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 "SigProc_FIX.h" |
| 33 | #include "resampler_private.h" |
| 34 | |
| 35 | /* Upsample by a factor 2, high quality */ |
| 36 | /* Uses 2nd order allpass filters for the 2x upsampling, followed by a */ |
| 37 | /* notch filter just above Nyquist. */ |
| 38 | void silk_resampler_private_up2_HQ( |
| 39 | opus_int32 *S, /* I/O Resampler state [ 6 ] */ |
| 40 | opus_int16 *out, /* O Output signal [ 2 * len ] */ |
| 41 | const opus_int16 *in, /* I Input signal [ len ] */ |
| 42 | opus_int32 len /* I Number of input samples */ |
| 43 | ) |
| 44 | { |
| 45 | opus_int32 k; |
| 46 | opus_int32 in32, out32_1, out32_2, Y, X; |
| 47 | |
| 48 | silk_assert( silk_resampler_up2_hq_0[ 0 ] > 0 ); |
| 49 | silk_assert( silk_resampler_up2_hq_0[ 1 ] > 0 ); |
| 50 | silk_assert( silk_resampler_up2_hq_0[ 2 ] < 0 ); |
| 51 | silk_assert( silk_resampler_up2_hq_1[ 0 ] > 0 ); |
| 52 | silk_assert( silk_resampler_up2_hq_1[ 1 ] > 0 ); |
| 53 | silk_assert( silk_resampler_up2_hq_1[ 2 ] < 0 ); |
| 54 | |
| 55 | /* Internal variables and state are in Q10 format */ |
| 56 | for( k = 0; k < len; k++ ) { |
| 57 | /* Convert to Q10 */ |
| 58 | in32 = silk_LSHIFT( (opus_int32)in[ k ], 10 ); |
| 59 | |
| 60 | /* First all-pass section for even output sample */ |
| 61 | Y = silk_SUB32( in32, S[ 0 ] ); |
| 62 | X = silk_SMULWB( Y, silk_resampler_up2_hq_0[ 0 ] ); |
| 63 | out32_1 = silk_ADD32( S[ 0 ], X ); |
| 64 | S[ 0 ] = silk_ADD32( in32, X ); |
| 65 | |
| 66 | /* Second all-pass section for even output sample */ |
| 67 | Y = silk_SUB32( out32_1, S[ 1 ] ); |
| 68 | X = silk_SMULWB( Y, silk_resampler_up2_hq_0[ 1 ] ); |
| 69 | out32_2 = silk_ADD32( S[ 1 ], X ); |
| 70 | S[ 1 ] = silk_ADD32( out32_1, X ); |
| 71 | |
| 72 | /* Third all-pass section for even output sample */ |
| 73 | Y = silk_SUB32( out32_2, S[ 2 ] ); |
| 74 | X = silk_SMLAWB( Y, Y, silk_resampler_up2_hq_0[ 2 ] ); |
| 75 | out32_1 = silk_ADD32( S[ 2 ], X ); |
| 76 | S[ 2 ] = silk_ADD32( out32_2, X ); |
| 77 | |
| 78 | /* Apply gain in Q15, convert back to int16 and store to output */ |
| 79 | out[ 2 * k ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( out32_1, 10 ) ); |
| 80 | |
| 81 | /* First all-pass section for odd output sample */ |
| 82 | Y = silk_SUB32( in32, S[ 3 ] ); |
| 83 | X = silk_SMULWB( Y, silk_resampler_up2_hq_1[ 0 ] ); |
| 84 | out32_1 = silk_ADD32( S[ 3 ], X ); |
| 85 | S[ 3 ] = silk_ADD32( in32, X ); |
| 86 | |
| 87 | /* Second all-pass section for odd output sample */ |
| 88 | Y = silk_SUB32( out32_1, S[ 4 ] ); |
| 89 | X = silk_SMULWB( Y, silk_resampler_up2_hq_1[ 1 ] ); |
| 90 | out32_2 = silk_ADD32( S[ 4 ], X ); |
| 91 | S[ 4 ] = silk_ADD32( out32_1, X ); |
| 92 | |
| 93 | /* Third all-pass section for odd output sample */ |
| 94 | Y = silk_SUB32( out32_2, S[ 5 ] ); |
| 95 | X = silk_SMLAWB( Y, Y, silk_resampler_up2_hq_1[ 2 ] ); |
| 96 | out32_1 = silk_ADD32( S[ 5 ], X ); |
| 97 | S[ 5 ] = silk_ADD32( out32_2, X ); |
| 98 | |
| 99 | /* Apply gain in Q15, convert back to int16 and store to output */ |
| 100 | out[ 2 * k + 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( out32_1, 10 ) ); |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | void silk_resampler_private_up2_HQ_wrapper( |
| 105 | void *SS, /* I/O Resampler state (unused) */ |
| 106 | opus_int16 *out, /* O Output signal [ 2 * len ] */ |
| 107 | const opus_int16 *in, /* I Input signal [ len ] */ |
| 108 | opus_int32 len /* I Number of input samples */ |
| 109 | ) |
| 110 | { |
| 111 | silk_resampler_state_struct *S = (silk_resampler_state_struct *)SS; |
| 112 | silk_resampler_private_up2_HQ( S->sIIR, out, in, len ); |
| 113 | } |