plugins/elements/gstidentity.c: Identity is not always a passthrough element, it...

Original commit message from CVS:
Patch by: Mark Nauwelaerts <manauw at skynet be>
* plugins/elements/gstidentity.c: (gst_identity_class_init),
(gst_identity_init), (gst_identity_prepare_output_buffer):
Identity is not always a passthrough element, it can modify the buffer
timestamps when it has a datarate and operates in single-segment mode.
We therefore make it an in_place filter with a custom buffer prepare
function that conditionally makes the input buffer metadata writable
when needed.  Fixes #523985.

diff --git a/ChangeLog b/ChangeLog
index 31fbea724c5e0c684b0ebae28b4c63a94e075d7f..dce9e5e7a116e81d9f674846f5a2f0be5db4f0cb 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2008-03-24  Wim Taymans  <wim.taymans@collabora.co.uk>
+
+       Patch by: Mark Nauwelaerts <manauw at skynet be>
+
+       * plugins/elements/gstidentity.c: (gst_identity_class_init),
+       (gst_identity_init), (gst_identity_prepare_output_buffer):
+       Identity is not always a passthrough element, it can modify the buffer
+       timestamps when it has a datarate and operates in single-segment mode.
+       We therefore make it an in_place filter with a custom buffer prepare
+       function that conditionally makes the input buffer metadata writable
+       when needed.  Fixes #523985.
+
 2008-03-24  Wim Taymans  <wim.taymans@collabora.co.uk>
 
        Patch by: Mark Nauwelaerts <manauw at skynet be>

diff --git a/plugins/elements/gstidentity.c b/plugins/elements/gstidentity.c
index b13ed741af2a511f4c3fc8ba57d1de52e5d67917..d10f42b86267aa7b9467d17e39053740b24acfc8 100644 (file)
--- a/plugins/elements/gstidentity.c
+++ b/plugins/elements/gstidentity.c
@@ -107,6 +107,9 @@ static void gst_identity_get_property (GObject * object, guint prop_id,
 static gboolean gst_identity_event (GstBaseTransform * trans, GstEvent * event);
 static GstFlowReturn gst_identity_transform_ip (GstBaseTransform * trans,
     GstBuffer * buf);
+static GstFlowReturn gst_identity_prepare_output_buffer (GstBaseTransform
+    * trans, GstBuffer * in_buf, gint out_size, GstCaps * out_caps,
+    GstBuffer ** out_buf);
 static gboolean gst_identity_start (GstBaseTransform * trans);
 static gboolean gst_identity_stop (GstBaseTransform * trans);
 
@@ -267,6 +270,8 @@ gst_identity_class_init (GstIdentityClass * klass)
   gstbasetrans_class->event = GST_DEBUG_FUNCPTR (gst_identity_event);
   gstbasetrans_class->transform_ip =
       GST_DEBUG_FUNCPTR (gst_identity_transform_ip);
+  gstbasetrans_class->prepare_output_buffer =
+      GST_DEBUG_FUNCPTR (gst_identity_prepare_output_buffer);
   gstbasetrans_class->start = GST_DEBUG_FUNCPTR (gst_identity_start);
   gstbasetrans_class->stop = GST_DEBUG_FUNCPTR (gst_identity_stop);
 }
@@ -274,8 +279,6 @@ gst_identity_class_init (GstIdentityClass * klass)
 static void
 gst_identity_init (GstIdentity * identity, GstIdentityClass * g_class)
 {
-  gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (identity), TRUE);
-
   identity->sleep_time = DEFAULT_SLEEP_TIME;
   identity->error_after = DEFAULT_ERROR_AFTER;
   identity->drop_probability = DEFAULT_DROP_PROBABILITY;
@@ -349,6 +352,28 @@ gst_identity_event (GstBaseTransform * trans, GstEvent * event)
   return ret;
 }
 
+static GstFlowReturn
+gst_identity_prepare_output_buffer (GstBaseTransform * trans,
+    GstBuffer * in_buf, gint out_size, GstCaps * out_caps, GstBuffer ** out_buf)
+{
+  GstIdentity *identity = GST_IDENTITY (trans);
+
+  /* only bother if we may have to alter metadata */
+  if (identity->datarate > 0 || identity->single_segment) {
+    if (gst_buffer_is_metadata_writable (in_buf))
+      *out_buf = gst_buffer_ref (in_buf);
+    else {
+      /* make even less writable */
+      gst_buffer_ref (in_buf);
+      /* extra ref is dropped going through the official process */
+      *out_buf = gst_buffer_make_metadata_writable (in_buf);
+    }
+  } else
+    *out_buf = gst_buffer_ref (in_buf);
+
+  return GST_FLOW_OK;
+}
+
 static void
 gst_identity_check_perfect (GstIdentity * identity, GstBuffer * buf)
 {