libs/gst/base/gstbasetransform.c (_GstBaseTransformPrivate): (gst_base_transform_init, gst_base_transform_sink_activa...

Original commit message from CVS:
2007-01-12  Andy Wingo  <wingo@pobox.com>

* libs/gst/base/gstbasetransform.c (_GstBaseTransformPrivate):
(gst_base_transform_init, gst_base_transform_sink_activate_push)
(gst_base_transform_src_activate_pull):
Track the activation mode.
(gst_base_transform_setcaps): In pull mode, when activating the
src pad, after activating the sink pad, activate the sink pad's
peer, as discussed in part-negotiation.txt.

* libs/gst/base/gstbasesrc.h:
* libs/gst/base/gstbasesrc.c (gst_base_src_fixate): Add fixate
vmethod, as in basesink.

* libs/gst/base/gstbasesink.h: Reformat docs, add fixate vmethod.

* libs/gst/base/gstbasesink.c (gst_base_sink_pad_setcaps): In pull
mode, first proxy the setcaps to the peer pad.
(gst_base_sink_pad_fixate): Add a fixate function that calls the
new fixate vmethod.
(gst_base_sink_default_activate_pull): Rename from
gst_base_sink_activate_pull.
(gst_base_sink_negotiate_pull): New function, performs negotiation
in pull mode before calling ::activate_pull().
(gst_base_sink_pad_activate_pull): Actually call the activate_pull
vmethod instead of the default implementation. I have no idea how
this worked before. Negotiate before calling activate_pull.

ChangeLog

@@ -1,5 +1,31 @@
 2007-01-12  Andy Wingo  <wingo@pobox.com>
 
+	* libs/gst/base/gstbasetransform.c (_GstBaseTransformPrivate):
+	(gst_base_transform_init, gst_base_transform_sink_activate_push)
+	(gst_base_transform_src_activate_pull): 
+	Track the activation mode.
+	(gst_base_transform_setcaps): In pull mode, when activating the
+	src pad, after activating the sink pad, activate the sink pad's
+	peer, as discussed in part-negotiation.txt.
+
+	* libs/gst/base/gstbasesrc.h: 
+	* libs/gst/base/gstbasesrc.c (gst_base_src_fixate): Add fixate
+	vmethod, as in basesink.
+
+	* libs/gst/base/gstbasesink.h: Reformat docs, add fixate vmethod.
+
+	* libs/gst/base/gstbasesink.c (gst_base_sink_pad_setcaps): In pull
+	mode, first proxy the setcaps to the peer pad.
+	(gst_base_sink_pad_fixate): Add a fixate function that calls the
+	new fixate vmethod.
+	(gst_base_sink_default_activate_pull): Rename from
+	gst_base_sink_activate_pull.
+	(gst_base_sink_negotiate_pull): New function, performs negotiation
+	in pull mode before calling ::activate_pull().
+	(gst_base_sink_pad_activate_pull): Actually call the activate_pull
+	vmethod instead of the default implementation. I have no idea how
+	this worked before. Negotiate before calling activate_pull.
+
 	* gst/gstpad.c (gst_pad_activate_pull): Refuse to activate unlinked
 	sink pads in pull mode. In addition to being correct, fixes
 	filesrc ! decodebin ! identity ! fakesink.

libs/gst/base/gstbasesink.c

@@ -274,7 +274,7 @@ static void gst_base_sink_get_times (GstBaseSink * basesink, GstBuffer * buffer,
     GstClockTime * start, GstClockTime * end);
 static gboolean gst_base_sink_set_flushing (GstBaseSink * basesink,
     GstPad * pad, gboolean flushing);
-static gboolean gst_base_sink_activate_pull (GstBaseSink * basesink,
+static gboolean gst_base_sink_default_activate_pull (GstBaseSink * basesink,
     gboolean active);
 
 static GstStateChangeReturn gst_base_sink_change_state (GstElement * element,
@@ -346,7 +346,8 @@ gst_base_sink_class_init (GstBaseSinkClass * klass)
   klass->set_caps = GST_DEBUG_FUNCPTR (gst_base_sink_set_caps);
   klass->buffer_alloc = GST_DEBUG_FUNCPTR (gst_base_sink_buffer_alloc);
   klass->get_times = GST_DEBUG_FUNCPTR (gst_base_sink_get_times);
-  klass->activate_pull = GST_DEBUG_FUNCPTR (gst_base_sink_activate_pull);
+  klass->activate_pull =
+      GST_DEBUG_FUNCPTR (gst_base_sink_default_activate_pull);
 }
 
 static GstCaps *
@@ -380,12 +381,24 @@ gst_base_sink_pad_setcaps (GstPad * pad, GstCaps * caps)
 {
   GstBaseSinkClass *bclass;
   GstBaseSink *bsink;
-  gboolean res = FALSE;
+  gboolean res = TRUE;
 
   bsink = GST_BASE_SINK (gst_pad_get_parent (pad));
   bclass = GST_BASE_SINK_GET_CLASS (bsink);
 
