视频流中的缓冲池处理

在视频处理中，为了让图像能流畅的播放，往往需要一个缓冲区、循环队列往往被用到其中。下面的无限循环队列就用来做流媒体中的缓冲区处理，用以解决视频的不流畅的问题：

#include "ssqueue.h"
#include <time.h>
#include <stdarg.h>
#include "trace.h"


int SSQ_Init(SS_QUEUE_OBJ_T *pObj, unsigned int sharememory, unsigned int channelid, wchar_t *sharename, unsigned int bufsize, unsigned int prerecordsecs, unsigned int createsharememory)
{
wchar_t wszHeaderName[36] = {0,};
wchar_t wszFramelistName[36] = {0,};
wchar_t wszDataName[36] = {0,};
if (NULL==pObj) return -1;
if (createsharememory==0x01 && bufsize<1) return -1;
if ( (sharememory==0x01) && (NULL==sharename || (0==wcscmp(sharename, TEXT("\0")))) ) return -1;


memset(pObj, 0x00, sizeof(SS_QUEUE_OBJ_T));
pObj->channelid = channelid;
pObj->shareinfo.id = channelid;
wcscpy(pObj->shareinfo.name, sharename);


wchar_t wszMutexName[36] = {0,};
wsprintf(wszMutexName, TEXT("%s%d_mutex"), sharename, channelid);
pObj->hMutex = OpenMutex(NULL, FALSE, wszMutexName);
if (NULL == pObj->hMutex)
{
pObj->hMutex = CreateMutex(NULL, FALSE, wszMutexName);
if (NULL == pObj->hMutex) return -1;
}


//Create Header map


#ifdef _WIN32
if (sharememory == 0x01)
{
wsprintf(wszHeaderName, TEXT("%s%d_h"), sharename, channelid);
pObj->hSSHeader = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, wszHeaderName);
if (NULL==pObj->hSSHeader && createsharememory==0x01)
{
pObj->hSSHeader = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE|SEC_COMMIT, 0, sizeof(SS_HEADER_T), wszHeaderName);
if (NULL==pObj->hSSHeader || pObj->hSSHeader==INVALID_HANDLE_VALUE)
{
return -1;
}
}
pObj->pQueHeader = (SS_HEADER_T*)MapViewOfFile(pObj->hSSHeader, FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, 0);
if (createsharememory==0x01)
{
if (pObj->pQueHeader->bufsize < 1)
{
memset(pObj->pQueHeader, 0x00, sizeof(SS_HEADER_T));
pObj->pQueHeader->bufsize = bufsize;
}
}
else if (NULL==pObj->pQueHeader)
{
return -1;
}
else
{
bufsize = pObj->pQueHeader->bufsize;
  }
}
else
{
pObj->pQueHeader = new SS_HEADER_T;
memset(pObj->pQueHeader, 0x00, sizeof(SS_HEADER_T));
}


//==========================================
//Create frame list map
if (prerecordsecs > 0)
{
wsprintf(wszFramelistName, TEXT("%s%d_f"), sharename, channelid);
unsigned int nFramelistNum = prerecordsecs * 30; //每秒30帧
unsigned int nFrameQueSize = nFramelistNum*sizeof(FRAMEINFO_LIST_T);


if (sharememory == 0x01)
{
pObj->hSSFrameList = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, wszFramelistName);
if (NULL==pObj->hSSFrameList && createsharememory==0x01)
{
pObj->hSSFrameList = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE|SEC_COMMIT, 0, nFrameQueSize, wszFramelistName);
if (NULL==pObj->hSSFrameList || pObj->hSSFrameList==INVALID_HANDLE_VALUE)
{
return -1;
}
}
pObj->pFrameinfoList = (FRAMEINFO_LIST_T*)MapViewOfFile(pObj->hSSFrameList, FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, 0);
if (createsharememory==0x01)
{
memset(pObj->pFrameinfoList, 0x00, nFrameQueSize);
pObj->pQueHeader->framelistNum = nFramelistNum;
}
else if (NULL==pObj->hSSFrameList)
{
return -1;
}
}
else
{
pObj->pFrameinfoList = new FRAMEINFO_LIST_T[nFramelistNum];
memset(&pObj->pFrameinfoList[0], 0x00, sizeof(FRAMEINFO_LIST_T)*nFramelistNum);
pObj->pQueHeader->framelistNum = nFramelistNum;
}
}


//Create data map
if (sharememory == 0x01)
{
wsprintf(wszDataName, TEXT("%s%d_b"), sharename, channelid);
pObj->hSSData = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, wszDataName);
if (NULL==pObj->hSSData && createsharememory==0x01)
{
pObj->hSSData = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE|SEC_COMMIT, 0, bufsize, wszDataName);
}
if (NULL == pObj->hSSData || pObj->hSSData==INVALID_HANDLE_VALUE)
{
return -1;
}
pObj->pQueData = (char*)MapViewOfFile(pObj->hSSData, FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, 0);
}
else
{
pObj->pQueData = new char [bufsize];
pObj->pQueHeader->bufsize = bufsize;
}
if (createsharememory==0x01)
{
//memset(pQueHeader, 0x00, sizeof(SS_HEADER_T));
memset(pObj->pQueData, 0x00, bufsize);
}
#else
int ret = shm_create((SYNC_VID_SHM_KEY<<8)|channelid, &pObj->shmHdrid, sizeof(SS_HEADER_T), (char**)&pObj->pQueHeader);
if (ret < 0)
{
return -1;
}
SSQ_TRACE("[%d]pQueHeader: %d\n", (SYNC_VID_SHM_KEY<<8)|channelid, pObj->shmHdrid);
ret = shm_create((SYNC_VID_SHM_KEY<<16)|channelid, &pObj->shmDatid, bufsize, (char**)&pObj->pQueData);
if (ret < 0)
{
shm_delete(&pObj->shmHdrid, (char*)pObj->pQueHeader);
return -1;
}
pObj->pQueHeader->bufsize = bufsize;
SSQ_TRACE("[%d]pQueData: %d\n", (SYNC_VID_SHM_KEY<<16)|channelid, pObj->shmDatid);
#endif


return 0;
}
int SSQ_Deinit(SS_QUEUE_OBJ_T *pObj)
{
if (NULL == pObj) return -1;




