MediaController::GstWrapper Class Reference

Manages the GStreamer instance. More...

#include <GstWrapper.h>

Public Member Functions
	GstWrapper ()
	Constructor. More...
	~GstWrapper ()
	Destructor. More...
void	SetWindowHandle (guintptr winhandle)
	Set the display window using the given window handle. More...
void	SetLocation (std::string location)
	Set the stream location. More...
void	SetPorts (int rtpPort, int rtcpPort)
	Set the receiver ports. More...
void	SetCaps (std::string caps, bool isMjpeg=false)
	Set the stream capabilities. More...
void	SetCookie (std::string cookie)
	Set the cookie for MJPEG streams. More...
void	SetRtcpHostIP (std::string hostIp)
	Set the RTCP host IP. More...
void	SetMulticastAddress (std::string multicastAddress)
	Set the multicast group address. More...
void	SetTimestamp (unsigned int seekTime)
	Set the internal timestamp variable. More...
unsigned int	GetLastTimestamp () const
	Get the last timestamp received from the stream. More...
void	SetMode (Controller::Mode mode)
	Set the playback mode. More...
Controller::Mode	GetMode () const
	Get the current playback mode. More...
float	GetSpeed () const
	Get the current playback speed. More...
bool	IsPipelineActive () const
	Get the status of the pipeline. More...
void	AddObserver (TimestampEventCallback observer)
	Add a new subscriber to timestamp events. More...
void	RemoveObserver (TimestampEventCallback observer)
	Remove an existing timestamp event subscriber. More...
void	ClearObservers ()
	Remove all existing timestamp event subscribers. More...
void	AddEventData (void *customData)
	Add custom data to be stored in here, which will be send back to caller inside TimestampEvent on TimestampEventCallback. More...
void	CreateVideoRtspPipeline (std::string encoding)
	Create the pipeline for an RTSP video stream. More...
void	CreateAudioRtspPipeline ()
	Create the pipeline for an RTSP audio stream. More...
void	CreateMjpegPipeline ()
	Create the pipeline for an MJPEG stream. More...
void	Play (float speed=1.0f)
	Set the pipeline state to playing and update the speed value for determining the framerate. More...
void	Pause () const
	Set the pipeline state to paused. More...
void	ClearPipeline ()
	Clear the pipeline and display window. More...

Private Member Functions
void	CreatePipeline ()
void	LinkBinElements ()

Static Private Member Functions
static void	Init ()

Private Attributes
GstVars	_gstVars

Detailed Description

Manages the GStreamer instance.

Definition at line 13 of file GstWrapper.h.

Constructor & Destructor Documentation

GstWrapper::GstWrapper

(

)

Constructor.

Definition at line 257 of file GstWrapper.cpp.

                       {
    SetMode(Controller::kStopped);
    Init();
    _gstVars.isPipelineActive = false;
}

GstWrapper::~GstWrapper

(

)

Destructor.

Definition at line 263 of file GstWrapper.cpp.

{ }

Member Function Documentation

void GstWrapper::AddEventData

(

void *

customData

)

Add custom data to be stored in here, which will be send back to caller inside TimestampEvent on TimestampEventCallback.

Parameters

customData

Custom data pointer.

Definition at line 340 of file GstWrapper.cpp.

                                              {
    _gstVars.eventData = customData;
}

void GstWrapper::AddObserver

(

TimestampEventCallback

observer

)

Add a new subscriber to timestamp events.

Parameters

observer

The TimestampEventCallback event handler.

Definition at line 328 of file GstWrapper.cpp.

                                                            {
    _gstVars.observerList.push_back(observer);
}

void GstWrapper::ClearObservers

(

)

Remove all existing timestamp event subscribers.

Definition at line 336 of file GstWrapper.cpp.

                                {
    _gstVars.observerList.clear();
}

void GstWrapper::ClearPipeline

(

)

Clear the pipeline and display window.

Definition at line 544 of file GstWrapper.cpp.

                               {
    g_print("Stopping receiver pipeline.\n");
    if (_gstVars.protocol == VxSdk::VxStreamProtocol::kMjpegPull) {
        g_source_remove(_gstVars.busWatchId);
        g_main_loop_unref(_gstVars.loop);
    }

    gst_element_set_state(_gstVars.pipeline, GST_STATE_NULL);
    gst_object_unref(_gstVars.pipeline);
    _gstVars.isPipelineActive = false;
    _gstVars.lastTimestamp = NULL;
}

void GstWrapper::CreateAudioRtspPipeline

(

)

Create the pipeline for an RTSP audio stream.

