Line data    Source code

       1             : /***********************************************************************
       2             : Copyright (c) 2006-2011, Skype Limited. All rights reserved.
       3             : Redistribution and use in source and binary forms, with or without
       4             : modification, are permitted provided that the following conditions
       5             : are met:
       6             : - Redistributions of source code must retain the above copyright notice,
       7             : this list of conditions and the following disclaimer.
       8             : - Redistributions in binary form must reproduce the above copyright
       9             : notice, this list of conditions and the following disclaimer in the
      10             : documentation and/or other materials provided with the distribution.
      11             : - Neither the name of Internet Society, IETF or IETF Trust, nor the
      12             : names of specific contributors, may be used to endorse or promote
      13             : products derived from this software without specific prior written
      14             : permission.
      15             : THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
      16             : AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      17             : IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      18             : ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
      19             : LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
      20             : CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
      21             : SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
      22             : INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
      23             : CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
      24             : ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
      25             : POSSIBILITY OF SUCH DAMAGE.
      26             : ***********************************************************************/
      27             : 
      28             : #ifdef HAVE_CONFIG_H
      29             : #include "config.h"
      30             : #endif
      31             : 
      32             : #include "main.h"
      33             : 
      34             : /* Convert adaptive Mid/Side representation to Left/Right stereo signal */
      35           0 : void silk_stereo_MS_to_LR(
      36             :     stereo_dec_state            *state,                         /* I/O  State                                       */
      37             :     opus_int16                  x1[],                           /* I/O  Left input signal, becomes mid signal       */
      38             :     opus_int16                  x2[],                           /* I/O  Right input signal, becomes side signal     */
      39             :     const opus_int32            pred_Q13[],                     /* I    Predictors                                  */
      40             :     opus_int                    fs_kHz,                         /* I    Samples rate (kHz)                          */
      41             :     opus_int                    frame_length                    /* I    Number of samples                           */
      42             : )
      43             : {
      44             :     opus_int   n, denom_Q16, delta0_Q13, delta1_Q13;
      45             :     opus_int32 sum, diff, pred0_Q13, pred1_Q13;
      46             : 
      47             :     /* Buffering */
      48           0 :     silk_memcpy( x1, state->sMid,  2 * sizeof( opus_int16 ) );
      49           0 :     silk_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) );
      50           0 :     silk_memcpy( state->sMid,  &x1[ frame_length ], 2 * sizeof( opus_int16 ) );
      51           0 :     silk_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) );
      52             : 
      53             :     /* Interpolate predictors and add prediction to side channel */
      54           0 :     pred0_Q13  = state->pred_prev_Q13[ 0 ];
      55           0 :     pred1_Q13  = state->pred_prev_Q13[ 1 ];
      56           0 :     denom_Q16  = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz );
      57           0 :     delta0_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 );
      58           0 :     delta1_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 );
      59           0 :     for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) {
      60           0 :         pred0_Q13 += delta0_Q13;
      61           0 :         pred1_Q13 += delta1_Q13;
      62           0 :         sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 );       /* Q11 */
      63           0 :         sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 );         /* Q8  */
      64           0 :         sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 );        /* Q8  */
      65           0 :         x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
      66             :     }
      67           0 :     pred0_Q13 = pred_Q13[ 0 ];
      68           0 :     pred1_Q13 = pred_Q13[ 1 ];
      69           0 :     for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) {
      70           0 :         sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 );       /* Q11 */
      71           0 :         sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 );         /* Q8  */
      72           0 :         sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 );        /* Q8  */
      73           0 :         x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) );
      74             :     }
      75           0 :     state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ];
      76           0 :     state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ];
      77             : 
      78             :     /* Convert to left/right signals */
      79           0 :     for( n = 0; n < frame_length; n++ ) {
      80           0 :         sum  = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ];
      81           0 :         diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ];
      82           0 :         x1[ n + 1 ] = (opus_int16)silk_SAT16( sum );
      83           0 :         x2[ n + 1 ] = (opus_int16)silk_SAT16( diff );
      84             :     }
      85           0 : }