/* * FAAC - Freeware Advanced Audio Coder * Copyright (C) 2001 Menno Bakker * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details.  * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * */ #include "util.h"#include "coder.h"  // FRAME_LEN /* Returns the sample rate index */int GetSRIndex(unsigned int sampleRate){    if (92017 <= sampleRate) return 0;    if (75132 <= sampleRate) return 1;    if (55426 <= sampleRate) return 2;    if (46009 <= sampleRate) return 3;    if (37566 <= sampleRate) return 4;    if (27713 <= sampleRate) return 5;    if (23004 <= sampleRate) return 6;    if (18783 <= sampleRate) return 7;    if (13856 <= sampleRate) return 8;    if (11502 <= sampleRate) return 9;    if (9391 <= sampleRate) return 10;     return 11;} /* Returns the maximum bitrate for that sampling frequency */unsigned int MaxBitrate(unsigned long sampleRate){    /* max ADTS frame size 8k */    return 0x2000 * 8 * (double)sampleRate/(double)FRAME_LEN;} /* Returns the minimum bitrate per channel for that sampling frequency */unsigned int MinBitrate(){    return 8000;} /* Calculate bit_allocation based on PE */unsigned int BitAllocation(double pe, int short_block){    double pew1;    double pew2;    double bit_allocation;     if (short_block) {        pew1 = 0.6;        pew2 = 24.0;    } else {        pew1 = 0.3;        pew2 = 6.0;    }    bit_allocation = pew1 * pe + pew2 * sqrt(pe);    bit_allocation = min(max(0.0, bit_allocation), 6144.0);     return (unsigned int)(bit_allocation+0.5);} /* Returns the maximum bit reservoir size */unsigned int MaxBitresSize(unsigned long bitRate, unsigned long sampleRate){    return 6144 - (unsigned int)((double)bitRate/(double)sampleRate*(double)FRAME_LEN);}