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comparison: media/libopus/silk/stereo_MS_to_LR.c
media/libopus/silk/stereo_MS_to_LR.c
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:c4748fbdbe47 |
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| 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 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 silk_memcpy( x1, state->sMid, 2 * sizeof( opus_int16 ) ); | |
| 49 silk_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) ); | |
| 50 silk_memcpy( state->sMid, &x1[ frame_length ], 2 * sizeof( opus_int16 ) ); | |
| 51 silk_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) ); | |
| 52 | |
| 53 /* Interpolate predictors and add prediction to side channel */ | |
| 54 pred0_Q13 = state->pred_prev_Q13[ 0 ]; | |
| 55 pred1_Q13 = state->pred_prev_Q13[ 1 ]; | |
| 56 denom_Q16 = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz ); | |
| 57 delta0_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 ); | |
| 58 delta1_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 ); | |
| 59 for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) { | |
| 60 pred0_Q13 += delta0_Q13; | |
| 61 pred1_Q13 += delta1_Q13; | |
| 62 sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */ | |
| 63 sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */ | |
| 64 sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ | |
| 65 x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); | |
| 66 } | |
| 67 pred0_Q13 = pred_Q13[ 0 ]; | |
| 68 pred1_Q13 = pred_Q13[ 1 ]; | |
| 69 for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) { | |
| 70 sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */ | |
| 71 sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */ | |
| 72 sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ | |
| 73 x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); | |
| 74 } | |
| 75 state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ]; | |
| 76 state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ]; | |
| 77 | |
| 78 /* Convert to left/right signals */ | |
| 79 for( n = 0; n < frame_length; n++ ) { | |
| 80 sum = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ]; | |
| 81 diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ]; | |
| 82 x1[ n + 1 ] = (opus_int16)silk_SAT16( sum ); | |
| 83 x2[ n + 1 ] = (opus_int16)silk_SAT16( diff ); | |
| 84 } | |
| 85 } |
