mp4atom.cpp

MPEG-4编解码的实现(包括MPEG4视音频编解码)

/*
 * 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"
#include "atoms.h"

MP4AtomInfo::MP4AtomInfo(const char* name, bool mandatory, bool onlyOne) 
{
	m_name = name;
	m_mandatory = mandatory;
	m_onlyOne = onlyOne;
	m_count = 0;
}

MP4Atom::MP4Atom(const char* type) 
{
	SetType(type);
	m_unknownType = FALSE;
	m_pFile = NULL;
	m_start = 0;
	m_end = 0;
	m_size = 0;
	m_pParentAtom = NULL;
	m_depth = 0xFF;
}

MP4Atom::~MP4Atom()
{
	u_int32_t i;

	for (i = 0; i < m_pProperties.Size(); i++) {
		delete m_pProperties[i];
	}
	for (i = 0; i < m_pChildAtomInfos.Size(); i++) {
		delete m_pChildAtomInfos[i];
	}
	for (i = 0; i < m_pChildAtoms.Size(); i++) {
		delete m_pChildAtoms[i];
	}
}

MP4Atom* MP4Atom::CreateAtom(const char* type)
{
	MP4Atom* pAtom = NULL;

	if (type == NULL) {
		pAtom = new MP4RootAtom();
	} else if (type[0] == 'c') {
		if (ATOMID(type) == ATOMID("ctts")) {
			pAtom = new MP4CttsAtom();
		} else if (ATOMID(type) == ATOMID("co64")) {
			pAtom = new MP4Co64Atom();
		} else if (ATOMID(type) == ATOMID("cprt")) {
			pAtom = new MP4CprtAtom();
		}
	} else if (type[0] == 'd') {
		if (ATOMID(type) == ATOMID("dinf")) {
			pAtom = new MP4DinfAtom();
		} else if (ATOMID(type) == ATOMID("dref")) {
			pAtom = new MP4DrefAtom();
		} else if (ATOMID(type) == ATOMID("dpnd")) {
			pAtom = new MP4TrefTypeAtom(type);
		} else if (ATOMID(type) == ATOMID("dmed")) {
			pAtom = new MP4DmedAtom();
		} else if (ATOMID(type) == ATOMID("dimm")) {
			pAtom = new MP4DimmAtom();
		} else if (ATOMID(type) == ATOMID("drep")) {
			pAtom = new MP4DrepAtom();
		} else if (ATOMID(type) == ATOMID("dmax")) {
			pAtom = new MP4DmaxAtom();
		}
	} else if (type[0] == 'e') {
		if (ATOMID(type) == ATOMID("esds")) {
			pAtom = new MP4EsdsAtom();
		} else if (ATOMID(type) == ATOMID("edts")) {
			pAtom = new MP4EdtsAtom();
		} else if (ATOMID(type) == ATOMID("elst")) {
			pAtom = new MP4ElstAtom();
		}
	} else if (type[0] == 'h') {
		if (ATOMID(type) == ATOMID("hdlr")) {
			pAtom = new MP4HdlrAtom();
		} else if (ATOMID(type) == ATOMID("hmhd")) {
			pAtom = new MP4HmhdAtom();
		} else if (ATOMID(type) == ATOMID("hint")) {
			pAtom = new MP4TrefTypeAtom(type);
		} else if (ATOMID(type) == ATOMID("hnti")) {
			pAtom = new MP4HntiAtom();
		} else if (ATOMID(type) == ATOMID("hinf")) {
			pAtom = new MP4HinfAtom();
		}
	} else if (type[0] == 'm') {
		if (ATOMID(type) == ATOMID("mdia")) {
			pAtom = new MP4MdiaAtom();
		} else if (ATOMID(type) == ATOMID("minf")) {
			pAtom = new MP4MinfAtom();
		} else if (ATOMID(type) == ATOMID("mdhd")) {
			pAtom = new MP4MdhdAtom();
		} else if (ATOMID(type) == ATOMID("mdat")) {
			pAtom = new MP4MdatAtom();
		} else if (ATOMID(type) == ATOMID("moov")) {
			pAtom = new MP4MoovAtom();
		} else if (ATOMID(type) == ATOMID("mvhd")) {
			pAtom = new MP4MvhdAtom();
		} else if (ATOMID(type) == ATOMID("mpod")) {
			pAtom = new MP4TrefTypeAtom(type);
		} else if (ATOMID(type) == ATOMID("mp4a")) {
			pAtom = new MP4Mp4aAtom();
		} else if (ATOMID(type) == ATOMID("mp4s")) {
			pAtom = new MP4Mp4sAtom();
		} else if (ATOMID(type) == ATOMID("mp4v")) {
			pAtom = new MP4Mp4vAtom();
		} else if (ATOMID(type) == ATOMID("moof")) {
			pAtom = new MP4MoofAtom();
		} else if (ATOMID(type) == ATOMID("mfhd")) {
			pAtom = new MP4MfhdAtom();
		} else if (ATOMID(type) == ATOMID("mvex")) {
			pAtom = new MP4MvexAtom();
