duplicate code from gstscreenshot.{c,h} and gstplaysink.{c,h}

ges/Makefile.am

@@ -35,6 +35,7 @@ libges_@GST_MAJORMINOR@_la_SOURCES = 		\
 	ges-track-audio-test-source.c			\
 	ges-track-title-source.c			\
 	ges-track-text-overlay.c			\
+	ges-screenshot.c				\
 	ges-utils.c
 
 libges_@GST_MAJORMINOR@includedir = $(includedir)/gstreamer-@GST_MAJORMINOR@/ges/
@@ -67,6 +68,7 @@ libges_@GST_MAJORMINOR@include_HEADERS = 	\
 	ges-track-audio-test-source.h			\
 	ges-track-title-source.h			\
 	ges-track-text-overlay.h			\
+	ges-screenshot.h
 	ges-utils.h
 
 libges_@GST_MAJORMINOR@_la_CFLAGS = -I$(top_srcdir) $(GST_PROFILE_CFLAGS) $(GST_DISCOVERER_CFLAGS) $(GST_CONTROLLER_CFLAGS) $(GST_PLUGINS_BASE_CFLAGS) $(GST_CFLAGS)

ges/ges-screenshot.c

@@ -0,0 +1,200 @@
+/* Small helper element for format conversion
+ * Copyright (C) 2005 Tim-Philipp Müller <tim centricular net>
+ * Copyright (C) 2010 Brandon Lewis <brandon.lewis@collabora.co.uk>
+ *
+ * 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 <glib-object.h>
+#include <string.h>
+#include "ges-screenshot.h"
+
+/* FIXME (merge into core): This code is duplicated from gstscreenshot.c and
+ * gstplaysink.c, adapted to handle encoding the converted frame into
+ *  arbitrary formats using gst-convenience.
+ */
+
+/* takes ownership of the input buffer */
+GstBuffer *gst_play_frame_conv_convert (GstBuffer * buf, GstCaps * to_caps);
+
+static gboolean
+create_element (const gchar * factory_name, GstElement ** element,
+    GError ** err);
+
+GstBuffer *
+gst_play_sink_convert_frame (GstElement * playsink, GstCaps * caps)
+{
+  GstBuffer *result = NULL;
+
+  g_object_get (G_OBJECT (playsink), "frame", (GstMiniObject *) & result, NULL);
+
+  GST_DEBUG ("got buffer %p from playsink", result);
+
+  if (result != NULL && caps != NULL) {
+    GstBuffer *temp;
+
+    temp = gst_play_frame_conv_convert (result, caps);
+    gst_buffer_unref (result);
+    result = temp;
+  }
+  return result;
+}
+
+static gboolean
+create_element (const gchar * factory_name, GstElement ** element,
+    GError ** err)
+{
+  *element = gst_element_factory_make (factory_name, NULL);
+  if (*element)
+    return TRUE;
+
+  if (err && *err == NULL) {
+    *err = g_error_new (GST_CORE_ERROR, GST_CORE_ERROR_MISSING_PLUGIN,
+        "cannot create element '%s' - please check your GStreamer installation",
+        factory_name);
+  }
+
+  return FALSE;
+}
+
+/* takes ownership of the input buffer */
+GstBuffer *
+gst_play_frame_conv_convert (GstBuffer * buf, GstCaps * to_caps)
+{
+  GstElement *src, *csp, *vscale, *sink, *pipeline;
+  GstMessage *msg;
+  GstBuffer *result = NULL;
+  GError *error = NULL;
+  GstBus *bus;
+  GstCaps *from_caps;
+  GstFlowReturn ret;
+
+  from_caps = GST_BUFFER_CAPS (buf);
+
+  g_return_val_if_fail (from_caps != NULL, NULL);
+
+  /* videoscale is here to correct for the pixel-aspect-ratio for us */
+  GST_DEBUG ("creating elements");
+  if (!create_element ("appsrc", &src, &error) ||
+      !create_element ("ffmpegcolorspace", &csp, &error) ||
+      !create_element ("videoscale", &vscale, &error) ||
+      !create_element ("appsink", &sink, &error))
+    goto no_elements;
+
+  pipeline = gst_pipeline_new ("screenshot-pipeline");
+  if (pipeline == NULL)
+    goto no_pipeline;
+
+  GST_DEBUG ("adding elements");
+  gst_bin_add_many (GST_BIN (pipeline), src, csp, vscale, sink, NULL);
+
+  /* set caps */
