Created
October 5, 2015 16:17
-
-
Save joanpau/4c3cac0586a7315f0ad4 to your computer and use it in GitHub Desktop.
Test whether idle pad probes are effectively blocking probes, as stated in the gstreamer's documentaion.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| /** | |
| * Test if idle probes are blocking or not. | |
| * | |
| * Build dynamic pipeline made of a videotestsrc and an autovideosink, | |
| * and add/remove a dummy idle probe (print a message) every 5 seconds. | |
| * | |
| * Probes of type GST_PAD_PROBE_TYPE_IDLE are described as blocking | |
| * in the design documents [1] and the reference documentation [2], | |
| * so that they block the pad until the probe is removed. | |
| * But it seems that they just block the pad during the execution of the | |
| * callback, and data flows through the pad after the callback has finished. | |
| * | |
| * If the intended behavior is the one described in the documentation, | |
| * then this is a bug probably caused by the following lines in function | |
| * `do_probe_callbacks` (gst/gstpad.c): | |
| * | |
| * is_block = | |
| * (info->type & GST_PAD_PROBE_TYPE_BLOCK) == GST_PAD_PROBE_TYPE_BLOCK; | |
| * | |
| * if (is_block && PROBE_TYPE_IS_SERIALIZED (info)) { | |
| * if (do_pad_idle_probe_wait (pad) == GST_FLOW_FLUSHING) | |
| * goto flushing; | |
| * } | |
| * | |
| * where `is_block` should be computed as: | |
| * | |
| * is_block = type & GST_PAD_PROBE_TYPE_BLOCKING; | |
| * | |
| * Otherwise, the documentation should state that an idle probe will block | |
| * the pad during the execution of the callback, which will be triggered | |
| * each time the pad becomes idle (that is: after dealing with some data, | |
| * and also including the case where the pad is idle at the insertion of the | |
| * probe). | |
| * | |
| * [1]: http://cgit.freedesktop.org/gstreamer/gstreamer/tree/docs/design/part-probes.txt | |
| * [2]: http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html | |
| */ | |
| #include <gst/gst.h> | |
| #include <stdlib.h> | |
| static GMainLoop * loop; | |
| static GstElement * pipeline; | |
| static GstElement * source, * sink; | |
| static GstBus * bus; | |
| static gulong pad_probe_id = 0; | |
| static gboolean | |
| message_cb (GstBus * bus, GstMessage * message, gpointer user_data) | |
| { | |
| GError * error; | |
| gchar * name, * debug; | |
| name = GST_MESSAGE_SRC_NAME(message); | |
| error = NULL; | |
| debug = NULL; | |
| switch (GST_MESSAGE_TYPE (message)) { | |
| case GST_MESSAGE_ERROR: | |
| gst_message_parse_error (message, &error, &debug); | |
| g_printerr ("%s: from element %s: %s (%s)\n", "ERROR", name, | |
| error->message, debug ? debug : "no debug info"); | |
| g_error_free (error); | |
| g_free (debug); | |
| g_main_loop_quit (loop); | |
| break; | |
| case GST_MESSAGE_WARNING: | |
| gst_message_parse_warning (message, &error, &debug); | |
| g_printerr ("%s: from element %s: %s (%s)\n", "WARNING", name, | |
| error->message, debug ? debug : "no debug info"); | |
| g_error_free (error); | |
| g_free (debug); | |
| break; | |
| case GST_MESSAGE_EOS: | |
| g_print ("Got EOS\n"); | |
| g_main_loop_quit (loop); | |
| break; | |
| default: | |
| break; | |
| } | |
| return TRUE; | |
| } | |
| static GstPadProbeReturn | |
| pad_probe_cb (GstPad * pad, GstPadProbeInfo * info, gpointer user_data) | |
| { | |
| g_print("[%ld] running probe callback\n", g_get_real_time()); | |
| return GST_PAD_PROBE_OK; | |
| } | |
| static gboolean | |
| timeout_cb (gpointer user_data) | |
| { | |
| GstPad * pad = gst_element_get_static_pad(source, "src"); | |
| if (pad_probe_id == 0) { | |
| pad_probe_id = gst_pad_add_probe(pad, GST_PAD_PROBE_TYPE_IDLE, | |
| pad_probe_cb, NULL, NULL); | |
| } else { | |
| gst_pad_remove_probe(pad, pad_probe_id); | |
| pad_probe_id = 0; | |
| } | |
| return TRUE; | |
| } | |
| int | |
| main (int argc, char **argv) | |
| { | |
| gst_init (&argc, &argv); | |
| pipeline = gst_pipeline_new (NULL); | |
| source = gst_element_factory_make ("videotestsrc", NULL); | |
| sink = gst_element_factory_make ("autovideosink", NULL); | |
| if (! pipeline || ! source || ! sink) { | |
| g_printerr("Could not create elements\n"); | |
| return EXIT_FAILURE; | |
| } | |
| g_object_set(source, "pattern", 18, NULL); | |
| gst_bin_add_many (GST_BIN(pipeline), source, sink, NULL); | |
| if (!gst_element_link_many (source, sink, NULL)) { | |
| g_printerr("Could not link elements\n"); | |
| gst_object_unref(pipeline); | |
| return EXIT_FAILURE; | |
| } | |
| loop = g_main_loop_new (NULL, FALSE); | |
| bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline)); | |
| gst_bus_add_signal_watch (bus); | |
| g_signal_connect (G_OBJECT (bus), "message", G_CALLBACK (message_cb), NULL); | |
| gst_object_unref (GST_OBJECT (bus)); | |
| g_timeout_add_seconds(10, timeout_cb, NULL); | |
| if (gst_element_set_state (pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) { | |
| g_printerr("Failed to go into PLAYING state\n"); | |
| gst_object_unref(pipeline); | |
| return EXIT_FAILURE; | |
| } | |
| g_main_loop_run (loop); | |
| gst_element_set_state (pipeline, GST_STATE_NULL); | |
| gst_object_unref(pipeline); | |
| g_main_loop_unref (loop); | |
| return EXIT_SUCCESS; | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment