Support negative --preset args (#248)

* Support negative `--preset` args

* Simplify preset arg type

CHANGELOG.md

@@ -1,3 +1,6 @@
+# Unreleased (0.8.1)
+* Support negative `--preset` args.
+
 # v0.8.0
 * crf-search: Tweak 2nd iteration logic that slices the crf range at the 25% or 75% crf point.
   - Widen to 20%/80% to account for searches of the "middle" two subranges being more optimal.

src/command/args/encode.rs

@@ -55,8 +55,8 @@ pub struct Encode {
     /// libaom-av1 preset is mapped to equivalent -cpu-used argument.
     ///
     /// [svt-av1 default: 8]
-    #[arg(long)]
-    pub preset: Option<Preset>,
+    #[arg(long, allow_hyphen_values = true)]
+    pub preset: Option<Arc<str>>,
 
     /// Interval between keyframes. Can be specified as a number of frames, or a duration.
     /// E.g. "300" or "10s". Defaults to 10s if the input duration is over 3m.
@@ -191,8 +191,7 @@ impl Encode {
         );
 
         let preset = match &self.preset {
-            Some(Preset::Number(n)) => Some(n.to_string().into()),
-            Some(Preset::Name(n)) => Some(n.clone()),
+            Some(n) => Some(n.clone()),
             None if svtav1 => Some("8".into()),
             None => None,
         };
@@ -391,32 +390,6 @@ impl std::str::FromStr for Encoder {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum Preset {
-    Number(u8),
-    Name(Arc<str>),
-}
-
-impl fmt::Display for Preset {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Self::Number(n) => n.fmt(f),
-            Self::Name(name) => name.fmt(f),
-        }
-    }
-}
-
-impl std::str::FromStr for Preset {
-    type Err = anyhow::Error;
-
-    fn from_str(s: &str) -> anyhow::Result<Self> {
-        match s.parse::<u8>() {
-            Ok(n) => Ok(Self::Number(n)),
-            _ => Ok(Self::Name(s.into())),
-        }
-    }
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum KeyInterval {
     Frames(i32),
@@ -610,7 +583,7 @@ fn svtav1_to_ffmpeg_args_default_under_3m() {
         encoder: Encoder("libsvtav1".into()),
         input: "vid.mp4".into(),
         vfilter: None,
-        preset: Some(Preset::Number(7)),
+        preset: Some("7".into()),
         pix_format: Some(PixelFormat::Yuv420p),
         keyint: None,
         scd: None,