From 2882fb286aea349154102d4385fe622b8473b313 Mon Sep 17 00:00:00 2001
From: Dominic <git@msrd0.de>
Date: Wed, 15 Nov 2023 15:44:58 +0100
Subject: [PATCH] support 50fps videos; enable +faststart

---
 230101/project.toml  |  4 +--
 src/render/ffmpeg.rs | 59 ++++++++++++++++++++++++++++++++------------
 src/render/mod.rs    | 28 +++++++++++++++------
 3 files changed, 65 insertions(+), 26 deletions(-)

diff --git a/230101/project.toml b/230101/project.toml
index 3907d26..8fff98f 100644
--- a/230101/project.toml
+++ b/230101/project.toml
@@ -9,8 +9,8 @@ end = "12"
 fast = [["5", "7"], ["9", "11"]]
 
 [source.metadata]
-source_duration = "12.533330"
-source_fps = "25/1"
+source_duration = "12.53333"
+source_fps = "50/1"
 source_tbn = "1/12800"
 source_res = "FullHD"
 source_sample_rate = 48000
diff --git a/src/render/ffmpeg.rs b/src/render/ffmpeg.rs
index 86f6f20..63657cd 100644
--- a/src/render/ffmpeg.rs
+++ b/src/render/ffmpeg.rs
@@ -50,25 +50,60 @@ impl FfmpegInput {
 	}
 }
 
+pub(crate) struct FfmpegOutput {
+	pub(crate) fps: Option<Rational>,
+	pub(crate) duration: Option<Time>,
+	pub(crate) time_base: Option<Rational>,
+	pub(crate) fps_mode_vfr: bool,
+	pub(crate) path: PathBuf
+}
+
+impl FfmpegOutput {
+	pub(crate) fn new(path: PathBuf) -> Self {
+		Self {
+			fps: None,
+			duration: None,
+			time_base: None,
+			fps_mode_vfr: false,
+			path
+		}
+	}
+
+	fn append_to_cmd(self, cmd: &mut Command) {
+		if let Some(fps) = self.fps {
+			cmd.arg("-r").arg(fps.to_string());
+		}
+		if let Some(duration) = self.duration {
+			cmd.arg("-t").arg(format_time(duration));
+		}
+		if let Some(time_base) = self.time_base {
+			cmd.arg("-enc_time_base").arg(time_base.to_string());
+		}
+		if self.fps_mode_vfr {
+			cmd.arg("-fps_mode").arg("vfr");
+		}
+		cmd.arg("-movflags").arg("+faststart");
+		cmd.arg(self.path);
+	}
+}
+
 pub(crate) struct Ffmpeg {
 	inputs: Vec<FfmpegInput>,
 	filters: Vec<Filter>,
 	filters_output: Cow<'static, str>,
 	loudnorm: bool,
-	duration: Option<Time>,
-	output: PathBuf,
+	output: FfmpegOutput,
 
 	filter_idx: usize
 }
 
 impl Ffmpeg {
-	pub fn new(output: PathBuf) -> Self {
+	pub fn new(output: FfmpegOutput) -> Self {
 		Self {
 			inputs: Vec::new(),
 			filters: Vec::new(),
 			filters_output: "0".into(),
 			loudnorm: false,
-			duration: None,
 			output,
 
 			filter_idx: 0
@@ -100,11 +135,6 @@ impl Ffmpeg {
 		self
 	}
 
-	pub fn set_duration(&mut self, duration: Time) -> &mut Self {
-		self.duration = Some(duration);
-		self
-	}
-
 	pub fn run(mut self) -> anyhow::Result<()> {
 		let mut cmd = cmd();
 		cmd.arg("ffmpeg").arg("-hide_banner").arg("-y");
@@ -157,13 +187,14 @@ impl Ffmpeg {
 		}
 
 		// append encoding options
+		const QUALITY: &str = "24";
 		if vaapi {
 			cmd.arg("-c:v").arg("h264_vaapi");
 			cmd.arg("-rc_mode").arg("CQP");
-			cmd.arg("-global_quality").arg("24");
+			cmd.arg("-global_quality").arg(QUALITY);
 		} else if venc {
 			cmd.arg("-c:v").arg("libx264");
-			cmd.arg("-crf").arg("22");
+			cmd.arg("-crf").arg(QUALITY);
 		} else {
 			cmd.arg("-c:v").arg("copy");
 		}
@@ -174,11 +205,7 @@ impl Ffmpeg {
 			cmd.arg("-c:a").arg("copy");
 		}
 
