gstreamer/ges/ges-screenshot.c
2010-07-16 17:22:19 +02:00

274 lines
7.7 KiB
C

/* 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 <gst/profile/gstfactorylists.h>
#include <glib-object.h>
#include <string.h>
#include "ges-screenshot.h"
#include "ges-internal.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);
static GstElement *get_encoder (GstCaps * caps);
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;
}
GstElement *
get_encoder (GstCaps * caps)
{
GValueArray *encoders = NULL;
GValueArray *filtered = NULL;
GValue *factory_value = NULL;
GstElementFactory *factory = NULL;
GstElement *encoder;
encoders =
gst_factory_list_get_elements (GST_FACTORY_LIST_ENCODER |
GST_FACTORY_LIST_IMAGE, GST_RANK_NONE);
GST_INFO ("got factory list %p", encoders);
gst_factory_list_debug (encoders);
if (!(encoders && encoders->n_values))
goto fail;
filtered = gst_factory_list_filter (encoders, caps, GST_PAD_SRC, FALSE);
GST_INFO ("got filtered list %p", filtered);
gst_factory_list_debug (filtered);
if (!(filtered && filtered->n_values))
goto fail;
factory_value = g_value_array_get_nth (filtered, 0);
factory = (GstElementFactory *) g_value_get_object (factory_value);
GST_INFO ("got factory %p", factory);
if (!factory)
goto fail;
encoder = gst_element_factory_create (factory, NULL);
GST_INFO ("created encoder element %p, %s", encoder,
gst_element_get_name (encoder));
if (!encoder)
goto fail;
g_value_array_free (filtered);
g_value_array_free (encoders);
gst_object_unref (factory);
return encoder;
fail:
if (encoders)
g_value_array_free (encoders);
if (filtered)
g_value_array_free (filtered);
if (factory)
gst_object_unref (factory);
return NULL;
}
/* takes ownership of the input buffer */
GstBuffer *
gst_play_frame_conv_convert (GstBuffer * buf, GstCaps * to_caps)
{
GstElement *src, *csp, *vscale, *sink, *encoder, *pipeline;
GstMessage *msg;
GstBuffer *result = NULL;
GError *error = NULL;
GstBus *bus;
GstCaps *from_caps;
GstFlowReturn ret;
encoder = get_encoder (to_caps);
if (!encoder)
goto no_encoder;
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, encoder, 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;
/* TODO: only plug an encoder if caps aren't raw ? */
GST_DEBUG ("linking vscale->encoder");
if (!gst_element_link (vscale, encoder))
goto link_failed;
GST_DEBUG ("linking encoder->sink");
if (!gst_element_link_pads (encoder, "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_encoder:
{
g_warning ("could not find an encoder for provided caps");
return NULL;
}
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;
}
}