[Gst Example] tutorial-3 and 3-exercise

Dynamic stream construction.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/gst_example/tutorial3/basic-tutorial-3-exercise.c b/gst_example/tutorial3/basic-tutorial-3-exercise.c
new file mode 100644 (file)
index 0000000..036dfec
--- /dev/null
+++ b/gst_example/tutorial3/basic-tutorial-3-exercise.c
@@ -0,0 +1,143 @@
+#include <gst/gst.h>
+
+typedef struct _CustomData {
+  GstElement *pipeline;
+  GstElement *source;
+  GstElement *convert;
+  GstElement *sink;
+
+  GstElement *vconvert;
+  GstElement *vsink;
+} CustomData;
+
+static void pad_added_handler (GstElement *src, GstPad *pad, CustomData *data);
+
+int main(int argc, char *argv[]) {
+  CustomData data;
+  GstBus *bus;
+  GstMessage *msg;
+  GstStateChangeReturn ret;
+  gboolean terminate = FALSE;
+
+  gst_init(&argc, &argv);
+
+  data.source = gst_element_factory_make("uridecodebin", "source");
+  data.convert = gst_element_factory_make("audioconvert", "convert");
+  data.sink = gst_element_factory_make("autoaudiosink", "sink");
+  data.vconvert = gst_element_factory_make("videoconvert", "vconvert");
+  data.vsink = gst_element_factory_make("autovideosink", "vsink");
+
+  data.pipeline = gst_pipeline_new("test-pipeline");
+
+  if (!data.pipeline || !data.source || !data.convert || !data.sink || !data.vconvert || !data.vsink) {
+    g_printerr("There is an element not created.\n");
+    return -1;
+  }
+
+  gst_bin_add_many(GST_BIN(data.pipeline), data.source, data.convert, data.sink, data.vconvert, data.vsink, NULL);
+  if (!gst_element_link(data.convert, data.sink)) {
+    g_printerr("Element cannot be linked for audio.\n");
+    gst_object_unref(data.pipeline);
+    return -1;
+  }
+  if (!gst_element_link(data.vconvert, data.vsink)) {
+    g_printerr("Element cannot be linked for video.\n");
+    gst_object_unref(data.pipeline);
+    return -1;
+  }
+
+  g_object_set(data.source, "uri", "https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm", NULL);
+
+  g_signal_connect(data.source, "pad-added", G_CALLBACK(pad_added_handler), &data);
+
+  ret = gst_element_set_state(data.pipeline, GST_STATE_PLAYING);
+  if (ret == GST_STATE_CHANGE_FAILURE) {
+    g_printerr("Unsable to set th epipeline to the playing state.\n");
+    gst_object_unref(data.pipeline);
+    return -1;
+  }
+
+  bus = gst_element_get_bus(data.pipeline);
+  do {
+    msg = gst_bus_timed_pop_filtered(bus, GST_CLOCK_TIME_NONE, GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_ERROR | GST_MESSAGE_EOS);
+
+    if (msg != NULL) {
+      GError *err;
+      gchar *debug_info;
+
+      switch(GST_MESSAGE_TYPE (msg)) {
+      case GST_MESSAGE_ERROR:
+        gst_message_parse_error(msg, &err, &debug_info);
+       g_printerr("Error from %s: %s\n", GST_OBJECT_NAME(msg->src), err->message);
+       g_printerr("Debug info: %s\n", debug_info ? debug_info : "none");
+       g_clear_error(&err);
+       g_free(debug_info);
+       terminate = TRUE;
+       break;
+      case GST_MESSAGE_EOS:
+        g_print("EOS.\n");
+       terminate = TRUE;
+       break;
+      case GST_MESSAGE_STATE_CHANGED:
+        if (GST_MESSAGE_SRC(msg) == GST_OBJECT(data.pipeline)) {
+         GstState old_state, new_state, pending_state;
