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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 等都不反对这些音频格式，那么咱们就须要将其音频转码成 AAC，能够应用 libSkeyeAACEncoder 库进行转码，而后写 MP4 或者推送；然而，在理论利用中，咱们发现转码过程其实还是比拟耗时的，它甚至会导致解码线程来不及从而使直播延时增大，所以，咱们采纳队列缓存 + 线程的形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> 录像线程解决
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，惟一区别是间接数据传入线程，进行 jpg 编码存文件，详见代码。
正文完
