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/*
* TwoLAME: an optimized MPEG Audio Layer Two encoder
*
* Copyright (C) 2001-2004 Michael Cheng
* Copyright (C) 2004-2006 The TwoLAME Project
*
* 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
*
* $Id$
*
*/
#include <stdio.h>
#include "twolame.h"
#include "common.h"
#include "availbits.h"
struct slotinfo {
FLOAT average;
FLOAT frac;
int whole;
FLOAT lag;
int extra;
} slots;
/* function returns the number of available bits */
int available_bits(twolame_options * glopts)
{
frame_header *header = &glopts->header;
int adb;
slots.extra = 0; /* be default, no extra slots */
slots.average = (1152.0 / ((FLOAT) glopts->samplerate_out / 1000.0))
* ((FLOAT) glopts->bitrate / 8.0);
// fprintf(stderr,"availbits says: sampling freq is %i. version %i. bitrateindex %i slots
// %f\n",header->sampling_frequency, header->version, header->bitrate_index, slots.average);
slots.whole = (int) slots.average;
slots.frac = slots.average - (FLOAT) slots.whole;
/* never allow padding for a VBR frame. Don't ask me why, I've forgotten why I set this */
if (slots.frac != 0 && glopts->padding && glopts->vbr == FALSE) {
if (slots.lag > (slots.frac - 1.0)) { /* no padding for this frame */
slots.lag -= slots.frac;
slots.extra = 0;
header->padding = 0;
} else { /* padding */
slots.extra = 1;
header->padding = 1;
slots.lag += (1 - slots.frac);
}
}
adb = (slots.whole + slots.extra) * 8;
return adb;
}
// vim:ts=4:sw=4:nowrap:
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