+         gst_message_parse_state_changed(msg, &old_state, &new_state, &pending_state);
+         g_print("Pipeline state %s --> %s\n", gst_element_state_get_name(old_state), gst_element_state_get_name(new_state));
+       }
+       break;
+      default:
+        g_printerr("Unexpected message.\n");
+       break;
+      }
+      gst_message_unref(msg);
+    }
+  } while(!terminate);
+
+  gst_object_unref(bus);
+  gst_element_set_state(data.pipeline, GST_STATE_NULL);
+  gst_object_unref(data.pipeline);
+  return 0;
+}
+
+static void pad_added_handler(GstElement *src, GstPad *new_pad, CustomData *data) {
+  GstPad *sink_pad = gst_element_get_static_pad(data->convert, "sink");
+  GstPad *vsink_pad = gst_element_get_static_pad(data->vconvert, "sink");
+  GstPadLinkReturn ret;
+  GstCaps *new_pad_caps = NULL;
+  GstStructure *new_pad_struct = NULL;
+  const gchar *new_pad_type = NULL;
+
+  g_print("Received new pad '%s' from '%s':\n", GST_PAD_NAME(new_pad), GST_ELEMENT_NAME(src));
+
+  if (gst_pad_is_linked(sink_pad)) {
+    g_print("  We are already linked. Ignoring\n");
+    goto exit;
+  }
+
+  new_pad_caps = gst_pad_query_caps(new_pad, NULL);
+  new_pad_struct = gst_caps_get_structure(new_pad_caps, 0);
+  new_pad_type = gst_structure_get_name(new_pad_struct);
+  if (g_str_has_prefix(new_pad_type, "audio/x-raw")) {
+    ret = gst_pad_link(new_pad, sink_pad);
+    if (GST_PAD_LINK_FAILED(ret)) {
+      g_print("  Type is '%s' but link failed\n", new_pad_type);
+    } else {
+      g_print("  Link succeeded (type '%s')\n", new_pad_type);
+    }
+  } else if (g_str_has_prefix(new_pad_type, "video/x-raw")) {
+    ret = gst_pad_link(new_pad, vsink_pad);
+    if (GST_PAD_LINK_FAILED(ret)) {
+      g_print("  Type is '%s' but link failed for video\n", new_pad_type);
+    } else {
+      g_print("  Link succeeded for video (type '%s')\n", new_pad_type);
+    }
+  } else {
+    g_print("  It has type '%s' which is not raw audio. Ignoring.\n", new_pad_type);
+    goto exit;
+  }
+
+exit:
+  if (new_pad_caps != NULL)
+    gst_caps_unref(new_pad_caps);
+  gst_object_unref(sink_pad);
+}

diff --git a/gst_example/tutorial3/basic-tutorial-3.c b/gst_example/tutorial3/basic-tutorial-3.c
new file mode 100644 (file)
index 0000000..bd0668a
--- /dev/null
+++ b/gst_example/tutorial3/basic-tutorial-3.c
@@ -0,0 +1,125 @@
+#include <gst/gst.h>
+
+typedef struct _CustomData {
+  GstElement *pipeline;
+  GstElement *source;
+  GstElement *convert;
+  GstElement *sink;
+} CustomData;
+
+static void pad_added_handler (GstElement *src, GstPad *pad, CustomData *data);
+
+int main(int argc, char *argv[]) {
+  CustomData data;
+  GstBus *bus;
+  GstMessage *msg;
+  GstStateChangeReturn ret;
+  gboolean terminate = FALSE;
+
+  gst_init(&argc, &argv);
+
+  data.source = gst_element_factory_make("uridecodebin", "source");
+  data.convert = gst_element_factory_make("audioconvert", "convert");
+  data.sink = gst_element_factory_make("autoaudiosink", "sink");
+
+  data.pipeline = gst_pipeline_new("test-pipeline");
+
+  if (!data.pipeline || !data.source || !data.convert || !data.sink) {
+    g_printerr("There is an element not created.\n");
+    return -1;
+  }
+
+  gst_bin_add_many(GST_BIN(data.pipeline), data.source, data.convert, data.sink, NULL);
