H264流式分析NALU单元代码实现

#include "NaluAnalyzer.h" #include <assert.h> #include "TImsIOBuffer.h" NaluAnalyzer::NaluAnalyzer(): m_pSink() { m_pBuffer = new ImsIOBuffer(); m_pBuffer->ensure(1024 * 800); } NaluAnalyzer::~NaluAnalyzer() { if (m_pBuffer != NULL) { delete m_pBuffer; m_pBuffer = NULL; } } bool NaluAnalyzer::inputData(const uint8_t* buffer, size_t length,long long nTimestamp) { if (length == 0) { return false; } m_pBuffer->write(buffer, length); bool found = false; while (true) { uint8_t* data = m_pBuffer->getReadPtr(); size_t size = m_pBuffer->readable(); NaluPacket firstPacket; if (!findNalu(data, size, 0, firstPacket)) { if (size > 3) { m_pBuffer->skip(size - 3 + 1); } break; } if (firstPacket.length != 0) { m_pBuffer->skip(firstPacket.length); continue; } NaluPacket secondPacket; if (!findNalu(data, size, firstPacket.length + firstPacket.prefix, secondPacket)) { if (m_analyzerAll) { firstPacket.data = data; firstPacket.length = size; firstPacket.nTimestamp = nTimestamp; writePacket(firstPacket); m_pBuffer->skipAll(); found = true; } break; } firstPacket.length = secondPacket.length - firstPacket.length; firstPacket.nTimestamp = nTimestamp; writePacket(firstPacket); m_pBuffer->skip(secondPacket.length); found = true; } return found; } void NaluAnalyzer::setSink(NaluAnalyzerSink* pSink,bool analyzerAll) { m_pSink = pSink; m_analyzerAll = analyzerAll; } void NaluAnalyzer::clear() { m_pBuffer->clear(); } void NaluAnalyzer::writePacket(NaluPacket& packet) { if (!m_pSink) { return ; } m_pSink->naluAnalyPacket(packet); } bool NaluAnalyzer::findNalu(uint8_t* buffer, size_t length, size_t start, NaluPacket& packet) { if ((length < 3) || ((length - start) < 3)) { return false; } bool found = false; uint8_t* p = buffer; for (size_t i = start; i < (length - 3); ++ i) { if ( p[i] == 0) { if (p[i+1] == 0) { if (p[i+2] == 0) { if (((i + 3) < length) && (p[i+3] == 1)) { packet.data = p + i; packet.length = i; packet.prefix = 4; packet.type = packet.data[4] & 0x1F; found = true; break; } } else { i++; } } else { i++; } } } return found; }