Optionally persist cross/fade overrides, add tests

CHANGES.md

@@ -11,6 +11,11 @@ Changes:
 - Added support for a Javascript build an interpreter.
 - Removed support for `%define` variables, superseeded by support for actual
   variables in encoders.
+- Switched default persistence for cross and fade-related overrides
+  to follow documented behavior. By default, `"liq_fade_out"`, `"liq_fade_skip"`,
+  `"liq_fade_in"`, `"liq_cross_duration"` and `"liq_fade_type"` now all reset on
+  new tracks. Use `persist_overrides` to revert to previous behavior
+  (`persist_override` for `cross`/`crossfade`) (#2488).
 
 ---
 2.0.6 (2022-06-20)

doc/content/migrating.md

@@ -4,6 +4,23 @@ Migrating to a new Liquidsoap version
 In this page, we list the most common catches when migrating to a new version of
 Liquidsoap.
 
+From 2.1.x to 2.2.x
+-------------------
+
+### Metadata overrides
+
+Some metadata overrides have been made to reset on track boundaries. Previously, those were permanent even though they 
+were documented as only applying to the current track. If you need to keep the previous behavior, you can used the 
+`persist_overrides` parameters (`persis_override` for `cross`/`crossfade`).
+
+The list of concerned metadata is:
+
+* `"liq_fade_out"`
+* `"liq_fade_skip"`
+* `"liq_fade_in"`
+* `"liq_cross_duration"`
+* `"liq_fade_type"`
+
 From 2.0.x to 2.1.x
 -------------------
 

src/core/operators/cross.ml

@@ -32,9 +32,11 @@ let finalise_child_clock child_clock source =
 (** [rms_width] and [minimum_length] are all in samples.
   * [cross_length] is in ticks (like #remaining estimations).
   * We are assuming a fixed audio kind -- at least for now. *)
-class cross ~kind val_source ~duration_getter ~override_duration ~rms_width
-  ~minimum_length ~conservative ~active transition =
+class cross ~kind val_source ~duration_getter ~override_duration
+  ~persist_override ~rms_width ~minimum_length ~conservative ~active transition
+  =
   let s = Lang.to_source val_source in
+  let original_duration_getter = duration_getter in
   object (self)
     inherit source ~name:"cross" kind as super
 
@@ -49,10 +51,11 @@ class cross ~kind val_source ~duration_getter ~override_duration ~rms_width
      * Going with the same choice as above for now. *)
     method self_sync = s#self_sync
     val mutable cross_length = 0
-    val mutable duration_getter = duration_getter
+    val mutable duration_getter = original_duration_getter
+    method cross_duration = duration_getter ()
 
     method set_cross_length =
-      let new_cross_length = duration_getter () in
+      let new_cross_length = self#cross_duration in
       let main_new_cross_length = Frame.main_of_seconds new_cross_length in
 
       if main_new_cross_length <> cross_length then
@@ -182,6 +185,8 @@ class cross ~kind val_source ~duration_getter ~override_duration ~rms_width
         | _ -> ()
 
     method private update_cross_length frame pos =
+      if Frame.is_partial frame && not persist_override then
+        duration_getter <- original_duration_getter;
       List.iter
         (fun (p, m) ->
           if p >= pos then (
@@ -439,6 +444,10 @@ let () =
         Some
           "Metadata field which, if present and containing a float, overrides \
            the 'duration' parameter for current track." );
+      ( "persist_override",
+        Lang.bool_t,
+        Some (Lang.bool false),
+        Some "Keep duration override on track change." );
       ( "minimum",
         Lang.float_t,
         Some (Lang.float (-1.)),
@@ -481,6 +490,13 @@ let () =
       ("", Lang.source_t k, None, None);
     ]
     ~return_t:k ~category:`Audio
+    ~meth:
+      [
+        ( "cross_duration",
+          Lang.([], fun_t [] float_t),
+          "Get the current crossfade duration.",
+          fun s -> Lang.val_fun [] (fun _ -> Lang.float s#cross_duration) );
+      ]
     ~descr:
       "Cross operator, allowing the composition of the _n_ last seconds of a \
        track with the beginning of the next track, using a transition function \
@@ -491,6 +507,7 @@ let () =
       let override_duration =
         Lang.to_string (List.assoc "override_duration" p)
       in
+      let persist_override = Lang.to_bool (List.assoc "persist_override" p) in
       let minimum = Lang.to_float (List.assoc "minimum" p) in
       let minimum_length = Frame.audio_of_seconds minimum in
       let rms_width = Lang.to_float (List.assoc "width" p) in
@@ -500,9 +517,6 @@ let () =
       let active = Lang.to_bool (List.assoc "active" p) in
       let source = Lang.assoc "" 2 p in
       let kind = Kind.of_kind kind in
-      let c =
-        new cross
-          ~kind source transition ~conservative ~active ~duration_getter
-          ~rms_width ~minimum_length ~override_duration
-      in
-      (c :> source))
+      new cross
+        ~kind source transition ~conservative ~active ~duration_getter
+        ~rms_width ~minimum_length ~override_duration ~persist_override)

