add mp3 import and playback support

9 files changed, 648 insertions, 0 deletions

diff --git a/modules/minimp3/SCsub b/modules/minimp3/SCsub
new file mode 100644
index 0000000000..f4d1605d55
--- /dev/null
+++ b/modules/minimp3/SCsub
@@ -0,0 +1,17 @@
+#!/usr/bin/env python
+
+Import("env")
+Import("env_modules")
+
+env_minimp3 = env_modules.Clone()
+
+thirdparty_dir = "#thirdparty/minimp3/"
+
+# Treat minimp3 headers as system headers to avoid raising warnings. Not supported on MSVC.
+if not env.msvc:
+    env_minimp3.Append(CPPFLAGS=["-isystem", Dir(thirdparty_dir).path])
+else:
+    env_minimp3.Prepend(CPPPATH=[thirdparty_dir])
+
+# Godot's own source files
+env_minimp3.add_source_files(env.modules_sources, "*.cpp")
diff --git a/modules/minimp3/audio_stream_mp3.cpp b/modules/minimp3/audio_stream_mp3.cpp
new file mode 100644
index 0000000000..b20c043e0c
--- /dev/null
+++ b/modules/minimp3/audio_stream_mp3.cpp
@@ -0,0 +1,228 @@
+/*************************************************************************/
+/*  audio_stream_mp3.cpp                                                 */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 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.                */
+/*************************************************************************/
+
+#define MINIMP3_ONLY_MP3
+#define MINIMP3_FLOAT_OUTPUT
+#define MINIMP3_IMPLEMENTATION
+#define MINIMP3_NO_STDIO
+
+#include "audio_stream_mp3.h"
+
+#include "core/os/file_access.h"
+
+void AudioStreamPlaybackMP3::_mix_internal(AudioFrame *p_buffer, int p_frames) {
+	ERR_FAIL_COND(!active);
+
+	int todo = p_frames;
+
+	while (todo && active) {
+		mp3dec_frame_info_t frame_info;
+		mp3d_sample_t *buf_frame = nullptr;
+
+		int samples_mixed = mp3dec_ex_read_frame(mp3d, &buf_frame, &frame_info, mp3_stream->channels);
+
+		if (samples_mixed) {
+			p_buffer[p_frames - todo] = AudioFrame(buf_frame[0], buf_frame[samples_mixed - 1]);
+			--todo;
+			++frames_mixed;
+		}
+
+		else {
+			//EOF
+			if (mp3_stream->loop) {
+				seek(mp3_stream->loop_offset);
+				loops++;
+			} else {
+				//fill remainder with silence
+				for (int i = p_frames - todo; i < p_frames; i++) {
+					p_buffer[i] = AudioFrame(0, 0);
+				}
+				active = false;
+				todo = 0;
+			}
+		}
+	}
+}
+
+float AudioStreamPlaybackMP3::get_stream_sampling_rate() {
+	return mp3_stream->sample_rate;
+}
+
+void AudioStreamPlaybackMP3::start(float p_from_pos) {
+	active = true;
+	seek(p_from_pos);
+	loops = 0;
+	_begin_resample();
+}
+
+void AudioStreamPlaybackMP3::stop() {
+	active = false;
+}
+
+bool AudioStreamPlaybackMP3::is_playing() const {
+	return active;
+}
+
+int AudioStreamPlaybackMP3::get_loop_count() const {
+	return loops;
+}
+
+float AudioStreamPlaybackMP3::get_playback_position() const {
+	return float(frames_mixed) / mp3_stream->sample_rate;
+}
+
+void AudioStreamPlaybackMP3::seek(float p_time) {
+	if (!active)
+		return;
+
+	if (p_time >= mp3_stream->get_length()) {
+		p_time = 0;
+	}
+
+	frames_mixed = uint32_t(mp3_stream->sample_rate * p_time);
+	mp3dec_ex_seek(mp3d, frames_mixed * mp3_stream->channels);
+}
+
+AudioStreamPlaybackMP3::~AudioStreamPlaybackMP3() {
+	if (mp3d) {
+		mp3dec_ex_close(mp3d);
+		memfree(mp3d);
+	}
+}
+
+Ref<AudioStreamPlayback> AudioStreamMP3::instance_playback() {
+	Ref<AudioStreamPlaybackMP3> mp3s;
+
