void MP4DescriptorProperty::Read(MP4File* pFile, u_int32_t index) { ASSERT(index == 0); if (m_implicit) { return; } u_int64_t start = pFile->GetPosition(); while (true) { // enforce size limitation if (m_sizeLimit && pFile->GetPosition() >= start + m_sizeLimit) { break; } u_int8_t tag; try { pFile->PeekBytes(&tag, 1); } catch (MP4Error* e) { if (pFile->GetPosition() >= pFile->GetSize()) { // EOF delete e; break; } throw e; } // check if tag is in desired range if (tag < m_tagsStart || tag > m_tagsEnd) { break; } MP4Descriptor* pDescriptor = AddDescriptor(tag); pDescriptor->Read(pFile); } // warnings if (m_mandatory && m_pDescriptors.Size() == 0) { VERBOSE_READ(pFile->GetVerbosity(), printf("Warning: Mandatory descriptor 0x%02x missing\n", m_tagsStart)); } else if (m_onlyOne && m_pDescriptors.Size() > 1) { VERBOSE_READ(pFile->GetVerbosity(), printf("Warning: Descriptor 0x%02x has more than one instance\n", m_tagsStart)); } }