2 files changed, 47 insertions, 0 deletions
diff --git a/transcoder/src/image.rs b/transcoder/src/image.rs
new file mode 100644
index 0000000..d721e7b
--- /dev/null
+++ b/transcoder/src/image.rs
@@ -0,0 +1,46 @@
+use jellybase::{cache_file, AssetLocationExt};
+use jellycommon::AssetLocation;
+use log::info;
+use rgb::FromSlice;
+use std::{
+    fs::File,
+    io::{BufReader, Write},
+    path::PathBuf,
+};
+
+pub fn transcode(
+    asset: AssetLocation,
+    quality: f32,
+    speed: u8,
+    width: usize,
+) -> anyhow::Result<PathBuf> {
+    let original_path = asset.path();
+    let path = cache_file(&[
+        original_path.as_os_str().to_str().unwrap(),
+        &format!("{width} {quality} {speed}"),
+    ]);
+    if !path.exists() {
+        info!("encoding {path:?} (speed={speed}, quality={quality}, width={width})");
+        let reader = image::io::Reader::new(BufReader::new(File::open(original_path)?))
+            .with_guessed_format()?;
+        let original = reader.decode()?.to_rgba8();
+        let image = image::imageops::resize(
+            &original,
+            width as u32,
+            width as u32 * original.height() / original.width(),
+            image::imageops::FilterType::Lanczos3,
+        );
+        let pixels = image.to_vec();
+        let encoded = ravif::Encoder::new()
+            .with_speed(speed.clamp(1, 10))
+            .with_quality(quality.clamp(1., 100.))
+            .encode_rgba(ravif::Img::new(
+                pixels.as_rgba(),
+                image.width() as usize,
+                image.height() as usize,
+            ))?;
+        info!("writing to cache: {path:?}");
+        File::create(&path)?.write_all(&encoded.avif_file)?;
+    }
+    Ok(path)
+}
diff --git a/transcoder/src/lib.rs b/transcoder/src/lib.rs
index 6ddc2a4..e74a7f5 100644
--- a/transcoder/src/lib.rs
+++ b/transcoder/src/lib.rs
@@ -3,3 +3,4 @@
     which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
     Copyright (C) 2023 metamuffin <metamuffin.org>
 */
+pub mod image;