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Diffstat (limited to 'src/mp4descriptor.cpp')
| -rw-r--r-- | src/mp4descriptor.cpp | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/mp4descriptor.cpp b/src/mp4descriptor.cpp new file mode 100644 index 0000000..70b585e --- /dev/null +++ b/src/mp4descriptor.cpp @@ -0,0 +1,221 @@ +/* + * 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 dmackie@cisco.com + */ + +#include "src/impl.h" + +namespace mp4v2 { +namespace impl { + +/////////////////////////////////////////////////////////////////////////////// + +MP4Descriptor::MP4Descriptor(uint8_t tag) { + m_tag = tag; + m_pParentAtom = NULL; + m_start = 0; + m_size = 0; + m_readMutatePoint = 0; +} + +MP4Descriptor::~MP4Descriptor() +{ + for (uint32_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, uint32_t* pIndex) +{ + uint32_t numProperties = m_pProperties.Size(); + + for (uint32_t i = 0; i < numProperties; i++) { + if (m_pProperties[i]->FindProperty(name, ppProperty, pIndex)) { + return true; + } + } + return false; +} + +void MP4Descriptor::Generate() +{ + // generate properties + for (uint32_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%" PRIx64 "\n", + pFile->GetPosition())); + + // read tag and length + uint8_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, + uint32_t propStartIndex, uint32_t propCount) +{ + uint32_t numProperties = min(propCount, + m_pProperties.Size() - propStartIndex); + + for (uint32_t i = propStartIndex; + i < propStartIndex + numProperties; i++) { + + MP4Property* pProperty = m_pProperties[i]; + + int32_t remaining = m_size - (pFile->GetPosition() - m_start); + + if (pProperty->GetType() == DescriptorProperty) { + if (remaining > 0) { + // place a limit on how far this sub-descriptor looks + ((MP4DescriptorProperty*)pProperty)->SetSizeLimit(remaining); + pProperty->Read(pFile); + } // else do nothing, empty descriptor + } else { + // non-descriptor property + if (remaining >= 0) { + pProperty->Read(pFile); + + if (pProperty->GetType() == TableProperty) { + VERBOSE_READ_TABLE(pFile->GetVerbosity(), + printf("Read: "); pProperty->Dump(stdout, 0, true)); + } else { + VERBOSE_READ(pFile->GetVerbosity(), + printf("Read: "); pProperty->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(); + + uint32_t numProperties = m_pProperties.Size(); + + if (numProperties == 0) { + WARNING(numProperties == 0); + return; + } + + // write tag and length placeholder + pFile->WriteUInt8(m_tag); + uint64_t lengthPos = pFile->GetPosition(); + pFile->WriteMpegLength(0); + uint64_t startPos = pFile->GetPosition(); + + for (uint32_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 + uint64_t endPos = pFile->GetPosition(); + pFile->SetPosition(lengthPos); + pFile->WriteMpegLength(endPos - startPos); + pFile->SetPosition(endPos); +} + +void MP4Descriptor::WriteToMemory(MP4File* pFile, + uint8_t** ppBytes, uint64_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, uint8_t indent, bool dumpImplicits) +{ + // call virtual function to adapt properties before dumping + Mutate(); + + uint32_t numProperties = m_pProperties.Size(); + + if (numProperties == 0) { + WARNING(numProperties == 0); + return; + } + for (uint32_t i = 0; i < numProperties; i++) { + m_pProperties[i]->Dump(pFile, indent, dumpImplicits); + } +} + +uint8_t MP4Descriptor::GetDepth() +{ + if (m_pParentAtom) { + return m_pParentAtom->GetDepth(); + } + return 0; +} + +/////////////////////////////////////////////////////////////////////////////// + +} +} // namespace mp4v2::impl |