Definition at line 458 of file GstWrapper.cpp.

                                         {
    // Create the pipeline.
    CreatePipeline();

    // Create the depayloader, decoder and audio sink.
    _gstVars.audioDepay = gst_element_factory_make(Constants::kRtpAudioDepay, "audioDepay");
    g_assert(_gstVars.audioDepay);
    _gstVars.audioDec = gst_element_factory_make(Constants::kRtpAudioDec, "audioDec");
    g_assert(_gstVars.audioDec);
    _gstVars.audioSink = gst_element_factory_make(Constants::kAudioSink, "audioSink");
    g_assert(_gstVars.audioSink);

    // Add elements to the pipeline and link.
    gst_bin_add_many(GST_BIN(_gstVars.pipeline), _gstVars.audioDepay, _gstVars.audioDec, _gstVars.audioSink, NULL);
    gst_element_link_many(_gstVars.audioDepay, _gstVars.audioDec, _gstVars.audioSink, NULL);

    // Create the bin element and start linking
    LinkBinElements();

    // The RTP pad that connects to the depayloader will be created dynamically.
    // So connect to the pad-added signal and pass the depayloader to link to it.
    g_signal_connect(_gstVars.bin, "pad-added", G_CALLBACK(OnPadAdded), _gstVars.audioDepay);

    _gstVars.protocol = VxSdk::VxStreamProtocol::kRtspRtp;
    g_print("Starting RTP audio receiver pipeline.\n");
}

void GstWrapper::CreateMjpegPipeline

(

)

Create the pipeline for an MJPEG stream.

Definition at line 485 of file GstWrapper.cpp.

                                     {
    // Create the pipeline.
    _gstVars.pipeline = gst_pipeline_new(nullptr);
    g_assert(_gstVars.pipeline);
    _gstVars.isPipelineActive = true;
    GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(_gstVars.pipeline));
    _gstVars.busWatchId = gst_bus_add_watch(bus, GstBusFunc(OnBusMessage), &_gstVars);
    gst_object_unref(bus);

    // Create the souphttpsrc.
    _gstVars.src = gst_element_factory_make(Constants::kHttpSrc, "httpSrc");
    g_assert(_gstVars.src);
    g_object_set(_gstVars.src, Constants::kRetries, 5, NULL);
    g_object_set(_gstVars.src, Constants::kKeepAlive, TRUE, NULL);
    g_object_set(_gstVars.src, Constants::kLocation, _gstVars.location.c_str(), NULL);
    g_object_set(_gstVars.src, Constants::kHttpLogLevel, SOUP_LOGGER_LOG_HEADERS, NULL);
    g_object_set(_gstVars.src, Constants::kSslStrict, FALSE, NULL);
    static const char *cookie[] = { _gstVars.cookie.c_str(), NULL };
    g_object_set(_gstVars.src, Constants::kCookies, cookie, NULL);

    // Create the decoder and video sink.
    _gstVars.videoDec = gst_element_factory_make(Constants::kJpegDec, "videoDec");
    g_assert(_gstVars.videoDec);
    _gstVars.videoSink = gst_element_factory_make(Constants::kVideoSink, "videoSink");
    g_assert(_gstVars.videoSink);

    // Add elements to the pipeline and link.
    gst_bin_add_many(GST_BIN(_gstVars.pipeline), _gstVars.src, _gstVars.videoDec, _gstVars.videoSink, NULL);
    gst_element_link_many(_gstVars.src, _gstVars.videoDec, _gstVars.videoSink, NULL);

    // Add a probe to souphttpsrc.
    GstPad *httpsrcpad = gst_element_get_static_pad(_gstVars.src, Constants::kSrc);
    gst_pad_add_probe(httpsrcpad, GST_PAD_PROBE_TYPE_EVENT_BOTH, GstPadProbeCallback(OnJpegPacketReceived), &_gstVars, nullptr);
    gst_object_unref(httpsrcpad);

    // Set the window handle for the video sink.
    gst_video_overlay_set_window_handle(GST_VIDEO_OVERLAY(_gstVars.videoSink), _gstVars.windowHandle);

    // Start the loop to receive bus messages.
    _gstVars.loop = g_main_loop_new(nullptr, FALSE);
    boost::thread _workerThread(g_main_loop_run, _gstVars.loop);

    _gstVars.protocol = VxSdk::VxStreamProtocol::kMjpegPull;
    g_print("Starting MJPEG receiver pipeline.\n");
}

void GstWrapper::CreatePipeline ( )

private

Definition at line 344 of file GstWrapper.cpp.

