Add property hints to MovieWriter settings

- Rename audio mix rate setting as the suffix is now part of the
  property hint. This is also more consistent with existing mix rate
  project settings.
- Improve the MovieWriter class reference.
- Tweak warning message about audio possibly going out of sync.

doc/classes/MovieWriter.xml

@@ -6,8 +6,8 @@
 	<description>
 		Godot can record videos with non-real-time simulation. Like the [code]--fixed-fps[/code] command line argument, this forces the reported [code]delta[/code] in [method Node._process] functions to be identical across frames, regardless of how long it actually took to render the frame. This can be used to record high-quality videos with perfect frame pacing regardless of your hardware's capabilities.
 		Godot has 2 built-in [MovieWriter]s:
-		- AVI container with MJPEG for video and uncompressed audio ([code].avi[/code] file extension). Lossy compression, medium file sizes, fast encoding. The lossy compression quality can be adjusted by changing [member ProjectSettings.editor/movie_writer/mjpeg_quality]. The resulting file can be viewed in most video players, but it must be converted to another format for viewing on the web or by Godot with [VideoStreamPlayer]. AVI output is currently limited to a file of 4 GB in size at most.
-		- PNG image sequence for video and WAV for audio ([code].png[/code] file extension). Lossless compression, large file sizes, slow encoding. Designed to be encoded to a video file with another tool such as [url=https://ffmpeg.org/]FFmpeg[/url] after recording. Transparency is currently not supported.
+		- AVI container with MJPEG for video and uncompressed audio ([code].avi[/code] file extension). Lossy compression, medium file sizes, fast encoding. The lossy compression quality can be adjusted by changing [member ProjectSettings.editor/movie_writer/mjpeg_quality]. The resulting file can be viewed in most video players, but it must be converted to another format for viewing on the web or by Godot with [VideoStreamPlayer]. MJPEG does not support transparency. AVI output is currently limited to a file of 4 GB in size at most.
+		- PNG image sequence for video and WAV for audio ([code].png[/code] file extension). Lossless compression, large file sizes, slow encoding. Designed to be encoded to a video file with another tool such as [url=https://ffmpeg.org/]FFmpeg[/url] after recording. Transparency is currently not supported, even if the root viewport is set to be transparent.
 		If you need to encode to a different format or pipe a stream through third-party software, you can extend the [MovieWriter] class to create your own movie writers. This should typically be done using GDExtension for performance reasons.
 		[b]Editor usage:[/b] A default movie file path can be specified in [member ProjectSettings.editor/movie_writer/movie_file]. Alternatively, for running single scenes, a [code]movie_path[/code] metadata can be added to the root node, specifying the path to a movie file that will be used when recording that scene. Once a path is set, click the video reel icon in the top-right corner of the editor to enable Movie Maker mode, then run any scene as usual. The engine will start recording as soon as the splash screen is finished, and it will only stop recording when the engine quits. Click the video reel icon again to disable Movie Maker mode. Note that toggling Movie Maker mode does not affect project instances that are already running.
 		[b]Note:[/b] MovieWriter is available for use in both the editor and exported projects, but it is [i]not[/i] designed for use by end users to record videos while playing. Players wishing to record gameplay videos should install tools such as [url=https://obsproject.com/]OBS Studio[/url] or [url=https://www.maartenbaert.be/simplescreenrecorder/]SimpleScreenRecorder[/url] instead.

