gstreamer/gst/playback/gstscreenshot.c

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/* Small helper element for format conversion
* Copyright (C) 2005 Tim-Philipp Müller <tim centricular net>
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <string.h>
#include "gstscreenshot.h"
static void
feed_fakesrc (GstElement * src, GstBuffer * buf, GstPad * pad, gpointer data)
{
GstBuffer *in_buf = GST_BUFFER (data);
gst_buffer_set_caps (buf, GST_BUFFER_CAPS (in_buf));
memcpy (GST_BUFFER_DATA (buf), GST_BUFFER_DATA (in_buf),
GST_BUFFER_SIZE (in_buf));
GST_BUFFER_SIZE (buf) = GST_BUFFER_SIZE (in_buf);
GST_DEBUG ("feeding buffer %p, size %u, caps %" GST_PTR_FORMAT,
buf, GST_BUFFER_SIZE (buf), GST_BUFFER_CAPS (buf));
}
static void
save_result (GstElement * sink, GstBuffer * buf, GstPad * pad, gpointer data)
{
GstBuffer **p_buf = (GstBuffer **) data;
*p_buf = gst_buffer_ref (buf);
GST_DEBUG ("received converted buffer %p with caps %" GST_PTR_FORMAT,
*p_buf, GST_BUFFER_CAPS (*p_buf));
}
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, *filter1, *vscale, *filter2, *sink, *pipeline;
GstMessage *msg;
GstBuffer *result = NULL;
GError *error = NULL;
GstBus *bus;
GstCaps *to_caps_no_par;
g_return_val_if_fail (GST_BUFFER_CAPS (buf) != NULL, NULL);
/* videoscale is here to correct for the pixel-aspect-ratio for us */
GST_DEBUG ("creating elements");
if (!create_element ("fakesrc", &src, &error) ||
!create_element ("ffmpegcolorspace", &csp, &error) ||
!create_element ("videoscale", &vscale, &error) ||
!create_element ("capsfilter", &filter1, &error) ||
!create_element ("capsfilter", &filter2, &error) ||
!create_element ("fakesink", &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, filter1, vscale, filter2,
sink, NULL);
g_signal_connect (src, "handoff", G_CALLBACK (feed_fakesrc), buf);
/* set to 'fixed' sizetype */
g_object_set (src, "sizemax", GST_BUFFER_SIZE (buf), "sizetype", 2,
"num-buffers", 1, "signal-handoffs", TRUE, NULL);
/* adding this superfluous capsfilter makes linking cheaper */
to_caps_no_par = gst_caps_copy (to_caps);
gst_structure_remove_field (gst_caps_get_structure (to_caps_no_par, 0),
"pixel-aspect-ratio");
g_object_set (filter1, "caps", to_caps_no_par, NULL);
gst_caps_unref (to_caps_no_par);
g_object_set (filter2, "caps", to_caps, NULL);
g_signal_connect (sink, "handoff", G_CALLBACK (save_result), &result);
g_object_set (sink, "preroll-queue-len", 1, "signal-handoffs", TRUE, 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"))
return NULL;
GST_DEBUG ("linking csp->filter1");
if (!gst_element_link_pads (csp, "src", filter1, "sink"))
return NULL;
GST_DEBUG ("linking filter1->vscale");
if (!gst_element_link_pads (filter1, "src", vscale, "sink"))
return NULL;
GST_DEBUG ("linking vscale->capsfilter");
if (!gst_element_link_pads (vscale, "src", filter2, "sink"))
return NULL;
GST_DEBUG ("linking capsfilter->sink");
if (!gst_element_link_pads (filter2, "src", sink, "sink"))
return NULL;
GST_DEBUG ("running conversion pipeline");
gst_element_set_state (pipeline, GST_STATE_PLAYING);
bus = gst_element_get_bus (pipeline);
msg =
gst_bus_poll (bus, GST_MESSAGE_ERROR | GST_MESSAGE_EOS, 25 * GST_SECOND);
if (msg) {
switch (GST_MESSAGE_TYPE (msg)) {
case GST_MESSAGE_EOS:{
if (result) {
GST_DEBUG ("conversion successful: result = %p", result);
} else {
GST_WARNING ("EOS 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);
result = NULL;
break;
}
default:{
g_return_val_if_reached (NULL);
}
}
2009-06-26 10:14:02 +00:00
gst_message_unref (msg);
} else {
g_warning ("Could not take screenshot: %s", "timeout during conversion");
result = NULL;
}
gst_element_set_state (pipeline, GST_STATE_NULL);
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;
}
}