#ifdef _WIN32


if (NULL != pObj->hMutex)
{
CloseHandle(pObj->hMutex);
pObj->hMutex = NULL;
}


if (NULL != pObj->hSSHeader)
{
if (! UnmapViewOfFile(pObj->pQueHeader))
{
}
pObj->pQueHeader = NULL;
CloseHandle(pObj->hSSHeader);
pObj->hSSHeader = NULL;
}
if (NULL != pObj->pQueHeader)
{
delete []pObj->pQueHeader;
pObj->pQueHeader = NULL;
}


if (NULL != pObj->hSSData)
{
if (! UnmapViewOfFile(pObj->pQueData))
{
}
pObj->pQueData = NULL;
CloseHandle(pObj->hSSData);
pObj->hSSData = NULL;
}
if (NULL != pObj->pQueData)
{
delete []pObj->pQueData;
pObj->pQueData = NULL;
}
if (NULL != pObj->hSSFrameList)
{
if (! UnmapViewOfFile(pObj->pFrameinfoList))
{
}
pObj->pFrameinfoList = NULL;
CloseHandle(pObj->hSSFrameList);
pObj->hSSFrameList = NULL;
}
if (NULL != pObj->pFrameinfoList)
{
delete []pObj->pFrameinfoList;
pObj->pFrameinfoList = NULL;
}


#else
if (pObj->shmHdrid>0 && pObj->pQueHeader!=NULL)
{
shm_delete(&pObj->shmHdrid, (char*)pObj->pQueHeader);
}
if (pObj->shmDatid>0 && pObj->pQueData!=NULL)
{
shm_delete(&pObj->shmDatid, (char*)pObj->pQueData);
pObj->pQueData = NULL;
}
#endif
return 0;
}


int SSQ_SetClearFlag(SS_QUEUE_OBJ_T *pObj, unsigned int _flag)
{
if (NULL == pObj) return -1;
if (NULL==pObj->pQueData) return -1;


pObj->pQueHeader->clear_flag = _flag;
return 0;
}
int SSQ_Clear(SS_QUEUE_OBJ_T *pObj)
{
if (NULL == pObj) return -1;
if (NULL==pObj->pQueData) return -1;




//WaitForSingleObject(pObj->hMutex, INFINITE);
//Lock();
pObj->pQueHeader->writepos = 0;
pObj->pQueHeader->readpos  = 0;
pObj->pQueHeader->totalsize= 0;


pObj->pQueHeader->videoframes = 0; //视频帧数


pObj->pQueHeader->maxframeno = 0;
pObj->pQueHeader->frameno = 0;


memset(pObj->pQueData, 0x00, pObj->pQueHeader->bufsize);


//ReleaseMutex(pObj->hMutex);


//Unlock();
return 0;
}


int SSQ_AddFrameInfo(SS_QUEUE_OBJ_T *pObj, unsigned int _pos, MEDIA_FRAME_INFO *frameinfo)
{
if (NULL == pObj) return -1;
if (NULL == pObj->pQueHeader) return -1;
if (NULL == pObj->pFrameinfoList) return -1;


if ( pObj->pQueHeader->frameno+1 > pObj->pQueHeader->framelistNum)
{
memmove((char*)pObj->pFrameinfoList, (char*)pObj->pFrameinfoList+sizeof(FRAMEINFO_LIST_T), sizeof(FRAMEINFO_LIST_T)*pObj->pQueHeader->framelistNum-1);
pObj->pQueHeader->frameno --;
pObj->pQueHeader->maxframeno = pObj->pQueHeader->frameno+1;
}


pObj->pFrameinfoList[pObj->pQueHeader->frameno].pos = pObj->pQueHeader->writepos;
#ifdef _DEBUG1
static int nTimestamp = 0;
pObj->pQueHeader->pFrameinfoList[pObj->pQueHeader->frameno].timestamp = ++nTimestamp;
#else
pObj->pFrameinfoList[pObj->pQueHeader->frameno].timestamp_sec = frameinfo->timestamp_sec;
pObj->pFrameinfoList[pObj->pQueHeader->frameno].rtp_timestamp = frameinfo->timestamp_sec*1000+frameinfo->timestamp_usec/1000;
#endif
//SSQ_TRACE("帧号: %d\n", pObj->pQueHeader->frameno);
pObj->pQueHeader->frameno ++;
pObj->pQueHeader->maxframeno = pObj->pQueHeader->frameno;


/*
if ( pObj->pQueHeader->frameno >= pObj->pQueHeader->framelistNum)
{
SSQ_TRACE("最大帧: %d\n", pObj->pQueHeader->maxframeno);
pObj->pQueHeader->frameno = 0;
}
if (pObj->pQueHeader->frameno > pObj->pQueHeader->maxframeno)
{
pObj->pQueHeader->maxframeno = pObj->pQueHeader->frameno;
}
*/
return 0;
}


int SSQ_AddData(SS_QUEUE_OBJ_T *pObj, unsigned int channelid, unsigned int mediatype, MEDIA_FRAME_INFO *frameinfo, char *pbuf)
{
int ret = 0;
SS_BUF_T bufNode;




if (NULL==pObj || NULL==frameinfo || NULL==pbuf) return -1;
if (NULL == pObj->pQueData) return -1;
if (NULL == pObj->pQueHeader) return -1;
if (frameinfo->length < 1)
{
#ifdef _DEBUG
SSQ_TRACE("帧长度小于1: %d\n", frameinfo->length);
#endif
return -1;
}
 
