Add AudioEffectCapture

AudioEffectCapture allows access to the microphone and other audio on an audio bus in real-time.

Co-Authored-By: K. S. Ernest (iFire) Lee <ernest.lee@chibifire.com>

2 files changed, 222 insertions, 0 deletions

diff --git a/servers/audio/effects/audio_effect_capture.cpp b/servers/audio/effects/audio_effect_capture.cpp
new file mode 100644
index 0000000000..f37938eec8
--- /dev/null
+++ b/servers/audio/effects/audio_effect_capture.cpp
@@ -0,0 +1,140 @@
+/*************************************************************************/
+/*  audio_effect_capture.cpp                                             */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 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 "audio_effect_capture.h"
+
+bool AudioEffectCapture::can_get_buffer(int p_frames) const {
+	return buffer.data_left() >= p_frames;
+}
+
+PackedVector2Array AudioEffectCapture::get_buffer(int p_frames) {
+	ERR_FAIL_COND_V(!buffer_initialized, PackedVector2Array());
+	ERR_FAIL_INDEX_V(p_frames, buffer.size(), PackedVector2Array());
+	int data_left = buffer.data_left();
+	if (data_left < p_frames || p_frames == 0) {
+		return PackedVector2Array();
+	}
+
+	PackedVector2Array ret;
+	ret.resize(p_frames);
+
+	Vector<AudioFrame> streaming_data;
+	streaming_data.resize(p_frames);
+	buffer.read(streaming_data.ptrw(), p_frames);
+	for (int32_t i = 0; i < p_frames; i++) {
+		ret.write[i] = Vector2(streaming_data[i].l, streaming_data[i].r);
+	}
+	return ret;
+}
+
+void AudioEffectCapture::clear_buffer() {
+	const int32_t data_left = buffer.data_left();
+	buffer.advance_read(data_left);
+}
+
+void AudioEffectCapture::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("can_get_buffer", "frames"), &AudioEffectCapture::can_get_buffer);
+	ClassDB::bind_method(D_METHOD("get_buffer", "frames"), &AudioEffectCapture::get_buffer);
+	ClassDB::bind_method(D_METHOD("clear_buffer"), &AudioEffectCapture::clear_buffer);
+	ClassDB::bind_method(D_METHOD("set_buffer_length", "buffer_length_seconds"), &AudioEffectCapture::set_buffer_length);
+	ClassDB::bind_method(D_METHOD("get_buffer_length"), &AudioEffectCapture::get_buffer_length);
+	ClassDB::bind_method(D_METHOD("get_frames_available"), &AudioEffectCapture::get_frames_available);
+	ClassDB::bind_method(D_METHOD("get_discarded_frames"), &AudioEffectCapture::get_discarded_frames);
+	ClassDB::bind_method(D_METHOD("get_buffer_length_frames"), &AudioEffectCapture::get_buffer_length_frames);
+	ClassDB::bind_method(D_METHOD("get_pushed_frames"), &AudioEffectCapture::get_pushed_frames);
+
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "buffer_length", PROPERTY_HINT_RANGE, "0.01,10,0.01"), "set_buffer_length", "get_buffer_length");
+}
+
+Ref<AudioEffectInstance> AudioEffectCapture::instance() {
+	if (!buffer_initialized) {
+		float target_buffer_size = AudioServer::get_singleton()->get_mix_rate() * buffer_length_seconds;
+		ERR_FAIL_COND_V(target_buffer_size <= 0 || target_buffer_size >= (1 << 27), Ref<AudioEffectInstance>());
+		buffer.resize(nearest_shift((int)target_buffer_size));
+		buffer_initialized = true;
+	}
+
+	clear_buffer();
+
+	Ref<AudioEffectCaptureInstance> ins;
+	ins.instance();
+	ins->base = Ref<AudioEffectCapture>(this);
+
+	return ins;
+}
+
+void AudioEffectCapture::set_buffer_length(float p_buffer_length_seconds) {
+	ERR_FAIL_COND(buffer_initialized);
+
+	buffer_length_seconds = p_buffer_length_seconds;
+}
+
+float AudioEffectCapture::get_buffer_length() {
+	return buffer_length_seconds;
+}
+
+int AudioEffectCapture::get_frames_available() const {
+	ERR_FAIL_COND_V(!buffer_initialized, 0);
+	return buffer.data_left();
+}
+
+int64_t AudioEffectCapture::get_discarded_frames() const {
+	return discarded_frames;
+}
+
+int AudioEffectCapture::get_buffer_length_frames() const {
+	ERR_FAIL_COND_V(!buffer_initialized, 0);
+	return buffer.size();
+}
+
+int64_t AudioEffectCapture::get_pushed_frames() const {
+	return pushed_frames;
+}
+
+void AudioEffectCaptureInstance::process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count) {
+	RingBuffer<AudioFrame> &buffer = base->buffer;
+
+	for (int i = 0; i < p_frame_count; i++) {
+		p_dst_frames[i] = p_src_frames[i];
+	}
+
+	if (buffer.space_left() >= p_frame_count) {
+		// Add incoming audio frames to the IO ring buffer
+		int32_t ret = buffer.write(p_src_frames, p_frame_count);
+		ERR_FAIL_COND_MSG(ret != p_frame_count, "Failed to add data to effect capture ring buffer despite sufficient space.");
+		atomic_add(&base->pushed_frames, p_frame_count);
+	} else {
+		atomic_add(&base->discarded_frames, p_frame_count);
+	}
+}
+
+bool AudioEffectCaptureInstance::process_silence() const {
+	return true;
+}
diff --git a/servers/audio/effects/audio_effect_capture.h b/servers/audio/effects/audio_effect_capture.h
new file mode 100644
index 0000000000..b154be85de
--- /dev/null
+++ b/servers/audio/effects/audio_effect_capture.h
@@ -0,0 +1,82 @@
+/*************************************************************************/
+/*  audio_effect_capture.h                                               */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 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_EFFECT_CAPTURE_H
+#define AUDIO_EFFECT_CAPTURE_H
+
+#include "core/config/engine.h"
+#include "core/math/audio_frame.h"
+#include "core/object/reference.h"
+#include "core/templates/vector.h"
+#include "servers/audio/audio_effect.h"
+#include "servers/audio_server.h"
+
+class AudioEffectCapture;
+
+class AudioEffectCaptureInstance : public AudioEffectInstance {
+	GDCLASS(AudioEffectCaptureInstance, AudioEffectInstance);
+	friend class AudioEffectCapture;
+	Ref<AudioEffectCapture> base;
+
+public:
+	virtual void process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count) override;
+	virtual bool process_silence() const override;
+};
+
+class AudioEffectCapture : public AudioEffect {
+	GDCLASS(AudioEffectCapture, AudioEffect)
+	friend class AudioEffectCaptureInstance;
+
+	RingBuffer<AudioFrame> buffer;
+	uint64_t discarded_frames = 0;
+	uint64_t pushed_frames = 0;
+	float buffer_length_seconds = 0.1f;
+	bool buffer_initialized = false;
+
+protected:
+	static void _bind_methods();
+
+public:
+	virtual Ref<AudioEffectInstance> instance() override;
+
+	void set_buffer_length(float p_buffer_length_seconds);
+	float get_buffer_length();
+
+	bool can_get_buffer(int p_frames) const;
+	PackedVector2Array get_buffer(int p_len);
+	void clear_buffer();
+
+	int get_frames_available() const;
+	int64_t get_discarded_frames() const;
+	int get_buffer_length_frames() const;
+	int64_t get_pushed_frames() const;
+};
+
+#endif // AUDIO_EFFECT_CAPTURE_H