我一直在尝试编写一个派生自Live555中FramedSource的类，它允许我将D3D9应用程序中的实时数据流式传输到MP4或类似的。
我做的每一帧都是将后备缓冲区作为纹理抓取到系统内存中，然后将其转换为RGB - ＆gt; YUV420P，然后使用x264对其进行编码，然后理想地将NAL数据包传递到Live555。我创建了一个名为H264FramedSource的类，它基本上是通过复制DeviceSource文件从FramedSource派生的。我没有将输入作为输入文件，而是将其作为NAL数据包，我更新每一帧。
我对编解码器和流媒体都很陌生，所以我可能做的一切都完全错了。在每个doGetNextFrame（）中，我应该抓住NAL数据包并执行类似
的操作memcpy(fTo, nal->p_payload, nal->i_payload)
我假设有效载荷是以字节为单位的帧数据？如果有人从FramedSource那里得到一个类的例子，它可能至少接近我想要做的事情，我很乐意看到它，这对我来说是全新的，并且弄清楚发生了什么有点棘手。 Live555的文档几乎就是代码本身，这并不能让我很容易理解。
答案 0 :(得分：13)
好的，我终于有时间花在这上面并让它运转起来！我相信还有其他人会乞求知道如何做到这一点。
您将需要自己的FramedSource来获取每个帧，进行编码并准备流式传输，我将尽快提供一些源代码。
基本上将FramedSource抛入H264VideoStreamDiscreteFramer，然后将其抛入H264RTPSink。像这样的东西
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();
现在在你的主渲染循环中，将你保存到系统内存的后备缓冲区扔到你的FramedSource上，这样它就可以编码等了。有关如何设置编码内容的更多信息，请查看这个答案{{3} }
我的实现非常处于hacky状态，并且尚未进行优化，我的d3d应用程序运行速度大约为15fps，因为编码，哎哟，所以我将不得不研究这个问题。但是对于所有意图和目的，这个StackOverflow问题得到了回答，因为我主要是在如何流式传输它之后。我希望这有助于其他人。
至于我的FramedSource，它看起来有点像这样
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(¶m, "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(¶m, "baseline");
encoder = x264_encoder_open(¶m);
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);
}
}
哦，对于那些想知道我的并发队列是什么的人来说，就是这样，它的工作非常出色How does one encode a series of images into H264 using the x264 C API?
享受并祝你好运！
答案 1 :(得分：2)
deliverFrame 方法在开始时缺少以下检查：
if (!isCurrentlyAwaitingData()) return;
在LIVE中查看DeviceSource.cpp