#ifdef _DEBUG1
SSQ_TRACE("frame: %02x%02x%02x%02x%02x\n", (unsigned char)pbuf[0],
(unsigned char)pbuf[1],
(unsigned char)pbuf[2],
(unsigned char)pbuf[3],
(unsigned char)pbuf[4]);
#endif


if (frameinfo->length > pObj->pQueHeader->bufsize)
{
SSQ_TRACE("Buffer too low.. Current Frame Size: %d\tBuffer Size: %d\n", frameinfo->length, pObj->pQueHeader->bufsize);
return -1;
}






WaitForSingleObject(pObj->hMutex, INFINITE); //Lock


if (pObj->pQueHeader->clear_flag == 0x01)
{
//SSQ_TRACE("Received clear signal... Clear Buffer..\n");
SSQ_TRACE("接收到清空信号.  清空缓存..  WritePos: %d\n", pObj->pQueHeader->writepos);
SSQ_Clear(pObj);
pObj->pQueHeader->clear_flag = 0x00;
}


if (pObj->pQueHeader->writepos == pObj->pQueHeader->readpos)
{
if (pObj->pQueHeader->totalsize < 0 || pObj->pQueHeader->videoframes < 0)
{
SSQ_TRACE("读的速度==写的速度...  数据大小异常: %d    视频帧数:%d\n", pObj->pQueHeader->totalsize, pObj->pQueHeader->videoframes);
}
//Clear();
}


if (sizeof(SS_BUF_T) + frameinfo->length + pObj->pQueHeader->totalsize > pObj->pQueHeader->bufsize)
{
SSQ_TRACE("超出缓冲区大小.. 帧长:%d\ttotalsize:%d\tbufsize:%d  缓存帧数:%d\n", frameinfo->length, pObj->pQueHeader->totalsize, pObj->pQueHeader->bufsize, pObj->pQueHeader->videoframes);
ReleaseMutex(pObj->hMutex);
pObj->pQueHeader->isfull = 0x01;
return -1;
}


pObj->pQueHeader->isfull = 0x00;


memset(&bufNode, 0x00, sizeof(SS_BUF_T));
memcpy(&bufNode.frameinfo, frameinfo, sizeof(MEDIA_FRAME_INFO));
bufNode.channelid = channelid;//++m_FrameTally;
bufNode.mediatype = mediatype;
bufNode.flag = BUF_QUE_FLAG;


//_TRACE("WritePos: %d    totalSize: %d\n", pQueHeader->writepos, pQueHeader->totalsize);


//Lock();
//从头到尾 写
if ((pObj->pQueHeader->writepos + sizeof(SS_BUF_T) + frameinfo->length) <= pObj->pQueHeader->bufsize)
{
//copy to queue


//记录帧位置
if (mediatype==MEDIA_TYPE_VIDEO) SSQ_AddFrameInfo(pObj, pObj->pQueHeader->writepos, frameinfo);


unsigned int nAdd = pObj->pQueHeader->writepos;
memcpy(pObj->pQueData+nAdd, &bufNode, sizeof(SS_BUF_T));
nAdd += sizeof(SS_BUF_T);


memcpy(pObj->pQueData+nAdd, pbuf, frameinfo->length);
nAdd += frameinfo->length;
pObj->pQueHeader->writepos = nAdd;
pObj->pQueHeader->totalsize+= sizeof(SS_BUF_T);
pObj->pQueHeader->totalsize+= frameinfo->length;


if (mediatype==MEDIA_TYPE_VIDEO) pObj->pQueHeader->videoframes ++;


//_TRACE("顺序新增..  writepos: %d   /   %d\n", pQueHeader->writepos, pQueHeader->size);
}
else if (pObj->pQueHeader->writepos == pObj->pQueHeader->bufsize) //从头开始
{
//记录帧位置
if (mediatype==MEDIA_TYPE_VIDEO) SSQ_AddFrameInfo(pObj, 0, frameinfo);




memcpy(pObj->pQueData, &bufNode, sizeof(SS_BUF_T));
pObj->pQueHeader->writepos = sizeof(SS_BUF_T);


memcpy(pObj->pQueData+pObj->pQueHeader->writepos, pbuf, frameinfo->length);
pObj->pQueHeader->writepos += frameinfo->length;


pObj->pQueHeader->totalsize= sizeof(SS_BUF_T);
pObj->pQueHeader->totalsize+= frameinfo->length;


if (mediatype==MEDIA_TYPE_VIDEO) pObj->pQueHeader->videoframes ++;


SSQ_TRACE("从头开始写..  writepos: %d\n", pObj->pQueHeader->writepos);
}
//else if (pQueHeader->size - pQueHeader->writepos+pQueHeader->readpos >= (int)(frameinfo->length+sizeof(SS_BUF_T))) //从尾写到头
//else if (pObj->pQueHeader->bufsize - pObj->pQueHeader->writepos+pObj->pQueHeader->readpos >= (int)(frameinfo->length+sizeof(SS_BUF_T))) //从尾写到头
else// if (pObj->pQueHeader->bufsize - pObj->pQueHeader->writepos >= (int)(frameinfo->length+sizeof(SS_BUF_T))) //从尾写到头
{
unsigned int remain = pObj->pQueHeader->bufsize - pObj->pQueHeader->writepos; //剩余空间
if (remain>=sizeof(SS_BUF_T))
{
unsigned int nAdd = pObj->pQueHeader->writepos;


