gstreamer/gst/playback/gstscreenshot.c
Wim Taymans 13f6829497 playbin2: improve screenshot code
Use appsrc and appsink in the screenshot code to make things nicer.
2010-06-05 12:27:12 +02:00

204 lines
6.1 KiB
C

/* 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"
void
gst_play_marshal_BUFFER__BOXED (GClosure * closure,
GValue * return_value G_GNUC_UNUSED,
guint n_param_values,
const GValue * param_values,
gpointer invocation_hint G_GNUC_UNUSED, gpointer marshal_data)
{
typedef GstBuffer *(*GMarshalFunc_OBJECT__BOXED) (gpointer data1,
gpointer arg_1, gpointer data2);
register GMarshalFunc_OBJECT__BOXED callback;
register GCClosure *cc = (GCClosure *) closure;
register gpointer data1, data2;
GstBuffer *v_return;
g_return_if_fail (return_value != NULL);
g_return_if_fail (n_param_values == 2);
if (G_CCLOSURE_SWAP_DATA (closure)) {
data1 = closure->data;
data2 = g_value_peek_pointer (param_values + 0);
} else {
data1 = g_value_peek_pointer (param_values + 0);
data2 = closure->data;
}
callback =
(GMarshalFunc_OBJECT__BOXED) (marshal_data ? marshal_data : cc->callback);
v_return = callback (data1, g_value_get_boxed (param_values + 1), data2);
gst_value_take_buffer (return_value, v_return);
}
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;
}
}