diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwb/src/isp_isf.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrwb/src/isp_isf.cpp | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrwb/src/isp_isf.cpp b/media/libstagefright/codecs/amrwb/src/isp_isf.cpp new file mode 100644 index 0000000..0552733 --- /dev/null +++ b/media/libstagefright/codecs/amrwb/src/isp_isf.cpp @@ -0,0 +1,175 @@ +/* ------------------------------------------------------------------ + * Copyright (C) 1998-2009 PacketVideo + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either + * express or implied. + * See the License for the specific language governing permissions + * and limitations under the License. + * ------------------------------------------------------------------- + */ +/**************************************************************************************** +Portions of this file are derived from the following 3GPP standard: + + 3GPP TS 26.173 + ANSI-C code for the Adaptive Multi-Rate - Wideband (AMR-WB) speech codec + Available from http://www.3gpp.org + +(C) 2007, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) +Permission to distribute, modify and use this file under the standard license +terms listed above has been obtained from the copyright holder. +****************************************************************************************/ +/* +------------------------------------------------------------------------------ + + + + Filename: isp_isf.cpp + + Date: 05/08/2004 + +------------------------------------------------------------------------------ + REVISION HISTORY + + + Description: + +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + int16 isf[], (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) + int16 isp[], (o) Q15 : isp[m] (range: -1<=val<1) + int16 m (i) : LPC order + + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + Isf_isp Transformation isf to isp + + The transformation from isf[i] to isp[i] is + approximated by a look-up table and interpolation. + + + +------------------------------------------------------------------------------ + REQUIREMENTS + + +------------------------------------------------------------------------------ + REFERENCES + +------------------------------------------------------------------------------ + PSEUDO-CODE + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ + + +#include "pv_amr_wb_type_defs.h" +#include "pvamrwbdecoder_basic_op.h" +#include "pvamrwbdecoder_acelp.h" + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL STORE/BUFFER/POINTER DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + +/* Look-up table for transformations */ + +/* table of cos(x) in Q15 */ + +static const int16 table[129] = +{ + 32767, + 32758, 32729, 32679, 32610, 32522, 32413, 32286, 32138, + 31972, 31786, 31581, 31357, 31114, 30853, 30572, 30274, + 29957, 29622, 29269, 28899, 28511, 28106, 27684, 27246, + 26791, 26320, 25833, 25330, 24812, 24279, 23732, 23170, + 22595, 22006, 21403, 20788, 20160, 19520, 18868, 18205, + 17531, 16846, 16151, 15447, 14733, 14010, 13279, 12540, + 11793, 11039, 10279, 9512, 8740, 7962, 7180, 6393, + 5602, 4808, 4011, 3212, 2411, 1608, 804, 0, + -804, -1608, -2411, -3212, -4011, -4808, -5602, -6393, + -7180, -7962, -8740, -9512, -10279, -11039, -11793, -12540, + -13279, -14010, -14733, -15447, -16151, -16846, -17531, -18205, + -18868, -19520, -20160, -20788, -21403, -22006, -22595, -23170, + -23732, -24279, -24812, -25330, -25833, -26320, -26791, -27246, + -27684, -28106, -28511, -28899, -29269, -29622, -29957, -30274, + -30572, -30853, -31114, -31357, -31581, -31786, -31972, -32138, + -32286, -32413, -32522, -32610, -32679, -32729, -32758, -32768 +}; + + +/*---------------------------------------------------------------------------- +; EXTERNAL FUNCTION REFERENCES +; Declare functions defined elsewhere and referenced in this module +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES +; Declare variables used in this module but defined elsewhere +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; FUNCTION CODE +----------------------------------------------------------------------------*/ + + +void Isf_isp( + int16 isf[], /* (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) */ + int16 isp[], /* (o) Q15 : isp[m] (range: -1<=val<1) */ + int16 m /* (i) : LPC order */ +) +{ + int16 i, ind, offset; + int32 L_tmp; + + for (i = 0; i < m - 1; i++) + { + isp[i] = isf[i]; + } + isp[m - 1] = shl_int16(isf[m - 1], 1); + + for (i = 0; i < m; i++) + { + ind = isp[i] >> 7; /* ind = b7-b15 of isf[i] */ + offset = (isp[i] & 0x007f); /* offset = b0-b6 of isf[i] */ + + /* isp[i] = table[ind]+ ((table[ind+1]-table[ind])*offset) / 128 */ + + L_tmp = mul_16by16_to_int32(table[ind + 1] - table[ind], offset); + isp[i] = add_int16(table[ind], (int16)(L_tmp >> 8)); + } + + return; +} |