gstreamer/ges/ges-formatter.c
2012-01-11 11:56:16 -03:00

453 lines
12 KiB
C

/* 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.
*/
/**
* SECTION:ges-formatter
* @short_description: Timeline saving and loading.
*
* The #GESFormatter is the object responsible for loading and/or saving the contents
* of a #GESTimeline to/from various formats.
*
* In order to save a #GESTimeline, you can either let GES pick a default formatter by
* using ges_timeline_save_to_uri(), or pick your own formatter and use
* ges_formatter_save_to_uri().
*
* To load a #GESTimeline, you might want to be able to track the progress of the loading,
* in which case you should create an empty #GESTimeline, connect to the relevant signals
* and call ges_formatter_load_from_uri().
*
* If you do not care about tracking the loading progress, you can use the convenience
* ges_timeline_new_from_uri() method.
*
* Support for saving or loading new formats can be added by creating a subclass of
* #GESFormatter and implement the various vmethods of #GESFormatterClass.
**/
#include <gst/gst.h>
#include <stdlib.h>
#include "ges-formatter.h"
#include "ges-keyfile-formatter.h"
#include "ges-internal.h"
G_DEFINE_ABSTRACT_TYPE (GESFormatter, ges_formatter, G_TYPE_OBJECT);
struct _GESFormatterPrivate
{
gchar *data;
gsize length;
};
static void ges_formatter_dispose (GObject * object);
static gboolean load_from_uri (GESFormatter * formatter, GESTimeline *
timeline, const gchar * uri);
static gboolean save_to_uri (GESFormatter * formatter, GESTimeline *
timeline, const gchar * uri);
static gboolean default_can_load_uri (const gchar * uri);
static gboolean default_can_save_uri (const gchar * uri);
static void
ges_formatter_class_init (GESFormatterClass * klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
g_type_class_add_private (klass, sizeof (GESFormatterPrivate));
object_class->dispose = ges_formatter_dispose;
klass->can_load_uri = default_can_load_uri;
klass->can_save_uri = default_can_save_uri;
klass->load_from_uri = load_from_uri;
klass->save_to_uri = save_to_uri;
}
static void
ges_formatter_init (GESFormatter * object)
{
object->priv = G_TYPE_INSTANCE_GET_PRIVATE (object,
GES_TYPE_FORMATTER, GESFormatterPrivate);
}
static void
ges_formatter_dispose (GObject * object)
{
GESFormatterPrivate *priv = GES_FORMATTER (object)->priv;
if (priv->data) {
g_free (priv->data);
}
}
/**
* ges_formatter_new_for_uri:
* @uri: a #gchar * pointing to the uri
*
* Creates a #GESFormatter that can handle the given URI.
*
* Returns: A GESFormatter that can load the given uri, or NULL if
* the uri is not supported.
*/
GESFormatter *
ges_formatter_new_for_uri (const gchar * uri)
{
if (ges_formatter_can_load_uri (uri))
return GES_FORMATTER (ges_keyfile_formatter_new ());
return NULL;
}
/**
* ges_default_formatter_new:
*
* Creates a new instance of the default GESFormatter type on this system
* (currently #GESKeyfileFormatter).
*
* Returns: (transfer full): a #GESFormatter instance or %NULL
*/
GESFormatter *
ges_default_formatter_new (void)
{
return GES_FORMATTER (ges_keyfile_formatter_new ());
}
static gboolean
default_can_load_uri (const gchar * uri)
{
GST_ERROR ("No 'can_load_uri' vmethod implementation");
return FALSE;
}
static gboolean
default_can_save_uri (const gchar * uri)
{
GST_ERROR ("No 'can_save_uri' vmethod implementation");
return FALSE;
}
/**
* ges_formatter_can_load_uri:
* @uri: a #gchar * pointing to the URI
*
* Checks if there is a #GESFormatter available which can load a #GESTimeline
* from the given URI.
*
* Returns: TRUE if there is a #GESFormatter that can support the given uri
* or FALSE if not.