doc/classes/ProjectSettings.xml

@@ -558,22 +558,21 @@
 			[b]Note:[/b] [member editor/movie_writer/disable_vsync] has no effect if the operating system or graphics driver forces V-Sync with no way for applications to disable it.
 		</member>
 		<member name="editor/movie_writer/fps" type="int" setter="" getter="" default="60">
-			The number of frames per second to record in the video when writing a movie. Simulation speed will adjust to always match the specified framerate, which means the engine will appear to run slower at higher [member editor/movie_writer/fps] values. Certain FPS values will require you to adjust [member editor/movie_writer/mix_rate_hz] to prevent audio from desynchronizing over time.
+			The number of frames per second to record in the video when writing a movie. Simulation speed will adjust to always match the specified framerate, which means the engine will appear to run slower at higher [member editor/movie_writer/fps] values. Certain FPS values will require you to adjust [member editor/movie_writer/mix_rate] to prevent audio from desynchronizing over time.
 			This can be specified manually on the command line using the [code]--fixed-fps &lt;fps&gt;[/code] command line argument.
 		</member>
-		<member name="editor/movie_writer/mix_rate_hz" type="int" setter="" getter="" default="48000">
+		<member name="editor/movie_writer/mix_rate" type="int" setter="" getter="" default="48000">
 			The audio mix rate to use in the recorded audio when writing a movie (in Hz). This can be different from [member audio/driver/mix_rate], but this value must be divisible by [member editor/movie_writer/fps] to prevent audio from desynchronizing over time.
 		</member>
 		<member name="editor/movie_writer/mjpeg_quality" type="float" setter="" getter="" default="0.75">
-			The JPEG quality to use when writing a video to an AVI file, between [code]0.01[/code] and [code]1.0[/code] (inclusive). Higher [code]quality[/code] values result in better-looking output at the cost of larger file sizes. Recommended [code]quality[/code] values are between [code]0.75[/code] and [code]0.90[/code]. Even at quality [code]1.00[/code], JPEG compression remains lossy.
-			[b]Note:[/b] JPEG does not saving an alpha channel. If the [Image] contains an alpha channel, the image will still be saved, but the resulting JPEG file won't contain the alpha channel.
+			The JPEG quality to use when writing a video to an AVI file, between [code]0.01[/code] and [code]1.0[/code] (inclusive). Higher [code]quality[/code] values result in better-looking output at the cost of larger file sizes. Recommended [code]quality[/code] values are between [code]0.75[/code] and [code]0.9[/code]. Even at quality [code]1.0[/code], JPEG compression remains lossy.
 			[b]Note:[/b] This does not affect the audio quality or writing PNG image sequences.
 		</member>
 		<member name="editor/movie_writer/movie_file" type="String" setter="" getter="" default="&quot;&quot;">
 			The output path for the movie. The file extension determines the [MovieWriter] that will be used.
 			Godot has 2 built-in [MovieWriter]s:
-			- AVI container with MJPEG for video and uncompressed audio ([code].avi[/code] file extension). Lossy compression, medium file sizes, fast encoding. The lossy compression quality can be adjusted by changing [member ProjectSettings.editor/movie_writer/mjpeg_quality]. The resulting file can be viewed in most video players, but it must be converted to another format for viewing on the web or by Godot with [VideoStreamPlayer]. AVI output is currently limited to a file of 4 GB in size at most.
-			- PNG image sequence for video and WAV for audio ([code].png[/code] file extension). Lossless compression, large file sizes, slow encoding. Designed to be encoded to a video file with another tool such as [url=https://ffmpeg.org/]FFmpeg[/url] after recording. Transparency is currently not supported.
+			- AVI container with MJPEG for video and uncompressed audio ([code].avi[/code] file extension). Lossy compression, medium file sizes, fast encoding. The lossy compression quality can be adjusted by changing [member ProjectSettings.editor/movie_writer/mjpeg_quality]. The resulting file can be viewed in most video players, but it must be converted to another format for viewing on the web or by Godot with [VideoStreamPlayer]. MJPEG does not support transparency. AVI output is currently limited to a file of 4 GB in size at most.
+			- PNG image sequence for video and WAV for audio ([code].png[/code] file extension). Lossless compression, large file sizes, slow encoding. Designed to be encoded to a video file with another tool such as [url=https://ffmpeg.org/]FFmpeg[/url] after recording. Transparency is currently not supported, even if the root viewport is set to be transparent.
 			If you need to encode to a different format or pipe a stream through third-party software, you can extend this [MovieWriter] class to create your own movie writers.
 			When using PNG output, the frame number will be appended at the end of the file name. It starts from 0 and is padded with 8 digits to ensure correct sorting and easier processing. For example, if the output path is [code]/tmp/hello.png[/code], the first two frames will be [code]/tmp/hello00000000.png[/code] and [code]/tmp/hello00000001.png[/code]. The audio will be saved at [code]/tmp/hello.wav[/code].
 		</member>

