Adaptive extra splits (#584)

* Adds adaptive extra splits

* docs

* correction

* squize

* more squize

README.md

@@ -88,7 +88,7 @@ With your own parameters:
 
     -s  --scenes            File to save/read scenes.
 
-    -x  --extra-split       Size of chunk after which it will be split [default: 240]
+    -x  --extra-split       Size of chunk after which it will be split [default: fps * 10]
 
     --min-scene-len         Specifies the minimum number of frames in each split.
 

av1an-cli/src/lib.rs

@@ -213,13 +213,8 @@ pub struct CliOpts {
   /// When a scenecut is found whose distance to the previous scenecut is greater than the value
   /// specified by this option, one or more extra splits (scenecuts) are added. Set this option
   /// to 0 to disable adding extra splits.
-  #[clap(
-    short = 'x',
-    long,
-    default_value_t = 240,
-    help_heading = "SCENE DETECTION"
-  )]
-  pub extra_split: usize,
+  #[clap(short = 'x', long, help_heading = "SCENE DETECTION")]
+  pub extra_split: Option<usize>,
 
   /// Minimum number of frames for a scenecut
   #[clap(long, default_value_t = 24, help_heading = "SCENE DETECTION")]
@@ -514,10 +509,14 @@ pub fn parse_cli(args: CliOpts) -> anyhow::Result<EncodeArgs> {
     chunk_order: args.chunk_order,
     concat: args.concat,
     encoder: args.encoder,
-    extra_splits_len: if args.extra_split > 0 {
-      Some(args.extra_split)
-    } else {
-      None
+    extra_splits_len: match args.extra_split {
+      Some(0) => None,
+      Some(x) => Some(x),
+      // Make sure it's at least 10 seconds
+      None => match input.frame_rate() {
+        Ok(fps) => Some((fps * 10.0) as usize),
+        Err(_) => Some(240_usize),
+      },
     },
     photon_noise: args.photon_noise,
     sc_pix_format: args.sc_pix_format,