EasyPlayer RTSP播放器源码解析系列之效率优化方案

来源：互联网发布：茶叶网络营销策划方案编辑：程序博客网时间：2024/06/02 18:28

测试发现，通过EasyPlayer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libEasyAACEncoder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==EASY_SDK_VIDEO_FRAME_I)//开启录制            {                //EnterCriticalSection(&pThread->critRecQueue);                             if (!pThread->m_pMP4Writer)                {                    pThread->m_pMP4Writer = new EasyMP4Writer();                }                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    EasyAACEncoder_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==EASY_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 (EASY_SDK_AUDIO_CODEC_G711U == frameinfo.codec                    || EASY_SDK_AUDIO_CODEC_G726 == frameinfo.codec                     || EASY_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 == EASY_SDK_AUDIO_CODEC_G711U)                        {                            initParam.ucAudioCodec = Law_ULaw;                        }                         else if (frameinfo.codec == EASY_SDK_AUDIO_CODEC_G726)                        {                            initParam.ucAudioCodec = Law_G726;                        }                        else if (frameinfo.codec == EASY_SDK_AUDIO_CODEC_G711A)                        {                            initParam.ucAudioCodec = Law_ALaw;                        }                        m_pAACEncoderHandle = Easy_AACEncoder_Init( initParam);                    }                    unsigned int out_len = 0;                    int nRet = Easy_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 = EASY_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。

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