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/*
* 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 "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"X64"\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++) {
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);
} 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);
}
u_int8_t MP4Descriptor::GetDepth()
{
if (m_pParentAtom) {
return m_pParentAtom->GetDepth();
}
return 0;
}
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