//记录帧位置
if (mediatype==MEDIA_TYPE_VIDEO) SSQ_AddFrameInfo(pObj, nAdd, frameinfo);


//_TRACE("WritePos111: %d\n", pQueHeader->writepos);
memcpy(pObj->pQueData+nAdd, &bufNode, sizeof(SS_BUF_T));
nAdd += sizeof(SS_BUF_T);
//pQueHeader->totalsize+= sizeof(SS_BUF_T);
//_TRACE("WritePos222: %d\n", pQueHeader->writepos+sizeof(SS_BUF_T));
remain = pObj->pQueHeader->bufsize - nAdd;//pQueHeader->writepos;
//_TRACE("WritePos: %d\n", pQueHeader->writepos+sizeof(SS_BUF_T)+remain);
if (remain>0)
{
memcpy(pObj->pQueData+nAdd, pbuf, remain);
memcpy(pObj->pQueData, pbuf+remain, frameinfo->length-remain);
nAdd = frameinfo->length-remain;


pObj->pQueHeader->writepos = nAdd;
pObj->pQueHeader->totalsize+= sizeof(SS_BUF_T);
pObj->pQueHeader->totalsize+= frameinfo->length;


if (pObj->pQueHeader->totalsize>pObj->pQueHeader->bufsize)
{
//原因:  rtsp server已停止读该队列(当前没有客户端访问)
SSQ_TRACE("[RTSP Server已停止读取该队列]错误 %d > %d    frameinfo->length:%d...\n", pObj->pQueHeader->totalsize, pObj->pQueHeader->bufsize, frameinfo->length);
//SSQ_Clear(pObj);
}
else
{
if (mediatype==MEDIA_TYPE_VIDEO) pObj->pQueHeader->videoframes ++;


//SSQ_TRACE("111Header及部分帧数据位于缓存尾, 部分帧数据位于缓存首..  remain: %d   writepos: %d  totalsize: %d\n", remain, pObj->pQueHeader->writepos, pObj->pQueHeader->totalsize);
}
}
else if (remain==0)
{
memcpy(pObj->pQueData, pbuf, frameinfo->length);
nAdd = frameinfo->length;
pObj->pQueHeader->writepos = nAdd;
pObj->pQueHeader->totalsize+= sizeof(SS_BUF_T);
pObj->pQueHeader->totalsize+= frameinfo->length;


if (mediatype==MEDIA_TYPE_VIDEO) pObj->pQueHeader->videoframes ++;


if (pObj->pQueHeader->totalsize>pObj->pQueHeader->bufsize)
{
SSQ_TRACE("错误222 %d > %d    frameinfo->length:%d...\n", pObj->pQueHeader->totalsize, pObj->pQueHeader->bufsize, frameinfo->length);
//SSQ_Clear(pObj);
}
else
{
SSQ_TRACE("22222Header位于缓存尾,帧数据位于缓存首..  writepos: %d\n", pObj->pQueHeader->writepos);
}
}
else
{
SSQ_TRACE("错误...  剩余空间小于0: %d\n", remain);
ret = -1;
}
}
else if (remain>0)
{
char *tmpbuf = (char *)&bufNode;



unsigned int nAdd = pObj->pQueHeader->writepos;


//记录帧位置
if (mediatype==MEDIA_TYPE_VIDEO) SSQ_AddFrameInfo(pObj, nAdd, frameinfo);




//SSQ_TRACE("ADD DATA...%d\n", nAdd);
memcpy(pObj->pQueData+nAdd, tmpbuf, remain);
//SSQ_TRACE("ADD DATA222...%d\n", sizeof(SS_BUF_T)-remain);
memcpy(pObj->pQueData, tmpbuf+remain, sizeof(SS_BUF_T)-remain);
nAdd = sizeof(SS_BUF_T)-remain;
memcpy(pObj->pQueData+nAdd, pbuf, frameinfo->length);


nAdd += frameinfo->length;
pObj->pQueHeader->writepos  = nAdd;
pObj->pQueHeader->totalsize+= sizeof(SS_BUF_T);
pObj->pQueHeader->totalsize+= frameinfo->length;


if (pObj->pQueHeader->totalsize>pObj->pQueHeader->bufsize)
{
SSQ_TRACE("错误333 %d > %d    frameinfo->length:%d...\n", pObj->pQueHeader->totalsize, pObj->pQueHeader->bufsize, frameinfo->length);
//SSQ_Clear(pObj);
}


if (mediatype==MEDIA_TYPE_VIDEO) pObj->pQueHeader->videoframes ++;
}
else
{
ret = -1;
SSQ_TRACE("ERROR...\n");
}
}
//else
{
//else if (pObj->pQueHeader->bufsize - pObj->pQueHeader->writepos+pObj->pQueHeader->readpos >= (int)(frameinfo->length+sizeof(SS_BUF_T))) //从尾写到头
//SSQ_TRACE("写尾错误..  未处理.  写位置:%d / pObj->pQueHeader->bufsize  读位置:%d\n", pObj->pQueHeader->writepos, pObj->pQueHeader->bufsize, pObj->pQueHeader->readpos);
}
//Unlock();


ReleaseMutex(pObj->hMutex);


//SSQ_TRACE("writepos: %d\ttotalsize: %d\n", pObj->pQueHeader->writepos, pObj->pQueHeader->totalsize);


