1 files changed, 102 insertions, 0 deletions
diff --git a/transcoder/src/fragment.rs b/transcoder/src/fragment.rs
new file mode 100644
index 0000000..90512c4
--- /dev/null
+++ b/transcoder/src/fragment.rs
@@ -0,0 +1,102 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2024 metamuffin <metamuffin.org>
+*/
+
+use crate::LOCAL_VIDEO_TRANSCODING_TASKS;
+use jellybase::cache::{async_cache_file, CachePath};
+use jellycommon::jhls::EncodingProfile;
+use log::{debug, info};
+use std::process::Stdio;
+use tokio::{
+    io::copy,
+    process::{ChildStdin, Command},
+};
+
+// TODO odd video resolutions can cause errors when transcoding to YUV42{0,2}
+// TODO with an implementation that cant handle it (SVT-AV1 such an impl).
+
+pub async fn transcode(
+    key: &str,
+    enc: &EncodingProfile,
+    input: impl FnOnce(ChildStdin),
+) -> anyhow::Result<CachePath> {
+    Ok(async_cache_file(
+        &["snip-tc", key, &format!("{enc:?}")],
+        move |mut output| async move {
+            let _permit = LOCAL_VIDEO_TRANSCODING_TASKS.acquire().await?;
+            debug!("transcoding snippet with {enc:?}");
+
+            let mut args = Vec::new();
+            match enc {
+                EncodingProfile::Video {
+                    codec,
+                    preset,
+                    bitrate,
+                    width,
+                } => {
+                    if let Some(width) = width {
+                        args.push("-vf".to_string());
+                        args.push(format!("scale={width}:-1"));
+                    }
+                    args.push("-c:v".to_string());
+                    args.push(codec.to_string());
+                    if let Some(preset) = preset {
+                        args.push("-preset".to_string());
+                        args.push(format!("{preset}"));
+                    }
+                    args.push("-b:v".to_string());
+                    args.push(format!("{bitrate}"));
+                }
+                EncodingProfile::Audio {
+                    codec,
+                    bitrate,
+                    sample_rate,
+                    channels,
+                } => {
+                    if let Some(channels) = channels {
+                        args.push("-ac".to_string());
+                        args.push(format!("{channels}"))
+                    }
+                    if let Some(sample_rate) = sample_rate {
+                        args.push("-ar".to_string());
+                        args.push(format!("{sample_rate}"))
+                    }
+                    args.push("-c:a".to_string());
+                    args.push(codec.to_string());
+                    args.push("-b:a".to_string());
+                    args.push(format!("{bitrate}"));
+                }
+                EncodingProfile::Subtitles { codec } => {
+                    args.push("-c:s".to_string());
+                    args.push(codec.to_string());
+                }
+            };
+            info!("encoding with {:?}", args.join(" "));
+
+            let mut proc = Command::new("ffmpeg")
+                .stdin(Stdio::piped())
+                .stdout(Stdio::piped())
+                .args(&["-f", "matroska", "-i", "pipe:0"])
+                .args(args)
+                .args(&["-f", "webm", "pipe:1"])
+                .spawn()?;
+            // let mut proc = Command::new("cat")
+            //     .stdin(Stdio::piped())
+            //     .stdout(Stdio::piped())
+            //     .spawn()?;
+
+            let stdin = proc.stdin.take().unwrap();
+            let mut stdout = proc.stdout.take().unwrap();
+
+            input(stdin);
+            copy(&mut stdout, &mut output).await?;
+
+            proc.wait().await.unwrap().exit_ok()?;
+            info!("done");
+            Ok(())
+        },
+    )
+    .await?)
+}