Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 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 | #include "tuning_parameters.h" |
| 34 | |
| 35 | /* Control SNR of redidual quantizer */ |
| 36 | opus_int silk_control_SNR( |
| 37 | silk_encoder_state *psEncC, /* I/O Pointer to Silk encoder state */ |
| 38 | opus_int32 TargetRate_bps /* I Target max bitrate (bps) */ |
| 39 | ) |
| 40 | { |
| 41 | opus_int k, ret = SILK_NO_ERROR; |
| 42 | opus_int32 frac_Q6; |
| 43 | const opus_int32 *rateTable; |
| 44 | |
| 45 | /* Set bitrate/coding quality */ |
| 46 | TargetRate_bps = silk_LIMIT( TargetRate_bps, MIN_TARGET_RATE_BPS, MAX_TARGET_RATE_BPS ); |
| 47 | if( TargetRate_bps != psEncC->TargetRate_bps ) { |
| 48 | psEncC->TargetRate_bps = TargetRate_bps; |
| 49 | |
| 50 | /* If new TargetRate_bps, translate to SNR_dB value */ |
| 51 | if( psEncC->fs_kHz == 8 ) { |
| 52 | rateTable = silk_TargetRate_table_NB; |
| 53 | } else if( psEncC->fs_kHz == 12 ) { |
| 54 | rateTable = silk_TargetRate_table_MB; |
| 55 | } else { |
| 56 | rateTable = silk_TargetRate_table_WB; |
| 57 | } |
| 58 | |
| 59 | /* Reduce bitrate for 10 ms modes in these calculations */ |
| 60 | if( psEncC->nb_subfr == 2 ) { |
| 61 | TargetRate_bps -= REDUCE_BITRATE_10_MS_BPS; |
| 62 | } |
| 63 | |
| 64 | /* Find bitrate interval in table and interpolate */ |
| 65 | for( k = 1; k < TARGET_RATE_TAB_SZ; k++ ) { |
| 66 | if( TargetRate_bps <= rateTable[ k ] ) { |
| 67 | frac_Q6 = silk_DIV32( silk_LSHIFT( TargetRate_bps - rateTable[ k - 1 ], 6 ), |
| 68 | rateTable[ k ] - rateTable[ k - 1 ] ); |
| 69 | psEncC->SNR_dB_Q7 = silk_LSHIFT( silk_SNR_table_Q1[ k - 1 ], 6 ) + silk_MUL( frac_Q6, silk_SNR_table_Q1[ k ] - silk_SNR_table_Q1[ k - 1 ] ); |
| 70 | break; |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | /* Reduce coding quality whenever LBRR is enabled, to free up some bits */ |
| 75 | if( psEncC->LBRR_enabled ) { |
| 76 | psEncC->SNR_dB_Q7 = silk_SMLABB( psEncC->SNR_dB_Q7, 12 - psEncC->LBRR_GainIncreases, SILK_FIX_CONST( -0.25, 7 ) ); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | return ret; |
| 81 | } |