gstreamer/gst/camerabin/camerabinpreview.c
Lasse Laukkanen 6a47f6f594 camerabin: preview image sending optimization
* decouple image capturing from image post-processing and encoding
 * post image-captured message after image is captured
 * post preview-image message with snapshot of captured image
2009-06-05 15:51:31 +03:00

257 lines
7.1 KiB
C

/*
* GStreamer
* Copyright (C) 2009 Nokia Corporation <multimedia@maemo.org>
*
* 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 "camerabingeneral.h"
#include "camerabinpreview.h"
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, const gchar * elem_name,
GstElement ** element, GError ** err)
{
*element = gst_element_factory_make (factory_name, elem_name);
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;
}
/**
* gst_camerabin_preview_create_pipeline:
* @camera: camerabin object
*
* Create a preview converter pipeline.
*
* Returns: TRUE if pipeline was constructed, otherwise FALSE.
*/
gboolean
gst_camerabin_preview_create_pipeline (GstCameraBin * camera)
{
GstElement *src, *csp, *filter, *vscale, *sink;
GError *error = NULL;
if (!camera->preview_caps) {
return FALSE;
}
/* Destroy old pipeline, if any */
gst_camerabin_preview_destroy_pipeline (camera);
GST_DEBUG ("creating elements");
if (!create_element ("appsrc", "prev_src", &src, &error) ||
!create_element ("videoscale", NULL, &vscale, &error) ||
!create_element ("ffmpegcolorspace", NULL, &csp, &error) ||
!create_element ("capsfilter", NULL, &filter, &error) ||
!create_element ("fakesink", "prev_sink", &sink, &error))
goto no_elements;
camera->preview_pipeline = gst_pipeline_new ("preview-pipeline");
if (camera->preview_pipeline == NULL)
goto no_pipeline;
GST_DEBUG ("adding elements");
gst_bin_add_many (GST_BIN (camera->preview_pipeline),
src, csp, filter, vscale, sink, NULL);
g_object_set (filter, "caps", camera->preview_caps, NULL);
g_object_set (sink, "preroll-queue-len", 1, "signal-handoffs", TRUE, NULL);
g_object_set (vscale, "method", 0, NULL);
/* FIXME: linking is still way too expensive, profile this properly */
GST_DEBUG ("linking src->vscale");
if (!gst_element_link_pads (src, "src", vscale, "sink"))
return FALSE;
GST_DEBUG ("linking vscale->csp");
if (!gst_element_link_pads (vscale, "src", csp, "sink"))
return FALSE;
GST_DEBUG ("linking csp->capsfilter");
if (!gst_element_link_pads (csp, "src", filter, "sink"))
return FALSE;
GST_DEBUG ("linking capsfilter->sink");
if (!gst_element_link_pads (filter, "src", sink, "sink"))
return FALSE;
return TRUE;
/* ERRORS */
no_elements:
{
g_warning ("Could not make preview pipeline: %s", error->message);
g_error_free (error);
return FALSE;
}
no_pipeline:
{
g_warning ("Could not make preview pipeline: %s",
"no pipeline (unknown error)");
return FALSE;
}
}
/**
* gst_camerabin_preview_destroy_pipeline:
* @camera: camerabin object
*
* Destroy preview converter pipeline.
*/
void
gst_camerabin_preview_destroy_pipeline (GstCameraBin * camera)
{
if (camera->preview_pipeline) {
gst_element_set_state (camera->preview_pipeline, GST_STATE_NULL);
gst_object_unref (camera->preview_pipeline);
camera->preview_pipeline = NULL;
}
}
/**
* gst_camerabin_preview_convert:
* @camera: camerabin object
* @buf: #GstBuffer that contains the frame to be converted
*
* Create a preview image of the given frame.
*
* Returns: converted preview image, or NULL if operation failed.
*/
GstBuffer *
gst_camerabin_preview_convert (GstCameraBin * camera, GstBuffer * buf)
{
GstMessage *msg;
GstBuffer *result = NULL;
GError *error = NULL;
GstBus *bus;
GstElement *src, *sink;
GstBufferFlag bflags;
GstFlowReturn fret;
g_return_val_if_fail (GST_BUFFER_CAPS (buf) != NULL, NULL);
if (camera->preview_pipeline == NULL) {
GST_WARNING ("pipeline is NULL");
goto no_pipeline;
}
src = gst_bin_get_by_name (GST_BIN (camera->preview_pipeline), "prev_src");
sink = gst_bin_get_by_name (GST_BIN (camera->preview_pipeline), "prev_sink");
if (!src || !sink) {
GST_WARNING ("pipeline doesn't have src / sink elements");
goto no_pipeline;
}
g_object_set (src, "size", (gint64) GST_BUFFER_SIZE (buf),
"blocksize", (guint32) GST_BUFFER_SIZE (buf),
"caps", GST_BUFFER_CAPS (buf), "num-buffers", 1, NULL);
g_signal_connect (sink, "handoff", G_CALLBACK (save_result), &result);
bflags = GST_BUFFER_FLAGS (buf);
GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_READONLY);
GST_DEBUG ("running conversion pipeline");
gst_element_set_state (camera->preview_pipeline, GST_STATE_PLAYING);
g_signal_emit_by_name (src, "push-buffer", buf, &fret);
/* TODO: do we need to use a bus poll, can we just register a callback to the bus? */
bus = gst_element_get_bus (camera->preview_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 ("preview image 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 make preview image: %s", error->message);
GST_DEBUG ("%s [debug: %s]", error->message, GST_STR_NULL (dbg));
g_error_free (error);
} else {
g_warning ("Could not make preview image (and NULL error!)");
}
g_free (dbg);
result = NULL;
break;
}
default:{
g_return_val_if_reached (NULL);
}
}
} else {
g_warning ("Could not make preview image: %s", "timeout during conversion");
result = NULL;
}
g_signal_handlers_disconnect_by_func (sink, G_CALLBACK (save_result),
&result);
gst_element_set_state (camera->preview_pipeline, GST_STATE_READY);
GST_BUFFER_FLAGS (buf) = bflags;
return result;
/* ERRORS */
no_pipeline:
{
g_warning ("Could not make preview image: %s",
"no pipeline (unknown error)");
return NULL;
}
}