diff --git a/crates/pinakes-core/src/error.rs b/crates/pinakes-core/src/error.rs
index c987dc6..7e43726 100644
--- a/crates/pinakes-core/src/error.rs
+++ b/crates/pinakes-core/src/error.rs
@@ -111,6 +111,15 @@ pub enum PinakesError {
 
   #[error("serialization error: {0}")]
   Serialization(String),
+
+  #[error("external tool `{tool}` failed: {stderr}")]
+  ExternalTool { tool: String, stderr: String },
+
+  #[error("subtitle track {index} not found in media")]
+  SubtitleTrackNotFound { index: u32 },
+
+  #[error("invalid language code: {0}")]
+  InvalidLanguageCode(String),
 }
 
 impl From<rusqlite::Error> for PinakesError {