-  if (bclass->set_caps)
+  if (bsink->pad_mode == GST_ACTIVATE_PULL) {
+    GstPad *peer = gst_pad_get_peer (pad);
+
+    if (peer)
+      res = gst_pad_set_caps (peer, caps);
+    else
+      res = FALSE;
+
+    if (!res)
+      GST_DEBUG_OBJECT (bsink, "peer setcaps() failed");
+  }
+
+  if (res && bclass->set_caps)
     res = bclass->set_caps (bsink, caps);
 
   gst_object_unref (bsink);
@@ -393,6 +406,21 @@ gst_base_sink_pad_setcaps (GstPad * pad, GstCaps * caps)
   return res;
 }
 
+static void
+gst_base_sink_pad_fixate (GstPad * pad, GstCaps * caps)
+{
+  GstBaseSinkClass *bclass;
+  GstBaseSink *bsink;
+
+  bsink = GST_BASE_SINK (gst_pad_get_parent (pad));
+  bclass = GST_BASE_SINK_GET_CLASS (bsink);
+
+  if (bclass->fixate)
+    bclass->fixate (bsink, caps);
+
+  gst_object_unref (bsink);
+}
+
 static GstFlowReturn
 gst_base_sink_pad_buffer_alloc (GstPad * pad, guint64 offset, guint size,
     GstCaps * caps, GstBuffer ** buf)
@@ -432,6 +460,8 @@ gst_base_sink_init (GstBaseSink * basesink, gpointer g_class)
       GST_DEBUG_FUNCPTR (gst_base_sink_pad_getcaps));
   gst_pad_set_setcaps_function (basesink->sinkpad,
       GST_DEBUG_FUNCPTR (gst_base_sink_pad_setcaps));
+  gst_pad_set_fixatecaps_function (basesink->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_base_sink_pad_fixate));
   gst_pad_set_bufferalloc_function (basesink->sinkpad,
       GST_DEBUG_FUNCPTR (gst_base_sink_pad_buffer_alloc));
   gst_pad_set_activate_function (basesink->sinkpad,
@@ -2121,7 +2151,7 @@ gst_base_sink_set_flushing (GstBaseSink * basesink, GstPad * pad,
 }
 
 static gboolean
-gst_base_sink_activate_pull (GstBaseSink * basesink, gboolean active)
+gst_base_sink_default_activate_pull (GstBaseSink * basesink, gboolean active)
 {
   gboolean result;
 
@@ -2203,6 +2233,48 @@ gst_base_sink_pad_activate_push (GstPad * pad, gboolean active)
   return result;
 }
 
+static gboolean
+gst_base_sink_negotiate_pull (GstBaseSink * basesink)
+{
+  GstCaps *caps;
+  GstPad *pad;
+
+  GST_OBJECT_LOCK (basesink);
+  pad = basesink->sinkpad;
+  gst_object_ref (pad);
+  GST_OBJECT_UNLOCK (basesink);
+
+  caps = gst_pad_get_allowed_caps (pad);
+  if (gst_caps_is_empty (caps))
+    goto no_caps_possible;
+
+  caps = gst_caps_make_writable (caps);
+  gst_pad_fixate_caps (pad, caps);
+
+  if (!gst_pad_set_caps (pad, caps))
+    goto could_not_set_caps;
+
+  gst_caps_unref (caps);
+  gst_object_unref (pad);
+
+  return TRUE;
+
+no_caps_possible:
+  {
+    GST_INFO_OBJECT (basesink, "Pipeline could not agree on caps");
+    GST_DEBUG_OBJECT (basesink, "get_allowed_caps() returned EMPTY");
+    gst_object_unref (pad);
+    return FALSE;
+  }
+could_not_set_caps:
+  {
+    GST_INFO_OBJECT (basesink, "Could not set caps: %" GST_PTR_FORMAT, caps);
+    gst_caps_unref (caps);
+    gst_object_unref (pad);
+    return FALSE;
+  }
+}
+
 /* this won't get called until we implement an activate function */
 static gboolean
 gst_base_sink_pad_activate_pull (GstPad * pad, gboolean active)
@@ -2236,9 +2308,15 @@ gst_base_sink_pad_activate_pull (GstPad * pad, gboolean active)
           basesink->have_newsegment = TRUE;
 
