Re: [Vala] clutter-gst and gst

[Steve Salazar <eagsalazar hotmail com>]

Thanks for your help, that vala code is a great reference for me to look at also.
One question, where is vala documentation for ClutterGst and Gst plugins?
Anyway, I finally got a working clutter-gst from a filesrc!  Once bug is resolved: 
https://bugzilla.gnome.org/show_bug.cgi?id=624648
This is working code (assuming bug fixed):
using Clutter;using Gst;using ClutterGst;
// You provide the filename and the sink and we'll make it just work.public class VideoPlayer { private 
string fileName;    private Pipeline pipeline;    private Element src;    private Element sink; private 
Element decode; private Element colorspace;
    public VideoPlayer(string? _fileName, Element _sink) {      fileName = _fileName;           sink = _sink; 
       setup_pipeline();    }
    public void play() {        if(pipeline.current_state == State.PLAYING)             
pipeline.set_state(State.PAUSED);       else            pipeline.set_state(State.PLAYING);    }
    public void stop() {        pipeline.set_state(State.READY);    }
    private void setup_pipeline() {             pipeline = new Pipeline("pipeline");
                // To play a video file you need these elements:                //              - "filesrc" 
to read file or "v4l2src" (src)             //              - "decodebin" to decode file (filter)           
//              - "ffmpegcolorspace" to do colorspace conversion (filter)               //              - 
Some sink that we have passed in.
                // If we don't have a fileName, then use the video camera, which is fun.                
if(fileName == null) {                  src = ElementFactory.make("v4l2src", null);             } else {      
                  src = ElementFactory.make("filesrc", null);                     // Unlike in GOBject where 
we use .set_attribute, here we use .set as this is                   // built into vala, I guess.             
       src.set("location", fileName);          }
                decode = ElementFactory.make("decodebin", null);                colorspace = 
ElementFactory.make("ffmpegcolorspace", null);
                // decodebins output (src) isnt created until after the state != State.READY.  So we wait     
          // for the new-decoded-pad event and hook up those pads at that time.           //              // 
The last argument is because on_new_decoded_pad is static so we need to              // provide a reference 
to the instance variables it will need.          //              // We should be able to simply do:           
   //              //              decode.new_decoded_pad.connect(on_new_decoded_pad);             //         
     // Where on_new_decoded_pad would be an instance method.  However               // There is a bug that 
requires we do this crap.  See on_new_decoded_pad comments.              Signal.connect(decode, 
"new-decoded-pad", (GLib.Callback) on_new_decoded_pad, colorspace);
                // Add all our elements to the pipeline         pipeline.add_many(src, decode, colorspace, 
sink);
                // Hook up the elements that we can hook up.  Which pads to hook up is          // resolved 
automatically by direction and type when not ambiguous.             src.link(decode);               
colorspace.link(sink);    }
        // The last argument inherits from GPointer in C which in the context means any reference type. // We 
declare this method to be static and use the last arg to get a ref back to the instance,  // instead of just 
making this an instance method because of bug: (which I don't totally understand)    //              
https://bugzilla.gnome.org/show_bug.cgi?id=615979       private static void on_new_decoded_pad(Element 
decodebin, Pad pad, bool last, Element colorspace) {             pad.link(colorspace.get_pad("sink"));   }}
// Clutter.Texture is an actor, for drawing images on.  We are going// to draw video frames on this texture.  
It exposes a public attribute// player which is an instance of VideoPlayer.class VideoTexture : 
Clutter.Texture {
        public VideoPlayer player;      private ClutterGst.VideoSink sink;
        // Input args   private string videoFile;
        public VideoTexture(string? _videoFile) {               videoFile = _videoFile;
                // ClutterGst.VideoSink is a Gst sink element.  We pass in this         // actor so that this 
sink knows to copy frames to that texture.                sink = new ClutterGst.VideoSink(this);
                // Create the player            player = new VideoPlayer(videoFile, sink);      }}
bool on_keypress_event(KeyEvent e) {    Clutter.main_quit();    return true;}
void main(string[] args) {      var vid1 = null;
        // Initialize both Clutter and ClutterGst       Clutter.init(ref args);    Gst.init (ref args); 
ClutterGst.init(ref args);
        // Each window by default has a stage associated with it        var stage = Stage.get_default();      
  stage.color = Color.from_string("black");       stage.title = "Awesome";        stage.x = 800;  stage.y = 
600;
        stage.hide.connect(Clutter.main_quit);  stage.key_press_event.connect(on_keypress_event);
        VideoTexture awesome1 = new VideoTexture(vid1);
        // Add the target of the pipeline, the clutter texture (this),  // to the stage so we can see it.     
  stage.add_actor(awesome1);      stage.show_all();
        // Play must be called after the stage has been shown or else segfault!!        // Calling play sets 
the gst pipelines state to State.PLAYING   awesome1.player.play();
        Clutter.main();}


On 18 July 2010 12:05, Steve Salazar <eagsalazar hotmail com> wrote:
> Sorry about the last post, here is the correct link:
>  http://gist.github.com/479975
> Also, to answer the last question about trying the pipeline with gst-launch, I've tried this and it works 
> fine:
> gst-launch filesrc location=/home/esalazar/Desktop/Rendezvous.avi ! decodebin ! ffmpegcolorspace ! 
> xvimagesink
> Which should be identical to what I'm doing.

Instead of linking decodebin to the next element, you should connect
to its `new-decoded-pad` event and link from there. See these C and
Vala examples:

http://cgit.freedesktop.org/gstreamer/gst-plugins-base/tree/gst/playback/test6.c
http://gitorious.org/spek/spek/blobs/bccc4997868333df89d1dc5594fcb2c88a8e28e8/src/spek-source.vala#line82

Alex