media/libopus/silk/stereo_MS_to_LR.c@6474c204b198 (annotated)
media/libopus/silk/stereo_MS_to_LR.c
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /*********************************************************************** |
| michael@0 | 2 | Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
| michael@0 | 3 | Redistribution and use in source and binary forms, with or without |
| michael@0 | 4 | modification, are permitted provided that the following conditions |
| michael@0 | 5 | are met: |
| michael@0 | 6 | - Redistributions of source code must retain the above copyright notice, |
| michael@0 | 7 | this list of conditions and the following disclaimer. |
| michael@0 | 8 | - Redistributions in binary form must reproduce the above copyright |
| michael@0 | 9 | notice, this list of conditions and the following disclaimer in the |
| michael@0 | 10 | documentation and/or other materials provided with the distribution. |
| michael@0 | 11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
| michael@0 | 12 | names of specific contributors, may be used to endorse or promote |
| michael@0 | 13 | products derived from this software without specific prior written |
| michael@0 | 14 | permission. |
| michael@0 | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| michael@0 | 16 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| michael@0 | 17 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| michael@0 | 18 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| michael@0 | 19 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| michael@0 | 20 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| michael@0 | 21 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| michael@0 | 22 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| michael@0 | 23 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| michael@0 | 24 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| michael@0 | 25 | POSSIBILITY OF SUCH DAMAGE. |
| michael@0 | 26 | ***********************************************************************/ |
| michael@0 | 27 | |
| michael@0 | 28 | #ifdef HAVE_CONFIG_H |
| michael@0 | 29 | #include "config.h" |
| michael@0 | 30 | #endif |
| michael@0 | 31 | |
| michael@0 | 32 | #include "main.h" |
| michael@0 | 33 | |
| michael@0 | 34 | /* Convert adaptive Mid/Side representation to Left/Right stereo signal */ |
| michael@0 | 35 | void silk_stereo_MS_to_LR( |
| michael@0 | 36 | stereo_dec_state *state, /* I/O State */ |
| michael@0 | 37 | opus_int16 x1[], /* I/O Left input signal, becomes mid signal */ |
| michael@0 | 38 | opus_int16 x2[], /* I/O Right input signal, becomes side signal */ |
| michael@0 | 39 | const opus_int32 pred_Q13[], /* I Predictors */ |
| michael@0 | 40 | opus_int fs_kHz, /* I Samples rate (kHz) */ |
| michael@0 | 41 | opus_int frame_length /* I Number of samples */ |
| michael@0 | 42 | ) |
| michael@0 | 43 | { |
| michael@0 | 44 | opus_int n, denom_Q16, delta0_Q13, delta1_Q13; |
| michael@0 | 45 | opus_int32 sum, diff, pred0_Q13, pred1_Q13; |
| michael@0 | 46 | |
| michael@0 | 47 | /* Buffering */ |
| michael@0 | 48 | silk_memcpy( x1, state->sMid, 2 * sizeof( opus_int16 ) ); |
| michael@0 | 49 | silk_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) ); |
| michael@0 | 50 | silk_memcpy( state->sMid, &x1[ frame_length ], 2 * sizeof( opus_int16 ) ); |
| michael@0 | 51 | silk_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) ); |
| michael@0 | 52 | |
| michael@0 | 53 | /* Interpolate predictors and add prediction to side channel */ |
| michael@0 | 54 | pred0_Q13 = state->pred_prev_Q13[ 0 ]; |
| michael@0 | 55 | pred1_Q13 = state->pred_prev_Q13[ 1 ]; |
| michael@0 | 56 | denom_Q16 = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz ); |
| michael@0 | 57 | delta0_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 ); |
| michael@0 | 58 | delta1_Q13 = silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 ); |
| michael@0 | 59 | for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) { |
| michael@0 | 60 | pred0_Q13 += delta0_Q13; |
| michael@0 | 61 | pred1_Q13 += delta1_Q13; |
| michael@0 | 62 | sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */ |
| michael@0 | 63 | sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */ |
| michael@0 | 64 | sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ |
| michael@0 | 65 | x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); |
| michael@0 | 66 | } |
| michael@0 | 67 | pred0_Q13 = pred_Q13[ 0 ]; |
| michael@0 | 68 | pred1_Q13 = pred_Q13[ 1 ]; |
| michael@0 | 69 | for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) { |
| michael@0 | 70 | sum = silk_LSHIFT( silk_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */ |
| michael@0 | 71 | sum = silk_SMLAWB( silk_LSHIFT( (opus_int32)x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */ |
| michael@0 | 72 | sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ |
| michael@0 | 73 | x2[ n + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); |
| michael@0 | 74 | } |
| michael@0 | 75 | state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ]; |
| michael@0 | 76 | state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ]; |
| michael@0 | 77 | |
| michael@0 | 78 | /* Convert to left/right signals */ |
| michael@0 | 79 | for( n = 0; n < frame_length; n++ ) { |
| michael@0 | 80 | sum = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ]; |
| michael@0 | 81 | diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ]; |
| michael@0 | 82 | x1[ n + 1 ] = (opus_int16)silk_SAT16( sum ); |
| michael@0 | 83 | x2[ n + 1 ] = (opus_int16)silk_SAT16( diff ); |
| michael@0 | 84 | } |
| michael@0 | 85 | } |