		} else if (ATOMID(type) == ATOMID("maxr")) {
			pAtom = new MP4MaxrAtom();
		}
	} else if (type[0] == 's') {
		if (ATOMID(type) == ATOMID("stbl")) {
			pAtom = new MP4StblAtom();
		} else if (ATOMID(type) == ATOMID("stsd")) {
			pAtom = new MP4StsdAtom();
		} else if (ATOMID(type) == ATOMID("stts")) {
			pAtom = new MP4SttsAtom();
		} else if (ATOMID(type) == ATOMID("stsz")) {
			pAtom = new MP4StszAtom();
		} else if (ATOMID(type) == ATOMID("stsc")) {
			pAtom = new MP4StscAtom();
		} else if (ATOMID(type) == ATOMID("stco")) {
			pAtom = new MP4StcoAtom();
		} else if (ATOMID(type) == ATOMID("stss")) {
			pAtom = new MP4StssAtom();
		} else if (ATOMID(type) == ATOMID("stsh")) {
			pAtom = new MP4StshAtom();
		} else if (ATOMID(type) == ATOMID("stdp")) {
			pAtom = new MP4StdpAtom();
		} else if (ATOMID(type) == ATOMID("smhd")) {
			pAtom = new MP4SmhdAtom();
		} else if (ATOMID(type) == ATOMID("sdp ")) {
			pAtom = new MP4SdpAtom();
		} else if (ATOMID(type) == ATOMID("snro")) {
			pAtom = new MP4SnroAtom();
		} else if (ATOMID(type) == ATOMID("sync")) {
			pAtom = new MP4TrefTypeAtom(type);
		} else if (ATOMID(type) == ATOMID("skip")) {
			pAtom = new MP4FreeAtom();
			pAtom->SetType("skip");
		}
	} else if (type[0] == 't') {
		if (ATOMID(type) == ATOMID("trak")) {
			pAtom = new MP4TrakAtom();
		} else if (ATOMID(type) == ATOMID("tkhd")) {
			pAtom = new MP4TkhdAtom();
		} else if (ATOMID(type) == ATOMID("tref")) {
			pAtom = new MP4TrefAtom();
		} else if (ATOMID(type) == ATOMID("traf")) {
			pAtom = new MP4TrafAtom();
		} else if (ATOMID(type) == ATOMID("tfhd")) {
			pAtom = new MP4TfhdAtom();
		} else if (ATOMID(type) == ATOMID("trex")) {
			pAtom = new MP4TrexAtom();
		} else if (ATOMID(type) == ATOMID("trun")) {
			pAtom = new MP4TrunAtom();
		} else if (ATOMID(type) == ATOMID("tmin")) {
			pAtom = new MP4TminAtom();
		} else if (ATOMID(type) == ATOMID("tmax")) {
			pAtom = new MP4TmaxAtom();
		} else if (ATOMID(type) == ATOMID("trpy")) {
			pAtom = new MP4TrpyAtom();
		} else if (ATOMID(type) == ATOMID("tpyl")) {
			pAtom = new MP4TpylAtom();
		} else if (ATOMID(type) == ATOMID("tims")) {
			pAtom = new MP4TimsAtom();
		} else if (ATOMID(type) == ATOMID("tsro")) {
			pAtom = new MP4TsroAtom();
		}
	} else if (type[0] == 'u') {
		if (ATOMID(type) == ATOMID("udta")) {
			pAtom = new MP4UdtaAtom();
		} else if (ATOMID(type) == ATOMID("url ")) {
			pAtom = new MP4UrlAtom();
		} else if (ATOMID(type) == ATOMID("urn ")) {
			pAtom = new MP4UrnAtom();
		}
	} else {
		if (ATOMID(type) == ATOMID("free")) {
			pAtom = new MP4FreeAtom();
		} else if (ATOMID(type) == ATOMID("ftyp")) {
			pAtom = new MP4FtypAtom();
		} else if (ATOMID(type) == ATOMID("iods")) {
			pAtom = new MP4IodsAtom();
		} else if (ATOMID(type) == ATOMID("ipir")) {
			pAtom = new MP4TrefTypeAtom(type);
		} else if (ATOMID(type) == ATOMID("nmhd")) {
			pAtom = new MP4NmhdAtom();
		} else if (ATOMID(type) == ATOMID("nump")) {
			pAtom = new MP4NumpAtom();
		} else if (ATOMID(type) == ATOMID("pmax")) {
			pAtom = new MP4PmaxAtom();
		} else if (ATOMID(type) == ATOMID("payt")) {
			pAtom = new MP4PaytAtom();
		} else if (ATOMID(type) == ATOMID("rtp ")) {
			pAtom = new MP4RtpAtom();
		} else if (ATOMID(type) == ATOMID("vmhd")) {
			pAtom = new MP4VmhdAtom();
		}
	}

	if (pAtom == NULL) {
		pAtom = new MP4Atom(type);
		pAtom->SetUnknownType(true);
	}

