Fix loading and exporting of Theora and WebM video streams

Theora and WebM video streams were mistakenly imported with a ResourceImporter,
but those imported ogvstr and webmstr were simply links to the local resource.
While that works fine in the editor, it no longer works when exporting a game
as the "source" ogv and webm files are ommitted and only the ogvstr and webmstr
references were exported.

As discussed with @reduz, it doesn't make sense to import videos, as we only
intend to play them back and not modify them/access their raw data. As such we
use a ResourceFormatLoader instead of an importer, to load the file on the fly.
ogv and webm files linked to this loader are now considered as resources, and
thus exported.

Note: The Theora and WebM loaders lack any kind of validity check beyond the
existence of the target file, but it was already the case with the importer.
Better checks and error reports could be added, but those loaders will eventually
be obsoleted by GDNative plugins anyway.

Fixes #14954.

6 files changed, 62 insertions, 174 deletions

diff --git a/modules/webm/doc_classes/ResourceImporterWebm.xml b/modules/webm/doc_classes/ResourceImporterWebm.xml
deleted file mode 100644
index 0cfab1baf0..0000000000
--- a/modules/webm/doc_classes/ResourceImporterWebm.xml
+++ /dev/null
@@ -1,15 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<class name="ResourceImporterWebm" inherits="ResourceImporter" category="Core" version="3.1">
-	<brief_description>
-	</brief_description>
-	<description>
-	</description>
-	<tutorials>
-	</tutorials>
-	<demos>
-	</demos>
-	<methods>
-	</methods>
-	<constants>
-	</constants>
-</class>
diff --git a/modules/webm/register_types.cpp b/modules/webm/register_types.cpp
index 1183dd41f7..121b528d5b 100644
--- a/modules/webm/register_types.cpp
+++ b/modules/webm/register_types.cpp
@@ -29,18 +29,22 @@
 /*************************************************************************/
 
 #include "register_types.h"
-#include "resource_importer_webm.h"
+
 #include "video_stream_webm.h"
 
+static ResourceFormatLoaderWebm *resource_loader_webm = NULL;
+
 void register_webm_types() {
 
-#ifdef TOOLS_ENABLED
-	Ref<ResourceImporterWebm> webm_import;
-	webm_import.instance();
-	ResourceFormatImporter::get_singleton()->add_importer(webm_import);
-#endif
+	resource_loader_webm = memnew(ResourceFormatLoaderWebm);
+	ResourceLoader::add_resource_format_loader(resource_loader_webm, true);
+
 	ClassDB::register_class<VideoStreamWebm>();
 }
 
