diff --git a/src/background/media_metadata.rs b/src/background/media_metadata.rs
new file mode 100644
index 0000000..205011a
--- /dev/null
+++ b/src/background/media_metadata.rs
@@ -0,0 +1,93 @@
+use crate::db::{Database, FileUpload};
+use crate::filesystem::FileStore;
+use crate::processing::probe_file;
+use anyhow::Result;
+use log::{error, info, warn};
+
+pub struct MediaMetadata {
+    db: Database,
+    fs: FileStore,
+}
+
+impl MediaMetadata {
+    pub fn new(db: Database, fs: FileStore) -> Self {
+        Self { db, fs }
+    }
+
+    pub async fn process(&mut self) -> Result<()> {
+        let to_migrate = self.db.get_missing_media_metadata().await?;
+
+        info!("{} files are missing metadata", to_migrate.len());
+
+        for file in to_migrate {
+            // probe file and update metadata
+            let path = self.fs.get(&file.id);
+            if let Ok(data) = probe_file(&path) {
+                let bv = data.best_video();
+                let duration = if data.duration < 0.0 {
+                    None
+                } else {
+                    Some(data.duration)
+                };
+                let bitrate = if data.bitrate == 0 {
+                    None
+                } else {
+                    Some(data.bitrate as u32)
+                };
+                info!(
+                    "Updating metadata: id={}, dim={}x{}, dur={}, br={}",
+                    hex::encode(&file.id),
+                    bv.map(|v| v.width).unwrap_or(0),
+                    bv.map(|v| v.height).unwrap_or(0),
+                    duration.unwrap_or(0.0),
+                    bitrate.unwrap_or(0)
+                );
+                if let Err(e) = self
+                    .db
+                    .update_metadata(
+                        &file.id,
+                        bv.map(|v| v.width as u32),
+                        bv.map(|v| v.height as u32),
+                        duration,
+                        bitrate,
+                    )
+                    .await
+                {
+                    error!("Failed to update metadata: {}", e);
+                }
+            } else {
+                warn!("Skipping missing file: {}", hex::encode(&file.id));
+            }
+        }
+        Ok(())
+    }
+}
+
+impl Database {
+    pub async fn get_missing_media_metadata(&mut self) -> Result<Vec<FileUpload>> {
+        let results: Vec<FileUpload> = sqlx::query_as("select * from uploads where (width is null or height is null or bitrate is null or duration is null) and (mime_type like 'image/%' or mime_type like 'video/%')")
+            .fetch_all(&self.pool)
+            .await?;
+
+        Ok(results)
+    }
+
+    pub async fn update_metadata(
+        &mut self,
+        id: &Vec<u8>,
+        width: Option<u32>,
+        height: Option<u32>,
+        duration: Option<f32>,
+        bitrate: Option<u32>,
+    ) -> Result<()> {
+        sqlx::query("update uploads set width=?, height=?, duration=?, bitrate=? where id=?")
+            .bind(width)
+            .bind(height)
+            .bind(duration)
+            .bind(bitrate)
+            .bind(id)
+            .execute(&self.pool)
+            .await?;
+        Ok(())
+    }
+}
diff --git a/src/background/mod.rs b/src/background/mod.rs
new file mode 100644
index 0000000..39dbbef
--- /dev/null
+++ b/src/background/mod.rs
@@ -0,0 +1,24 @@
+use crate::db::Database;
+use crate::filesystem::FileStore;
+use anyhow::Result;
+use log::info;
+use tokio::task::JoinHandle;
+
+#[cfg(feature = "media-compression")]
+mod media_metadata;
+
+pub fn start_background_tasks(db: Database, file_store: FileStore) -> Vec<JoinHandle<Result<()>>> {
+    let mut ret = vec![];
+
+    #[cfg(feature = "media-compression")]
+    {
+        ret.push(tokio::spawn(async move {
+            info!("Starting MediaMetadata background task");
+            let mut m = media_metadata::MediaMetadata::new(db.clone(), file_store.clone());
+            m.process().await?;
+            info!("MediaMetadata background task completed");
+            Ok(())
+        }));
+    }
+    ret
+}
diff --git a/src/bin/main.rs b/src/bin/main.rs
index cbe29a7..add9594 100644
--- a/src/bin/main.rs
+++ b/src/bin/main.rs
@@ -12,6 +12,7 @@ use rocket::shield::Shield;
 use route96::analytics::plausible::PlausibleAnalytics;
 #[cfg(feature = "analytics")]
 use route96::analytics::AnalyticsFairing;
+use route96::background::start_background_tasks;
 use route96::cors::CORS;
 use route96::db::Database;
 use route96::filesystem::FileStore;
@@ -63,8 +64,9 @@ async fn main() -> Result<(), Error> {
         .limit("form", upload_limit);
     config.ident = Ident::try_new("route96").unwrap();
 
+    let fs = FileStore::new(settings.clone());
     let mut rocket = rocket::Rocket::custom(config)
-        .manage(FileStore::new(settings.clone()))
+        .manage(fs.clone())
         .manage(settings.clone())
         .manage(db.clone())
         .attach(CORS)
@@ -93,10 +95,19 @@ async fn main() -> Result<(), Error> {
     {
         rocket = rocket.mount("/", routes![routes::get_blob_thumb]);
     }
+
+    let jh = start_background_tasks(db, fs);
+
     if let Err(e) = rocket.launch().await {
         error!("Rocker error {}", e);
+        for j in jh {
+            let _ = j.await?;
+        }
         Err(Error::from(e))
     } else {
+        for j in jh {
+            let _ = j.await?;
+        }
         Ok(())
     }
 }
diff --git a/src/filesystem.rs b/src/filesystem.rs
index 52f7085..bd4fbc0 100644
--- a/src/filesystem.rs
+++ b/src/filesystem.rs
@@ -43,6 +43,7 @@ pub struct NewFileResult {
     pub labels: Vec<FileLabel>,
 }
 
+#[derive(Clone)]
 pub struct FileStore {
     settings: Settings,
 }
diff --git a/src/lib.rs b/src/lib.rs
index b0d1c99..0423c35 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,7 @@
 #[cfg(feature = "analytics")]
 pub mod analytics;
 pub mod auth;
+pub mod background;
 pub mod cors;
 pub mod db;
 pub mod filesystem;
diff --git a/src/processing/mod.rs b/src/processing/mod.rs
index 6137d6f..57c747e 100644
--- a/src/processing/mod.rs
+++ b/src/processing/mod.rs
@@ -137,7 +137,7 @@ pub fn can_compress(mime_type: &str) -> bool {
 }
 
 pub fn compress_file(
-    stream: &Path,
+    path: &Path,
     mime_type: &str,
     out_dir: &Path,
 ) -> Result<NewFileProcessorResult, Error> {
@@ -147,12 +147,12 @@ pub fn compress_file(
 
     if mime_type.starts_with("image/") {
         let mut proc = WebpProcessor::new();
-        return proc.compress(stream, mime_type, out_dir);
+        return proc.compress(path, mime_type, out_dir);
     }
     bail!("No media processor")
 }
 
-pub fn probe_file(stream: &Path) -> Result<DemuxerInfo> {
-    let mut demuxer = Demuxer::new(stream.to_str().unwrap())?;
+pub fn probe_file(path: &Path) -> Result<DemuxerInfo> {
+    let mut demuxer = Demuxer::new(path.to_str().unwrap())?;
     unsafe { demuxer.probe_input() }
 }