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// Authors
// Copyright (C) 2014 Stephan Sundermann <stephansundermann@gmail.com>
using System;
using Gst;
using System.Runtime.InteropServices;
namespace GstreamerSharp
{
class Playback
{
// Functions below print the capabilities in a human-friendly format
static void PrintCaps (Caps caps, string pfx) {
if (caps == null)
return;
if (caps.IsAny) {
Console.WriteLine ("{0}ANY", pfx);
return;
}
if (caps.IsEmpty) {
Console.WriteLine ("{0}EMPTY", pfx);
return;
}
for (uint i = 0; i < caps.Size; i++) {
var structure = caps.GetStructure (i);
Console.WriteLine ("{0}{1}", pfx, structure.Name);
structure.Foreach ((field_id, value) => {
var ptr = g_quark_to_string (field_id);
var quark = GLib.Marshaller.Utf8PtrToString (ptr);
Console.WriteLine ("{0} {1}: {2}", pfx, quark, value.Val);
return true;
});
}
}
// Prints information about a Pad Template, including its Capabilities*/
static void PrintPadTemplateInformation (ElementFactory factory) {
Console.WriteLine ("Pad Templates for {0}:", factory.Name);
if (factory.NumPadTemplates == 0) {
Console.WriteLine (" none");
return;
}
var pads = factory.StaticPadTemplates;
foreach (var p in pads) {
var pad = (StaticPadTemplate) p;
if (pad.Direction == PadDirection.Src)
Console.WriteLine (" SRC template: '{0}'", pad.NameTemplate);
else if (pad.Direction == PadDirection.Sink)
Console.WriteLine (" SINK template: '{0}'", pad.NameTemplate);
else
Console.WriteLine (" UNKNOWN!!! template: '{0}'", pad.NameTemplate);
if (pad.Presence == PadPresence.Always)
Console.WriteLine (" Availability: Always");
else if (pad.Presence == PadPresence.Sometimes)
Console.WriteLine (" Availability: Sometimes");
else if (pad.Presence == PadPresence.Request) {
Console.WriteLine (" Availability: On request");
} else
Console.WriteLine (" Availability: UNKNOWN!!!");
if (pad.StaticCaps.String != null) {
Console.WriteLine (" Capabilities:");
PrintCaps (pad.StaticCaps.Get (), " ");
}
Console.WriteLine ();
}
}
// Shows the CURRENT capabilities of the requested pad in the given element */
static void PrintPadCapabilities (Element element, string padName) {
// Retrieve pad
var pad = element.GetStaticPad (padName);
if (pad == null) {
Console.WriteLine ("Could not retrieve pad '{0}'", padName);
return;
}
// Retrieve negotiated caps (or acceptable caps if negotiation is not finished yet)
var caps = pad.CurrentCaps;
if (caps == null)
caps = pad.Caps;
/* Print and free */
Console.WriteLine ("Caps for the {0} pad:", padName);
PrintCaps (caps, " ");
}
public static void Main (string[] args)
{
// Initialize Gstreamer
Gst.Application.Init(ref args);
// Create the element factories
var sourceFactory = ElementFactory.Find ("audiotestsrc");
var sinkFactory = ElementFactory.Find ("autoaudiosink");
if (sourceFactory == null || sinkFactory == null) {
Console.WriteLine ("Not all element factories could be created.");
return;
}
// Print information about the pad templates of these factories
PrintPadTemplateInformation (sourceFactory);
PrintPadTemplateInformation (sinkFactory);
// Ask the factories to instantiate actual elements
var source = sourceFactory.Create ("source");
var sink = sinkFactory.Create ("sink");
// Create the empty pipeline
var pipeline = new Pipeline ("test-pipeline");
if (pipeline == null || source == null || sink == null) {
Console.WriteLine ("Not all elements could be created.");
return;
}
// Build the pipeline
pipeline.Add (source, sink);
if (!source.Link (sink)) {
Console.WriteLine ("Elements could not be linked.");
return;
}
// Print initial negotiated caps (in NULL state)
Console.WriteLine ("In NULL state:");
PrintPadCapabilities (sink, "sink");
// Start playing
var ret = pipeline.SetState (State.Playing);
if (ret == StateChangeReturn.Failure) {
Console.WriteLine ("Unable to set the pipeline to the playing state (check the bus for error messages).");
}
// Wait until error, EOS or State Change
var bus = pipeline.Bus;
var terminate = false;
do {
var msg = bus.TimedPopFiltered (Constants.CLOCK_TIME_NONE, MessageType.Error | MessageType.Eos | MessageType.StateChanged);
// Parse message
if (msg != null) {
switch (msg.Type) {
case MessageType.Error:
string debug;
GLib.GException exc;
msg.ParseError (out exc, out debug);
Console.WriteLine ("Error received from element {0}: {1}", msg.Src.Name, exc.Message);
Console.WriteLine ("Debugging information: {0}", debug != null ? debug : "none");
terminate = true;
break;
case MessageType.Eos:
Console.WriteLine ("End-Of-Stream reached.\n");
terminate = true;
break;
case MessageType.StateChanged:
// We are only interested in state-changed messages from the pipeline
if (msg.Src == pipeline) {
State oldState, newState, pendingState;
msg.ParseStateChanged (out oldState, out newState, out pendingState);
Console.WriteLine ("Pipeline state changed from {0} to {1}:",
Element.StateGetName (oldState), Element.StateGetName (newState));
// Print the current capabilities of the sink element
PrintPadCapabilities (sink, "sink");
}
break;
default:
// We should not reach here because we only asked for ERRORs, EOS and STATE_CHANGED
Console.WriteLine ("Unexpected message received.");
break;
}
}
} while (!terminate);
// Free resources
pipeline.SetState (State.Null);
}
[DllImport ("libglib-2.0.so.0")]
static extern IntPtr g_quark_to_string (uint quark);
}
}
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