Add audio transcode functions

transcoder/src/transcode.rs

@@ -3,6 +3,8 @@ use rand::distributions::Alphanumeric;
 use rand::{thread_rng, Rng};
 use serde::Serialize;
 use std::collections::HashMap;
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hasher, Hash};
 use std::path::PathBuf;
 use std::process::Stdio;
 use std::slice::Iter;
@@ -10,10 +12,12 @@ use std::str::FromStr;
 use std::sync::RwLock;
 use tokio::io::{AsyncBufReadExt, BufReader};
 use tokio::process::{Child, Command};
-use tokio::sync::watch::{self, Receiver};
+use tokio::sync::watch;
 
 use crate::utils::Signalable;
 
+const SEGMENT_TIME: u32 = 10;
+
 #[derive(PartialEq, Eq, Serialize, Display)]
 pub enum Quality {
 	#[display(fmt = "240p")]
@@ -119,6 +123,18 @@ impl FromStr for Quality {
 	}
 }
 
+fn get_transcode_audio_args(audio_idx: u32) -> Vec<String> {
+	// TODO: Support multy audio qualities.
+	return vec![
+		"-map".to_string(),
+		format!("0:a:{}", audio_idx),
+		"-c:a".to_string(),
+		"aac".to_string(),
+		"-b:a".to_string(),
+		"128k".to_string(),
+	];
+}
+
 fn get_transcode_video_quality_args(quality: &Quality, segment_time: u32) -> Vec<String> {
 	if *quality == Quality::Original {
 		return vec!["-map", "0:v:0", "-c:v", "copy"]
@@ -156,8 +172,23 @@ fn get_transcode_video_quality_args(quality: &Quality, segment_time: u32) -> Vec
 	.collect()
 }
 
-// TODO: Add audios streams (and transcode them only when necesarry)
-async fn start_transcode(path: String, quality: Quality, start_time: u32) -> TranscodeInfo {
+async fn transcode_audio(path: String, audio: u32) -> TranscodeInfo {
+	let mut hasher = DefaultHasher::new();
+	path.hash(&mut hasher);
+	audio.hash(&mut hasher);
+	let hash = hasher.finish();
+
+	let child = start_transcode(
+		&path,
+		&format!("/cache/{hash}"),
+		get_transcode_audio_args(audio),
+		0,
+	)
+	.await;
+	todo!()
+}
+
+async fn transcode_video(path: String, quality: Quality, start_time: u32) -> TranscodeInfo {
 	// TODO: Use the out path below once cached segments can be reused.
 	// let out_dir = format!("/cache/{show_hash}/{quality}");
 	let uuid: String = thread_rng()
@@ -168,7 +199,26 @@ async fn start_transcode(path: String, quality: Quality, start_time: u32) -> Tra
 	let out_dir = format!("/cache/{uuid}");
 	std::fs::create_dir(&out_dir).expect("Could not create cache directory");
 
-	let segment_time: u32 = 10;
+	let child = start_transcode(
+		&path,
+		&out_dir,
+		get_transcode_video_quality_args(&quality, SEGMENT_TIME),
+		start_time,
+	)
+	.await;
+	TranscodeInfo {
+		show: (path, quality),
+		job: child,
+		uuid,
+	}
+}
+
+async fn start_transcode(
+	path: &String,
+	out_dir: &String,
+	encode_args: Vec<String>,
+	start_time: u32,
+) -> Child {
 	let mut cmd = Command::new("ffmpeg");
 	cmd.args(&["-progress", "pipe:1"])
 		.arg("-nostats")
@@ -181,8 +231,8 @@ async fn start_transcode(path: String, quality: Quality, start_time: u32) -> Tra
 		// .args(&["-hls_allow_cache", "1"])
 		// Keep all segments in the list (else only last X are presents, useful for livestreams)
 		.args(&["-hls_list_size", "0"])
-		.args(&["-hls_time", segment_time.to_string().as_str()])
-		.args(get_transcode_video_quality_args(&quality, segment_time))
+		.args(&["-hls_time", SEGMENT_TIME.to_string().as_str()])
+		.args(&encode_args)
 		.args(&[
 			"-hls_segment_filename".to_string(),
 			format!("{out_dir}/segments-%02d.ts"),
@@ -213,18 +263,10 @@ async fn start_transcode(path: String, quality: Quality, start_time: u32) -> Tra
 	loop {
 		rx.changed().await.unwrap();
 		let ready_time = *rx.borrow();
-		if ready_time >= (1.5 * segment_time as f32) as u32 + start_time {
-			break;
+		if ready_time >= (1.5 * SEGMENT_TIME as f32) as u32 + start_time {
+			return child;
 		}
 	}
-
-	TranscodeInfo {
-		show: (path, quality),
-		job: child,
-		uuid,
-		start_time,
-		ready_time: rx,
-	}
 }
 
 fn get_cache_path(info: &TranscodeInfo) -> PathBuf {
@@ -235,15 +277,10 @@ fn get_cache_path_from_uuid(uuid: &String) -> PathBuf {
 	return PathBuf::from(format!("/cache/{uuid}/", uuid = &uuid));
 }
 
-struct TranscodeInfo {
+pub struct TranscodeInfo {
 	show: (String, Quality),
-	// TODO: Store if the process as ended (probably Option<Child> for the job)
 	job: Child,
 	uuid: String,
-	#[allow(dead_code)]
-	start_time: u32,
-	#[allow(dead_code)]
-	ready_time: Receiver<u32>,
 }
 
 pub struct Transcoder {
@@ -311,7 +348,7 @@ impl Transcoder {
 			}
 		}
 
-		let info = start_transcode(path, quality, start_time).await;
+		let info = transcode_video(path, quality, start_time).await;
 		let mut path = get_cache_path(&info);
 		path.push("stream.m3u8");
 		self.running.write().unwrap().insert(client_id, info);