+  g_object_set (src, "caps", from_caps, NULL);
+  g_object_set (sink, "caps", to_caps, NULL);
+
+  /* FIXME: linking is still way too expensive, profile this properly */
+  GST_DEBUG ("linking src->csp");
+  if (!gst_element_link_pads (src, "src", csp, "sink"))
+    goto link_failed;
+
+  GST_DEBUG ("linking csp->vscale");
+  if (!gst_element_link_pads (csp, "src", vscale, "sink"))
+    goto link_failed;
+
+  GST_DEBUG ("linking vscale->sink");
+  if (!gst_element_link_pads (vscale, "src", sink, "sink"))
+    goto link_failed;
+
+  /* now set the pipeline to the paused state, after we push the buffer into
+   * appsrc, this should preroll the converted buffer in appsink */
+  GST_DEBUG ("running conversion pipeline to caps %" GST_PTR_FORMAT, to_caps);
+  gst_element_set_state (pipeline, GST_STATE_PAUSED);
+
+  /* feed buffer in appsrc */
+  GST_DEBUG ("feeding buffer %p, size %u, caps %" GST_PTR_FORMAT,
+      buf, GST_BUFFER_SIZE (buf), from_caps);
+  g_signal_emit_by_name (src, "push-buffer", buf, &ret);
+
+  /* now see what happens. We either got an error somewhere or the pipeline
+   * prerolled */
+  bus = gst_element_get_bus (pipeline);
+  msg =
+      gst_bus_poll (bus, GST_MESSAGE_ERROR | GST_MESSAGE_ASYNC_DONE,
+      25 * GST_SECOND);
+
+  if (msg) {
+    switch (GST_MESSAGE_TYPE (msg)) {
+      case GST_MESSAGE_ASYNC_DONE:
+      {
+        /* we're prerolled, get the frame from appsink */
+        g_signal_emit_by_name (sink, "pull-preroll", &result);
+
+        if (result) {
+          GST_DEBUG ("conversion successful: result = %p", result);
+        } else {
+          GST_WARNING ("prerolled but no result frame?!");
+        }
+        break;
+      }
+      case GST_MESSAGE_ERROR:{
+        gchar *dbg = NULL;
+
+        gst_message_parse_error (msg, &error, &dbg);
+        if (error) {
+          g_warning ("Could not take screenshot: %s", error->message);
+          GST_DEBUG ("%s [debug: %s]", error->message, GST_STR_NULL (dbg));
+          g_error_free (error);
+        } else {
+          g_warning ("Could not take screenshot (and NULL error!)");
+        }
+        g_free (dbg);
+        break;
+      }
+      default:{
+        g_return_val_if_reached (NULL);
+      }
+    }
+    gst_message_unref (msg);
+  } else {
+    g_warning ("Could not take screenshot: %s", "timeout during conversion");
+  }
+
+  gst_element_set_state (pipeline, GST_STATE_NULL);
+  gst_object_unref (bus);
+  gst_object_unref (pipeline);
+
+  return result;
+
+  /* ERRORS */
+no_elements:
+  {
+    g_warning ("Could not take screenshot: %s", error->message);
+    g_error_free (error);
+    return NULL;
+  }
+no_pipeline:
+  {
+    g_warning ("Could not take screenshot: %s", "no pipeline (unknown error)");
+    return NULL;
+  }
+link_failed:
+  {
+    g_warning ("Could not take screenshot: %s", "failed to link elements");
+    gst_object_unref (pipeline);
+    return NULL;
+  }
+}

ges/ges-screenshot.h

@@ -0,0 +1,33 @@
+/* GStreamer Editing Services
+ * Copyright (C) 2010 Brandon Lewis <brandon.lewis@collabora.co.uk>
+ *               2010 Nokia Corporation
+ *
+ * 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.
+ */
+
+#ifndef __GES_SCREENSHOT_H__
+#define __GES_SCREENSHOT_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+GstBuffer *
+gst_play_sink_convert_frame (GstElement * playsink, GstCaps * caps);
+
+G_END_DECLS
+
+#endif /* __GES_SCREENSHOT_H__ */