src/libs/fades.liq

@@ -81,27 +81,31 @@ end
 # @category Source / Sound Processing
 # @param ~id Force the value of the source ID.
 # @param ~duration Duration of the fading. This value can be set on a per-file basis using the metadata field passed as override.
-# @param ~override_duration Metadata field which, if present and containing a float, overrides the 'duration' parameter for current track.
-# @param ~override_type Metadata field which, if present and correct, overrides the 'type' parameter for current track.
+# @param ~override_duration Metadata field which, if present and containing a float, overrides the 'duration' parameter for the current track.
+# @param ~override_type Metadata field which, if present and correct, overrides the 'type' parameter for the current track.
+# @param ~persist_overrides Keep duration and type overrides on track change.
 # @param ~track_sensitive Be track sensitive (if `false` we only fade ou once at the beginning of the track).
 # @param ~type Fader shape (lin|sin|log|exp): linear, sinusoidal, logarithmic or exponential.
 def fade.out(~id="fade.out",~duration=3.,
              ~override_duration="liq_fade_out",
              ~override_type="liq_fade_type",
+             ~persist_overrides=false,
              ~track_sensitive=true,
              ~type="lin",s) =
   def log(x) = log(label=source.id(s),level=4,x) end
   fn = ref(fun () -> 1.)
+  original_type = type
   type = ref(type)
+  original_duration = duration
   duration = ref(duration)
   start_time = ref(-1.)
   started = ref(false)
 
   def start_fade(d,_) =
-    log("Fading out with #{d}s remaining.")
+    log("Fading out with type #{!type}, duration: #{!duration} and #{d}s remaining.")
     start_time := source.time(s)
-    duration = if d < !duration then d else !duration end
-    fn := mkfade(start=1.,stop=0.,type=!type,duration=duration,s)
+    d = if d < !duration then d else !duration end
+    fn := mkfade(start=1.,stop=0.,type=!type,duration=d,s)
     started := true
   end
 
@@ -129,35 +133,48 @@ def fade.out(~id="fade.out",~duration=3.,
     end
   end
 
+  def reset_overrides(_) =
+    if not persist_overrides then
+      duration := original_duration
+      type := original_type
+    end
+  end
+
+  s = source.on_track(s, reset_overrides)
   s = source.on_metadata(s, update_fade)
-  delay = fun () -> !duration
   s =
     if track_sensitive then
       source.on_track(s, stop_fade)
     else
       start_fade(!duration, [])
       s
     end
+
+  delay = fun () -> !duration
   s = if track_sensitive then source.on_end(s, delay=delay, start_fade) else s end
-  fade.scale(id=id, apply, s)
+  fade.scale(id=id, apply, s).{fade_duration = {!duration}, fade_type = {!type}}
 end
 
 # Fade when the metadata trigger is received and then skip.
 # @category Source / Sound Processing
 # @param ~id Force the value of the source ID.
 # @param ~duration Duration of the fading. This value can be set on a per-file basis using the metadata field passed as override.
-# @param ~override_duration Metadata field which, if present and containing a float, overrides the 'duration' parameter for current track.
-# @param ~override_type Metadata field which, if present and correct, overrides the 'type' parameter for current track.
+# @param ~override_duration Metadata field which, if present and containing a float, overrides the 'duration' parameter for the current track.
+# @param ~override_type Metadata field which, if present and correct, overrides the 'type' parameter for the current track.
 # @param ~override_skip Metadata field which, when present and set to "true", will trigger the fade
+# @param ~persist_overrides Keep duration and type overrides on track change.
 # @param ~type Fader shape (lin|sin|log|exp): linear, sinusoidal, logarithmic or exponential.
 def fade.skip(~id="fade.skip",~duration=5.,
              ~override_duration="liq_fade_skip",
-             ~override_type="liq_fade_skip",
+             ~override_type="liq_fade_type",
+             ~persist_overrides=false,
              ~override_skip="liq_skip_meta",
              ~type="lin",s) =
   def log(x) = log(label=source.id(s),level=4,x) end
   fn = ref(fun () -> 1.)
+  original_type = type
   type = ref(type)
+  original_duration = duration
   duration = ref(duration)
 
   def apply() =
@@ -193,27 +210,39 @@ def fade.skip(~id="fade.skip",~duration=5.,
     end
   end
 
