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|
/*****************************************************************
|
| AP4 - mdhd Atoms
|
| Copyright 2002-2008 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL 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, or (at your option)
| any later version.
|
| Bento4|GPL 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 Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4MdhdAtom.h"
#include "Ap4AtomFactory.h"
#include "Ap4Utils.h"
/*----------------------------------------------------------------------
| dynamic cast support
+---------------------------------------------------------------------*/
AP4_DEFINE_DYNAMIC_CAST_ANCHOR(AP4_MdhdAtom)
/*----------------------------------------------------------------------
| AP4_MdhdAtom::Create
+---------------------------------------------------------------------*/
AP4_MdhdAtom*
AP4_MdhdAtom::Create(AP4_Size size, AP4_ByteStream& stream)
{
AP4_UI08 version;
AP4_UI32 flags;
if (AP4_FAILED(AP4_Atom::ReadFullHeader(stream, version, flags))) return NULL;
if (version > 1) return NULL;
return new AP4_MdhdAtom(size, version, flags, stream);
}
/*----------------------------------------------------------------------
| AP4_MdhdAtom::AP4_MdhdAtom
+---------------------------------------------------------------------*/
AP4_MdhdAtom::AP4_MdhdAtom(AP4_UI32 creation_time,
AP4_UI32 modification_time,
AP4_UI32 time_scale,
AP4_UI64 duration,
const char* language) :
AP4_Atom(AP4_ATOM_TYPE_MDHD, AP4_FULL_ATOM_HEADER_SIZE+20, 0, 0),
m_CreationTime(creation_time),
m_ModificationTime(modification_time),
m_TimeScale(time_scale),
m_Duration(duration)
{
m_Language.Assign(language, 3);
if (duration > 0xFFFFFFFF) {
m_Version = 1;
m_Size32 += 12;
}
}
/*----------------------------------------------------------------------
| AP4_MdhdAtom::AP4_MdhdAtom
+---------------------------------------------------------------------*/
AP4_MdhdAtom::AP4_MdhdAtom(AP4_UI32 size,
AP4_UI08 version,
AP4_UI32 flags,
AP4_ByteStream& stream) :
AP4_Atom(AP4_ATOM_TYPE_MDHD, size, version, flags)
{
if (m_Version == 0) {
AP4_UI32 creation_time;
stream.ReadUI32(creation_time);
m_CreationTime = creation_time;
AP4_UI32 modification_time;
stream.ReadUI32(modification_time);
m_ModificationTime = modification_time;
stream.ReadUI32(m_TimeScale);
AP4_UI32 duration;
stream.ReadUI32(duration);
m_Duration = duration;
} else {
stream.ReadUI64(m_CreationTime);
stream.ReadUI64(m_ModificationTime);
stream.ReadUI32(m_TimeScale);
stream.ReadUI64(m_Duration);
}
unsigned char lang[2];
stream.Read(lang, 2);
char l0 = ((lang[0]>>2)&0x1F);
char l1 = (((lang[0]&0x3)<<3) | ((lang[1]>>5)&0x7));
char l2 = ((lang[1]&0x1F));
if (l0 && l1 && l2) {
char lang_str[3] = {(char)(l0+0x60), (char)(l1+0x60), (char)(l2+0x60)};
m_Language.Assign(lang_str, 3);
} else {
m_Language.Assign("```", 3);
}
}
/*----------------------------------------------------------------------
| AP4_MdhdAtom::WriteFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_MdhdAtom::WriteFields(AP4_ByteStream& stream)
{
AP4_Result result;
if (m_Version == 0) {
result = stream.WriteUI32((AP4_UI32)m_CreationTime);
if (AP4_FAILED(result)) return result;
result = stream.WriteUI32((AP4_UI32)m_ModificationTime);
if (AP4_FAILED(result)) return result;
result = stream.WriteUI32(m_TimeScale);
if (AP4_FAILED(result)) return result;
result = stream.WriteUI32((AP4_UI32)m_Duration);
if (AP4_FAILED(result)) return result;
} else {
result = stream.WriteUI64(m_CreationTime);
if (AP4_FAILED(result)) return result;
result = stream.WriteUI64(m_ModificationTime);
if (AP4_FAILED(result)) return result;
result = stream.WriteUI32(m_TimeScale);
if (AP4_FAILED(result)) return result;
result = stream.WriteUI64(m_Duration);
if (AP4_FAILED(result)) return result;
}
// write the language
AP4_UI08 l0 = m_Language[0]-0x60;
AP4_UI08 l1 = m_Language[1]-0x60;
AP4_UI08 l2 = m_Language[2]-0x60;
result = stream.WriteUI08((l0<<2 | l1>>3)&0xFF);
if (AP4_FAILED(result)) return result;
result = stream.WriteUI08((l1<<5 | l2)&0xFF);
if (AP4_FAILED(result)) return result;
// pre-defined
return stream.WriteUI16(0);
}
/*----------------------------------------------------------------------
| AP4_MdhdAtom::GetDurationMs
+---------------------------------------------------------------------*/
AP4_UI32
AP4_MdhdAtom::GetDurationMs()
{
return AP4_DurationMsFromUnits(m_Duration, m_TimeScale);
}
/*----------------------------------------------------------------------
| AP4_MdhdAtom::InspectFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_MdhdAtom::InspectFields(AP4_AtomInspector& inspector)
{
inspector.AddField("timescale", m_TimeScale);
inspector.AddField("duration", m_Duration);
inspector.AddField("duration(ms)", GetDurationMs());
inspector.AddField("language", m_Language.GetChars());
return AP4_SUCCESS;
}
|
