appsrc: Add example that shows gst_app_src_push_sample() usage

tests/examples/app/Makefile.am

@@ -1,6 +1,6 @@
 
 noinst_PROGRAMS = appsrc_ex appsrc-stream appsrc-stream2 appsrc-ra \
-		  appsrc-seekable appsink-src
+		  appsrc-seekable appsink-src appsink-src2
 
 appsrc_ex_SOURCES = appsrc_ex.c
 appsrc_ex_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS)
@@ -30,3 +30,8 @@ appsink_src_LDADD = \
     $(top_builddir)/gst-libs/gst/app/libgstapp-@GST_API_VERSION@.la \
     $(GST_BASE_LIBS) $(GST_LIBS)
 
+appsink_src2_SOURCES = appsink-src2.c
+appsink_src2_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS)
+appsink_src2_LDADD = \
+    $(top_builddir)/gst-libs/gst/app/libgstapp-@GST_API_VERSION@.la \
+    $(GST_BASE_LIBS) $(GST_LIBS)

tests/examples/app/appsink-src2.c

@@ -0,0 +1,177 @@
+#include <gst/gst.h>
+
+#include <string.h>
+
+#include <gst/app/gstappsrc.h>
+#include <gst/app/gstappsink.h>
+
+/*
+ * In this sample we show the usage of gst_app_src_push_sample in push 
+ * mode, this method set the appsrc caps based on the caps from the sample 
+ *
+ */
+
+typedef struct
+{
+  GMainLoop *loop;
+  GstElement *source;
+  GstElement *sink;
+} ProgramData;
+
+/* called when the appsink notifies us that there is a new buffer ready for
+ * processing */
+
+static GstFlowReturn
+on_new_sample_from_sink (GstElement * elt, ProgramData * data)
+{
+  GstSample *sample;
+  GstElement *source;
+  GstFlowReturn ret;
+
+  /* get the sample from appsink */
+  sample = gst_app_sink_pull_sample (GST_APP_SINK (elt));
+
+  /* get source an push new sample */
+  source = gst_bin_get_by_name (GST_BIN (data->sink), "testsource");
+  ret = gst_app_src_push_sample (GST_APP_SRC (source), sample);
+  gst_object_unref (source);
+
+  /* we don't need the appsink sample anymore */
+  gst_sample_unref (sample);
+
+  return ret;
+}
+
+/* called when we get a GstMessage from the source pipeline when we get EOS, we
+ * notify the appsrc of it. */
+static gboolean
+on_source_message (GstBus * bus, GstMessage * message, ProgramData * data)
+{
+  GstElement *source;
+
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_EOS:
+      g_print ("The source got dry\n");
+      source = gst_bin_get_by_name (GST_BIN (data->sink), "testsource");
+      gst_app_src_end_of_stream (GST_APP_SRC (source));
+      gst_object_unref (source);
+      break;
+    case GST_MESSAGE_ERROR:
+      g_print ("Received error\n");
+      g_main_loop_quit (data->loop);
+      break;
+    default:
+      break;
+  }
+  return TRUE;
+}
+
+/* called when we get a GstMessage from the sink pipeline when we get EOS, we
+ * exit the mainloop and this testapp. */
+static gboolean
+on_sink_message (GstBus * bus, GstMessage * message, ProgramData * data)
+{
+  /* nil */
+  switch (GST_MESSAGE_TYPE (message)) {
+    case GST_MESSAGE_EOS:
+      g_print ("Finished playback\n");
+      g_main_loop_quit (data->loop);
+      break;
+    case GST_MESSAGE_ERROR:
+      g_print ("Received error\n");
+      g_main_loop_quit (data->loop);
+      break;
+    default:
+      break;
+  }
+  return TRUE;
+}
+
+int
+main (int argc, char *argv[])
+{
+  gchar *filename = NULL;
+  ProgramData *data = NULL;
+  gchar *string = NULL;
+  GstBus *bus = NULL;
+  GstElement *testsink = NULL;
+  GstElement *testsource = NULL;
+
+  gst_init (&argc, &argv);
+
+  data = g_new0 (ProgramData, 1);
+
+  data->loop = g_main_loop_new (NULL, FALSE);
+
+  /* setting up source pipeline, we read from a file and convert to our desired
+   * caps. */
+  string =
+      g_strdup_printf
+      ("audiotestsrc num-buffers=200 ! wavenc ! wavparse ! appsink name=testsink");
+  g_free (filename);
+  data->source = gst_parse_launch (string, NULL);
+  g_free (string);
+
+  if (data->source == NULL) {
+    g_print ("Bad source\n");
+    return -1;
+  }
+
+  /* to be notified of messages from this pipeline, mostly EOS */
+  bus = gst_element_get_bus (data->source);
+  gst_bus_add_watch (bus, (GstBusFunc) on_source_message, data);
+  gst_object_unref (bus);
+
+  /* we use appsink in push mode, it sends us a signal when data is available
+   * and we pull out the data in the signal callback. We want the appsink to
+   * push as fast as it can, hence the sync=false */
+  testsink = gst_bin_get_by_name (GST_BIN (data->source), "testsink");
+  g_object_set (G_OBJECT (testsink), "emit-signals", TRUE, "sync", FALSE, NULL);
+  g_signal_connect (testsink, "new-sample",
+      G_CALLBACK (on_new_sample_from_sink), data);
+  gst_object_unref (testsink);
+
+  /* setting up sink pipeline, we push audio data into this pipeline that will
+   * then play it back using the default audio sink. */
+  string =
+      g_strdup_printf
+      ("appsrc name=testsource ! audioconvert ! audioresample ! autoaudiosink");
+  data->sink = gst_parse_launch (string, NULL);
+  g_free (string);
+
+  if (data->sink == NULL) {
+    g_print ("Bad sink\n");
+    return -1;
+  }
+
+  testsource = gst_bin_get_by_name (GST_BIN (data->sink), "testsource");
+  /* configure for time-based format */
+  g_object_set (testsource, "format", GST_FORMAT_TIME, NULL);
+  /* uncomment the next line to block when appsrc has buffered enough */
+  /* g_object_set (testsource, "block", TRUE, NULL); */
+  gst_object_unref (testsource);
+
+  bus = gst_element_get_bus (data->sink);
+  gst_bus_add_watch (bus, (GstBusFunc) on_sink_message, data);
+  gst_object_unref (bus);
+
+  /* launching things */
+  gst_element_set_state (data->sink, GST_STATE_PLAYING);
+  gst_element_set_state (data->source, GST_STATE_PLAYING);
+
+  /* let's run !, this loop will quit when the sink pipeline goes EOS or when an
+   * error occurs in the source or sink pipelines. */
+  g_print ("Let's run!\n");
+  g_main_loop_run (data->loop);
+  g_print ("Going out\n");
+
+  gst_element_set_state (data->source, GST_STATE_NULL);
+  gst_element_set_state (data->sink, GST_STATE_NULL);
+
+  gst_object_unref (data->source);
+  gst_object_unref (data->sink);
+  g_main_loop_unref (data->loop);
+  g_free (data);
+
+  return 0;
+}