+  def reset_overrides(_) =
+    if not persist_overrides then
+      duration := original_duration
+      type := original_type
+    end
+  end
+
+  s = source.on_track(s, reset_overrides)
   s = source.on_metadata(s, update_fade)
   s = source.on_track(s, stop_fade)
-  fade.scale(id=id, apply, s)
+  fade.scale(id=id, apply, s).{fade_duration = {!duration}, fade_type = {!type} }
 end
 
 # Fade the beginning of tracks.
 # @category Source / Sound Processing
 # @param ~id Force the value of the source ID.
 # @param ~duration Duration of the fading. This value can be set on a per-file basis using the metadata field passed as override.
-# @param ~override_duration Metadata field which, if present and containing a float, overrides the 'duration' parameter for current track.
-# @param ~override_type Metadata field which, if present and correct, overrides the 'type' parameter for current track.
+# @param ~override_duration Metadata field which, if present and containing a float, overrides the 'duration' parameter for the current track.
+# @param ~override_type Metadata field which, if present and correct, overrides the 'type' parameter for the current track.
+# @param ~persist_overrides Keep duration and type overrides on track change.
 # @param ~track_sensitive Be track sensitive (if `false` we only fade in once at the beginning of the track).
 # @param ~type Fader shape (lin|sin|log|exp): linear, sinusoidal, logarithmic or exponential.
 def fade.in(~id="fade.in",~duration=3.,
             ~override_duration="liq_fade_in",
             ~override_type="liq_fade_type",
+            ~persist_overrides=false,
             ~track_sensitive=true,
             ~type="lin",s) =
   def log(x) = log(label=source.id(s),level=4,x) end
   fn = ref(fun () -> 0.)
+  original_duration = duration
   duration = ref(duration)
+  original_type = type
   type = ref(type)
 
   def apply() =
@@ -222,7 +251,7 @@ def fade.in(~id="fade.in",~duration=3.,
   end
 
   def start_fade(_) =
-    log("Fading in (type: #{!type}, duration: #{!duration}s).")
+    log("Fading in with type: #{!type} and duration: #{!duration}s.")
     fn := mkfade(start=0.,stop=1.,type=!type,duration=!duration,s)
   end
 
@@ -238,10 +267,18 @@ def fade.in(~id="fade.in",~duration=3.,
     end
   end
 
+  def reset_overrides(_) =
+    if not persist_overrides then
+      duration := original_duration
+      type := original_type
+    end
+  end
+
+  s = source.on_track(s, reset_overrides)
   s = source.on_metadata(s, update_fade)
   s = if track_sensitive then source.on_track(s, start_fade) else start_fade([]); s end
 
-  fade.scale(id=id,apply,s)
+  fade.scale(id=id, apply, s).{fade_duration = {!duration}, fade_type = {!type} }
 end
 
 # Simple transition for crossfade
@@ -342,6 +379,7 @@ end
 #                      Metadata field which, if present and containing a \
 #                      float, overrides the 'duration' parameter for current \
 #                      track. 
+# @param ~persist_override Keep duration override on track change.
 # @param ~fade_in      Fade-in duration, if any.
 # @param ~fade_out     Fade-out duration, if any.
 # @param ~width        Width of the volume analysis window.
@@ -363,7 +401,7 @@ end
 #                      removes duplicate metadata from the returned source.
 # @param s             The input source.
 def crossfade(~id=null(), ~duration=5.,~override_duration="liq_cross_duration",
-              ~fade_in=3.,~fade_out=3.,~smart=false,
+              ~persist_override=false,~fade_in=3.,~fade_out=3.,~smart=false,
               ~default=(fun (a,b) -> (sequence([a, b]):source)),
               ~high=-15., ~medium=-32., ~margin=4., ~deduplicate=true,
               ~minimum=(-1.),~width=2.,~conservative=true,s)
@@ -395,14 +433,16 @@ def crossfade(~id=null(), ~duration=5.,~override_duration="liq_cross_duration",
 
   let (cross_id, deduplicate_id) = deduplicate ? (null(), null(id)) : (null(id), null())
 
-  s = cross(id=cross_id, width=width, duration=duration, override_duration=override_duration,
+  crossed = cross(id=cross_id, width=width, duration=duration, persist_override=persist_override, override_duration=override_duration,
             conservative=conservative, minimum=minimum, transition, s)
 
-  if deduplicate then
-    metadata.deduplicate(id=deduplicate_id, s)
+  s = if deduplicate then
+    metadata.deduplicate(id=deduplicate_id, crossed)
   else
-    s
+    crossed
   end
+
+  s.{cross_duration={crossed.cross_duration()}}
 end
 
 # Mixes two streams, with faded transitions between the state when only the