#ifdef _DEBUG1
if (mediatype==MEDIA_TYPE_VIDEO)
{
SSQ_TRACE("==========================\n");
for (int i=0; i<pObj->pQueHeader->maxframeno; i++)
{
SSQ_TRACE("[%d] times: %d   pos: %d   %02X%02X%02X%02X%02X\n", i, pObj->pQueHeader->pFrameinfoList[i].timestamp, pObj->pQueHeader->pFrameinfoList[i].pos,
(unsigned char)pObj->pQueData[pObj->pQueHeader->pFrameinfoList[i].pos+sizeof(SS_BUF_T)+0], (unsigned char)pObj->pQueData[pObj->pQueHeader->pFrameinfoList[i].pos+sizeof(SS_BUF_T)+1], (unsigned char)pObj->pQueData[pObj->pQueHeader->pFrameinfoList[i].pos+sizeof(SS_BUF_T)+2], 
(unsigned char)pObj->pQueData[pObj->pQueHeader->pFrameinfoList[i].pos+sizeof(SS_BUF_T)+3], (unsigned char)pObj->pQueData[pObj->pQueHeader->pFrameinfoList[i].pos+sizeof(SS_BUF_T)+4]);
}
}
#endif




return ret;
}
int SSQ_GetData(SS_QUEUE_OBJ_T *pObj, unsigned int *channelid, unsigned int *mediatype, MEDIA_FRAME_INFO *frameinfo, char *pbuf)
{
int ret = 0;
unsigned int remain = 0;


if (NULL == pObj) return -1;

if (NULL == pObj->pQueHeader) return -1;
if (NULL == pObj->pFrameinfoList) return -1;




WaitForSingleObject(pObj->hMutex, INFINITE); //Lock


if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("pObj->pQueHeader->totalsize<0: %d\n", pObj->pQueHeader->totalsize);
ReleaseMutex(pObj->hMutex);
return -1;
}


if (pObj->pQueHeader->totalsize <= sizeof(SS_BUF_T))
{
ReleaseMutex(pObj->hMutex);
return -1;
}
//_TRACE("读位置: %d\n", pQueHeader->readpos);





//if (NULL != chid) *chid = m_chid;



//Lock();




#if 0
ret = -1;
for (unsigned int i=0; i<pObj->pQueHeader->maxframeno; i++)
{
if (pObj->pFrameinfoList[i].rtp_timestamp > frameinfo->rtptimestamp)
{
pObj->pQueHeader->readpos = pObj->pFrameinfoList[i].pos;
ret = SSQ_GetDataByPosition(pObj, pObj->pFrameinfoList[i].pos, channelid, mediatype, frameinfo, pbuf);
break;
}
}
#else


if (pObj->pQueHeader->readpos == pObj->pQueHeader->bufsize)
{
SSQ_TRACE("重置读位置[%d / %d]..\n", pObj->pQueHeader->readpos, pObj->pQueHeader->bufsize);
pObj->pQueHeader->readpos = 0;
}


if ((pObj->pQueHeader->readpos + sizeof(SS_BUF_T)) <= pObj->pQueHeader->bufsize)
{
SS_BUF_T *pNode = (SS_BUF_T *)(pObj->pQueData + pObj->pQueHeader->readpos);
//if (pNode->id<1)
if (pNode->flag != BUF_QUE_FLAG)
{
SSQ_TRACE("标志位错误... 缓存视频帧:%d  字节数:%d  清空队列\n", pObj->pQueHeader->videoframes, pObj->pQueHeader->totalsize);
if (pObj->hSSHeader == NULL) //同一个进程内使用
{
SSQ_Clear(pObj);
}
else
{
pObj->pQueHeader->clear_flag = 0x01;
#ifdef _WIN32
while (pObj->pQueHeader->clear_flag!=0x00) {Sleep(1);}
#else
while (pObj->pQueHeader->clear_flag!=0x00) {usleep(100);}
#endif
}
//Unlock();
SSQ_TRACE("111标志位错误... 缓存视频帧:%d  字节数:%d\n", pObj->pQueHeader->videoframes, pObj->pQueHeader->totalsize);
SSQ_TRACE("标志位错误.. 清空队列..  readpos: %d\n", pObj->pQueHeader->readpos);
//pObj->pQueHeader->clear_flag = 0x01;


//_TRACE("标志位错误.. 清空队列完成..\n");


ReleaseMutex(pObj->hMutex);
return -1;
}




if (NULL!=mediatype) *mediatype = pNode->mediatype;
if (NULL != channelid) *channelid = pNode->channelid;




memcpy(frameinfo, &pNode->frameinfo, sizeof(MEDIA_FRAME_INFO));
if ( (pObj->pQueHeader->readpos + pNode->frameinfo.length+sizeof(SS_BUF_T)) <= pObj->pQueHeader->bufsize)
{
//从头到尾读


if (pObj->pQueHeader->totalsize < frameinfo->length+sizeof(SS_BUF_T))
{
//数据量不够
SSQ_TRACE("数据量不够... 总字节数[%d]<帧长[%d]. 读位置:%d\n", pObj->pQueHeader->totalsize, frameinfo->length+sizeof(SS_BUF_T), pObj->pQueHeader->readpos);
ReleaseMutex(pObj->hMutex);
return -1;
}


if (frameinfo->length+sizeof(SS_BUF_T) > pObj->pQueHeader->totalsize)
{
SSQ_TRACE("总字节数[%d]<帧长[%d]. 读位置:%d\n", pObj->pQueHeader->totalsize, frameinfo->length+sizeof(SS_BUF_T), pObj->pQueHeader->readpos);
}


//_TRACE("读位置00000000...: %d  /  %d\n", pQueHeader->readpos, pQueHeader->size);
pObj->pQueHeader->readpos += sizeof(SS_BUF_T);


unsigned int total1 = pObj->pQueHeader->totalsize;
pObj->pQueHeader->totalsize -= sizeof(SS_BUF_T);


if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData+pObj->pQueHeader->readpos, frameinfo->length);