+	ERR_FAIL_COND_V(data == nullptr, mp3s);
+
+	mp3s.instance();
+	mp3s->mp3_stream = Ref<AudioStreamMP3>(this);
+	mp3s->mp3d = (mp3dec_ex_t *)memalloc(sizeof(mp3dec_ex_t));
+
+	int errorcode = mp3dec_ex_open_buf(mp3s->mp3d, (const uint8_t *)data, data_len, MP3D_SEEK_TO_SAMPLE);
+
+	mp3s->frames_mixed = 0;
+	mp3s->active = false;
+	mp3s->loops = 0;
+
+	if (errorcode) {
+		ERR_FAIL_COND_V(errorcode, Ref<AudioStreamPlaybackMP3>());
+	}
+
+	return mp3s;
+}
+
+String AudioStreamMP3::get_stream_name() const {
+	return ""; //return stream_name;
+}
+
+void AudioStreamMP3::clear_data() {
+	if (data) {
+		memfree(data);
+		data = nullptr;
+		data_len = 0;
+	}
+}
+
+void AudioStreamMP3::set_data(const Vector<uint8_t> &p_data) {
+	int src_data_len = p_data.size();
+	const uint8_t *src_datar = p_data.ptr();
+
+	mp3dec_ex_t mp3d;
+	mp3dec_ex_open_buf(&mp3d, src_datar, src_data_len, MP3D_SEEK_TO_SAMPLE);
+
+	channels = mp3d.info.channels;
+	sample_rate = mp3d.info.hz;
+	length = float(mp3d.samples) / (sample_rate * float(channels));
+
+	mp3dec_ex_close(&mp3d);
+
+	clear_data();
+
+	data = memalloc(src_data_len);
+	copymem(data, src_datar, src_data_len);
+	data_len = src_data_len;
+}
+
+Vector<uint8_t> AudioStreamMP3::get_data() const {
+	Vector<uint8_t> vdata;
+
+	if (data_len && data) {
+		vdata.resize(data_len);
+		{
+			uint8_t *w = vdata.ptrw();
+			copymem(w, data, data_len);
+		}
+	}
+
+	return vdata;
+}
+
+void AudioStreamMP3::set_loop(bool p_enable) {
+	loop = p_enable;
+}
+
+bool AudioStreamMP3::has_loop() const {
+	return loop;
+}
+
+void AudioStreamMP3::set_loop_offset(float p_seconds) {
+	loop_offset = p_seconds;
+}
+
+float AudioStreamMP3::get_loop_offset() const {
+	return loop_offset;
+}
+
+float AudioStreamMP3::get_length() const {
+	return length;
+}
+
+void AudioStreamMP3::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_data", "data"), &AudioStreamMP3::set_data);
+	ClassDB::bind_method(D_METHOD("get_data"), &AudioStreamMP3::get_data);
+
+	ClassDB::bind_method(D_METHOD("set_loop", "enable"), &AudioStreamMP3::set_loop);
+	ClassDB::bind_method(D_METHOD("has_loop"), &AudioStreamMP3::has_loop);
+
+	ClassDB::bind_method(D_METHOD("set_loop_offset", "seconds"), &AudioStreamMP3::set_loop_offset);
+	ClassDB::bind_method(D_METHOD("get_loop_offset"), &AudioStreamMP3::get_loop_offset);
+
+	ADD_PROPERTY(PropertyInfo(Variant::PACKED_BYTE_ARRAY, "data", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_data", "get_data");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "loop", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_loop", "has_loop");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "loop_offset", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NOEDITOR), "set_loop_offset", "get_loop_offset");
+}
+
+AudioStreamMP3::AudioStreamMP3() {
+}
+
+AudioStreamMP3::~AudioStreamMP3() {
+	clear_data();
+}
diff --git a/modules/minimp3/audio_stream_mp3.h b/modules/minimp3/audio_stream_mp3.h
new file mode 100644
index 0000000000..8d67190ac5
--- /dev/null
+++ b/modules/minimp3/audio_stream_mp3.h
@@ -0,0 +1,110 @@
+/*************************************************************************/
+/*  audio_stream_mp3.h                                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 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 AUDIO_STREAM_MP3_H
+#define AUDIO_STREAM_MP3_H
+
