Implement BPM support

Based on #62896, only implements the BPM support part.

* Implements BPM support in the AudioStreamOGG/MP3 importers.
* Can select BPM/Bar Size and total beats in a song file, as well as edit looping points.
* Looping is now BPM aware
* Added a special importer UI for configuring this.
* Added a special preview showing the audio waveform as well as the playback position in the resource picker.
* Renamed `AudioStream::instance` to `instantiate` for correctness.

7 files changed, 13 insertions, 7 deletions

diff --git a/scene/2d/audio_stream_player_2d.cpp b/scene/2d/audio_stream_player_2d.cpp
index eaab58c4ae..94d22111ea 100644
--- a/scene/2d/audio_stream_player_2d.cpp
+++ b/scene/2d/audio_stream_player_2d.cpp
@@ -69,7 +69,7 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 
 			if (setplay.get() >= 0 && stream.is_valid()) {
 				active.set();
-				Ref<AudioStreamPlayback> new_playback = stream->instance_playback();
+				Ref<AudioStreamPlayback> new_playback = stream->instantiate_playback();
 				ERR_FAIL_COND_MSG(new_playback.is_null(), "Failed to instantiate playback.");
 				AudioServer::get_singleton()->start_playback_stream(new_playback, _get_actual_bus(), volume_vector, setplay.get(), pitch_scale);
 				stream_playbacks.push_back(new_playback);
diff --git a/scene/3d/audio_stream_player_3d.cpp b/scene/3d/audio_stream_player_3d.cpp
index 824ea0407e..65b00742ee 100644
--- a/scene/3d/audio_stream_player_3d.cpp
+++ b/scene/3d/audio_stream_player_3d.cpp
@@ -281,7 +281,7 @@ void AudioStreamPlayer3D::_notification(int p_what) {
 
 			if (setplay.get() >= 0 && stream.is_valid()) {
 				active.set();
-				Ref<AudioStreamPlayback> new_playback = stream->instance_playback();
+				Ref<AudioStreamPlayback> new_playback = stream->instantiate_playback();
 				ERR_FAIL_COND_MSG(new_playback.is_null(), "Failed to instantiate playback.");
 				HashMap<StringName, Vector<AudioFrame>> bus_map;
 				bus_map[_get_actual_bus()] = volume_vector;
diff --git a/scene/audio/audio_stream_player.cpp b/scene/audio/audio_stream_player.cpp
index efb647af29..04debcab05 100644
--- a/scene/audio/audio_stream_player.cpp
+++ b/scene/audio/audio_stream_player.cpp
@@ -136,7 +136,7 @@ void AudioStreamPlayer::play(float p_from_pos) {
 	if (stream->is_monophonic() && is_playing()) {
 		stop();
 	}
-	Ref<AudioStreamPlayback> stream_playback = stream->instance_playback();
+	Ref<AudioStreamPlayback> stream_playback = stream->instantiate_playback();
 	ERR_FAIL_COND_MSG(stream_playback.is_null(), "Failed to instantiate playback.");
 
 	AudioServer::get_singleton()->start_playback_stream(stream_playback, bus, _get_volume_vector(), p_from_pos, pitch_scale);
diff --git a/scene/gui/video_stream_player.cpp b/scene/gui/video_stream_player.cpp
index 86334882fa..f20a2ad67b 100644
--- a/scene/gui/video_stream_player.cpp
+++ b/scene/gui/video_stream_player.cpp
@@ -225,7 +225,7 @@ void VideoStreamPlayer::set_stream(const Ref<VideoStream> &p_stream) {
 	stream = p_stream;
 	if (stream.is_valid()) {
 		stream->set_audio_track(audio_track);
-		playback = stream->instance_playback();
+		playback = stream->instantiate_playback();
 	} else {
 		playback = Ref<VideoStreamPlayback>();
 	}
diff --git a/scene/resources/audio_stream_sample.cpp b/scene/resources/audio_stream_sample.cpp
index 30c222bdff..dcd36284d4 100644
--- a/scene/resources/audio_stream_sample.cpp
+++ b/scene/resources/audio_stream_sample.cpp
@@ -406,6 +406,10 @@ int AudioStreamPlaybackSample::mix(AudioFrame *p_buffer, float p_rate_scale, int
 	return p_frames;
 }
 
+void AudioStreamPlaybackSample::tag_used_streams() {
+	base->tag_used(get_playback_position());
+}
+
 AudioStreamPlaybackSample::AudioStreamPlaybackSample() {}
 
 /////////////////////
@@ -599,7 +603,7 @@ Error AudioStreamSample::save_to_wav(const String &p_path) {
 	return OK;
 }
 
-Ref<AudioStreamPlayback> AudioStreamSample::instance_playback() {
+Ref<AudioStreamPlayback> AudioStreamSample::instantiate_playback() {
 	Ref<AudioStreamPlaybackSample> sample;
 	sample.instantiate();
 	sample->base = Ref<AudioStreamSample>(this);
diff --git a/scene/resources/audio_stream_sample.h b/scene/resources/audio_stream_sample.h
index 357febc27a..2e694cffe2 100644
--- a/scene/resources/audio_stream_sample.h
+++ b/scene/resources/audio_stream_sample.h
@@ -75,6 +75,8 @@ public:
 
 	virtual int mix(AudioFrame *p_buffer, float p_rate_scale, int p_frames) override;
 
+	virtual void tag_used_streams() override;
+
 	AudioStreamPlaybackSample();
 };
 
@@ -144,7 +146,7 @@ public:
 
 	Error save_to_wav(const String &p_path);
 
-	virtual Ref<AudioStreamPlayback> instance_playback() override;
+	virtual Ref<AudioStreamPlayback> instantiate_playback() override;
 	virtual String get_stream_name() const override;
 
 	AudioStreamSample();
diff --git a/scene/resources/video_stream.h b/scene/resources/video_stream.h
index 3e154d539b..e368ffc030 100644
--- a/scene/resources/video_stream.h
+++ b/scene/resources/video_stream.h
@@ -72,7 +72,7 @@ class VideoStream : public Resource {
 
 public:
 	virtual void set_audio_track(int p_track) = 0;
-	virtual Ref<VideoStreamPlayback> instance_playback() = 0;
+	virtual Ref<VideoStreamPlayback> instantiate_playback() = 0;
 };
 
 #endif