media/libopus/silk/stereo_decode_pred.c@6474c204b198 (annotated)
media/libopus/silk/stereo_decode_pred.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 | /* Decode mid/side predictors */ |
| michael@0 | 35 | void silk_stereo_decode_pred( |
| michael@0 | 36 | ec_dec *psRangeDec, /* I/O Compressor data structure */ |
| michael@0 | 37 | opus_int32 pred_Q13[] /* O Predictors */ |
| michael@0 | 38 | ) |
| michael@0 | 39 | { |
| michael@0 | 40 | opus_int n, ix[ 2 ][ 3 ]; |
| michael@0 | 41 | opus_int32 low_Q13, step_Q13; |
| michael@0 | 42 | |
| michael@0 | 43 | /* Entropy decoding */ |
| michael@0 | 44 | n = ec_dec_icdf( psRangeDec, silk_stereo_pred_joint_iCDF, 8 ); |
| michael@0 | 45 | ix[ 0 ][ 2 ] = silk_DIV32_16( n, 5 ); |
| michael@0 | 46 | ix[ 1 ][ 2 ] = n - 5 * ix[ 0 ][ 2 ]; |
| michael@0 | 47 | for( n = 0; n < 2; n++ ) { |
| michael@0 | 48 | ix[ n ][ 0 ] = ec_dec_icdf( psRangeDec, silk_uniform3_iCDF, 8 ); |
| michael@0 | 49 | ix[ n ][ 1 ] = ec_dec_icdf( psRangeDec, silk_uniform5_iCDF, 8 ); |
| michael@0 | 50 | } |
| michael@0 | 51 | |
| michael@0 | 52 | /* Dequantize */ |
| michael@0 | 53 | for( n = 0; n < 2; n++ ) { |
| michael@0 | 54 | ix[ n ][ 0 ] += 3 * ix[ n ][ 2 ]; |
| michael@0 | 55 | low_Q13 = silk_stereo_pred_quant_Q13[ ix[ n ][ 0 ] ]; |
| michael@0 | 56 | step_Q13 = silk_SMULWB( silk_stereo_pred_quant_Q13[ ix[ n ][ 0 ] + 1 ] - low_Q13, |
| michael@0 | 57 | SILK_FIX_CONST( 0.5 / STEREO_QUANT_SUB_STEPS, 16 ) ); |
| michael@0 | 58 | pred_Q13[ n ] = silk_SMLABB( low_Q13, step_Q13, 2 * ix[ n ][ 1 ] + 1 ); |
| michael@0 | 59 | } |
| michael@0 | 60 | |
| michael@0 | 61 | /* Subtract second from first predictor (helps when actually applying these) */ |
| michael@0 | 62 | pred_Q13[ 0 ] -= pred_Q13[ 1 ]; |
| michael@0 | 63 | } |
| michael@0 | 64 | |
| michael@0 | 65 | /* Decode mid-only flag */ |
| michael@0 | 66 | void silk_stereo_decode_mid_only( |
| michael@0 | 67 | ec_dec *psRangeDec, /* I/O Compressor data structure */ |
| michael@0 | 68 | opus_int *decode_only_mid /* O Flag that only mid channel has been coded */ |
| michael@0 | 69 | ) |
| michael@0 | 70 | { |
| michael@0 | 71 | /* Decode flag that only mid channel is coded */ |
| michael@0 | 72 | *decode_only_mid = ec_dec_icdf( psRangeDec, silk_stereo_only_code_mid_iCDF, 8 ); |
| michael@0 | 73 | } |
