permitted provided that the following conditions cannam@154: are met: cannam@154: - Redistributions of source code must retain the above copyright notice, cannam@154: this list of conditions and the following disclaimer. cannam@154: - Redistributions in binary form must reproduce the above copyright cannam@154: notice, this list of conditions and the following disclaimer in the cannam@154: documentation and/or other materials provided with the distribution. cannam@154: - Neither the name of Internet Society, IETF or IETF Trust, nor the cannam@154: names of specific contributors, may be used to endorse or promote cannam@154: products derived from this software without specific prior written cannam@154: permission. cannam@154: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" cannam@154: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE cannam@154: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE cannam@154: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE cannam@154: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR cannam@154: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF cannam@154: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS cannam@154: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN cannam@154: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) cannam@154: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE cannam@154: POSSIBILITY OF SUCH DAMAGE. cannam@154: ***********************************************************************/ cannam@154: cannam@154: #ifdef HAVE_CONFIG_H cannam@154: #include "config.h" cannam@154: #endif cannam@154: cannam@154: #include "main.h" cannam@154: cannam@154: /* Convert adaptive Mid/Side representation to Left/Right stereo signal */ cannam@154: void silk_stereo_MS_to_LR( cannam@154: stereo_dec_state *state, /* I/O State */ cannam@154: opus_int16 x1[], /* I/O Left input signal, becomes mid signal */ cannam@154: opus_int16 x2[], /* I/O Right input signal, becomes side signal */ cannam@154: const opus_int32 pred_Q13[], /* I Predictors */ cannam@154: opus_int fs_kHz, /* I Samples rate (kHz) */ cannam@154: opus_int frame_length /* I Number of samples */ cannam@154: ) cannam@154: { cannam@154: opus_int n, denom_Q16, delta0_Q13, delta1_Q13; cannam@154: opus_int32 sum, diff, pred0_Q13, pred1_Q13; cannam@154: cannam@154: /* Buffering */ cannam@154: silk_memcpy( x1, state->sMid, 2 * sizeof( opus_int16 ) ); cannam@154: silk_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) ); cannam@154: silk_memcpy( state->sMid, &x1[ frame_length ], 2 * sizeof( opus_int16 ) ); cannam@154: silk_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) ); cannam@154: cannam@154: /* Interpolate predictors and add prediction to side channel */ cannam@154: pred0_Q13 = state->pred_prev_Q13[ 0 ]; cannam@154: pred1_Q13 = state->pred_prev_Q13[ 1 ]; cannam@154: denom_Q16 = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz ); cannam@154: delta0_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 ); cannam@154: delta1_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 ); cannam@154: for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) { cannam@154: pred0_Q13 += delta0_Q13; cannam@154: pred1_Q13 += delta1_Q13; cannam@154: sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */ cannam@154: sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */ cannam@154: sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ cannam@154: x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); cannam@154: } cannam@154: pred0_Q13 = pred_Q13[ 0 ]; cannam@154: pred1_Q13 = pred_Q13[ 1 ]; cannam@154: for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) { cannam@154: sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */ cannam@154: sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */ cannam@154: sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ cannam@154: x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); cannam@154: } cannam@154: state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ]; cannam@154: state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ]; cannam@154: cannam@154: /* Convert to left/right signals */ cannam@154: for( n = 0; n < frame_length; n++ ) { cannam@154: sum = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ]; cannam@154: diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ]; cannam@154: x1[ n + 1 ] = (opus_int16)silk_SAT16( sum ); cannam@154: x2[ n + 1 ] = (opus_int16)silk_SAT16( diff ); cannam@154: } cannam@154: }