ref: 50cd3b2fbb9a3993164e0ff25f700b8fe9d27e9f
dir: /common/mp4v2/mp4descriptor.cpp/
/* * 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 [email protected] */ #include "mp4common.h" MP4Descriptor::MP4Descriptor(u_int8_t tag) { m_tag = tag; m_pParentAtom = NULL; m_start = 0; m_size = 0; m_readMutatePoint = 0; } MP4Descriptor::~MP4Descriptor() { for (u_int32_t i = 0; i < m_pProperties.Size(); i++) { delete m_pProperties[i]; } } void MP4Descriptor::AddProperty(MP4Property* pProperty) { ASSERT(pProperty); m_pProperties.Add(pProperty); pProperty->SetParentAtom(m_pParentAtom); } bool MP4Descriptor::FindContainedProperty(const char *name, MP4Property** ppProperty, u_int32_t* pIndex) { u_int32_t numProperties = m_pProperties.Size(); for (u_int32_t i = 0; i < numProperties; i++) { if (m_pProperties[i]->FindProperty(name, ppProperty, pIndex)) { return true; } } return false; } void MP4Descriptor::Generate() { // generate properties for (u_int32_t i = 0; i < m_pProperties.Size(); i++) { m_pProperties[i]->Generate(); } } void MP4Descriptor::Read(MP4File* pFile) { ReadHeader(pFile); ReadProperties(pFile, 0, m_readMutatePoint); Mutate(); ReadProperties(pFile, m_readMutatePoint); // flush any leftover read bits pFile->FlushReadBits(); } void MP4Descriptor::ReadHeader(MP4File* pFile) { VERBOSE_READ(pFile->GetVerbosity(), printf("ReadDescriptor: pos = 0x%llx\n", pFile->GetPosition())); // read tag and length u_int8_t tag = pFile->ReadUInt8(); if (m_tag) { ASSERT(tag == m_tag); } else { m_tag = tag; } m_size = pFile->ReadMpegLength(); m_start = pFile->GetPosition(); VERBOSE_READ(pFile->GetVerbosity(), printf("ReadDescriptor: tag 0x%02x data size %u (0x%x)\n", m_tag, m_size, m_size)); } void MP4Descriptor::ReadProperties(MP4File* pFile, u_int32_t propStartIndex, u_int32_t propCount) { u_int32_t numProperties = MIN(propCount, m_pProperties.Size() - propStartIndex); for (u_int32_t i = propStartIndex; i < propStartIndex + numProperties; i++) { int32_t remaining = m_size - (pFile->GetPosition() - m_start); if (m_pProperties[i]->GetType() == DescriptorProperty && remaining >= 0) { // place a limit on how far this sub-descriptor looks ((MP4DescriptorProperty*)m_pProperties[i])->SetSizeLimit(remaining); m_pProperties[i]->Read(pFile); } else if (remaining >= 0) { m_pProperties[i]->Read(pFile); if (m_pProperties[i]->GetType() == TableProperty) { VERBOSE_READ_TABLE(pFile->GetVerbosity(), printf("Read: "); m_pProperties[i]->Dump(stdout, 0, true)); } else { VERBOSE_READ(pFile->GetVerbosity(), printf("Read: "); m_pProperties[i]->Dump(stdout, 0, true)); } } else { VERBOSE_ERROR(pFile->GetVerbosity(), printf("Overran descriptor, tag %u data size %u property %u\n", m_tag, m_size, i)); throw new MP4Error("overran descriptor", "MP4Descriptor::ReadProperties"); } } } void MP4Descriptor::Write(MP4File* pFile) { // call virtual function to adapt properties before writing Mutate(); u_int32_t numProperties = m_pProperties.Size(); if (numProperties == 0) { WARNING(numProperties == 0); return; } // write tag and length placeholder pFile->WriteUInt8(m_tag); u_int64_t lengthPos = pFile->GetPosition(); pFile->WriteMpegLength(0); u_int64_t startPos = pFile->GetPosition(); for (u_int32_t i = 0; i < numProperties; i++) { m_pProperties[i]->Write(pFile); } // align with byte boundary (rarely necessary) pFile->PadWriteBits(); // go back and write correct length u_int64_t endPos = pFile->GetPosition(); pFile->SetPosition(lengthPos); pFile->WriteMpegLength(endPos - startPos); pFile->SetPosition(endPos); } void MP4Descriptor::WriteToMemory(MP4File* pFile, u_int8_t** ppBytes, u_int64_t* pNumBytes) { // use memory buffer to save descriptor in memory // instead of going directly to disk pFile->EnableMemoryBuffer(); Write(pFile); pFile->DisableMemoryBuffer(ppBytes, pNumBytes); } void MP4Descriptor::Dump(FILE* pFile, u_int8_t indent, bool dumpImplicits) { // call virtual function to adapt properties before dumping Mutate(); u_int32_t numProperties = m_pProperties.Size(); if (numProperties == 0) { WARNING(numProperties == 0); return; } for (u_int32_t i = 0; i < numProperties; i++) { m_pProperties[i]->Dump(pFile, indent, dumpImplicits); } } u_int8_t MP4Descriptor::GetDepth() { if (m_pParentAtom) { return m_pParentAtom->GetDepth(); } return 0; }