海康威视实时预览回调PS流用EasyRTMP向RTMP服务器推流中视频数据处理的代码
在上一篇方案《EasyRTMP结合海康HCNetSDK获取海康摄像机H.264实时流并转化成为RTMP直播推流（附源码）》我们介绍了将海康安防摄像机进行互联网直播的整体方案流程，其中有一个流程“数据处理与分析”我们当时没有展开详述，今天我们将海康HCNetSDK实时预览回调接口数据处理的过程，尤其是在RealDataCallback中对AVData的处理过程：
case NET_DVR_STREAMDATA:
{
BOOL inData=PlayM4_InputData(nPort,pBuffer,dwBufSize);
while (!inData)
{
Sleep(10);
inData=PlayM4_InputData(nPort,pBuffer,dwBufSize);
OutputDebugString("PlayM4_InputData failed \n");
}
//PS流数据解析处理
{
int nI = 0;
int nCacheSize = 0;
nI = m_mFrameCacheLenth[lRealHandle];
//直接--提取H264数据
BOOL bVideo = FALSE;
BOOL bPatialData = FALSE;
bPatialData = GetH246FromPS(pBuffer,dwBufSize, &m_pFrameCache[lRealHandle][nI].pCacheBuffer,
m_pFrameCache[lRealHandle][nI].nCacheBufLenth, bVideo);
if (bVideo)
{
if (bPatialData)//部分包数据
{
//缓存数据
m_pFrameCache[lRealHandle][nI].lTimeStamp = clock();
m_mFrameCacheLenth[lRealHandle]++;
}
else//包头
{
int i = 0;
if(m_mFrameCacheLenth[lRealHandle]>0)
{
long lH264DataLenth = m_mFrameCacheLenth[lRealHandle]*MAX_PACK_SIZE;
BYTE* pH264Nal = NULL;
pH264Nal = new BYTE[lH264DataLenth];
memset(pH264Nal, 0x00, lH264DataLenth);
BYTE* pTempBuffer = pH264Nal;
int nTempBufLenth = 0;
//TRACE("m_mFrameCacheLenth==%d\r\n", pDemoDlg->m_mFrameCacheLenth);
// 最大缓存数据个数设为pDemoDlg->m_mFrameCacheLenth，程序会过程中报错，Why? [5/6/2014-13:19:51 Dingshuai]
for (i=0; i</*MAX_FRAME_LENTH*/m_mFrameCacheLenth[lRealHandle]; i++)
{
if(m_pFrameCache[lRealHandle][i].pCacheBuffer!=NULL&&m_pFrameCache[lRealHandle][i].nCacheBufLenth>0)
{
// memcpy(pTempBuffer, m_pFrameCache[i].pCacheBuffer, m_pFrameCache[i].nCacheBufLenth);
// pTempBuffer = pTempBuffer + m_pFrameCache[i].nCacheBufLenth;
memcpy(pH264Nal+nTempBufLenth, m_pFrameCache[lRealHandle][i].pCacheBuffer,
m_pFrameCache[lRealHandle][i].nCacheBufLenth);
nTempBufLenth += m_pFrameCache[lRealHandle][i].nCacheBufLenth;
}
if (m_pFrameCache[lRealHandle][i].pCacheBuffer)
{
delete [](m_pFrameCache[lRealHandle][i].pCacheBuffer);
m_pFrameCache[lRealHandle][i].pCacheBuffer = NULL;
}
m_pFrameCache[lRealHandle][i].nCacheBufLenth = 0;
}
if (m_bRtmpRunning && pH264Nal && nTempBufLenth>0)
{
BOOL bIsKeyFrame = FALSE;
//查找是否为关键帧
if(pH264Nal[4]==0x67)
{
bIsKeyFrame = TRUE;
}
long lTimeStamp = clock();
WriteH264DataToChace(lRealHandle, pH264Nal, nTempBufLenth, bIsKeyFrame, lTimeStamp);
