/// <summary>
/// Used to connect a C# delegate to AppSrc's need-data action signal
/// </summary>
/// <param name="appsrc">AppSrc instance whose need-data signal needs to be changed</param>
/// <param name="callback">need-data C# callback, might be called in a separate thread!</param>
/// <returns></returns>
public static bool AppSrcConnect(AppSrc appsrc, GStreamer.NeedDataDelegate callback)
{
if (appsrc == AppSrc.Zero)
{
return(false);
}
return(GsignalNativeMethods.g_signal_connect_data(appsrc, "need-data", callback, GPointer.Zero, GPointer.Zero, ConnectFlags.G_CONNECT_NONE) > 0);
}
internal static extern ulong g_signal_connect_data(GPointer instance, string detailed_signal, GStreamer.NeedDataDelegate c_handler, GPointer data, GPointer destroy_data, GSignal.ConnectFlags connect_flags);
/// <summary>
/// Attempts to construct a GStreamer pipeline that streams an ARGB C# byte array
/// encoded with JPEG and multiplexed into HTTP multi part frames.
/// THROWS if it cannot construct the pipeline.
/// Receiver can be (in case of UDP transport):
/// gst-launch-1.0 udpsrc address=<host> port=<port> ! decodebin ! autovideosink
/// </summary>
/// <param name="width">width of the input image buffer</param>
/// <param name="height">height of the input image buffer</param>
/// <param name="netopts">network options to launch the ByteStreamer instance with</param>
public ByteStreamer(int width, int height, NetworkOptions netopts = null)
{
Disposed = false;
if (!GStreamer.IsInitialized &&
!GStreamer.Initialize())
{
throw new ExternalException("Unable to initialize GStreamer.");
}
if (netopts == null)
{
netopts = new NetworkOptions();
}
string appsrc_name = "AppSrc";
string appsrc_sink = string.Empty;
string appsrc_opts = "is-live=true do-timestamp=true";
string appsrc_caps = string.Format("video/x-raw,format=ARGB,framerate=0/1,width={0},height={1}", width, height);
if (netopts.StreamType == TransportType.Udp)
{
appsrc_sink = string.Format("udpsink host={0} port={1}",
netopts.Address, netopts.Port);
}
else
if (netopts.StreamType == TransportType.Tcp)
{
appsrc_sink = string.Format("tcpserversink host={0} port={1}",
netopts.Address, netopts.Port);
}
else
if (netopts.StreamType == TransportType.All)
{
appsrc_sink = string.Format("tee name=t ! queue ! tcpserversink host={0} port={1} t. ! queue ! udpsink host={0} port={1}",
netopts.Address, netopts.Port);
}
string[] pipeline_elements = new string[]
{
string.Format("appsrc name=\"{0}\" caps=\"{1}\" {2}", appsrc_name, appsrc_caps, appsrc_opts),
"videoconvert",
"video/x-raw,format=I420",
"jpegenc quality=75",
appsrc_sink
};
string pipeline_description = string.Join(" ! ", pipeline_elements);
m_Pipeline = GStreamer.ParseLaunch(pipeline_description);
if (m_Pipeline == IntPtr.Zero)
{
throw new ExternalException("Unable to launch the pipeline.");
}
m_AppSrc = GStreamer.BinGetByName(m_Pipeline, appsrc_name);
if (m_AppSrc == IntPtr.Zero)
{
throw new ExternalException("Unable to obtain pipeline's AppSrc.");
}
var need_data_cb = new GStreamer.NeedDataDelegate((appsrc, size, data) => { NeedData = true; });
m_NeedDataCallbackHandle = GCHandle.Alloc(need_data_cb, GCHandleType.Pinned);
if (!GSignal.AppSrcConnect(m_AppSrc, need_data_cb))
{
throw new ExternalException("Failed to connect the need-data action signal.");
}
if (GStreamer.ElementSetState(m_Pipeline, GStreamer.State.GST_STATE_PLAYING)
== GStreamer.StateChangeReturn.GST_STATE_CHANGE_FAILURE)
{
throw new ExternalException("Pipeline state change failed.");
}
}