atom_tkhd.cpp

6410BSP1

/*
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is MPEG4IP.
 * 
 * The Initial Developer of the Original Code is Cisco Systems Inc.
 * Portions created by Cisco Systems Inc. are
 * Copyright (C) Cisco Systems Inc. 2001.  All Rights Reserved.
 * 
 * Contributor(s): 
 *        Dave Mackie        [e-mail]
 */

#include "mp4common.h"

MP4TkhdAtom::MP4TkhdAtom() 
    : MP4Atom("tkhd")
{
    AddVersionAndFlags();
}

void MP4TkhdAtom::AddProperties(u_int8_t version) 
{
    if (version == 1) {
        AddProperty( /* 2 */
            new MP4Integer64Property("creationTime"));
        AddProperty( /* 3 */
            new MP4Integer64Property("modificationTime"));
    } else { // version == 0
        AddProperty( /* 2 */
            new MP4Integer32Property("creationTime"));
        AddProperty( /* 3 */
            new MP4Integer32Property("modificationTime"));
    }

    AddProperty( /* 4 */
        new MP4Integer32Property("trackId"));
    AddReserved("reserved1", 4); /* 5 */

    if (version == 1) {
        AddProperty( /* 6 */
            new MP4Integer64Property("duration"));
    } else {
        AddProperty( /* 6 */
            new MP4Integer32Property("duration"));
    }

    AddReserved("reserved2", 12); /* 7 */

    MP4Float32Property* pProp;

    pProp = new MP4Float32Property("volume");
    pProp->SetFixed16Format();
    AddProperty(pProp); /* 8 */

    AddReserved("reserved3", 38); /* 9 */

    pProp = new MP4Float32Property("width");
    pProp->SetFixed32Format();
    AddProperty(pProp); /* 10 */

    pProp = new MP4Float32Property("height");
    pProp->SetFixed32Format();
    AddProperty(pProp); /* 11 */
}

void MP4TkhdAtom::Generate() 
{
    u_int8_t version = m_pFile->Use64Bits(GetType()) ? 1 : 0;
    SetVersion(version);
    AddProperties(version);

    MP4Atom::Generate();

    // set creation and modification times
    MP4Timestamp now = MP4GetAbsTimestamp();
    if (version == 1) {
        ((MP4Integer64Property*)m_pProperties[2])->SetValue(now);
        ((MP4Integer64Property*)m_pProperties[3])->SetValue(now);
    } else {
        ((MP4Integer32Property*)m_pProperties[2])->SetValue(now);
        ((MP4Integer32Property*)m_pProperties[3])->SetValue(now);
    }

    // property reserved3 has non-zero fixed values
    static u_int8_t reserved3[38] = {
        0x00, 0x00, 
        0x00, 0x01, 0x00, 0x00, 
        0x00, 0x00, 0x00, 0x00, 
        0x00, 0x00, 0x00, 0x00, 
        0x00, 0x00, 0x00, 0x00, 
        0x00, 0x01, 0x00, 0x00, 
        0x00, 0x00, 0x00, 0x00, 
        0x00, 0x00, 0x00, 0x00, 
        0x00, 0x00, 0x00, 0x00, 
        0x40, 0x00, 0x00, 0x00, 
    };
    m_pProperties[9]->SetReadOnly(false);
    ((MP4BytesProperty*)m_pProperties[9])->
        SetValue(reserved3, sizeof(reserved3));
    m_pProperties[9]->SetReadOnly(true);
}

void MP4TkhdAtom::Read() 
{
    /* read atom version */
    ReadProperties(0, 1);

    /* need to create the properties based on the atom version */
    AddProperties(GetVersion());

    /* now we can read the remaining properties */
    ReadProperties(1);

    Skip();    // to end of atom
}