servers/movie_writer/movie_writer.cpp

@@ -107,7 +107,7 @@ void MovieWriter::begin(const Size2i &p_movie_size, uint32_t p_fps, const String
 	AudioDriverDummy::get_dummy_singleton()->set_speaker_mode(AudioDriver::SpeakerMode(get_audio_speaker_mode()));
 	fps = p_fps;
 	if ((mix_rate % fps) != 0) {
-		WARN_PRINT("Audio mix rate (" + itos(mix_rate) + ") can not be divided by fps (" + itos(fps) + "). Audio may go out of sync over time.");
+		WARN_PRINT("MovieWriter's audio mix rate (" + itos(mix_rate) + ") can not be divided by the recording FPS (" + itos(fps) + "). Audio may go out of sync over time.");
 	}
 
 	audio_channels = AudioDriverDummy::get_dummy_singleton()->get_channels();
@@ -128,15 +128,17 @@ void MovieWriter::_bind_methods() {
 	GDVIRTUAL_BIND(_write_frame, "frame_image", "audio_frame_block")
 	GDVIRTUAL_BIND(_write_end)
 
-	GLOBAL_DEF("editor/movie_writer/mix_rate_hz", 48000);
+	GLOBAL_DEF("editor/movie_writer/mix_rate", 48000);
+	ProjectSettings::get_singleton()->set_custom_property_info("editor/movie_writer/mix_rate", PropertyInfo(Variant::INT, "editor/movie_writer/mix_rate", PROPERTY_HINT_RANGE, "8000,192000,1,suffix:Hz"));
 	GLOBAL_DEF("editor/movie_writer/speaker_mode", 0);
 	ProjectSettings::get_singleton()->set_custom_property_info("editor/movie_writer/speaker_mode", PropertyInfo(Variant::INT, "editor/movie_writer/speaker_mode", PROPERTY_HINT_ENUM, "Stereo,3.1,5.1,7.1"));
 	GLOBAL_DEF("editor/movie_writer/mjpeg_quality", 0.75);
+	ProjectSettings::get_singleton()->set_custom_property_info("editor/movie_writer/mjpeg_quality", PropertyInfo(Variant::FLOAT, "editor/movie_writer/mjpeg_quality", PROPERTY_HINT_RANGE, "0.01,1.0,0.01"));
 	// used by the editor
 	GLOBAL_DEF_BASIC("editor/movie_writer/movie_file", "");
 	GLOBAL_DEF_BASIC("editor/movie_writer/disable_vsync", false);
 	GLOBAL_DEF_BASIC("editor/movie_writer/fps", 60);
-	ProjectSettings::get_singleton()->set_custom_property_info("editor/movie_writer/fps", PropertyInfo(Variant::INT, "editor/movie_writer/fps", PROPERTY_HINT_RANGE, "1,300,1"));
+	ProjectSettings::get_singleton()->set_custom_property_info("editor/movie_writer/fps", PropertyInfo(Variant::INT, "editor/movie_writer/fps", PROPERTY_HINT_RANGE, "1,300,1,suffix:FPS"));
 }
 
 void MovieWriter::set_extensions_hint() {
@@ -301,6 +303,6 @@ void MovieWriterPNGWAV::write_end() {
 }
 
 MovieWriterPNGWAV::MovieWriterPNGWAV() {
-	mix_rate = GLOBAL_GET("editor/movie_writer/mix_rate_hz");
+	mix_rate = GLOBAL_GET("editor/movie_writer/mix_rate");
 	speaker_mode = AudioServer::SpeakerMode(int(GLOBAL_GET("editor/movie_writer/speaker_mode")));
 }

servers/movie_writer/movie_writer_mjpeg.cpp

@@ -257,7 +257,7 @@ void MovieWriterMJPEG::write_end() {
 }
 
 MovieWriterMJPEG::MovieWriterMJPEG() {
-	mix_rate = GLOBAL_GET("editor/movie_writer/mix_rate_hz");
+	mix_rate = GLOBAL_GET("editor/movie_writer/mix_rate");
 	speaker_mode = AudioServer::SpeakerMode(int(GLOBAL_GET("editor/movie_writer/speaker_mode")));
 	quality = GLOBAL_GET("editor/movie_writer/mjpeg_quality");
 }