                                {
    // Create the pipeline.
    _gstVars.pipeline = gst_pipeline_new(nullptr);
    g_assert(_gstVars.pipeline);
    _gstVars.isPipelineActive = true;

    // Create the udpsrc.
    _gstVars.src = gst_element_factory_make(Constants::kUdpSrc, "rtpSrc");
    g_assert(_gstVars.src);
    g_object_set(_gstVars.src, Constants::kPort, _gstVars.rtpPort, NULL);
    if (!_gstVars.multicastAddress.empty())
        g_object_set(_gstVars.src, Constants::kAddress, _gstVars.multicastAddress.c_str(), NULL);

    // Set the caps on udpsrc.
    _gstVars.caps = gst_caps_from_string(_gstVars.rtpCaps.c_str());
    g_object_set(_gstVars.src, Constants::kCaps, _gstVars.caps, NULL);
    gst_caps_unref(_gstVars.caps);

    // Create the udpsrc for RTCP.
    _gstVars.rtcpSrc = gst_element_factory_make(Constants::kUdpSrc, "rtcpSrc");
    g_assert(_gstVars.rtcpSrc);
    g_object_set(_gstVars.rtcpSrc, Constants::kPort, _gstVars.rtcpPort, NULL);

    // Create the udpsink for RTCP.
    _gstVars.rtcpSink = gst_element_factory_make(Constants::kUdpSink, "rtcpSink");
    g_assert(_gstVars.rtcpSink);
    g_object_set(_gstVars.rtcpSink, Constants::kPort, _gstVars.rtcpSinkPort, Constants::kHost, _gstVars.hostIp.c_str(), NULL);
    g_object_set(_gstVars.rtcpSink, Constants::kAsync, FALSE, Constants::kSync, FALSE, NULL);

    // Add the elements to the pipeline.
    gst_bin_add_many(GST_BIN(_gstVars.pipeline), _gstVars.src, _gstVars.rtcpSrc, _gstVars.rtcpSink, NULL);
}

void GstWrapper::CreateVideoRtspPipeline

(

std::string

encoding

)

Create the pipeline for an RTSP video stream.

Parameters

encoding

The video encoding type.

Definition at line 412 of file GstWrapper.cpp.

                                                        {
    // Create the pipeline.
    CreatePipeline();

    // Determine which depayloader and decoder to use based on the encoding type.
    const char* videoDepay;
    const char* videoDec;
    if (encoding == Constants::kEncodingJpeg) {
        videoDepay = Constants::kRtpJpegDepay;
        videoDec = Constants::kJpegDec;
    }
    else if (encoding == Constants::kEncodingMpeg) {
        videoDepay = Constants::kRtpMp4vDepay;
        videoDec = Constants::kRtpMp4vDec;
    }
    else {
        videoDepay = Constants::kRtpH264Depay;
        videoDec = Constants::kRtpH264Dec;
    }

    // Create the depayloader, decoder and video sink.
    _gstVars.videoDepay = gst_element_factory_make(videoDepay, "videoDepay");
    g_assert(_gstVars.videoDepay);
    _gstVars.videoDec = gst_element_factory_make(videoDec, "videoDec");
    g_assert(_gstVars.videoDec);
    _gstVars.videoSink = gst_element_factory_make(Constants::kVideoSink, "videoSink");
    g_assert(_gstVars.videoSink);

    // Add elements to the pipeline and link.
    gst_bin_add_many(GST_BIN(_gstVars.pipeline), _gstVars.videoDepay, _gstVars.videoDec, _gstVars.videoSink, NULL);
    gst_element_link_many(_gstVars.videoDepay, _gstVars.videoDec, _gstVars.videoSink, NULL);

    // Create the bin element and start linking
    LinkBinElements();

    // The RTP pad that connects to the depayloader will be created dynamically.
    // So connect to the pad-added signal and pass the depayloader to link to it.
    g_signal_connect(_gstVars.bin, "pad-added", G_CALLBACK(OnPadAdded), _gstVars.videoDepay);

    // Set the window handle for the video sink.
    gst_video_overlay_set_window_handle(GST_VIDEO_OVERLAY(_gstVars.videoSink), _gstVars.windowHandle);

    _gstVars.protocol = VxSdk::VxStreamProtocol::kRtspRtp;
    g_print("Starting RTP video receiver pipeline.\n");
}

unsigned int GstWrapper::GetLastTimestamp

(

)

const

Get the last timestamp received from the stream.