           /* set the pad mode before starting the task so that it's in the
-             correct state for the new thread... */
+             correct state for the new thread. also the sink set_caps function
+             checks this */
           basesink->pad_mode = GST_ACTIVATE_PULL;
-          result = gst_base_sink_activate_pull (basesink, TRUE);
+          if ((result = gst_base_sink_negotiate_pull (basesink))) {
+            if (bclass->activate_pull)
+              result = bclass->activate_pull (basesink, TRUE);
+            else
+              result = FALSE;
+          }
           /* but if starting the thread fails, set it back */
           if (!result)
             basesink->pad_mode = GST_ACTIVATE_NONE;

libs/gst/base/gstbasesink.h

@@ -108,25 +108,26 @@ struct _GstBaseSink {
  * @set_caps: Notify subclass of changed caps
  * @buffer_alloc: Subclasses can override to perform custom buffer allocations
  * @get_times: Called to get the start and end times for synchronising
- *             the passed buffer to the clock
+ *     the passed buffer to the clock
  * @start: Start processing. Ideal for opening resources in the subclass
  * @stop: Stop processing. Subclasses should use this to close resources.
  * @unlock: Unlock any pending access to the resource. Subclasses should
- *          unblock any blocked function ASAP
+ *     unblock any blocked function ASAP
  * @event: Override this to handle events arriving on the sink pad
  * @preroll: Called to present the preroll buffer if desired
  * @render: Called when a buffer should be presented or output, at the
- *          correct moment if the #GstBaseSink has been set to sync to
+ *     correct moment if the #GstBaseSink has been set to sync to the clock.
- *          the clock.
  * @async_play: Subclasses should override this when they need to perform
- *              special processing when changing to the PLAYING state
+ *     special processing when changing to the PLAYING state asynchronously.
- *              asynchronously.  Called with the OBJECT_LOCK held.
+ *     Called with the OBJECT_LOCK held.
  * @activate_pull: Subclasses should override this when they can provide an
- *                 alternate method of spawning a thread to drive the pipeline
+ *     alternate method of spawning a thread to drive the pipeline in pull mode.
- *                 in pull mode. Should start or stop the pulling thread,
+ *     Should start or stop the pulling thread, depending on the value of the
- *                 depending on the value of the "active" argument. Called after
+ *     "active" argument. Called after actually activating the sink pad in pull
- *                 actually activating the sink pad in pull mode. The default
+ *     mode. The default implementation starts a task on the sink pad.
- *                 implementation starts a task on the sink pad.
+ * @fixate: Only useful in pull mode, this vmethod will be called in response to
+ *     gst_pad_fixate_caps() being called on the sink pad. Implement if you have
+ *     ideas about what should be the default values for the caps you support.
  *
  * Subclasses can override any of the available virtual methods or not, as
  * needed. At the minimum, the render method should be overridden to
@@ -169,8 +170,11 @@ struct _GstBaseSinkClass {
   /* start or stop a pulling thread */
   gboolean	(*activate_pull)(GstBaseSink *sink, gboolean active);
 
+  /* fixate sink caps during pull-mode negotiation */
+  void		(*fixate)	(GstBaseSink *sink, GstCaps *caps);
+
   /*< private >*/
-  gpointer       _gst_reserved[GST_PADDING_LARGE-2];
+  gpointer       _gst_reserved[GST_PADDING_LARGE-3];
 };
 
 GType gst_base_sink_get_type(void);

libs/gst/base/gstbasesrc.c

@@ -269,6 +269,7 @@ gst_base_src_get_type (void)
 }
 static GstCaps *gst_base_src_getcaps (GstPad * pad);
 static gboolean gst_base_src_setcaps (GstPad * pad, GstCaps * caps);
+static void gst_base_src_fixate (GstPad * pad, GstCaps * caps);
 
 static gboolean gst_base_src_activate_push (GstPad * pad, gboolean active);
 static gboolean gst_base_src_activate_pull (GstPad * pad, gboolean active);
@@ -391,6 +392,8 @@ gst_base_src_init (GstBaseSrc * basesrc, gpointer g_class)
       GST_DEBUG_FUNCPTR (gst_base_src_pad_get_range));
   gst_pad_set_getcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_getcaps));
   gst_pad_set_setcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_setcaps));
+  gst_pad_set_fixatecaps_function (pad,
+      GST_DEBUG_FUNCPTR (gst_base_src_fixate));
 