	ASSERT(pAtom);
	return pAtom;
}

// generate a skeletal self

void MP4Atom::Generate()
{
	u_int32_t i;

	// for all properties
	for (i = 0; i < m_pProperties.Size(); i++) {
		// ask it to self generate
		m_pProperties[i]->Generate();
	}

	// for all mandatory, single child atom types
	for (i = 0; i < m_pChildAtomInfos.Size(); i++) {
		if (m_pChildAtomInfos[i]->m_mandatory
		  && m_pChildAtomInfos[i]->m_onlyOne) {

			// create the mandatory, single child atom
			MP4Atom* pChildAtom = 
				CreateAtom(m_pChildAtomInfos[i]->m_name);

			AddChildAtom(pChildAtom);

			// and ask it to self generate
			pChildAtom->Generate();
		}
	}
}

MP4Atom* MP4Atom::ReadAtom(MP4File* pFile, MP4Atom* pParentAtom)
{
	u_int8_t hdrSize = 8;
	u_int8_t extendedType[16];

	u_int64_t pos = pFile->GetPosition();

	VERBOSE_READ(pFile->GetVerbosity(), 
		printf("ReadAtom: pos = 0x"LLX"\n", pos));

	u_int64_t dataSize = pFile->ReadUInt32();

	if (dataSize == 1) {
		dataSize = pFile->ReadUInt64(); 
		hdrSize += 8;
	}

	char type[5];
	pFile->ReadBytes((u_int8_t*)&type[0], 4);
	type[4] = '\0';

	// extended type
	if (ATOMID(type) == ATOMID("uuid")) {
		pFile->ReadBytes(extendedType, sizeof(extendedType));
		hdrSize += sizeof(extendedType);
	}

	if (dataSize == 0) {
		// extends to EOF
		dataSize = pFile->GetSize() - pos;
	}

	dataSize -= hdrSize;

	VERBOSE_READ(pFile->GetVerbosity(), 
		printf("ReadAtom: type = %s data-size = "LLU" (0x"LLX")\n", 
			type, dataSize, dataSize));

	if (pos + hdrSize + dataSize > pParentAtom->GetEnd()) {
		VERBOSE_READ(pFile->GetVerbosity(), 
			printf("ReadAtom: invalid atom size, extends outside parent atom\n"));
		throw new MP4Error("invalid atom size", "ReadAtom");
	}


	MP4Atom* pAtom = CreateAtom(type);
	pAtom->SetFile(pFile);
	pAtom->SetStart(pos);
	pAtom->SetEnd(pos + hdrSize + dataSize);
	pAtom->SetSize(dataSize);
	if (ATOMID(type) == ATOMID("uuid")) {
		pAtom->SetExtendedType(extendedType);
	}
	if (pAtom->IsUnknownType()) {
		if (!IsReasonableType(pAtom->GetType())) {
			VERBOSE_READ(pFile->GetVerbosity(),
				printf("Warning: atom type %s is suspect\n", pAtom->GetType()));
		} else {
			VERBOSE_READ(pFile->GetVerbosity(),
				printf("Info: atom type %s is unknown\n", pAtom->GetType()));
		}

		if (dataSize > 0) {
			pAtom->AddProperty(
				new MP4BytesProperty("data", dataSize));
		}
	}

	pAtom->SetParentAtom(pParentAtom);

	pAtom->Read();

	return pAtom;
}

bool MP4Atom::IsReasonableType(const char* type)
{
	for (u_int8_t i = 0; i < 4; i++) {
		if (isalnum(type[i])) {
			continue;
		}
		if (i == 3 && type[i] == ' ') {
			continue;
		}
		return false;
	}
	return true;
}

// generic read
void MP4Atom::Read()
{
	ASSERT(m_pFile);

	if (ATOMID(m_type) != 0 && m_size > 1000000) {
		VERBOSE_READ(GetVerbosity(), 
			printf("Warning: %s atom size "LLU" is suspect\n",
				m_type, m_size));
	}

	ReadProperties();

	// read child atoms, if we expect there to be some
	if (m_pChildAtomInfos.Size() > 0) {
		ReadChildAtoms();
	}

	Skip();	// to end of atom
}

void MP4Atom::Skip()
{
	if (m_pFile->GetPosition() != m_end) {
		VERBOSE_READ(m_pFile->GetVerbosity(),
			printf("Skip: "LLU" bytes\n", m_end - m_pFile->GetPosition()));
	}
	m_pFile->SetPosition(m_end);
}

MP4Atom* MP4Atom::FindAtom(const char* name)
{
	if (!IsMe(name)) {
		return NULL;
	}

	if (!IsRootAtom()) {