Returns

The unix timestamp.

Definition at line 306 of file GstWrapper.cpp.

                                                {
    // If the protocol is MjpegPull do not convert the timestamp.
    if (_gstVars.protocol == VxSdk::VxStreamProtocol::kMjpegPull) {
        return _gstVars.currentTimestamp;
    }
    // If the current mode is playback do not convert the timestamp.
    if (_gstVars.mode == Controller::kPlayback) {
        return _gstVars.currentTimestamp;
    }

    return static_cast<unsigned int>(_gstVars.rtcpTimestamp / Constants::kMillisecondsInt);
}

Controller::Mode MediaController::GstWrapper::GetMode ( ) const

inline

Get the current playback mode.

Returns

The current stream Controller::Mode.

Definition at line 90 of file GstWrapper.h.

{ return _gstVars.mode; }

float MediaController::GstWrapper::GetSpeed ( ) const

inline

Get the current playback speed.

Returns

The current stream speed.

Definition at line 96 of file GstWrapper.h.

{ return _gstVars.speed; }

void GstWrapper::Init ( )

staticprivate

Definition at line 265 of file GstWrapper.cpp.

                      {
    if (!gst_is_initialized())
        gst_init(nullptr, nullptr);
}

bool GstWrapper::IsPipelineActive

(

)

const

Get the status of the pipeline.

Returns

True if pipeline is active, otherwise false.

Definition at line 324 of file GstWrapper.cpp.

                                        {
    return _gstVars.isPipelineActive;
}

void GstWrapper::LinkBinElements ( )

private

Definition at line 377 of file GstWrapper.cpp.

                                 {
    // Create the bin element.
    _gstVars.bin = gst_element_factory_make(Constants::kRtpBin, "rtpBin");
    g_assert(_gstVars.bin);

    // Add the bin element to the pipeline.
    gst_bin_add(GST_BIN(_gstVars.pipeline), _gstVars.bin);

    // Start linking elements to the bin, beginning with the RTP sinkPad for session 0.
    _gstVars.srcPad = gst_element_get_static_pad(_gstVars.src, Constants::kSrc);
    gst_pad_add_probe(_gstVars.srcPad, GST_PAD_PROBE_TYPE_BUFFER, GstPadProbeCallback(OnRtpPacketReceived), &_gstVars, nullptr);
    _gstVars.sinkPad = gst_element_get_request_pad(_gstVars.bin, "recv_rtp_sink_0");
    _gstVars.linkReturn = gst_pad_link(_gstVars.srcPad, _gstVars.sinkPad);
    g_assert(_gstVars.linkReturn == GST_PAD_LINK_OK);
    gst_object_unref(_gstVars.srcPad);
    gst_object_unref(_gstVars.sinkPad);

    // Link the RTCP sinkPad for session 0.
    _gstVars.srcPad = gst_element_get_static_pad(_gstVars.rtcpSrc, Constants::kSrc);
    gst_pad_add_probe(_gstVars.srcPad, GST_PAD_PROBE_TYPE_BUFFER, GstPadProbeCallback(OnRtcpPacketReceived), &_gstVars, nullptr);
    _gstVars.sinkPad = gst_element_get_request_pad(_gstVars.bin, "recv_rtcp_sink_0");
    _gstVars.linkReturn = gst_pad_link(_gstVars.srcPad, _gstVars.sinkPad);
    g_assert(_gstVars.linkReturn == GST_PAD_LINK_OK);
    gst_object_unref(_gstVars.srcPad);
    gst_object_unref(_gstVars.sinkPad);

    // Link the RTCP srcPad for session 0.
    _gstVars.srcPad = gst_element_get_request_pad(_gstVars.bin, "send_rtcp_src_0");
    _gstVars.sinkPad = gst_element_get_static_pad(_gstVars.rtcpSink, Constants::kSink);
    _gstVars.linkReturn = gst_pad_link(_gstVars.srcPad, _gstVars.sinkPad);
    g_assert(_gstVars.linkReturn == GST_PAD_LINK_OK);
    gst_object_unref(_gstVars.srcPad);
    gst_object_unref(_gstVars.sinkPad);
}

void GstWrapper::Pause

(

)

const

Set the pipeline state to paused.