*/
gboolean
ges_formatter_can_load_uri (const gchar * uri)
{
if (!(gst_uri_is_valid (uri))) {
GST_ERROR ("Invalid uri!");
return FALSE;
}
if (!(gst_uri_has_protocol (uri, "file"))) {
gchar *proto = gst_uri_get_protocol (uri);
GST_ERROR ("Unspported protocol '%s'", proto);
g_free (proto);
return FALSE;
}
/* TODO: implement file format registry */
/* TODO: search through the registry and chose a GESFormatter class that can
* handle the URI.*/
return TRUE;
}
/**
* ges_formatter_can_save_uri:
* @uri: a #gchar * pointing to a URI
*
* Returns TRUE if there is a #GESFormatter available which can save a
* #GESTimeline to the given URI.
*
* Returns: TRUE if the given @uri is supported, else FALSE.
*/
gboolean
ges_formatter_can_save_uri (const gchar * uri)
{
if (!(gst_uri_is_valid (uri))) {
GST_ERROR ("Invalid uri!");
return FALSE;
}
if (!(gst_uri_has_protocol (uri, "file"))) {
gchar *proto = gst_uri_get_protocol (uri);
GST_ERROR ("Unspported protocol '%s'", proto);
g_free (proto);
return FALSE;
}
/* TODO: implement file format registry */
/* TODO: search through the registry and chose a GESFormatter class that can
* handle the URI.*/
return TRUE;
}
/**
* ges_formatter_set_data:
* @formatter: a #GESFormatter
* @data: the data to be set on the formatter
* @length: the length of the data in bytes
*
* Set the data that this formatter will use for loading. The formatter will
* takes ownership of the data and will free the data if
* @ges_formatter_set_data is called again or when the formatter itself is
* disposed. You should call @ges_formatter_clear_data () if you do not wish
* this to happen.
*/
void
ges_formatter_set_data (GESFormatter * formatter, void *data, gsize length)
{
GESFormatterPrivate *priv = GES_FORMATTER (formatter)->priv;
if (priv->data)
g_free (priv->data);
priv->data = data;
priv->length = length;
}
/**
* ges_formatter_get_data:
* @formatter: a #GESFormatter
* @length: location into which to store the size of the data in bytes.
*
* Lets you get the data @formatter used for loading.
*
* Returns: (transfer none): a pointer to the data.
*/
void *
ges_formatter_get_data (GESFormatter * formatter, gsize * length)
{
GESFormatterPrivate *priv = GES_FORMATTER (formatter)->priv;
*length = priv->length;
return priv->data;
}
/**
* ges_formatter_clear_data:
* @formatter: a #GESFormatter
*
* clears the data from a #GESFormatter without freeing it. You should call
* this before disposing or setting data on a #GESFormatter if the current data
* pointer should not be freed.
*/
void
ges_formatter_clear_data (GESFormatter * formatter)
{
GESFormatterPrivate *priv = GES_FORMATTER (formatter)->priv;
priv->data = NULL;
priv->length = 0;
}
/**
* ges_formatter_load:
* @formatter: a #GESFormatter
* @timeline: a #GESTimeline
*
* Loads data from formatter to into timeline. You should first call
* ges_formatter_set_data() with the location and size of a block of data
* from which to read.
*
* Returns: TRUE if the data was successfully loaded into timeline
* or FALSE if an error occured during loading.
*/
gboolean
ges_formatter_load (GESFormatter * formatter, GESTimeline * timeline)
{
GESFormatterClass *klass;
klass = GES_FORMATTER_GET_CLASS (formatter);
if (klass->load)
return klass->load (formatter, timeline);
GST_ERROR ("not implemented!");
return FALSE;
}
/**
* ges_formatter_save:
* @formatter: a #GESFormatter
* @timeline: a #GESTimeline
*
* Save data from timeline into a block of data. You can retrieve the location
* and size of this data with ges_formatter_get_data().
*
* Returns: TRUE if the timeline data was successfully saved for FALSE if
* an error occured during saving.