}
if (pH264Nal)
{
delete []pH264Nal;
pH264Nal = NULL;
}
// 缓存数据个数 清0
m_mFrameCacheLenth[lRealHandle] = 0;
}
}
}
}
}
通过对上述代码的分析，整个视频流回调过程还是比较简单的：判断回调数据类型（NET_DVR_STREAMDATA）–》海康PS数据Demux成音视频ES数据（GetH246FromPS）–》对关键帧数据做缓存和处理（bIsKeyFrame ）–》进入转推RTMP缓存队列（WriteH264DataToChace）
海康PS流解析：
BOOL CDecCallBack_DemoDlg::GetH246FromPS(IN BYTE* pBuffer, IN int nBufLenth, BYTE** pH264, int& nH264Lenth, BOOL& bVideo)
{
if (!pBuffer || nBufLenth<=0)
{
return FALSE;
}
BYTE* pH264Buffer = NULL;
int nHerderLen = 0;
if( pBuffer
&& pBuffer[0]==0x00
&& pBuffer[1]==0x00
&& pBuffer[2]==0x01
&& pBuffer[3]==0xE0)//E==视频数据(此处E0标识为视频)
{
bVideo = TRUE;
nHerderLen = 9 + (int)pBuffer[8];//9个为固定的数据包头长度，pBuffer[8]为填充头部分的长度
pH264Buffer = pBuffer+nHerderLen;
if (*pH264 == NULL)
{
*pH264 = new BYTE[nBufLenth];
}
if (*pH264&&pH264Buffer&&(nBufLenth-nHerderLen)>0)
{
memcpy(*pH264, pH264Buffer, (nBufLenth-nHerderLen));
}
nH264Lenth = nBufLenth-nHerderLen;
return TRUE;
}
else if(pBuffer
&& pBuffer[0]==0x00
&& pBuffer[1]==0x00
&& pBuffer[2]==0x01
&& pBuffer[3]==0xC0) //C==音频数据
{
*pH264 = NULL;
nH264Lenth = 0;
bVideo = FALSE;
}
else if(pBuffer
&& pBuffer[0]==0x00
&& pBuffer[1]==0x00
&& pBuffer[2]==0x01
&& pBuffer[3]==0xBA)//视频流数据包 包头
{
bVideo = TRUE;
*pH264 = NULL;
nH264Lenth = 0;
return FALSE;
}
return FALSE;
}
海康音视频数据进行RTMP推流：
int CDecCallBack_DemoDlg::WriteH264DataToChace(int nDevId, BYTE* pBuffer, int nBufSize, BOOL bIsKeyFrame, long lTimeStamp)
{
if (!pBuffer || nBufSize<=0 || lTimeStamp<0)
{
return -1;
}
BOOL bKeyFrame = bIsKeyFrame;
int nDeviceType = nDevId+1;
if (m_RtmpHandle && m_bRtmpRunning)
{
//H264推送RTMP
EASY_AV_Frame avFrame;
memset(&avFrame, 0x00, sizeof(EASY_AV_Frame));
avFrame.pBuffer = (unsigned char*)pBuffer;
avFrame.u32AVFrameLen = nBufSize;
avFrame.u32VFrameType = (bKeyFrame)?EASY_SDK_VIDEO_FRAME_I:EASY_SDK_VIDEO_FRAME_P;
avFrame.u32AVFrameFlag = EASY_SDK_VIDEO_FRAME_FLAG;
avFrame.u32TimestampSec = lTimeStamp/1000000;
avFrame.u32TimestampUsec = (lTimeStamp%1000000);
//EnterCriticalSection(&m_cs);
EasyRTMP_SendPacket(m_RtmpHandle, &avFrame);
}
return 1;
}
经过上述步骤，基本完成了对一路SDK数据回调的处理，如果需要一个完整的、系统的、中间件级别的流转服务，那还需要一套完整的控制机制和配套接口以及前端界面，就类似于EasyNVR一样。
本文中所述详细代码见：https://github.com/EasyDSS/EasyRTMP/tree/master/EasyRTMP_HIK