   /* hold pointer to pad */
   basesrc->srcpad = pad;
@@ -578,6 +581,21 @@ gst_base_src_getcaps (GstPad * pad)
   return caps;
 }
 
+static void
+gst_base_src_fixate (GstPad * pad, GstCaps * caps)
+{
+  GstBaseSrcClass *bclass;
+  GstBaseSrc *bsrc;
+
+  bsrc = GST_BASE_SRC (gst_pad_get_parent (pad));
+  bclass = GST_BASE_SRC_GET_CLASS (bsrc);
+
+  if (bclass->fixate)
+    bclass->fixate (bsrc, caps);
+
+  gst_object_unref (bsrc);
+}
+
 static gboolean
 gst_base_src_default_query (GstBaseSrc * src, GstQuery * query)
 {

libs/gst/base/gstbasesrc.h

@@ -142,6 +142,8 @@ struct _GstBaseSrc {
  *   cycles. The default implementation will open and close the resource 
  *   to find out whether get_range is supported, and that is usually 
  *   undesirable. 
+ * @fixate: Called during negotation if caps need fixating. Implement instead of
+ *   setting a fixate function on the source pad.
  */
 struct _GstBaseSrcClass {
   GstElementClass parent_class;
@@ -199,8 +201,11 @@ struct _GstBaseSrcClass {
    * undesirable. */
   gboolean      (*check_get_range) (GstBaseSrc *src);
 
+  /* called if, in negotation, caps need fixating */
+  void		(*fixate)	(GstBaseSrc *src, GstCaps *caps);
+
   /*< private >*/
-  gpointer       _gst_reserved[GST_PADDING_LARGE - 3];
+  gpointer       _gst_reserved[GST_PADDING_LARGE - 4];
 };
 
 GType gst_base_src_get_type (void);

libs/gst/base/gstbasetransform.c

@@ -230,6 +230,8 @@ struct _GstBaseTransformPrivate
   gboolean qos_enabled;
   gdouble proportion;
   GstClockTime earliest_time;
+
+  GstActivateMode pad_mode;
 };
 
 static GstElementClass *parent_class = NULL;
@@ -398,6 +400,7 @@ gst_base_transform_init (GstBaseTransform * trans,
   trans->priv->qos_enabled = DEFAULT_PROP_QOS;
   trans->cache_caps1 = NULL;
   trans->cache_caps2 = NULL;
+  trans->priv->pad_mode = GST_ACTIVATE_NONE;
 
   trans->passthrough = FALSE;
   if (bclass->transform == NULL) {
@@ -811,6 +814,14 @@ gst_base_transform_setcaps (GstPad * pad, GstCaps * caps)
   /* we know this will work, we implement the setcaps */
   gst_pad_set_caps (otherpad, othercaps);
 
+  if (pad == trans->srcpad && trans->priv->pad_mode == GST_ACTIVATE_PULL) {
+    ret &= gst_pad_set_caps (otherpeer, othercaps);
+    if (!ret) {
+      GST_INFO_OBJECT (trans, "otherpeer setcaps(%" GST_PTR_FORMAT ") failed",
+          othercaps);
+    }
+  }
+
 done:
   if (otherpeer)
     gst_object_unref (otherpeer);
@@ -1604,7 +1615,12 @@ gst_base_transform_sink_activate_push (GstPad * pad, gboolean active)
   if (active) {
     if (bclass->start)
       result = bclass->start (trans);
+    if (result)
+      trans->priv->pad_mode = GST_ACTIVATE_PUSH;
+  } else {
+    trans->priv->pad_mode = GST_ACTIVATE_NONE;
   }
+
   gst_object_unref (trans);
 
   return result;
@@ -1625,7 +1641,12 @@ gst_base_transform_src_activate_pull (GstPad * pad, gboolean active)
   if (active) {
     if (result && bclass->start)
       result &= bclass->start (trans);
+    if (result)
+      trans->priv->pad_mode = GST_ACTIVATE_PULL;
+  } else {
+    trans->priv->pad_mode = GST_ACTIVATE_NONE;
   }
+
   gst_object_unref (trans);
 
   return result;