diff options
author | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-09-16 12:16:53 +0400 |
---|---|---|
committer | Jean-Marc Valin <jmvalin@jmvalin.ca> | 2011-09-16 12:16:53 +0400 |
commit | 1c2f5633d101c08b5ef8095a8682d3d52cbd952d (patch) | |
tree | 66f80e67f075db5fa5233759a89f475d8bedade2 /silk/ana_filt_bank_1.c | |
parent | fb3a437c9dabb4aafe4a3927158161590ed745ab (diff) |
Removed all the silk_ prefixes in source file names (not symbols)
Diffstat (limited to 'silk/ana_filt_bank_1.c')
-rw-r--r-- | silk/ana_filt_bank_1.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/silk/ana_filt_bank_1.c b/silk/ana_filt_bank_1.c new file mode 100644 index 00000000..3cca817a --- /dev/null +++ b/silk/ana_filt_bank_1.c @@ -0,0 +1,75 @@ +/*********************************************************************** +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 "SigProc_FIX.h" + +/* Coefficients for 2-band filter bank based on first-order allpass filters */ +/* old*/ +static opus_int16 A_fb1_20[ 1 ] = { 5394 << 1 }; +static opus_int16 A_fb1_21[ 1 ] = { 20623 << 1 }; /* wrap-around to negative number is intentional */ + +/* Split signal into two decimated bands using first-order allpass filters */ +void silk_ana_filt_bank_1( + const opus_int16 *in, /* I: Input signal [N] */ + opus_int32 *S, /* I/O: State vector [2] */ + opus_int16 *outL, /* O: Low band [N/2] */ + opus_int16 *outH, /* O: High band [N/2] */ + const opus_int32 N /* I: Number of input samples */ +) +{ + opus_int k, N2 = silk_RSHIFT( N, 1 ); + opus_int32 in32, X, Y, out_1, out_2; + + /* Internal variables and state are in Q10 format */ + for( k = 0; k < N2; k++ ) { + /* Convert to Q10 */ + in32 = silk_LSHIFT( (opus_int32)in[ 2 * k ], 10 ); + + /* All-pass section for even input sample */ + Y = silk_SUB32( in32, S[ 0 ] ); + X = silk_SMLAWB( Y, Y, A_fb1_21[ 0 ] ); + out_1 = silk_ADD32( S[ 0 ], X ); + S[ 0 ] = silk_ADD32( in32, X ); + + /* Convert to Q10 */ + in32 = silk_LSHIFT( (opus_int32)in[ 2 * k + 1 ], 10 ); + + /* All-pass section for odd input sample, and add to output of previous section */ + Y = silk_SUB32( in32, S[ 1 ] ); + X = silk_SMULWB( Y, A_fb1_20[ 0 ] ); + out_2 = silk_ADD32( S[ 1 ], X ); + S[ 1 ] = silk_ADD32( in32, X ); + + /* Add/subtract, convert back to int16 and store to output */ + outL[ k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_ADD32( out_2, out_1 ), 11 ) ); + outH[ k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SUB32( out_2, out_1 ), 11 ) ); + } +} |