*/
gboolean
ges_formatter_save (GESFormatter * formatter, GESTimeline * timeline)
{
GESFormatterClass *klass;
GList *layers;
/* Saving an empty timeline is not allowed */
/* FIXME : Having a ges_timeline_is_empty() would be more efficient maybe */
layers = ges_timeline_get_layers (timeline);
g_return_val_if_fail (layers != NULL, FALSE);
g_list_foreach (layers, (GFunc) g_object_unref, NULL);
g_list_free (layers);
klass = GES_FORMATTER_GET_CLASS (formatter);
if (klass->save)
return klass->save (formatter, timeline);
GST_ERROR ("not implemented!");
return FALSE;
}
/**
* ges_formatter_load_from_uri:
* @formatter: a #GESFormatter
* @timeline: a #GESTimeline
* @uri: a #gchar * pointing to a URI
*
* Load data from the given URI into timeline.
*
* Returns: TRUE if the timeline data was successfully loaded from the URI,
* else FALSE.
*/
gboolean
ges_formatter_load_from_uri (GESFormatter * formatter, GESTimeline * timeline,
const gchar * uri)
{
GESFormatterClass *klass = GES_FORMATTER_GET_CLASS (formatter);
if (klass->load_from_uri)
return klass->load_from_uri (formatter, timeline, uri);
return FALSE;
}
static gboolean
load_from_uri (GESFormatter * formatter, GESTimeline * timeline,
const gchar * uri)
{
gchar *location;
GError *e = NULL;
gboolean ret = TRUE;
GESFormatterPrivate *priv = GES_FORMATTER (formatter)->priv;
if (priv->data) {
GST_ERROR ("formatter already has data! please set data to NULL");
}
if (!(location = gst_uri_get_location (uri))) {
return FALSE;
}
if (g_file_get_contents (location, &priv->data, &priv->length, &e)) {
if (!ges_formatter_load (formatter, timeline)) {
GST_ERROR ("couldn't deserialize formatter");
ret = FALSE;
}
} else {
GST_ERROR ("couldn't read file '%s': %s", location, e->message);
ret = FALSE;
}
if (e)
g_error_free (e);
g_free (location);
return ret;
}
/**
* ges_formatter_save_to_uri:
* @formatter: a #GESFormatter
* @timeline: a #GESTimeline
* @uri: a #gchar * pointing to a URI
*
* Save data from timeline to the given URI.
*
* Returns: TRUE if the timeline data was successfully saved to the URI
* else FALSE.
*/
gboolean
ges_formatter_save_to_uri (GESFormatter * formatter, GESTimeline *
timeline, const gchar * uri)
{
GESFormatterClass *klass = GES_FORMATTER_GET_CLASS (formatter);
GList *layers;
/* Saving an empty timeline is not allowed */
/* FIXME : Having a ges_timeline_is_empty() would be more efficient maybe */
layers = ges_timeline_get_layers (timeline);
g_return_val_if_fail (layers != NULL, FALSE);
g_list_foreach (layers, (GFunc) g_object_unref, NULL);
g_list_free (layers);
if (klass->save_to_uri)
return klass->save_to_uri (formatter, timeline, uri);
GST_ERROR ("not implemented!");
return FALSE;
}
static gboolean
save_to_uri (GESFormatter * formatter, GESTimeline * timeline,
const gchar * uri)
{
gchar *location;
GError *e = NULL;
gboolean ret = TRUE;
GESFormatterPrivate *priv = GES_FORMATTER (formatter)->priv;
if (!(location = g_filename_from_uri (uri, NULL, NULL))) {
return FALSE;
}
if (!ges_formatter_save (formatter, timeline)) {
GST_ERROR ("couldn't serialize formatter");
} else {
if (!g_file_set_contents (location, priv->data, priv->length, &e)) {
GST_ERROR ("couldn't write file '%s': %s", location, e->message);
ret = FALSE;
}
}
if (e)
g_error_free (e);
g_free (location);
return ret;
}