//memset(pObj->pQueData+pObj->pQueHeader->readpos, 0x00, frameinfo->length); //clear


pObj->pQueHeader->readpos += frameinfo->length;
unsigned int total2 = pObj->pQueHeader->totalsize;
pObj->pQueHeader->totalsize -= (frameinfo->length);


if (pObj->pQueHeader->readpos == pObj->pQueHeader->bufsize)
{
pObj->pQueHeader->readpos = 0;
}


if (pObj->pQueHeader->readpos > pObj->pQueHeader->bufsize)
{
SSQ_TRACE("读位置错误11111...: %d  /  %d\n", pObj->pQueHeader->readpos, pObj->pQueHeader->bufsize);
}
if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("读位置: %d\t写位置: %d  当前帧大小:%d   total1:%d\ttotal2:%d\ttotal3:%d\n", pObj->pQueHeader->readpos, pObj->pQueHeader->writepos, frameinfo->length, total1, total2, pObj->pQueHeader->totalsize);
SSQ_TRACE("总字节数错误: %d\n", pObj->pQueHeader->totalsize);
}
}
else
{
if (pObj->pQueHeader->totalsize < (pNode->frameinfo.length+sizeof(SS_BUF_T)))
{
SSQ_TRACE("总字节数<帧长+sizeof(SS_BUF_T)..\n");
//Unlock();
ReleaseMutex(pObj->hMutex);
return -1;
}


remain = pObj->pQueHeader->bufsize-pObj->pQueHeader->readpos;
if (remain>=sizeof(SS_BUF_T))
{
pObj->pQueHeader->readpos += sizeof(SS_BUF_T);
remain = pObj->pQueHeader->bufsize - pObj->pQueHeader->readpos;
if (remain>0)
{
//SSQ_TRACE("111尾有部分数据... 首有部分数据... remain>0: %d\n", remain);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData+pObj->pQueHeader->readpos, remain);
//memset(pObj->pQueData+pObj->pQueHeader->readpos, 0x00, remain); //clear
if (NULL!=pbuf) memcpy(pbuf+remain, pObj->pQueData, frameinfo->length-remain);
//memset(pObj->pQueData, 0x00, frameinfo->length-remain); //clear

pObj->pQueHeader->readpos = frameinfo->length-remain;
pObj->pQueHeader->totalsize -= frameinfo->length;
pObj->pQueHeader->totalsize -= sizeof(SS_BUF_T);


if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("3333pObj->pQueHeader->totalsize<0: %d\n", pObj->pQueHeader->totalsize);
}
}
else
{
if (remain < 0)
{
SSQ_TRACE("位移错误: 剩余字节数<0:%d\n", remain);


}
else
{
SSQ_TRACE("111尾有部分数据... 首有部分数据... remain<=0: %d\n", remain);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData, frameinfo->length);
//memset(pObj->pQueData, 0x00, frameinfo->length-remain); //clear
pObj->pQueHeader->readpos = frameinfo->length;
pObj->pQueHeader->totalsize -= frameinfo->length;
pObj->pQueHeader->totalsize -= sizeof(SS_BUF_T);


if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("4444pObj->pQueHeader->totalsize<0: %d\n", pObj->pQueHeader->totalsize);
}
}
}

//SSQ_TRACE("remain > sizeof(SS_BUF_T): %d\t\treadpos: %d\n", remain, pObj->pQueHeader->readpos);
}
else
{
//SSQ_TRACE("remain < sizeof(SS_BUF_T): %d\n", remain);


//执行到此处,说明异常


//remain = pObj->pQueHeader->bufsize - pObj->pQueHeader->readpos;
if (remain>0)
{
SSQ_TRACE("222尾有部分数据... 首有部分数据... remain>0: %d\n", remain);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData+pObj->pQueHeader->readpos, remain);
//memset(pObj->pQueData+pObj->pQueHeader->readpos, 0x00, remain); //clear
if (NULL!=pbuf) memcpy(pbuf+remain, pObj->pQueData, frameinfo->length-remain);
//memset(pObj->pQueData, 0x00, frameinfo->length-remain); //clear



pObj->pQueHeader->readpos = frameinfo->length-remain;
pObj->pQueHeader->totalsize -= frameinfo->length;


if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("555pObj->pQueHeader->totalsize<0: %d\n", pObj->pQueHeader->totalsize);
}


}
else
{
SSQ_TRACE("222尾有部分数据... 首有部分数据... remain<=0: %d\n", remain);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData, frameinfo->length);
//memset(pObj->pQueData, 0x00, frameinfo->length-remain); //clear
pObj->pQueHeader->readpos = frameinfo->length;
pObj->pQueHeader->totalsize -= frameinfo->length;
if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("666pObj->pQueHeader->totalsize<0: %d\n", pObj->pQueHeader->totalsize);
}
}
pObj->pQueHeader->totalsize -= sizeof(SS_BUF_T);


if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("777pObj->pQueHeader->totalsize<0: %d\n", pObj->pQueHeader->totalsize);
}
}




//pObj->pQueHeader->readpos += sizeof(SS_BUF_T);
//pObj->pQueHeader->totalsize -= sizeof(SS_BUF_T);






if (pObj->pQueHeader->readpos>pObj->pQueHeader->bufsize)
{
SSQ_TRACE("读位置错误...: %d  /  %d\n", pObj->pQueHeader->readpos, pObj->pQueHeader->bufsize);
}



/*
if (NULL!=pbuf) memcpy(pbuf, pShareMemoryBuff+pQueHeader->readpos, remain);
memset(pShareMemoryBuff+pQueHeader->readpos, 0x00, remain); //clear
if (NULL!=pbuf) memcpy(pbuf+remain, pShareMemoryBuff, frameinfo->length-remain);
memset(pShareMemoryBuff, 0x00, frameinfo->length-remain); //clear


pQueHeader->readpos = frameinfo->length-remain;
pQueHeader->totalsize -= (frameinfo->length-remain);
*/
}


if (MEDIA_TYPE_VIDEO==pNode->mediatype) pObj->pQueHeader->videoframes --;


