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author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-09-16 01:16:53 -0700 |
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committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-09-16 01:16:53 -0700 |
commit | 1c2f5633d101c08b5ef8095a8682d3d52cbd952d (patch) | |
tree | 66f80e67f075db5fa5233759a89f475d8bedade2 /silk/control_SNR.c | |
parent | fb3a437c9dabb4aafe4a3927158161590ed745ab (diff) | |
download | opus-1c2f5633d101c08b5ef8095a8682d3d52cbd952d.tar.gz |
Removed all the silk_ prefixes in source file names (not symbols)
Diffstat (limited to 'silk/control_SNR.c')
-rw-r--r-- | silk/control_SNR.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/silk/control_SNR.c b/silk/control_SNR.c new file mode 100644 index 00000000..3c65fd72 --- /dev/null +++ b/silk/control_SNR.c @@ -0,0 +1,81 @@ +/*********************************************************************** +Copyright (c) 2006-2011, Skype Limited. All rights reserved. +Redistribution and use in source and binary forms, with or without +modification, (subject to the limitations in the disclaimer below) +are permitted provided that the following conditions are met: +- Redistributions of source code must retain the above copyright notice, +this list of conditions and the following disclaimer. +- Redistributions in binary form must reproduce the above copyright +notice, this list of conditions and the following disclaimer in the +documentation and/or other materials provided with the distribution. +- Neither the name of Skype Limited, nor the names of specific +contributors, may be used to endorse or promote products derived from +this software without specific prior written permission. +NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED +BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND +CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, +BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND +FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON +ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +***********************************************************************/ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "main.h" +#include "tuning_parameters.h" + +/* Control SNR of redidual quantizer */ +opus_int silk_control_SNR( + silk_encoder_state *psEncC, /* I/O Pointer to Silk encoder state */ + opus_int32 TargetRate_bps /* I Target max bitrate (bps) */ +) +{ + opus_int k, ret = SILK_NO_ERROR; + opus_int32 frac_Q6; + const opus_int32 *rateTable; + + /* Set bitrate/coding quality */ + TargetRate_bps = silk_LIMIT( TargetRate_bps, MIN_TARGET_RATE_BPS, MAX_TARGET_RATE_BPS ); + if( TargetRate_bps != psEncC->TargetRate_bps ) { + psEncC->TargetRate_bps = TargetRate_bps; + + /* If new TargetRate_bps, translate to SNR_dB value */ + if( psEncC->fs_kHz == 8 ) { + rateTable = silk_TargetRate_table_NB; + } else if( psEncC->fs_kHz == 12 ) { + rateTable = silk_TargetRate_table_MB; + } else { + rateTable = silk_TargetRate_table_WB; + } + + /* Reduce bitrate for 10 ms modes in these calculations */ + if( psEncC->nb_subfr == 2 ) { + TargetRate_bps -= REDUCE_BITRATE_10_MS_BPS; + } + + /* Find bitrate interval in table and interpolate */ + for( k = 1; k < TARGET_RATE_TAB_SZ; k++ ) { + if( TargetRate_bps <= rateTable[ k ] ) { + frac_Q6 = silk_DIV32( silk_LSHIFT( TargetRate_bps - rateTable[ k - 1 ], 6 ), + rateTable[ k ] - rateTable[ k - 1 ] ); + 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 ] ); + break; + } + } + + /* Reduce coding quality whenever LBRR is enabled, to free up some bits */ + if( psEncC->LBRR_enabled ) { + psEncC->SNR_dB_Q7 = silk_SMLABB( psEncC->SNR_dB_Q7, 12 - psEncC->LBRR_GainIncreases, SILK_FIX_CONST( -0.25, 7 ) ); + } + } + + return ret; +} |