diff --git a/docs/pwg/advanced-request.xml b/docs/pwg/advanced-request.xml
index dc71d82b65..8ef98977c6 100644
--- a/docs/pwg/advanced-request.xml
+++ b/docs/pwg/advanced-request.xml
@@ -53,17 +53,18 @@ typedef struct _GstMyFilter {
GList *srcpadlist;
} GstMyFilter;
+static GstStaticPadTemplate src_factory =
+GST_STATIC_PAD_TEMPLATE (
+ "src_%u",
+ GST_PAD_SRC,
+ GST_PAD_SOMETIMES,
+ GST_STATIC_CAPS ("ANY")
+);
+
static void
-gst_my_filter_base_init (GstMyFilterClass *klass)
+gst_my_filter_class_init (GstMyFilterClass *klass)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
- static GstStaticPadTemplate src_factory =
- GST_STATIC_PAD_TEMPLATE (
- "src_%02d",
- GST_PAD_SRC,
- GST_PAD_SOMETIMES,
- GST_STATIC_CAPS ("ANY")
- );
[..]
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&src_factory));
@@ -96,11 +97,11 @@ gst_my_filter_getline (GstMyFilter *filter)
/* newline? */
if (data[n] == '\n') {
- GstBuffer *buf = gst_buffer_new_and_alloc (n + 1);
+ GstBuffer *buf = gst_buffer_new_allocate (NULL, n + 1, NULL);
gst_bytestream_peek_bytes (filter->bs, &data, n);
- memcpy (GST_BUFFER_DATA (buf), data, n);
- GST_BUFFER_DATA (buf)[n] = '\0';
+ gst_buffer_fill (buf, 0, data, n);
+ gst_buffer_memset (buf, n, '\0', 1);
gst_bytestream_flush_fast (filter->bs, n + 1);
return buf;
@@ -114,31 +115,33 @@ gst_my_filter_loopfunc (GstElement *element)
GstMyFilter *filter = GST_MY_FILTER (element);
GstBuffer *buf;
GstPad *pad;
+ GstMapInfo map;
gint num, n;
/* parse header */
if (filter->firstrun) {
- GstElementClass *klass;
- GstPadTemplate *templ;
gchar *padname;
+ guint8 id;
if (!(buf = gst_my_filter_getline (filter))) {
gst_element_error (element, STREAM, READ, (NULL),
("Stream contains no header"));
return;
}
- num = atoi (GST_BUFFER_DATA (buf));
+ gst_buffer_extract (buf, 0, &id, 1);
+ num = atoi (id);
gst_buffer_unref (buf);
/* for each of the streams, create a pad */
- klass = GST_ELEMENT_GET_CLASS (filter);
- templ = gst_element_class_get_pad_template (klass, "src_%02d");
for (n = 0; n < num; n++) {
- padname = g_strdup_printf ("src_%02d", n);
- pad = gst_pad_new_from_template (templ, padname);
+ padname = g_strdup_printf ("src_%u", n);
+ pad = gst_pad_new_from_static_template (src_factory, padname);
g_free (padname);
- /* here, you would set _getcaps () and _link () functions */
+ /* here, you would set _event () and _query () functions */
+
+ /* need to activate the pad before adding */
+ gst_pad_set_active (pad, TRUE);
gst_element_add_pad (element, pad);
filter->srcpadlist = g_list_append (filter->srcpadlist, pad);
@@ -153,36 +156,37 @@ gst_my_filter_loopfunc (GstElement *element)
for (padlist = srcpadlist;
padlist != NULL; padlist = g_list_next (padlist)) {
pad = GST_PAD (padlist->data);
- gst_event_ref (event);
- gst_pad_push (pad, GST_DATA (event));
+ gst_pad_push_event (pad, gst_event_ref (event));
}
gst_event_unref (event);
- gst_element_set_eos (element);
-
+ /* pause the task here */
return;
}
/* parse stream number and go beyond the ':' in the data */
- num = atoi (GST_BUFFER_DATA (buf));
+ gst_buffer_map (buf, &map, GST_MAP_READ);
+ num = atoi (map.data[0]);
if (num >= 0 && num < g_list_length (filter->srcpadlist)) {
pad = GST_PAD (g_list_nth_data (filter->srcpadlist, num);
/* magic buffer parsing foo */
- for (n = 0; GST_BUFFER_DATA (buf)[n] != ':' &&
- GST_BUFFER_DATA (buf)[n] != '\0'; n++) ;
- if (GST_BUFFER_DATA (buf)[n] != '\0') {
+ for (n = 0; map.data[n] != ':' &&
+ map.data[n] != '\0'; n++) ;
+ if (map.data[n] != '\0') {
GstBuffer *sub;
- /* create subbuffer that starts right past the space. The reason
+ /* create region copy that starts right past the space. The reason
* that we don't just forward the data pointer is because the
* pointer is no longer the start of an allocated block of memory,
* but just a pointer to a position somewhere in the middle of it.
* That cannot be freed upon disposal, so we'd either crash or have
- * a memleak. Creating a subbuffer is a simple way to solve that. */
- sub = gst_buffer_create_sub (buf, n + 1, GST_BUFFER_SIZE (buf) - n - 1);
- gst_pad_push (pad, GST_DATA (sub));
+ * a memleak. Creating a region copy is a simple way to solve that. */
+ sub = gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL,
+ n + 1, map.size - n - 1);
+ gst_pad_push (pad, sub);
}
}
+ gst_buffer_unmap (buf, &map);
gst_buffer_unref (buf);
}
]]>
@@ -207,46 +211,52 @@ gst_my_filter_loopfunc (GstElement *element)
where - for each elementary stream that is to be placed in the output
system stream - one sink pad will be requested. It can also be used in
elements with a variable number of input or outputs pads, such as the
- tee (multi-output), switch
- or aggregator (both multi-input) elements. At the
- time of writing this, it is unclear to me who is responsible for cleaning
- up the created pad and how or when that should be done. Below is a simple
- example of an aggregator based on request pads.
+ tee (multi-output) or
+ input-selector (multi-input) elements.
+
+
+ To implement request pads, you need to provide a padtemplate with a
+ GST_PAD_REQUEST presence and implement the
+ request_new_pad virtual method in
+ GstElement.
+ To clean up, you will need to implement the
+ release_pad virtual method.
request_new_pad = gst_my_filter_request_new_pad;
+ element_class->release_pad = gst_my_filter_release_pad;
}
static GstPad *
gst_my_filter_request_new_pad (GstElement *element,
GstPadTemplate *templ,
- const gchar *name)
+ const gchar *name,
+ const GstCaps *caps)
{
GstPad *pad;
GstMyFilterInputContext *context;
@@ -255,12 +265,25 @@ gst_my_filter_request_new_pad (GstElement *element,
pad = gst_pad_new_from_template (templ, name);
gst_pad_set_element_private (pad, context);
- /* normally, you would set _link () and _getcaps () functions here */
+ /* normally, you would set _chain () and _event () functions here */
gst_element_add_pad (element, pad);
return pad;
}
+
+static void
+gst_my_filter_release_pad (GstElement *element,
+ GstPad *pad)
+{
+ GstMyFilterInputContext *context;
+
+ context = gst_pad_get_element_private (pad);
+ g_free (context);
+
+ gst_element_remove_pad (element, pad);
+}
+
]]>