 void unregister_webm_types() {
+
+	if (resource_loader_webm) {
+		memdelete(resource_loader_webm);
+	}
 }
diff --git a/modules/webm/resource_importer_webm.cpp b/modules/webm/resource_importer_webm.cpp
deleted file mode 100644
index 7124a503e8..0000000000
--- a/modules/webm/resource_importer_webm.cpp
+++ /dev/null
@@ -1,96 +0,0 @@
-/*************************************************************************/
-/*  resource_importer_webm.cpp                                           */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
-/*                                                                       */
-/* Permission is hereby granted, free of charge, to any person obtaining */
-/* a copy of this software and associated documentation files (the       */
-/* "Software"), to deal in the Software without restriction, including   */
-/* without limitation the rights to use, copy, modify, merge, publish,   */
-/* distribute, sublicense, and/or sell copies of the Software, and to    */
-/* permit persons to whom the Software is furnished to do so, subject to */
-/* the following conditions:                                             */
-/*                                                                       */
-/* The above copyright notice and this permission notice shall be        */
-/* included in all copies or substantial portions of the Software.       */
-/*                                                                       */
-/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
-/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
-/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
-/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
-/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
-/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
-/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
-/*************************************************************************/
-
-#include "resource_importer_webm.h"
-
-#include "io/resource_saver.h"
-#include "os/file_access.h"
-#include "scene/resources/texture.h"
-#include "video_stream_webm.h"
-
-String ResourceImporterWebm::get_importer_name() const {
-
-	return "Webm";
-}
-
-String ResourceImporterWebm::get_visible_name() const {
-
-	return "Webm";
-}
-void ResourceImporterWebm::get_recognized_extensions(List<String> *p_extensions) const {
-
-	p_extensions->push_back("webm");
-}
-
-String ResourceImporterWebm::get_save_extension() const {
-	return "webmstr";
-}
-
-String ResourceImporterWebm::get_resource_type() const {
-
-	return "VideoStreamWebm";
-}
-
-bool ResourceImporterWebm::get_option_visibility(const String &p_option, const Map<StringName, Variant> &p_options) const {
-
-	return true;
-}
-
-int ResourceImporterWebm::get_preset_count() const {
-	return 0;
-}
-String ResourceImporterWebm::get_preset_name(int p_idx) const {
-
-	return String();
-}
-
-void ResourceImporterWebm::get_import_options(List<ImportOption> *r_options, int p_preset) const {
-
-	r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL, "loop"), true));
-}
-
-Error ResourceImporterWebm::import(const String &p_source_file, const String &p_save_path, const Map<StringName, Variant> &p_options, List<String> *r_platform_variants, List<String> *r_gen_files) {
-
-	FileAccess *f = FileAccess::open(p_source_file, FileAccess::READ);
-	if (!f) {
-		ERR_FAIL_COND_V(!f, ERR_CANT_OPEN);
-	}
-	memdelete(f);
-
-	VideoStreamWebm *stream = memnew(VideoStreamWebm);
-	stream->set_file(p_source_file);
-
-	Ref<VideoStreamWebm> webm_stream = Ref<VideoStreamWebm>(stream);
-
-	return ResourceSaver::save(p_save_path + ".webmstr", webm_stream);
-}
-
-ResourceImporterWebm::ResourceImporterWebm() {
-}
diff --git a/modules/webm/resource_importer_webm.h b/modules/webm/resource_importer_webm.h
deleted file mode 100644
index d61e6e2a93..0000000000
--- a/modules/webm/resource_importer_webm.h
+++ /dev/null
@@ -1,56 +0,0 @@
-/*************************************************************************/
-/*  resource_importer_webm.h                                             */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
-/*                                                                       */
-/* Permission is hereby granted, free of charge, to any person obtaining */
-/* a copy of this software and associated documentation files (the       */
-/* "Software"), to deal in the Software without restriction, including   */
-/* without limitation the rights to use, copy, modify, merge, publish,   */
-/* distribute, sublicense, and/or sell copies of the Software, and to    */
-/* permit persons to whom the Software is furnished to do so, subject to */
-/* the following conditions:                                             */
-/*                                                                       */
-/* The above copyright notice and this permission notice shall be        */
-/* included in all copies or substantial portions of the Software.       */
-/*                                                                       */
-/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
-/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
-/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
-/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
-/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
-/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
-/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
-/*************************************************************************/
-
-#ifndef RESOURCEIMPORTERWEBM_H
-#define RESOURCEIMPORTERWEBM_H
-
-#include "io/resource_import.h"
-
-class ResourceImporterWebm : public ResourceImporter {
-	GDCLASS(ResourceImporterWebm, ResourceImporter)
-public:
-	virtual String get_importer_name() const;
-	virtual String get_visible_name() const;
-	virtual void get_recognized_extensions(List<String> *p_extensions) const;
-	virtual String get_save_extension() const;
-	virtual String get_resource_type() const;
-
-	virtual int get_preset_count() const;
-	virtual String get_preset_name(int p_idx) const;
-
-	virtual void get_import_options(List<ImportOption> *r_options, int p_preset = 0) const;
-	virtual bool get_option_visibility(const String &p_option, const Map<StringName, Variant> &p_options) const;
-
-	virtual Error import(const String &p_source_file, const String &p_save_path, const Map<StringName, Variant> &p_options, List<String> *r_platform_variants, List<String> *r_gen_files = NULL);
-
-	ResourceImporterWebm();
-};
-
-#endif // RESOURCEIMPORTERWEBM_H
diff --git a/modules/webm/video_stream_webm.cpp b/modules/webm/video_stream_webm.cpp
index fac47225bc..1bb9a43886 100644
--- a/modules/webm/video_stream_webm.cpp
+++ b/modules/webm/video_stream_webm.cpp
@@ -443,3 +443,46 @@ void VideoStreamWebm::set_audio_track(int p_track) {
 
 	audio_track = p_track;
 }
+
+////////////
+
+RES ResourceFormatLoaderWebm::load(const String &p_path, const String &p_original_path, Error *r_error) {
+
+	FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
+	if (!f) {
+		if (r_error) {
+			*r_error = ERR_CANT_OPEN;
+		}
+		memdelete(f);
+		return RES();
+	}
+
+	VideoStreamWebm *stream = memnew(VideoStreamWebm);
+	stream->set_file(p_path);
+
+	Ref<VideoStreamWebm> webm_stream = Ref<VideoStreamWebm>(stream);
+
+	if (r_error) {
+		*r_error = OK;
+	}
+
+	return webm_stream;
+}
+
+void ResourceFormatLoaderWebm::get_recognized_extensions(List<String> *p_extensions) const {
+
+	p_extensions->push_back("webm");
+}
+
+bool ResourceFormatLoaderWebm::handles_type(const String &p_type) const {
+
+	return ClassDB::is_parent_class(p_type, "VideoStream");
+}
+
+String ResourceFormatLoaderWebm::get_resource_type(const String &p_path) const {
+
+	String el = p_path.get_extension().to_lower();
+	if (el == "webm")
+		return "VideoStreamWebm";
+	return "";
+}
diff --git a/modules/webm/video_stream_webm.h b/modules/webm/video_stream_webm.h
index dde993d154..08be50846d 100644
--- a/modules/webm/video_stream_webm.h
+++ b/modules/webm/video_stream_webm.h
@@ -109,7 +109,7 @@ private:
 class VideoStreamWebm : public VideoStream {
 
 	GDCLASS(VideoStreamWebm, VideoStream);
-	RES_BASE_EXTENSION("webmstr");
+	RES_BASE_EXTENSION("webm");
 
 	String file;
 	int audio_track;
@@ -127,4 +127,12 @@ public:
 	virtual void set_audio_track(int p_track);
 };
 
+class ResourceFormatLoaderWebm : public ResourceFormatLoader {
+public:
+	virtual RES load(const String &p_path, const String &p_original_path = "", Error *r_error = NULL);
+	virtual void get_recognized_extensions(List<String> *p_extensions) const;
+	virtual bool handles_type(const String &p_type) const;
+	virtual String get_resource_type(const String &p_path) const;
+};
+
 #endif // VIDEO_STREAM_WEBM_H