FreeCalypso > hg > gsm-codec-lib
view libtwamr/c2_9pf.h @ 485:751f06541fbb
doc/Codec-utils: clarify lack of DHF in gsmfr-decode-rb
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 20 May 2024 01:47:22 +0000 |
parents | ee64aabcc7a0 |
children |
line wrap: on
line source
/* ***************************************************************************** * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ***************************************************************************** * * File : c2_9pf.h * Purpose : Searches a 9 bit algebraic codebook containing * 2 pulses in a frame of 40 samples. * ***************************************************************************** */ #ifndef c2_9pf_h #define c2_9pf_h "$Id $" /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include "typedef.h" /* ***************************************************************************** * LOCAL VARIABLES AND TABLES ***************************************************************************** */ /* ***************************************************************************** * DEFINITION OF DATA TYPES ***************************************************************************** */ /* ***************************************************************************** * DECLARATION OF PROTOTYPES ***************************************************************************** */ /************************************************************************* * * FUNCTION: code_2i40_9bits() * * PURPOSE: Searches a 9 bit algebraic codebook containing 2 pulses * in a frame of 40 samples. * * DESCRIPTION: * The code length is 40, containing 2 nonzero pulses: i0...i1. * All pulses can have two possible amplitudes: +1 or -1. * Pulse i0 can have 8 possible positions, pulse i1 can have * 8 positions. Also coded is which track pair should be used, * i.e. first or second pair. Where each pair contains 2 tracks. * * First subframe: * first i0 : 0, 5, 10, 15, 20, 25, 30, 35. * i1 : 2, 7, 12, 17, 22, 27, 32, 37. * second i0 : 1, 6, 11, 16, 21, 26, 31, 36. * i1 : 3, 8, 13, 18, 23, 28, 33, 38. * * Second subframe: * first i0 : 0, 5, 10, 15, 20, 25, 30, 35. * i1 : 3, 8, 13, 18, 23, 28, 33, 38. * second i0 : 2, 7, 12, 17, 22, 27, 32, 37. * i1 : 4, 9, 14, 19, 24, 29, 34, 39. * * Third subframe: * first i0 : 0, 5, 10, 15, 20, 25, 30, 35. * i1 : 2, 7, 12, 17, 22, 27, 32, 37. * second i0 : 1, 6, 11, 16, 21, 26, 31, 36. * i1 : 4, 9, 14, 19, 24, 29, 34, 39. * * Fourth subframe: * first i0 : 0, 5, 10, 15, 20, 25, 30, 35. * i1 : 3, 8, 13, 18, 23, 28, 33, 38. * second i0 : 1, 6, 11, 16, 21, 26, 31, 36. * i1 : 4, 9, 14, 19, 24, 29, 34, 39. * *************************************************************************/ Word16 code_2i40_9bits( Word16 subNr, /* i : subframe number */ Word16 x[], /* i : target vector */ Word16 h[], /* i : impulse response of weighted synthesis filter */ /* h[-L_subfr..-1] must be set to zero. */ Word16 T0, /* i : Pitch lag */ Word16 pitch_sharp, /* i : Last quantized pitch gain */ Word16 code[], /* o : Innovative codebook */ Word16 y[], /* o : filtered fixed codebook excitation */ Word16 * sign /* o : Signs of 2 pulses */ ); #endif