docs: pwd: fix typos

https://bugzilla.gnome.org/show_bug.cgi?id=738612

docs/pwg/advanced-allocation.xml

@@ -117,7 +117,7 @@
     </para>
     <para>
       The buffer contains one or more <classname>GstMemory</classname>
-      objects thet represent the data in the buffer.
+      objects that represent the data in the buffer.
     </para>
     <para>
       Metadata in the buffer consists of:
@@ -398,7 +398,7 @@ my_example_meta_api_get_type (void)
           macro. You will also make a method to add your metadata
           implementation to a <classname>GstBuffer</classname>.
           Your <filename>my-example-meta.h</filename> header file will
-          need thse additions:
+          need these additions:
         </para>
         <programlisting>
 <![CDATA[

docs/pwg/advanced-clock.xml

@@ -64,7 +64,7 @@
     <title> Buffer running-time </title>
     <para>
       To calculate a buffer running-time, we need a buffer timestamp and
-      the SEGMENT event that preceeded the buffer. First we can convert
+      the SEGMENT event that preceded the buffer. First we can convert
       the SEGMENT event into a <classname>GstSegment</classname> object
       and then we can use the
       <function>gst_segment_to_running_time ()</function> function to

docs/pwg/advanced-events.xml

@@ -372,7 +372,7 @@ gst_my_filter_sink_event (GstPad  *pad, GstObject * parent, GstEvent * event)
         The flush-stop event is created with
         <function>gst_event_new_flush_stop ()</function>. It has one
         parameter that controls if the running-time of the pipeline should
-        be reset to 0 or not. Normally aftera flushing seek, the
+        be reset to 0 or not. Normally after a flushing seek, the
         running_time is set back to 0.
       </para>
     </sect2>

docs/pwg/advanced-qos.xml

@@ -2,7 +2,7 @@
   <title>Quality Of Service (QoS)</title>
 
   <para>
-    Quality of Service in &GStreamer; is about measuring and ajusting
+    Quality of Service in &GStreamer; is about measuring and adjusting
     the real-time performance of a pipeline. The real-time performance is
     always measured relative to the pipeline clock and typically happens in
     the sinks when they synchronize buffers against the clock.
@@ -82,7 +82,7 @@
     </para>
     <para>
       A synchronizing element also needs to measure its own performance in
-      order to figure out if the performace problem is upstream of itself.
+      order to figure out if the performance problem is upstream of itself.
     </para>
     <para>
       These measurements are used to construct a QOS event that is sent
@@ -184,7 +184,7 @@
       <para>
         Long term corrections are a bit more difficult to perform. They
         rely on the value of the proportion in the QOS event. Elements should
-        reduce the amount of resources they comsume by the proportion 
+        reduce the amount of resources they consume by the proportion
         field in the QoS message.
       </para>
       <para>

docs/pwg/advanced-tagging.xml

@@ -109,7 +109,7 @@ gst_my_filter_class_init (GstMyFilterClass *klass)
       TagSetter interface (which is just a layer). Pipeline tags are tags
       provided to the element from within the pipeline. The element receives
       such tags via the <symbol>GST_EVENT_TAG</symbol> event, which means
-      that tags writers should implment an event handler. The tag writer is
+      that tags writers should implement an event handler. The tag writer is
       responsible for combining all these three into one list and writing them
       to the output stream.
     </para>