Added a pull function in the gstpad. Modified the videosink to implement the pull. This function allows a source elem...

Original commit message from CVS:
Added a pull function in the gstpad. Modified the videosink to implement
the pull. This function allows a source element to request a buffer
from the destination. This is much more efficient because the
videosink can then pass a buffer with SHM to the element, which does
not require an aditional memcpy.
removed scaling from the videosink. I need something better.

gst/gstpad.c

@@ -79,6 +79,7 @@ static void gst_pad_init(GstPad *pad) {
   pad->direction = GST_PAD_UNKNOWN;
   pad->peer = NULL;
   pad->chain = NULL;
+  pad->pull = NULL;
   pad->parent = NULL;
   pad->ghostparents = NULL;
 }
@@ -128,6 +129,15 @@ gchar *gst_pad_get_name(GstPad *pad) {
   return pad->name;
 }
 
+void gst_pad_set_pull_function(GstPad *pad,GstPadPullFunction pull) {
+  g_return_if_fail(pad != NULL);
+  g_return_if_fail(GST_IS_PAD(pad));
+
+	fprintf(stderr, "pad setting pull function\n");
+  
+  pad->pull = pull;
+}
+
 void gst_pad_set_chain_function(GstPad *pad,GstPadChainFunction chain) {
   g_return_if_fail(pad != NULL);
   g_return_if_fail(GST_IS_PAD(pad));
@@ -163,7 +173,11 @@ GstBuffer *gst_pad_pull(GstPad *pad) {
   g_return_if_fail(pad != NULL);
   g_return_if_fail(GST_IS_PAD(pad));
 
-  if (pad->bufpen == NULL) {
+	// if the pull function exists for the pad, call it directly
+	if (pad->pull) {
+		return (pad->pull)(pad->peer);
+  // else we're likely going to have to coroutine it
+	} else if (pad->bufpen == NULL) {
     g_print("no buffer available, will have to do something about it\n");
     peerparent = GST_ELEMENT(pad->peer->parent);
     // if they're a cothread too, we can just switch to them
@@ -221,6 +235,8 @@ void gst_pad_connect(GstPad *srcpad,GstPad *sinkpad) {
 
   /* now copy the chain pointer from sink to src */
   srcpad->chain = sinkpad->chain;
+  /* and the pull function */
+  srcpad->pull = sinkpad->pull;
 
   /* set the connected flag */
   /* FIXME: set connected flag */

gst/gstpad.h

@@ -45,6 +45,7 @@ extern "C" {
 
 // quick test to see if the pad is connected
 #define GST_PAD_CONNECTED(pad) ((pad)->peer != NULL)
+#define GST_PAD_CAN_PULL(pad) ((pad)->pull != NULL)
 
 typedef struct _GstPad GstPad;
 typedef struct _GstPadClass GstPadClass;
@@ -53,6 +54,7 @@ typedef struct _GstPadClass GstPadClass;
  * pad is the sink pad (so the same chain function can be used for N pads)
  * buf is the buffer being passed */
 typedef void (*GstPadChainFunction) (GstPad *pad,GstBuffer *buf);
+typedef GstBuffer *(*GstPadPullFunction) (GstPad *pad);
 typedef void (*GstPadPushFunction) (GstPad *pad);
 
 typedef enum {
@@ -77,6 +79,7 @@ struct _GstPad {
   GstBuffer *bufpen;
 
   GstPadChainFunction chain;
+  GstPadPullFunction pull;
 
   GstObject *parent;
   GList *ghostparents;
@@ -92,6 +95,7 @@ void gst_pad_destroy(GstPad *pad);
 
 GstPadDirection gst_pad_get_direction(GstPad *pad);
 void gst_pad_set_chain_function(GstPad *pad,GstPadChainFunction chain);
+void gst_pad_set_pull_function(GstPad *pad, GstPadPullFunction pull);
 
 guint32 gst_pad_get_type_id(GstPad *pad);
 void gst_pad_set_type_id(GstPad *pad,guint16 id);

test/mp1parse.c

@@ -70,7 +70,7 @@ void new_pad_created(GstElement *parse,GstPad *pad,GstElement *pipeline) {
     g_return_if_fail(decode_video != NULL);
     show = gst_elementfactory_make("videosink","show");
     g_return_if_fail(show != NULL);
-    gtk_object_set(GTK_OBJECT(show),"scale",2.0,NULL);
+    //gtk_object_set(GTK_OBJECT(show),"width",640, "height", 480,NULL);
 
 		appwindow = gnome_app_new("MPEG1 player","MPEG1 player");
 		gnome_app_set_contents(GNOME_APP(appwindow),

test/videotest.c

@@ -5,17 +5,22 @@ extern gboolean _gst_plugin_spew;
 
 gboolean idle_func(gpointer data);
 
-GtkWidget *drawingarea;
+GstElement *src;
 
 void eof(GstSrc *src) {
   g_print("have eos, quitting\n");
   exit(0);
 }
 
+void resize(GstSink *sink) {
+  g_print("have resize\n");
+  gtk_object_set(GTK_OBJECT(src),"width",640,"height",480,NULL);
+}
+
+
 int main(int argc,char *argv[]) {
   GstElement *bin;
   GstElementFactory *srcfactory;
-  GstElement *src;
   GstElementFactory *videosinkfactory;
   GstElement *videosink;
 
@@ -37,7 +42,7 @@ int main(int argc,char *argv[]) {
 
   src = gst_elementfactory_create(srcfactory,"src");
   videosink = gst_elementfactory_create(videosinkfactory,"videosink");
-  gtk_object_set(GTK_OBJECT(videosink),"width",320,"height",240,NULL);
+  gtk_object_set(GTK_OBJECT(videosink),"width",640,"height",480,NULL);
 
 
   gst_bin_add(GST_BIN(bin),GST_ELEMENT(src));
@@ -50,7 +55,6 @@ int main(int argc,char *argv[]) {
 							         GTK_SIGNAL_FUNC(eof),NULL);
 
   appwindow = gnome_app_new("Videotest","Videotest");
-  drawingarea = gtk_drawing_area_new();
   gnome_app_set_contents(GNOME_APP(appwindow),
 									gst_util_get_widget_arg(GTK_OBJECT(videosink),"widget"));
   gtk_widget_show_all(appwindow);