mp4atom.c

AAC编解码源码

/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through [e-mail].
**
** $Id: mp4atom.c,v 1.17 2004/01/11 15:52:18 menno Exp $
**/

#include <stdlib.h>
#include "mp4ffint.h"

#include "drms.h"

/* parse atom header size */
static int32_t mp4ff_atom_get_size(const int8_t *data)
{
    uint32_t result;
    uint32_t a, b, c, d;

    a = (uint8_t)data[0];
    b = (uint8_t)data[1];
    c = (uint8_t)data[2];
    d = (uint8_t)data[3];

    result = (a<<24) | (b<<16) | (c<<8) | d;
    //if (result > 0 && result < 8) result = 8;

    return (int32_t)result;
}

/* comnapre 2 atom names, returns 1 for equal, 0 for unequal */
static int32_t mp4ff_atom_compare(const int8_t a1, const int8_t b1, const int8_t c1, const int8_t d1,
                                  const int8_t a2, const int8_t b2, const int8_t c2, const int8_t d2)
{
    if (a1 == a2 && b1 == b2 && c1 == c2 && d1 == d2)
        return 1;
    else
        return 0;
}

static uint8_t mp4ff_atom_name_to_type(const int8_t a, const int8_t b,
                                       const int8_t c, const int8_t d)
{
    if (a == 'm')
    {
        if (mp4ff_atom_compare(a,b,c,d, 'm','o','o','v'))
            return ATOM_MOOV;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','i','n','f'))
            return ATOM_MINF;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','d','i','a'))
            return ATOM_MDIA;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','d','a','t'))
            return ATOM_MDAT;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','d','h','d'))
            return ATOM_MDHD;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','v','h','d'))
            return ATOM_MVHD;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','p','4','a'))
            return ATOM_MP4A;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','p','4','v'))
            return ATOM_MP4V;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','p','4','s'))
            return ATOM_MP4S;
        else if (mp4ff_atom_compare(a,b,c,d, 'm','e','t','a'))
            return ATOM_META;
    } else if (a == 't') {
        if (mp4ff_atom_compare(a,b,c,d, 't','r','a','k'))
            return ATOM_TRAK;
        else if (mp4ff_atom_compare(a,b,c,d, 't','k','h','d'))
            return ATOM_TKHD;
        else if (mp4ff_atom_compare(a,b,c,d, 't','r','e','f'))
            return ATOM_TREF;
        else if (mp4ff_atom_compare(a,b,c,d, 't','r','k','n'))
            return ATOM_TRACK;
        else if (mp4ff_atom_compare(a,b,c,d, 't','m','p','o'))
            return ATOM_TEMPO;
    } else if (a == 's') {
        if (mp4ff_atom_compare(a,b,c,d, 's','t','b','l'))
            return ATOM_STBL;
        else if (mp4ff_atom_compare(a,b,c,d, 's','m','h','d'))
            return ATOM_SMHD;
        else if (mp4ff_atom_compare(a,b,c,d, 's','t','s','d'))
            return ATOM_STSD;
        else if (mp4ff_atom_compare(a,b,c,d, 's','t','t','s'))
            return ATOM_STTS;
        else if (mp4ff_atom_compare(a,b,c,d, 's','t','c','o'))
            return ATOM_STCO;
        else if (mp4ff_atom_compare(a,b,c,d, 's','t','s','c'))
            return ATOM_STSC;
        else if (mp4ff_atom_compare(a,b,c,d, 's','t','s','z'))
            return ATOM_STSZ;
        else if (mp4ff_atom_compare(a,b,c,d, 's','t','z','2'))
            return ATOM_STZ2;
        else if (mp4ff_atom_compare(a,b,c,d, 's','k','i','p'))
            return ATOM_SKIP;
        else if (mp4ff_atom_compare(a,b,c,d, 's','i','n','f'))
            return ATOM_SINF;
        else if (mp4ff_atom_compare(a,b,c,d, 's','c','h','i'))
            return ATOM_SCHI;
    } else if (a == '