+  if (!gst_element_link(data.convert, data.sink)) {
+    g_printerr("Element cannot be linked.\n");
+    gst_object_unref(data.pipeline);
+    return -1;
+  }
+
+  g_object_set(data.source, "uri", "https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm", NULL);
+
+  g_signal_connect(data.source, "pad-added", G_CALLBACK(pad_added_handler), &data);
+
+  ret = gst_element_set_state(data.pipeline, GST_STATE_PLAYING);
+  if (ret == GST_STATE_CHANGE_FAILURE) {
+    g_printerr("Unsable to set th epipeline to the playing state.\n");
+    gst_object_unref(data.pipeline);
+    return -1;
+  }
+
+  bus = gst_element_get_bus(data.pipeline);
+  do {
+    msg = gst_bus_timed_pop_filtered(bus, GST_CLOCK_TIME_NONE, GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_ERROR | GST_MESSAGE_EOS);
+
+    if (msg != NULL) {
+      GError *err;
+      gchar *debug_info;
+
+      switch(GST_MESSAGE_TYPE (msg)) {
+      case GST_MESSAGE_ERROR:
+        gst_message_parse_error(msg, &err, &debug_info);
+       g_printerr("Error from %s: %s\n", GST_OBJECT_NAME(msg->src), err->message);
+       g_printerr("Debug info: %s\n", debug_info ? debug_info : "none");
+       g_clear_error(&err);
+       g_free(debug_info);
+       terminate = TRUE;
+       break;
+      case GST_MESSAGE_EOS:
+        g_print("EOS.\n");
+       terminate = TRUE;
+       break;
+      case GST_MESSAGE_STATE_CHANGED:
+        if (GST_MESSAGE_SRC(msg) == GST_OBJECT(data.pipeline)) {
+         GstState old_state, new_state, pending_state;
+         gst_message_parse_state_changed(msg, &old_state, &new_state, &pending_state);
+         g_print("Pipeline state %s --> %s\n", gst_element_state_get_name(old_state), gst_element_state_get_name(new_state));
+       }
+       break;
+      default:
+        g_printerr("Unexpected message.\n");
+       break;
+      }
+      gst_message_unref(msg);
+    }
+  } while(!terminate);
+
+  gst_object_unref(bus);
+  gst_element_set_state(data.pipeline, GST_STATE_NULL);
+  gst_object_unref(data.pipeline);
+  return 0;
+}
+
+static void pad_added_handler(GstElement *src, GstPad *new_pad, CustomData *data) {
+  GstPad *sink_pad = gst_element_get_static_pad(data->convert, "sink");
+  GstPadLinkReturn ret;
+  GstCaps *new_pad_caps = NULL;
+  GstStructure *new_pad_struct = NULL;
+  const gchar *new_pad_type = NULL;
+
+  g_print("Received new pad '%s' from '%s':\n", GST_PAD_NAME(new_pad), GST_ELEMENT_NAME(src));
+
+  if (gst_pad_is_linked(sink_pad)) {
+    g_print("  We are already linked. Ignoring\n");
+    goto exit;
+  }
+
+  new_pad_caps = gst_pad_query_caps(new_pad, NULL);
+  new_pad_struct = gst_caps_get_structure(new_pad_caps, 0);
+  new_pad_type = gst_structure_get_name(new_pad_struct);
+  if (!g_str_has_prefix(new_pad_type, "audio/x-raw")) {
+    g_print("  It has type '%s' which is not raw audio. Ignoring.\n", new_pad_type);
+    goto exit;
+  }
+
+  ret = gst_pad_link(new_pad, sink_pad);
+  if (GST_PAD_LINK_FAILED(ret)) {
+    g_print("  Type is '%s' but link failed\n", new_pad_type);
+  } else {
+    g_print("  Link succeeded (type '%s')\n", new_pad_type);
+  }
+
+exit:
+  if (new_pad_caps != NULL)
+    gst_caps_unref(new_pad_caps);
+  gst_object_unref(sink_pad);
+}