//memset(pNode, 0x00, sizeof(SS_BUF_T));
}
else
{
unsigned int remain = pObj->pQueHeader->bufsize-pObj->pQueHeader->readpos;
SS_BUF_T bufnode;
char *pp = (char *)&bufnode;
memset(&bufnode, 0x00, sizeof(SS_BUF_T));


//SSQ_TRACE("GET DATA...\n");


//SSQ_TRACE("1 REMAIN: %d\n", remain);
if (remain>0)
{
memcpy(pp, pObj->pQueData+pObj->pQueHeader->readpos, remain);
//memset(pObj->pQueData+pObj->pQueHeader->readpos, 0x00, remain); //clear
//SSQ_TRACE("2 read: %d\n", sizeof(SS_BUF_T)-remain);
memcpy(pp+remain, pObj->pQueData, sizeof(SS_BUF_T)-remain);
//memset(pObj->pQueData, 0x00, sizeof(SS_BUF_T)-remain); //clear


memcpy(frameinfo, &bufnode.frameinfo, sizeof(MEDIA_FRAME_INFO));
if (NULL != channelid) *channelid = bufnode.channelid;


//if (bufnode.id<1)
if (bufnode.flag != BUF_QUE_FLAG)
{
//Unlock();
SSQ_Clear(pObj);
ReleaseMutex(pObj->hMutex);
SSQ_TRACE("SSQ_标志符错误...\n");
return -1;
}


pObj->pQueHeader->readpos = sizeof(SS_BUF_T)-remain;


if (NULL!=mediatype) *mediatype = bufnode.mediatype;
//SSQ_TRACE("3 frame length: %d\n", bufnode.frameinfo.length);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData+pObj->pQueHeader->readpos, bufnode.frameinfo.length);
//memset(pObj->pQueData+pObj->pQueHeader->readpos, 0x00, bufnode.frameinfo.length); //clear
pObj->pQueHeader->readpos += bufnode.frameinfo.length;


pObj->pQueHeader->totalsize -= sizeof(SS_BUF_T);
//pObj->pQueHeader->totalsize -= (frameinfo->length-remain);
pObj->pQueHeader->totalsize -= (frameinfo->length);//20140521


if (pObj->pQueHeader->totalsize < 0)
{
SSQ_TRACE("888pObj->pQueHeader->totalsize<0: %d\n", pObj->pQueHeader->totalsize);
}


//SSQ_TRACE("GET DATA OK..\n");
if (MEDIA_TYPE_VIDEO==bufnode.mediatype) pObj->pQueHeader->videoframes --;
}
else
{
SSQ_TRACE("异常...   REMAIN <= 0....\n");
}




ret = 1000;
}
#endif

//Unlock();
ReleaseMutex(pObj->hMutex);


return ret;
}




//===========================================
//根据位置获取对应的帧数据
int SSQ_GetDataByPosition(SS_QUEUE_OBJ_T *pObj, unsigned int position, unsigned int clearflag, unsigned int *channelid, unsigned int *mediatype, MEDIA_FRAME_INFO *frameinfo, char *pbuf)
{
int ret = 0;
unsigned int remain = 0;


if (NULL == pObj) return -1;
if (NULL == pObj->pQueHeader) return -1;
if (NULL == pObj->pFrameinfoList) return -1;


unsigned int *pOffset = (unsigned int *)&position;
unsigned int totalsize = pObj->pQueHeader->totalsize;
unsigned int *pTotalSize = (unsigned int*)&totalsize;


if (clearflag == 0x01)
{
pOffset    = (unsigned int*)&pObj->pQueHeader->readpos;
pTotalSize = (unsigned int*)&pObj->pQueHeader->totalsize;
}


WaitForSingleObject(pObj->hMutex, INFINITE); //Lock


if (*pOffset == pObj->pQueHeader->bufsize)
{
SSQ_TRACE("重置读位置[%d / %d]..\n", *pOffset, pObj->pQueHeader->bufsize);
*pOffset = 0;
}


if (clearflag==0x01)
{
if (pObj->pQueHeader->totalsize <= sizeof(SS_BUF_T))
{
ReleaseMutex(pObj->hMutex);
return -1;
}




if (pObj->pQueHeader->readpos == pObj->pQueHeader->bufsize)
{
pObj->pQueHeader->readpos = 0;
}
}


if ((*pOffset + sizeof(SS_BUF_T)) <= pObj->pQueHeader->bufsize)
{
SS_BUF_T *pNode = (SS_BUF_T *)(pObj->pQueData + *pOffset);
if (pNode->flag != BUF_QUE_FLAG)
{
SSQ_TRACE("[SSQ_GetDataByPosition]标志位错误...\n");
if (clearflag == 0x01)
{
if (pObj->hSSHeader==NULL) //同一进程
{
SSQ_Clear(pObj);
}
else
{
pObj->pQueHeader->clear_flag = 0x01;
while (pObj->pQueHeader->clear_flag!=0x00) {Sleep(1);}
}
}
ReleaseMutex(pObj->hMutex);
return -1;
}


if (NULL!=mediatype) *mediatype = pNode->mediatype;
if (NULL != channelid) *channelid = pNode->channelid;




memcpy(frameinfo, &pNode->frameinfo, sizeof(MEDIA_FRAME_INFO));
if ( (*pOffset + pNode->frameinfo.length+sizeof(SS_BUF_T)) <= pObj->pQueHeader->bufsize)
{
//从头到尾读
*pOffset += sizeof(SS_BUF_T);


if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData+*pOffset, frameinfo->length);
*pOffset += frameinfo->length;
*pTotalSize -= (frameinfo->length+sizeof(SS_BUF_T));


if (*pOffset == pObj->pQueHeader->bufsize)
{
*pOffset = 0;
}


if (*pOffset > pObj->pQueHeader->bufsize)
{
SSQ_TRACE("[SSQ_GetDataByPosition]读位置错误11111...: %d  /  %d\n", *pOffset, pObj->pQueHeader->bufsize);
}
}
else
{
remain = pObj->pQueHeader->bufsize - *pOffset;
if (remain>=sizeof(SS_BUF_T))
{
*pOffset += sizeof(SS_BUF_T);
remain = pObj->pQueHeader->bufsize - *pOffset;
if (remain>0)
{
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData + *pOffset, remain);
if (NULL!=pbuf) memcpy(pbuf+remain, pObj->pQueData, frameinfo->length-remain);