-		if let Some(duration) = self.duration {
-			cmd.arg("-t").arg(format_time(duration));
-		}
-		cmd.arg("-movflags").arg("+faststart");
-		cmd.arg(&self.output);
+		self.output.append_to_cmd(&mut cmd);
 
 		let status = cmd.status()?;
 		if status.success() {
diff --git a/src/render/mod.rs b/src/render/mod.rs
index 5e4257c..a4fafec 100644
--- a/src/render/mod.rs
+++ b/src/render/mod.rs
@@ -3,7 +3,7 @@
 pub mod ffmpeg;
 mod filter;
 
-use self::filter::Filter;
+use self::{ffmpeg::FfmpegOutput, filter::Filter};
 use crate::{
 	iotro::{intro, outro},
 	render::ffmpeg::{Ffmpeg, FfmpegInput},
@@ -117,10 +117,22 @@ pub(crate) struct Renderer<'a> {
 	target: PathBuf
 }
 
-fn svg2mp4(svg: PathBuf, mp4: PathBuf, duration: Time) -> anyhow::Result<()> {
-	let mut ffmpeg = Ffmpeg::new(mp4);
+fn svg2mp4(
+	meta: &ProjectSourceMetadata,
+	svg: PathBuf,
+	mp4: PathBuf,
+	duration: Time
+) -> anyhow::Result<()> {
+	let mut ffmpeg = Ffmpeg::new(FfmpegOutput {
+		fps: None,
+		duration: Some(duration),
+		time_base: Some(meta.source_tbn),
+		fps_mode_vfr: true,
+		path: mp4
+	});
 	ffmpeg.add_input(FfmpegInput {
 		loop_input: true,
+		fps: Some(meta.source_fps),
 		..FfmpegInput::new(svg)
 	});
 	ffmpeg.add_filter(Filter::GenerateSilence {
@@ -128,7 +140,6 @@ fn svg2mp4(svg: PathBuf, mp4: PathBuf, duration: Time) -> anyhow::Result<()> {
 		output: "out".into()
 	});
 	ffmpeg.set_filter_output("out");
-	ffmpeg.set_duration(duration);
 	ffmpeg.run()
 }
 
@@ -185,7 +196,7 @@ impl<'a> Renderer<'a> {
 		let source_sample_rate =
 			ffprobe_audio("stream=sample_rate", &recording_txt)?.parse()?;
 		let recording_mp4 = self.recording_mp4();
-		let mut ffmpeg = Ffmpeg::new(recording_mp4.clone());
+		let mut ffmpeg = Ffmpeg::new(FfmpegOutput::new(recording_mp4.clone()));
 		ffmpeg.add_input(FfmpegInput {
 			concat: true,
 			..FfmpegInput::new(recording_txt)
@@ -210,6 +221,7 @@ impl<'a> Renderer<'a> {
 			source_res,
 			source_sample_rate
 		});
+		let metadata = project.source.metadata.as_ref().unwrap();
 
 		println!("\x1B[1m ==> Preparing assets ...\x1B[0m");
 
@@ -222,7 +234,7 @@ impl<'a> Renderer<'a> {
 				.into_bytes()
 		)?;
 		let intro_mp4 = self.target.join("intro.mp4");
-		svg2mp4(intro_svg, intro_mp4, INTRO_LEN)?;
+		svg2mp4(metadata, intro_svg, intro_mp4, INTRO_LEN)?;
 
 		// render outro to svg then mp4
 		let outro_svg = self.target.join("outro.svg");
@@ -231,7 +243,7 @@ impl<'a> Renderer<'a> {
 			outro(source_res).to_string_pretty().into_bytes()
 		)?;
 		let outro_mp4 = self.target.join("outro.mp4");
-		svg2mp4(outro_svg, outro_mp4, OUTRO_LEN)?;
+		svg2mp4(metadata, outro_svg, outro_mp4, OUTRO_LEN)?;
 
 		// copy logo then render to png
 		let logo_svg = self.target.join("logo.svg");
@@ -272,7 +284,7 @@ impl<'a> Renderer<'a> {
 
 	pub(crate) fn render(&self, project: &mut Project) -> anyhow::Result<PathBuf> {
 		let output = self.video_mp4(project);
-		let mut ffmpeg = Ffmpeg::new(output.clone());
+		let mut ffmpeg = Ffmpeg::new(FfmpegOutput::new(output.clone()));
 
 		// add all of our inputs
 		let intro = ffmpeg.add_input(FfmpegInput::new(self.target.join("intro.mp4")));