+#include "core/io/resource_loader.h"
+#include "servers/audio/audio_stream.h"
+
+#include "minimp3_ex.h"
+
+class AudioStreamMP3;
+
+class AudioStreamPlaybackMP3 : public AudioStreamPlaybackResampled {
+	GDCLASS(AudioStreamPlaybackMP3, AudioStreamPlaybackResampled);
+
+	mp3dec_ex_t *mp3d = nullptr;
+	uint32_t frames_mixed = 0;
+	bool active = false;
+	int loops = 0;
+
+	friend class AudioStreamMP3;
+
+	Ref<AudioStreamMP3> mp3_stream;
+
+protected:
+	virtual void _mix_internal(AudioFrame *p_buffer, int p_frames) override;
+	virtual float get_stream_sampling_rate() override;
+
+public:
+	virtual void start(float p_from_pos = 0.0) override;
+	virtual void stop() override;
+	virtual bool is_playing() const override;
+
+	virtual int get_loop_count() const override; //times it looped
+
+	virtual float get_playback_position() const override;
+	virtual void seek(float p_time) override;
+
+	AudioStreamPlaybackMP3() {}
+	~AudioStreamPlaybackMP3();
+};
+
+class AudioStreamMP3 : public AudioStream {
+	GDCLASS(AudioStreamMP3, AudioStream);
+	OBJ_SAVE_TYPE(AudioStream) //children are all saved as AudioStream, so they can be exchanged
+	RES_BASE_EXTENSION("mp3str");
+
+	friend class AudioStreamPlaybackMP3;
+
+	void *data = nullptr;
+	uint32_t data_len = 0;
+
+	float sample_rate = 1;
+	int channels = 1;
+	float length = 0;
+	bool loop = false;
+	float loop_offset = 0;
+	void clear_data();
+
+protected:
+	static void _bind_methods();
+
+public:
+	void set_loop(bool p_enable);
+	bool has_loop() const;
+
+	void set_loop_offset(float p_seconds);
+	float get_loop_offset() const;
+
+	virtual Ref<AudioStreamPlayback> instance_playback() override;
+	virtual String get_stream_name() const override;
+
+	void set_data(const Vector<uint8_t> &p_data);
+	Vector<uint8_t> get_data() const;
+
+	virtual float get_length() const override;
+
+	AudioStreamMP3();
+	virtual ~AudioStreamMP3();
+};
+
+#endif // AUDIO_STREAM_MP3_H
diff --git a/modules/minimp3/config.py b/modules/minimp3/config.py
new file mode 100644
index 0000000000..bd35d099b9
--- /dev/null
+++ b/modules/minimp3/config.py
@@ -0,0 +1,16 @@
+def can_build(env, platform):
+    return True
+
+
+def configure(env):
+    pass
+
+
+def get_doc_classes():
+    return [
+        "AudioStreamMP3",
+    ]
+
+
+def get_doc_path():
+    return "doc_classes"
diff --git a/modules/minimp3/doc_classes/AudioStreamMP3.xml b/modules/minimp3/doc_classes/AudioStreamMP3.xml
new file mode 100644
index 0000000000..92e777ca0f
--- /dev/null
+++ b/modules/minimp3/doc_classes/AudioStreamMP3.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="AudioStreamMP3" inherits="AudioStream" version="4.0">
+	<brief_description>
+		MP3 audio stream driver.
+	</brief_description>
+	<description>
+		MP3 audio stream driver.
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+	</methods>
+	<members>
+		<member name="data" type="PackedByteArray" setter="set_data" getter="get_data" default="PackedByteArray(  )">
+			Contains the audio data in bytes.
+		</member>
+		<member name="loop" type="bool" setter="set_loop" getter="has_loop" default="false">
+			If [code]true[/code], the stream will automatically loop when it reaches the end.
+		</member>
+		<member name="loop_offset" type="float" setter="set_loop_offset" getter="get_loop_offset" default="0.0">
+			Time in seconds at which the stream starts after being looped.
