--- /dev/null
+/* GStreamer snapshot example
+ * Copyright (C) <2007> Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <gst/gst.h>
+#include <gtk/gtk.h>
+
+#include <stdlib.h>
+
+#define CAPS "video/x-raw-rgb,width=160,pixel-aspect-ratio=1/1,bpp=(int)24,depth=(int)24,endianness=(int)4321,red_mask=(int)0xff0000, green_mask=(int)0x00ff00, blue_mask=(int)0x0000ff"
+
+int
+main (int argc, char *argv[])
+{
+ GstElement *pipeline, *sink;
+ gint width, height;
+ GstBuffer *buffer;
+ gchar *descr;
+ GError *error = NULL;
+ GdkPixbuf *pixbuf;
+ gint64 duration, position;
+ GstFormat format;
+ GstStateChangeReturn ret;
+ gboolean res;
+
+ gst_init (&argc, &argv);
+
+ if (argc != 2) {
+ g_print ("usage: %s <uri>\n Writes snapshot.png in the current directory\n",
+ argv[0]);
+ exit (-1);
+ }
+
+ /* create a new pipeline */
+ descr =
+ g_strdup_printf ("uridecodebin uri=%s ! ffmpegcolorspace ! videoscale ! "
+ " appsink name=sink caps=\"" CAPS "\"", argv[1]);
+ pipeline = gst_parse_launch (descr, &error);
+
+ if (error != NULL) {
+ g_print ("could not construct pipeline: %s\n", error->message);
+ g_error_free (error);
+ exit (-1);
+ }
+
+ /* get sink */
+ sink = gst_bin_get_by_name (GST_BIN (pipeline), "sink");
+
+ /* set to PAUSED to make the first frame arrive in the sink */
+ ret = gst_element_set_state (pipeline, GST_STATE_PAUSED);
+ switch (ret) {
+ case GST_STATE_CHANGE_FAILURE:
+ g_print ("failed to play the file\n");
+ exit (-1);
+ case GST_STATE_CHANGE_NO_PREROLL:
+ /* for live sources, we need to set the pipeline to PLAYING before we can
+ * receive a buffer. We don't do that yet */
+ g_print ("live sources not supported yet\n");
+ exit (-1);
+ default:
+ break;
+ }
+ /* This can block for up to 5 seconds. If your machine is really overloaded,
+ * it might time out before the pipeline prerolled and we generate an error. A
+ * better way is to run a mainloop and catch errors there. */
+ ret = gst_element_get_state (pipeline, NULL, NULL, 5 * GST_SECOND);
+ if (ret == GST_STATE_CHANGE_FAILURE) {
+ g_print ("failed to play the file\n");
+ exit (-1);
+ }
+
+ /* get the duration */
+ format = GST_FORMAT_TIME;
+ gst_element_query_duration (pipeline, &format, &duration);
+
+ if (duration != -1)
+ /* we have a duration, seek to 5% */
+ position = duration * 5 / 100;
+ else
+ /* no duration, seek to 1 second, this could EOS */
+ position = 1 * GST_SECOND;
+
+ /* seek to the a position in the file. Most files have a black first frame so
+ * by seeking to somewhere else we have a bigger chance of getting something
+ * more interesting. An optimisation would be to detect black images and then
+ * seek a little more */
+ gst_element_seek_simple (pipeline, GST_FORMAT_TIME,
+ GST_SEEK_FLAG_KEY_UNIT | GST_SEEK_FLAG_FLUSH, position);
+
+ /* get the preroll buffer from appsink, this block untils appsink really
+ * prerolls */
+ g_signal_emit_by_name (sink, "pull-preroll", &buffer, NULL);
+
+ /* if we have a buffer now, convert it to a pixbuf. It's possible that we
+ * don't have a buffer because we went EOS right away or had an error. */
+ if (buffer) {
+ GstCaps *caps;
+ GstStructure *s;
+
+ /* get the snapshot buffer format now. We set the caps on the appsink so
+ * that it can only be an rgb buffer. The only thing we have not specified
+ * on the caps is the height, which is dependant on the pixel-aspect-ratio
+ * of the source material */
+ caps = GST_BUFFER_CAPS (buffer);
+ if (!caps) {
+ g_print ("could not get snapshot format\n");
+ exit (-1);
+ }
+ s = gst_caps_get_structure (caps, 0);
+
+ /* we need to get the final caps on the buffer to get the size */
+ res = gst_structure_get_int (s, "width", &width);
+ res |= gst_structure_get_int (s, "height", &height);
+ if (!res) {
+ g_print ("could not get snapshot dimension\n");
+ exit (-1);
+ }
+
+ /* create pixmap from buffer and save, gstreamer video buffers have a stride
+ * that is rounded up to the nearest multiple of 4 */
+ pixbuf = gdk_pixbuf_new_from_data (GST_BUFFER_DATA (buffer),
+ GDK_COLORSPACE_RGB, FALSE, 8, width, height,
+ GST_ROUND_UP_4 (width * 3), NULL, NULL);
+
+ /* save the pixbuf */
+ gdk_pixbuf_save (pixbuf, "snapshot.png", "png", &error, NULL);
+ } else {
+ g_print ("could not make snapshot\n");
+ }
+
+ /* cleanup and exit */
+ gst_element_set_state (pipeline, GST_STATE_NULL);
+ gst_object_unref (pipeline);
+
+ exit (0);
+}
projects / mafwsubrenderer / blobdiff