How to write a Live555 FramedSource to allow me to stream H.264 live

Ok, I finally got some time to spend on this and got it working! I'm sure there are others who will be begging to know how to do it so here it is.

You will need your own FramedSource to take each frame, encode, and prepare it for streaming, I will provide some of the source code for this soon.

Essentially throw your FramedSource into the H264VideoStreamDiscreteFramer, then throw this into the H264RTPSink. Something like this

scheduler = BasicTaskScheduler::createNew();
env = BasicUsageEnvironment::createNew(*scheduler);   

framedSource = H264FramedSource::createNew(*env, 0,0);

h264VideoStreamDiscreteFramer 
= H264VideoStreamDiscreteFramer::createNew(*env, framedSource);

// initialise the RTP Sink stuff here, look at 
// testH264VideoStreamer.cpp to find out how

videoSink->startPlaying(*h264VideoStreamDiscreteFramer, NULL, videoSink);

env->taskScheduler().doEventLoop();

Now in your main render loop, throw over your backbuffer which you've saved to system memory to your FramedSource so it can be encoded etc. For more info on how to setup the encoding stuff check out this answer How does one encode a series of images into H264 using the x264 C API?

My implementation is very much in a hacky state and is yet to be optimised at all, my d3d application runs at around 15fps due to the encoding, ouch, so I will have to look into this. But for all intents and purposes this StackOverflow question is answered because I was mostly after how to stream it. I hope this helps other people.

As for my FramedSource it looks a little something like this

concurrent_queue<x264_nal_t> m_queue;
SwsContext* convertCtx;
x264_param_t param;
x264_t* encoder;
x264_picture_t pic_in, pic_out;


EventTriggerId H264FramedSource::eventTriggerId = 0;
unsigned H264FramedSource::FrameSize = 0;
unsigned H264FramedSource::referenceCount = 0;

int W = 720;
int H = 960;

H264FramedSource* H264FramedSource::createNew(UsageEnvironment& env,
                                              unsigned preferredFrameSize, 
                                              unsigned playTimePerFrame) 
{
        return new H264FramedSource(env, preferredFrameSize, playTimePerFrame);
}

H264FramedSource::H264FramedSource(UsageEnvironment& env,
                                   unsigned preferredFrameSize, 
                                   unsigned playTimePerFrame)
    : FramedSource(env),
    fPreferredFrameSize(fMaxSize),
    fPlayTimePerFrame(playTimePerFrame),
    fLastPlayTime(0),
    fCurIndex(0)
{
        if (referenceCount == 0) 
        {

        }
        ++referenceCount;

        x264_param_default_preset(&param, "veryfast", "zerolatency");
        param.i_threads = 1;
        param.i_width = 720;
        param.i_height = 960;
        param.i_fps_num = 60;
        param.i_fps_den = 1;
        // Intra refres:
        param.i_keyint_max = 60;
        param.b_intra_refresh = 1;
        //Rate control:
        param.rc.i_rc_method = X264_RC_CRF;
        param.rc.f_rf_constant = 25;
        param.rc.f_rf_constant_max = 35;
        param.i_sps_id = 7;
        //For streaming:
        param.b_repeat_headers = 1;
        param.b_annexb = 1;
        x264_param_apply_profile(&param, "baseline");


        encoder = x264_encoder_open(&param);
        pic_in.i_type            = X264_TYPE_AUTO;   
        pic_in.i_qpplus1         = 0;
        pic_in.img.i_csp         = X264_CSP_I420;   
        pic_in.img.i_plane       = 3;


        x264_picture_alloc(&pic_in, X264_CSP_I420, 720, 920);

        convertCtx = sws_getContext(720, 960, PIX_FMT_RGB24, 720, 760, PIX_FMT_YUV420P, SWS_FAST_BILINEAR, NULL, NULL, NULL);


        if (eventTriggerId == 0) 
        {
            eventTriggerId = envir().taskScheduler().createEventTrigger(deliverFrame0);
        }
}

H264FramedSource::~H264FramedSource() 
{
    --referenceCount;
    if (referenceCount == 0) 
    {
        // Reclaim our 'event trigger'
        envir().taskScheduler().deleteEventTrigger(eventTriggerId);
        eventTriggerId = 0;
    }
}

void H264FramedSource::AddToBuffer(uint8_t* buf, int surfaceSizeInBytes)
{
    uint8_t* surfaceData = (new uint8_t[surfaceSizeInBytes]);

    memcpy(surfaceData, buf, surfaceSizeInBytes);

    int srcstride = W*3;
    sws_scale(convertCtx, &surfaceData, &srcstride,0, H, pic_in.img.plane, pic_in.img.i_stride);
    x264_nal_t* nals = NULL;
    int i_nals = 0;
    int frame_size = -1;


    frame_size = x264_encoder_encode(encoder, &nals, &i_nals, &pic_in, &pic_out);

    static bool finished = false;

    if (frame_size >= 0)
    {
        static bool alreadydone = false;
        if(!alreadydone)
        {

            x264_encoder_headers(encoder, &nals, &i_nals);
            alreadydone = true;
        }
        for(int i = 0; i < i_nals; ++i)
        {
            m_queue.push(nals[i]);
        }   
    }
    delete [] surfaceData;
    surfaceData = NULL;

    envir().taskScheduler().triggerEvent(eventTriggerId, this);
}

void H264FramedSource::doGetNextFrame() 
{
    deliverFrame();
}

void H264FramedSource::deliverFrame0(void* clientData) 
{
    ((H264FramedSource*)clientData)->deliverFrame();
}

void H264FramedSource::deliverFrame() 
{
    x264_nal_t nalToDeliver;

    if (fPlayTimePerFrame > 0 && fPreferredFrameSize > 0) {
        if (fPresentationTime.tv_sec == 0 && fPresentationTime.tv_usec == 0) {
            // This is the first frame, so use the current time:
            gettimeofday(&fPresentationTime, NULL);
        } else {
            // Increment by the play time of the previous data:
            unsigned uSeconds   = fPresentationTime.tv_usec + fLastPlayTime;
            fPresentationTime.tv_sec += uSeconds/1000000;
            fPresentationTime.tv_usec = uSeconds%1000000;
        }

        // Remember the play time of this data:
        fLastPlayTime = (fPlayTimePerFrame*fFrameSize)/fPreferredFrameSize;
        fDurationInMicroseconds = fLastPlayTime;
    } else {
        // We don't know a specific play time duration for this data,
        // so just record the current time as being the 'presentation time':
        gettimeofday(&fPresentationTime, NULL);
    }

    if(!m_queue.empty())
    {
        m_queue.wait_and_pop(nalToDeliver);

        uint8_t* newFrameDataStart = (uint8_t*)0xD15EA5E;

        newFrameDataStart = (uint8_t*)(nalToDeliver.p_payload);
        unsigned newFrameSize = nalToDeliver.i_payload;

        // Deliver the data here:
        if (newFrameSize > fMaxSize) {
            fFrameSize = fMaxSize;
            fNumTruncatedBytes = newFrameSize - fMaxSize;
        }
        else {
            fFrameSize = newFrameSize;
        }

        memcpy(fTo, nalToDeliver.p_payload, nalToDeliver.i_payload);

        FramedSource::afterGetting(this);
    }
}

Oh and for those who want to know what my concurrent queue is, here it is, and it works brilliantly http://www.justsoftwaresolutions.co.uk/threading/implementing-a-thread-safe-queue-using-condition-variables.html

Enjoy and good luck!


The deliverFrame method lacks the following check at its start:

if (!isCurrentlyAwaitingData()) return;    

see DeviceSource.cpp in LIVE