diff options
Diffstat (limited to 'opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d2_11pf.cpp')
| -rw-r--r-- | opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d2_11pf.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d2_11pf.cpp b/opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d2_11pf.cpp new file mode 100644 index 0000000..8a70032 --- /dev/null +++ b/opencore/codecs_v2/audio/gsm_amr/amr_nb/dec/src/d2_11pf.cpp @@ -0,0 +1,192 @@ +/* ------------------------------------------------------------------ + * 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 26.073 + ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec + Available from http://www.3gpp.org + +(C) 2004, 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: d2_11pf.cpp + +------------------------------------------------------------------------------ + MODULE DESCRIPTION +*/ + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "d2_11pf.h" +#include "typedef.h" +#include "cnst.h" + + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ +#define NB_PULSE 2 + + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL VARIABLE DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: decode_2i40_11bits +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + sign -- Word16 -- signs of 2 pulses. + index -- Word16 -- Positions of the 2 pulses. + + Outputs: + cod[] -- array of type Word16 -- algebraic (fixed) codebook excitation + + Returns: + None + + Global Variables Used: + None + + Local Variables Needed: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + +------------------------------------------------------------------------------ + REQUIREMENTS + + None + +------------------------------------------------------------------------------ + REFERENCES + + d2_11pf.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + + +------------------------------------------------------------------------------ + CAUTION [optional] + [State any special notes, constraints or cautions for users of this function] + +------------------------------------------------------------------------------ +*/ + +void decode_2i40_11bits( + Word16 sign, /* i : signs of 2 pulses. */ + Word16 index, /* i : Positions of the 2 pulses. */ + Word16 cod[] /* o : algebraic (fixed) codebook excitation */ +) + +{ + Word16 i; + Word16 j; + + Word16 pos[NB_PULSE]; + + /* Decode the positions */ + + j = index & 0x1; + + index >>= 1; + + i = index & 0x7; + + pos[0] = i * 5 + j * 2 + 1; + + + + + index >>= 3; + + j = index & 0x3; + + index >>= 2; + + i = index & 0x7; + + if (j == 3) + { + pos[1] = i * 5 + 4; + } + else + { + pos[1] = i * 5 + j; + } + + + + + /* decode the signs and build the codeword */ + for (i = 0; i < L_SUBFR; i++) + { + cod[i] = 0; + } + + for (j = 0; j < NB_PULSE; j++) + { + i = sign & 1; + + /* This line is equivalent to... + * + * + * if (i == 1) + * { + * cod[pos[j]] = 8191; + * } + * if (i == 0) + * { + * cod[pos[j]] = -8192; + * } + */ + + cod[pos[j]] = i * 16383 - 8192; + + sign >>= 1; + } + + return; +} |