Definition at line 540 of file GstWrapper.cpp.

                             {
    gst_element_set_state(_gstVars.pipeline, GST_STATE_PAUSED);
}

void GstWrapper::Play

(

float

speed = 1.0f

)

Set the pipeline state to playing and update the speed value for determining the framerate.

Definition at line 531 of file GstWrapper.cpp.

                                 {
    _gstVars.rtcpTimestamp = 0;
    _gstVars.speed = speed;

    if (_gstVars.pipeline) {
        gst_element_set_state(_gstVars.pipeline, GST_STATE_PLAYING);
    }
}

void GstWrapper::RemoveObserver

(

TimestampEventCallback

observer

)

Remove an existing timestamp event subscriber.

Parameters

observer

The TimestampEventCallback event handler.

Definition at line 332 of file GstWrapper.cpp.

                                                               {
    _gstVars.observerList.erase(remove(_gstVars.observerList.begin(), _gstVars.observerList.end(), observer), _gstVars.observerList.end());
}

void GstWrapper::SetCaps	(	std::string	caps,
		bool	isMjpeg = false
	)

Set the stream capabilities.

Parameters

caps	The stream capabilities.

Definition at line 284 of file GstWrapper.cpp.

                                                     {
    _gstVars.rtpCaps = "application/x-rtp,media=(string)" + caps;
    _gstVars.isMjpeg = isMjpeg;
}

void GstWrapper::SetCookie

(

std::string

cookie

)

Set the cookie for MJPEG streams.

Parameters

cookie

The cookie value.

Definition at line 289 of file GstWrapper.cpp.

                                           {
    _gstVars.cookie = cookie;
}

void GstWrapper::SetLocation

(

std::string

location

)

Set the stream location.

Parameters

location

The URI of the new stream location.

Definition at line 274 of file GstWrapper.cpp.

                                               {
    _gstVars.location = location;
}

void GstWrapper::SetMode

(

Controller::Mode

mode

)

Set the playback mode.

Parameters

mode	The stream Controller::Mode to set.

Definition at line 319 of file GstWrapper.cpp.

                                            {
    _gstVars.rtcpTimestamp = 0;
    _gstVars.mode = mode;
}

void GstWrapper::SetMulticastAddress

(

std::string

multicastAddress

)

Set the multicast group address.

Parameters

multicastAddress

The multicast group address.

Definition at line 297 of file GstWrapper.cpp.

                                                               {
    _gstVars.multicastAddress = multicastAddress;
}

void GstWrapper::SetPorts	(	int	rtpPort,
		int	rtcpPort
	)

Set the receiver ports.

Parameters

rtpPort	The port to receive RTP data.
rtcpPort	The port to receive RTCP data.

Definition at line 278 of file GstWrapper.cpp.

                                             {
    _gstVars.rtpPort = port;
    _gstVars.rtcpPort = port2;
    _gstVars.rtcpSinkPort = port2 + 4;
}

void GstWrapper::SetRtcpHostIP

(

std::string

hostIp

)

Set the RTCP host IP.

Parameters

hostIp

The IP of the RTCP host.

Definition at line 293 of file GstWrapper.cpp.

                                               {
    _gstVars.hostIp = hostIp;
}

void GstWrapper::SetTimestamp

(

unsigned int

seekTime

)

Set the internal timestamp variable.

Parameters

seekTime

A unix timestamp.

Definition at line 301 of file GstWrapper.cpp.

                                                   {
    _gstVars.currentTimestamp = seekTime;
    _gstVars.lastTimestamp = NULL;
}

void GstWrapper::SetWindowHandle

(

guintptr

winhandle

)

Set the display window using the given window handle.

Parameters

winhandle

The window handle of the display.

Definition at line 270 of file GstWrapper.cpp.

                                                   {
    _gstVars.windowHandle = winhandle;
}

Member Data Documentation

GstVars MediaController::GstWrapper::_gstVars

private

Definition at line 161 of file GstWrapper.h.

---

The documentation for this class was generated from the following files:

• C:/Git/VxSDK-Samples/MediaController/Include/GstWrapper.h
• C:/Git/VxSDK-Samples/MediaController/Source/GstWrapper.cpp