*pOffset = frameinfo->length-remain;
*pTotalSize -= (frameinfo->length+sizeof(SS_BUF_T));
}
else
{
if (remain < 0)
{
SSQ_TRACE("[SSQ_GetDataByPosition]位移错误: 剩余字节数<0:%d\n", remain);
}
else
{
SSQ_TRACE("[SSQ_GetDataByPosition]尾有部分数据... 首有部分数据... remain<=0: %d\n", remain);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData, frameinfo->length);
//memset(pObj->pQueData, 0x00, frameinfo->length-remain); //clear
*pOffset = frameinfo->length;
*pTotalSize -= (frameinfo->length+sizeof(SS_BUF_T));
}
}
}
else
{
//SSQ_TRACE("remain < sizeof(SS_BUF_T): %d\n", remain);


//执行到此处,说明异常
SSQ_TRACE("[SSQ_GetDataByPosition]  异常   #########... remain>0: %d\n", remain);
if (remain>0)
{
SSQ_TRACE("[SSQ_GetDataByPosition]222尾有部分数据... 首有部分数据... remain>0: %d\n", remain);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData + *pOffset, remain);
if (NULL!=pbuf) memcpy(pbuf+remain, pObj->pQueData, frameinfo->length-remain);

*pOffset = frameinfo->length-remain;
*pTotalSize -= (frameinfo->length);
}
else
{
SSQ_TRACE("[SSQ_GetDataByPosition]222尾有部分数据... 首有部分数据... remain<=0: %d\n", remain);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData, frameinfo->length);
//memset(pObj->pQueData, 0x00, frameinfo->length-remain); //clear
*pOffset = frameinfo->length;
}
}


if (*pOffset > pObj->pQueHeader->bufsize)
{
SSQ_TRACE("[SSQ_GetDataByPosition]读位置错误...: %d  /  %d\n", *pOffset, pObj->pQueHeader->bufsize);
}
}


if (MEDIA_TYPE_VIDEO==pNode->mediatype && clearflag==0x01) pObj->pQueHeader->videoframes --;
}
else
{
unsigned int remain = pObj->pQueHeader->bufsize - *pOffset;
SS_BUF_T bufnode;
char *pp = (char *)&bufnode;
memset(&bufnode, 0x00, sizeof(SS_BUF_T));


//SSQ_TRACE("GET DATA...\n");


SSQ_TRACE("[SSQ_GetDataByPosition]1 REMAIN: %d\n", remain);
if (remain>0)
{
memcpy(pp, pObj->pQueData + *pOffset, remain);
SSQ_TRACE("[SSQ_GetDataByPosition]2 read: %d\n", sizeof(SS_BUF_T)-remain);
memcpy(pp+remain, pObj->pQueData, sizeof(SS_BUF_T)-remain);


memcpy(frameinfo, &bufnode.frameinfo, sizeof(MEDIA_FRAME_INFO));
if (NULL != channelid) *channelid = bufnode.channelid;


if (bufnode.flag != BUF_QUE_FLAG)
{
//Unlock();
SSQ_Clear(pObj);
ReleaseMutex(pObj->hMutex);
SSQ_TRACE("[SSQ_GetDataByPosition]SSQ_标志符错误...\n");
return -1;
}


*pOffset = sizeof(SS_BUF_T)-remain;


if (NULL!=mediatype) *mediatype = bufnode.mediatype;
SSQ_TRACE("[SSQ_GetDataByPosition]3 frame length: %d\n", bufnode.frameinfo.length);
if (NULL!=pbuf) memcpy(pbuf, pObj->pQueData + *pOffset, bufnode.frameinfo.length);
*pOffset += bufnode.frameinfo.length;
*pTotalSize -= (frameinfo->length+sizeof(SS_BUF_T));


SSQ_TRACE("[SSQ_GetDataByPosition]GET DATA OK..\n");
if (MEDIA_TYPE_VIDEO==bufnode.mediatype && clearflag==0x01) pObj->pQueHeader->videoframes --;
}
else
{
SSQ_TRACE("[SSQ_GetDataByPosition]异常...   REMAIN <= 0....\n");
}


ret = 1000;
}

//Unlock();
ReleaseMutex(pObj->hMutex);


return ret;
}




int SSQ_TRACE(char* szFormat, ...)
{
#ifdef _DEBUG
  char buff[1024] = {0,};
  wchar_t wszbuff[1024] = {0,};
  va_list args;
  va_start(args,szFormat);
  _vsnprintf(buff, 1023, szFormat,args);
  va_end(args);


  MByteToWChar(buff, wszbuff, sizeof(wszbuff)/sizeof(wszbuff[0]));
#ifdef _WIN32
OutputDebugString(wszbuff);
#endif
printf("TRACE: %s", buff);
#endif


return 0;

}

buffer大小可以调节。大小将影响视频的延迟。

相关代码可以参考 https://github.com/Car-eye-team 欢迎加入QQ群聊进行技术切磋：590411159