add audio waveform thumbnails

src/previews/audio.rs

@@ -0,0 +1,43 @@
+use anyhow::anyhow;
+use std::io::Read;
+use std::path::Path;
+use std::process::Command;
+
+use anyhow::Result;
+
+use super::Previewable;
+
+pub struct AudioPath<'a>(pub &'a Path);
+
+const COLOR: &str = "#dc322f"; // solarized red
+
+impl<'a> Previewable for AudioPath<'a> {
+    fn get_thumbnail(&self) -> Result<Option<Vec<u8>>> {
+        let outfile = tempfile::Builder::new().suffix(".webp").tempfile()?;
+        let thumbnail_cmd = Command::new("ffmpeg")
+            .args(["-i", &self.0.to_string_lossy()])
+            .args([
+                "-filter_complex",
+                &format!(
+                    "[0:a]aformat=channel_layouts=mono, compand=gain=-2,
+                     showwavespic=s=860x256:colors={COLOR},
+                     drawbox=x=(iw-w)/2:y=(ih-h)/2:w=iw:h=1:color={COLOR}"
+                ),
+            ])
+            .args(["-vframes", "1"])
+            .arg(&*outfile.path().to_string_lossy())
+            .arg("-y")
+            .output()?;
+
+        if !thumbnail_cmd.status.success() {
+            return Err(anyhow!(
+                "Failed to render thumbnail: {:?}",
+                String::from_utf8_lossy(&thumbnail_cmd.stderr)
+            ));
+        }
+
+        let mut buffer = Vec::new();
+        outfile.as_file().read_to_end(&mut buffer)?;
+        Ok(Some(buffer))
+    }
+}

src/previews/mod.rs

@@ -12,10 +12,12 @@ use std::{
 use self::image::ImagePath;
 use self::text::TextPath;
 use self::video::VideoPath;
+use self::audio::AudioPath;
 
 pub mod image;
 pub mod text;
 pub mod video;
+pub mod audio;
 
 pub trait Previewable {
     fn get_thumbnail(&self) -> Result<Option<Vec<u8>>>;
@@ -63,6 +65,9 @@ impl PreviewStore {
                     Some(tm) if tm.starts_with("video") || tm == "application/x-matroska" => {
                         Ok(VideoPath(&file.path).get_thumbnail()?)
                     }
+                    Some(tm) if tm.starts_with("audio") => {
+                        Ok(AudioPath(&file.path).get_thumbnail()?)
+                    }
                     Some(tm) if tm.starts_with("image") => {
                         Ok(ImagePath(&file.path).get_thumbnail()?)
                     }

webui/src/components/display/BlobPreview.svelte

@@ -31,10 +31,19 @@
       </div>
     {/if}
     {#if audio}
+      {#if imageLoaded != address}
+        <Spinner />
+      {/if}
+      <img
+        src="/api/thumb/{address}"
+        alt={address}
+        on:load={() => (imageLoaded = address)}
+        on:error={() => (imageLoaded = address)}
+      />
       <audio controls preload="auto" src="/api/raw/{address}" />
     {/if}
     {#if video}
-      {#if imageLoaded != address }
+      {#if imageLoaded != address}
         <Spinner />
 
         <img
@@ -83,6 +92,7 @@
     display: flex;
     justify-content: center;
     align-items: center;
+    flex-direction: column;
   }
 
   audio,