mpegaudio.c 1.43 KB
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/*
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 * MPEG Audio common code
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 * Copyright (c) 2001, 2002 Fabrice Bellard
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 *
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 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * MPEG Audio common code.
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 */
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#include "mpegaudio.h"

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/* bitrate is in kb/s */
int ff_mpa_l2_select_table(int bitrate, int nb_channels, int freq, int lsf)
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{
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    int ch_bitrate, table;
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    ch_bitrate = bitrate / nb_channels;
    if (!lsf) {
        if ((freq == 48000 && ch_bitrate >= 56) ||
            (ch_bitrate >= 56 && ch_bitrate <= 80))
            table = 0;
        else if (freq != 48000 && ch_bitrate >= 96)
            table = 1;
        else if (freq != 32000 && ch_bitrate <= 48)
            table = 2;
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        else
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            table = 3;
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    } else {
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        table = 4;
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    }
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    return table;
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}