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https://gitlab.freedesktop.org/gstreamer/gstreamer.git
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130 lines
3.4 KiB
C
130 lines
3.4 KiB
C
#include <stdlib.h>
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#include <gst/gst.h>
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static void
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event_loop (GstElement * pipe)
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{
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GstBus *bus;
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GstMessage *message = NULL;
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bus = gst_element_get_bus (GST_ELEMENT (pipe));
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while (TRUE) {
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message = gst_bus_timed_pop_filtered (bus, GST_MESSAGE_ANY, -1);
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g_assert (message != NULL);
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switch (message->type) {
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case GST_MESSAGE_EOS:
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g_message ("got EOS");
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gst_message_unref (message);
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return;
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case GST_MESSAGE_WARNING:
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case GST_MESSAGE_ERROR:
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{
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GError *gerror;
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gchar *debug;
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gst_message_parse_error (message, &gerror, &debug);
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gst_object_default_error (GST_MESSAGE_SRC (message), gerror, debug);
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gst_message_unref (message);
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g_error_free (gerror);
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g_free (debug);
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return;
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}
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case GST_MESSAGE_STEP_DONE:
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{
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GstFormat format;
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guint64 amount;
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gdouble rate;
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guint64 duration;
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gboolean intermediate;
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gst_message_parse_step_done (message, &format, &amount, &rate,
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&duration, &intermediate);
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g_message ("step done: %" GST_TIME_FORMAT " skipped in %"
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G_GUINT64_FORMAT " frames", GST_TIME_ARGS (duration), amount);
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return;
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}
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default:
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gst_message_unref (message);
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break;
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}
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}
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}
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/* signalled when a new preroll buffer is available */
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static void
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new_preroll (GstElement * appsink, gpointer user_data)
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{
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GstBuffer *buffer;
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g_signal_emit_by_name (appsink, "pull-preroll", &buffer);
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g_message ("have new-preroll buffer %p, timestamp %" GST_TIME_FORMAT, buffer,
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GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (buffer)));
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gst_buffer_unref (buffer);
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}
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int
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main (int argc, char *argv[])
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{
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GstElement *bin, *videotestsrc, *appsink;
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gst_init (&argc, &argv);
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/* create a new bin to hold the elements */
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bin = gst_pipeline_new ("pipeline");
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g_assert (bin);
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/* create a fake source */
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videotestsrc = gst_element_factory_make ("videotestsrc", "videotestsrc");
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g_assert (videotestsrc);
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g_object_set (videotestsrc, "num-buffers", 10, NULL);
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/* and a fake sink */
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appsink = gst_element_factory_make ("appsink", "appsink");
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g_assert (appsink);
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g_object_set (appsink, "emit-signals", TRUE, NULL);
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g_object_set (appsink, "sync", TRUE, NULL);
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g_signal_connect (appsink, "new-preroll", (GCallback) new_preroll, NULL);
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/* add objects to the main pipeline */
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gst_bin_add (GST_BIN (bin), videotestsrc);
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gst_bin_add (GST_BIN (bin), appsink);
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/* link the elements */
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gst_element_link_many (videotestsrc, appsink, NULL);
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/* go to the PAUSED state and wait for preroll */
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g_message ("prerolling first frame");
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gst_element_set_state (bin, GST_STATE_PAUSED);
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gst_element_get_state (bin, NULL, NULL, -1);
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/* step two frames, flush so that new preroll is queued */
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g_message ("stepping two frames");
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g_assert (gst_element_send_event (bin,
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gst_event_new_step (GST_FORMAT_BUFFERS, 2, 1.0, TRUE, FALSE)));
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/* blocks and returns when we received the step done message */
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event_loop (bin);
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/* wait for step to really complete */
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gst_element_get_state (bin, NULL, NULL, -1);
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g_message ("stepped two frames");
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g_message ("playing until EOS");
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gst_element_set_state (bin, GST_STATE_PLAYING);
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/* Run event loop listening for bus messages until EOS or ERROR */
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event_loop (bin);
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g_message ("finished");
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/* stop the bin */
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gst_element_set_state (bin, GST_STATE_NULL);
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exit (0);
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}
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