测试发现，通过SkeyePlayer拉取网络摄像机的流, 其音频可能是G711，G726等，而写MP4或者转推RTMP等都不支持这些音频格式，那么我们就需要将其音频转码成AAC，可以使用libSkeyeAACEncoder库进行转码，然后写MP4或者推送；然而，在实际应用中，我们发现转码过程其实还是比较耗时的，它甚至会导致解码线程来不及从而使直播延时增大，所以，我们采用队列缓存 线程的方式来优化录像和抓图。
实现如下：
- 录像优化 1> 开启录像
if (pThread->manuRecording == 0x01 && NULL==pThread->m_pMP4Writer && frameinfo.type==Skeye_SDK_VIDEO_FRAME_I)//开启录制
{
//EnterCriticalSection(&pThread->critRecQueue);
if (!pThread->m_pMP4Writer)
{
pThread->m_pMP4Writer = new SkeyeMP4Writer();
}
unsigned int timestamp = (unsigned int)time(NULL);
time_t tt = timestamp;
struct tm *_time = localtime(&tt);
char szTime[64] = {0,};
strftime(szTime, 32, "%Y%m%d%H%M%S", _time);
int nRecordPathLen = strlen(pThread->manuRecordingPath);
if (nRecordPathLen==0 || (pThread->manuRecordingPath[nRecordPathLen-1] != '/' && pThread->manuRecordingPath[nRecordPathLen-1] != '\') )
{
pThread->manuRecordingPath[nRecordPathLen] = '/';
}
char sFileName[512] = {0,};
sprintf(sFileName, "%sch%d_%s.mp4", pThread->manuRecordingPath, pThread->channelId, szTime);
if (!pThread->m_pMP4Writer->CreateMP4File(sFileName, ZOUTFILE_FLAG_FULL))
{
delete pThread->m_pMP4Writer;
pThread->m_pMP4Writer = NULL;
//return -1;
}
else
{
}
//LeaveCriticalSection(&pThread->critRecQueue);
}2> 录像数据写缓存 if (NULL != pThread->pRecAVQueue)
{
SSQ_AddData(pThread->pRecAVQueue, channelid, MEDIA_TYPE_VIDEO, (MEDIA_FRAME_INFO*)&frameinfo, pbuf);
}3> 录像线程处理LPTHREAD_START_ROUTINE CChannelManager::_lpRecordThread( LPVOID _pParam )
{
PLAY_THREAD_OBJ *pThread = (PLAY_THREAD_OBJ*)_pParam;
if (NULL == pThread) return 0;
pThread->recordThread.flag = 0x02;
#ifdef _DEBUG
_TRACE("录像线程[%d]已启动. ThreadId:%d ...n", pThread->channelId, GetCurrentThreadId());
#endif
SkeyeAACEncoder_Handle m_pAACEncoderHandle = NULL;
int buf_size = 1024*1024;
char *pbuf = new char[buf_size];
if (NULL == pbuf)
{
pThread->recordThread.flag = 0x00;
return 0;
}
char* m_pAACEncBufer = new char[buf_size];
memset(m_pAACEncBufer, 0x00, buf_size);
//#define AVCODEC_MAX_AUDIO_FRAME_SIZE (192000)
#define AVCODEC_MAX_AUDIO_FRAME_SIZE (64000)
int audbuf_len = (AVCODEC_MAX_AUDIO_FRAME_SIZE * 3) / 2;
unsigned char *audio_buf = new unsigned char[audbuf_len 1];
memset(audio_buf, 0x00, audbuf_len);
MEDIA_FRAME_INFO frameinfo;
unsigned int channelid = 0;
unsigned int mediatype = 0;
while (1)
{
if (pThread->recordThread.flag == 0x03) break;
int ret = SSQ_GetData(pThread->pRecAVQueue, &channelid, &mediatype, &frameinfo, pbuf);
if (ret < 0)
{
_VS_BEGIN_TIME_PERIOD(1);
__VS_Delay(1);
_VS_END_TIME_PERIOD(1);
continue;
}
long long nTimeStamp = frameinfo.timestamp_sec*1000 frameinfo.timestamp_usec/1000;
byte*pdata=NULL;
int datasize=0;
bool keyframe=false;
try
{
if (mediatype == MEDIA_TYPE_VIDEO)
{
pdata = (byte*)pbuf;//获取到的编码数据
datasize = frameinfo.length;
int nVideoWidth = frameinfo.width;
int nVideoHeight = frameinfo.height;
keyframe = frameinfo.type==Skeye_SDK_VIDEO_FRAME_I?true:false;
if (pThread->m_pMP4Writer)
{
pThread->m_pMP4Writer->WriteMp4File((unsigned char*)pdata, datasize, keyframe, nTimeStamp, nVideoWidth, nVideoHeight);
}
}
else //音频
{
pdata = (byte*)pbuf;//获取到的编码数据
datasize = frameinfo.length;
int bits_per_sample = frameinfo.bits_per_sample;
int channels = frameinfo.channels;
int sampleRate = frameinfo.sample_rate;
if (Skeye_SDK_AUDIO_CODEC_G711U == frameinfo.codec
|| Skeye_SDK_AUDIO_CODEC_G726 == frameinfo.codec
|| Skeye_SDK_AUDIO_CODEC_G711A == frameinfo.codec )
{
if (!m_pAACEncoderHandle)
{
InitParam initParam;
initParam.u32AudioSamplerate=frameinfo.sample_rate;
initParam.ucAudioChannel=frameinfo.channels;
initParam.u32PCMBitSize=frameinfo.bits_per_sample;
if (frameinfo.codec == Skeye_SDK_AUDIO_CODEC_G711U)
{
initParam.ucAudioCodec = Law_ULaw;
}
else if (frameinfo.codec == Skeye_SDK_AUDIO_CODEC_G726)
{
initParam.ucAudioCodec = Law_G726;
}
else if (frameinfo.codec == Skeye_SDK_AUDIO_CODEC_G711A)
{
initParam.ucAudioCodec = Law_ALaw;
}
m_pAACEncoderHandle = Skeye_AACEncoder_Init( initParam);
}
unsigned int out_len = 0;
int nRet = Skeye_AACEncoder_Encode(m_pAACEncoderHandle,
(unsigned char*)pbuf, frameinfo.length, (unsigned char*)m_pAACEncBufer, &out_len) ;
if (nRet>0&&out_len>0)
{
pdata = (byte*)m_pAACEncBufer;
datasize = out_len;
frameinfo.codec = Skeye_SDK_AUDIO_CODEC_AAC;
}
else
{
continue;
}
}
if (pThread->m_pMP4Writer)
{
if (pThread->m_pMP4Writer->CanWrite())
{
pThread->m_pMP4Writer->WriteAACToMp4File((unsigned char*)pdata,
datasize, nTimeStamp, sampleRate, channels, bits_per_sample);
}
}
}
}
catch (...)
{
continue;
}
}
pThread->recordThread.flag = 0x00;
#ifdef _DEBUG
_TRACE("录像线程[%d]已退出 ThreadId:%d.n", pThread->channelId, GetCurrentThreadId());
#endif
return 0- 抓图优化
抓图原理同录像，唯一区别是直接数据传入线程，进行jpg编码存文件，详见代码。