+		</member>
+	</members>
+	<constants>
+	</constants>
+</class>
diff --git a/modules/minimp3/register_types.cpp b/modules/minimp3/register_types.cpp
new file mode 100644
index 0000000000..2c648b8efe
--- /dev/null
+++ b/modules/minimp3/register_types.cpp
@@ -0,0 +1,52 @@
+/*************************************************************************/
+/*  register_types.cpp                                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 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 "register_types.h"
+
+#include "audio_stream_mp3.h"
+
+#ifdef TOOLS_ENABLED
+#include "core/config/engine.h"
+#include "resource_importer_mp3.h"
+#endif
+
+void register_minimp3_types() {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		Ref<ResourceImporterMP3> mp3_import;
+		mp3_import.instance();
+		ResourceFormatImporter::get_singleton()->add_importer(mp3_import);
+	}
+#endif
+	ClassDB::register_class<AudioStreamMP3>();
+}
+
+void unregister_minimp3_types() {
+}
diff --git a/modules/minimp3/register_types.h b/modules/minimp3/register_types.h
new file mode 100644
index 0000000000..0d841e4987
--- /dev/null
+++ b/modules/minimp3/register_types.h
@@ -0,0 +1,37 @@
+/*************************************************************************/
+/*  register_types.h                                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 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 MINIMP3_REGISTER_TYPES_H
+#define MINIMP3_REGISTER_TYPES_H
+
+void register_minimp3_types();
+void unregister_minimp3_types();
+
+#endif // MINIMP3_REGISTER_TYPES_H
diff --git a/modules/minimp3/resource_importer_mp3.cpp b/modules/minimp3/resource_importer_mp3.cpp
new file mode 100644
index 0000000000..82e536a755
--- /dev/null
+++ b/modules/minimp3/resource_importer_mp3.cpp
@@ -0,0 +1,104 @@
+/*************************************************************************/
+/*  resource_importer_mp3.cpp                                            */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 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_mp3.h"
+
+#include "core/io/resource_saver.h"
+#include "core/os/file_access.h"
+#include "scene/resources/texture.h"
+
+String ResourceImporterMP3::get_importer_name() const {
+	return "mp3";
+}
+
+String ResourceImporterMP3::get_visible_name() const {
+	return "MP3";
+}
+
+void ResourceImporterMP3::get_recognized_extensions(List<String> *p_extensions) const {
+	p_extensions->push_back("mp3");
+}
+
+String ResourceImporterMP3::get_save_extension() const {
+	return "mp3str";
+}
+
+String ResourceImporterMP3::get_resource_type() const {
+	return "AudioStreamMP3";
+}
+
+bool ResourceImporterMP3::get_option_visibility(const String &p_option, const Map<StringName, Variant> &p_options) const {
+	return true;
+}
+
+int ResourceImporterMP3::get_preset_count() const {
+	return 0;
+}
+
+String ResourceImporterMP3::get_preset_name(int p_idx) const {
+	return String();
+}
+
+void ResourceImporterMP3::get_import_options(List<ImportOption> *r_options, int p_preset) const {
+	r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL, "loop"), true));
+	r_options->push_back(ImportOption(PropertyInfo(Variant::FLOAT, "loop_offset"), 0));
+}
+
+Error ResourceImporterMP3::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, Variant *r_metadata) {
+	bool loop = p_options["loop"];
+	float loop_offset = p_options["loop_offset"];
+
+	FileAccess *f = FileAccess::open(p_source_file, FileAccess::READ);
+
+	ERR_FAIL_COND_V(!f, ERR_CANT_OPEN);
+
+	size_t len = f->get_len();
+
+	Vector<uint8_t> data;
+	data.resize(len);
+	uint8_t *w = data.ptrw();
+
+	f->get_buffer(w, len);
+
+	memdelete(f);
+
+	Ref<AudioStreamMP3> mp3_stream;
+	mp3_stream.instance();
+
+	mp3_stream->set_data(data);
+	ERR_FAIL_COND_V(!mp3_stream->get_data().size(), ERR_FILE_CORRUPT);
+	mp3_stream->set_loop(loop);
+	mp3_stream->set_loop_offset(loop_offset);
+
+	return ResourceSaver::save(p_save_path + ".mp3str", mp3_stream);
+}
+
+ResourceImporterMP3::ResourceImporterMP3() {
+}
diff --git a/modules/minimp3/resource_importer_mp3.h b/modules/minimp3/resource_importer_mp3.h
new file mode 100644
index 0000000000..c1e8315e21
--- /dev/null
+++ b/modules/minimp3/resource_importer_mp3.h
@@ -0,0 +1,58 @@
+/*************************************************************************/
+/*  resource_importer_mp3.h                                              */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 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 RESOURCE_IMPORTER_MP3_H
+#define RESOURCE_IMPORTER_MP3_H
+
+#include "audio_stream_mp3.h"
+#include "core/io/resource_importer.h"
+
+class ResourceImporterMP3 : public ResourceImporter {
+	GDCLASS(ResourceImporterMP3, ResourceImporter);
+
+public:
+	virtual String get_importer_name() const override;
+	virtual String get_visible_name() const override;
+	virtual void get_recognized_extensions(List<String> *p_extensions) const override;
+	virtual String get_save_extension() const override;
+	virtual String get_resource_type() const override;
+
+	virtual int get_preset_count() const override;
+	virtual String get_preset_name(int p_idx) const override;
+
+	virtual void get_import_options(List<ImportOption> *r_options, int p_preset = 0) const override;
+	virtual bool get_option_visibility(const String &p_option, const Map<StringName, Variant> &p_options) const override;
+
+	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 = nullptr, Variant *r_metadata = nullptr) override;
+
+	ResourceImporterMP3();
+};
+
+#endif // RESOURCE_IMPORTER_MP3_H