Cue more! (#3634)

src/libs/extra/source.liq

@@ -262,30 +262,36 @@ end
 stdlib_file = file
 
 # Generate a CUE file for the source. This function will generate a new track in
-# the file for each metadata of the source.
+# the file for each metadata of the source. This function tries to map metadata to
+# the appropriate CUE file standard values. You can use the `map_metadata` argument
+# to add your own pre-processing. The following metadata are recognized on tracks:
+# `"title"`, `"artist"`, `"album"`, `"isrc"`, and `"cue_year"`.
 # @category Source / Track processing
 # @flag extra
 # @param filename Path where the CUE file should be written.
-# @param max_length Set the maximum of track info retained by the function. \
-#                   Infinite when `null`.
+# @param ~last_tracks Only report the number of last tracks.
 # @param ~title Title of the stream.
 # @param ~file File where the stream is stored.
 # @param ~file_type Format in which the stream is stored.
 # @param ~comment Comment about the stream.
-# @param ~date Year for the stream.
+# @param ~year Year for the stream.
 # @param ~map_metadata Function to apply to metadata before writing the CUE file (useful for pre-processing metadata).
 # @param ~temp_dir Temporary directory for atomic write.
+# @param ~deduplicate_using To avoid duplicate entries, duplicate metadata are \
+#                           filtered. Set this to a list of labels to use for detecting \
+#                           duplicated metadata.
 # @param ~delete Delete the CUE files when starting if it exists.
 def source.cue(
   ~title=null(),
   ~performer=null(),
   ~file=null(),
-  ~file_type="mp3",
+  ~file_type=null(),
   ~comment=null(),
-  ~date=null(),
+  ~year=null(),
   ~map_metadata=fun (m) -> (m : [(string*string)]),
-  ~max_length=null(),
+  ~last_tracks=null(),
   ~temp_dir=null(),
+  ~deduplicate_using=["title", "artist", "album", "isrc", "cue_year"],
   ~delete=true,
   filename,
   s
@@ -296,6 +302,8 @@ def source.cue(
     stdlib_file.remove(filename)
   end
 
+  file_type = file_type ?? stdlib_file.extension(leading_dot=false, file ?? "")
+
   is_first = ref(true)
 
   def write(~append, entries) =
@@ -326,12 +334,14 @@ def source.cue(
     end
 
     # Write a tag.
-    def tag(~indent=0, name, (value:string?)) =
+    def tag(~indent=0, ~quote=true, name, (value:string?)) =
+      quote = if quote then fun (v) -> string.quote(v) else fun (v) -> v end
+
       if
         null.defined(value)
       then
         s =
-          "#{string.spaces(indent)}#{name} #{string.quote(null.get(value))}"
+          "#{string.spaces(indent)}#{name} #{quote(null.get(value))}"
         w(s)
       end
     end
@@ -347,13 +357,11 @@ def source.cue(
         "REM COMMENT",
         comment
       )
-      if
-        null.defined(date)
-      then
-        w(
-          "DATE #{(null.get(date) : int)}"
-        )
-      end
+      tag(
+        quote=false,
+        "REM DATE",
+        null.map(string.of_int, year)
+      )
       if
         null.defined(file)
       then
@@ -368,8 +376,11 @@ def source.cue(
         begin
           let {position = p, time = t, metadata = m} = entry
 
-          w(
-            "  TRACK #{string.of_int(digits=2, p)} AUDIO"
+          tag(
+            indent=2,
+            quote=false,
+            "TRACK",
+            "#{string.of_int(digits=2, p)} AUDIO"
           )
           tag(indent=4, "TITLE", list.assoc.nullable("title", m))
           tag(indent=4, "PERFORMER", list.assoc.nullable("artist", m))
@@ -378,6 +389,13 @@ def source.cue(
             "REM ALBUM",
             list.assoc.nullable("album", m)
           )
+          tag(
+            indent=4,
+            quote=false,
+            "REM DATE",
+            list.assoc.nullable("cue_year", m)
+          )
+          tag(indent=4, quote=false, "ISRC", list.assoc.nullable("isrc", m))
 
           frames = int_of_float((t - floor(t)) * 75.)
           t = int_of_float(t)
@@ -386,8 +404,11 @@ def source.cue(
           m = string.of_int(digits=2, minutes)
           s = string.of_int(digits=2, seconds)
           f = string.of_int(digits=2, frames)
-          w(
-            "    INDEX 01 #{m}:#{s}:#{f}"
+          tag(
+            indent=4,
+            quote=false,
+            "INDEX 01",
+            "#{m}:#{s}:#{f}"
           )
         end,
       entries
@@ -406,25 +427,22 @@ def source.cue(
     ref.incr(current_position)
 
     if
-      null.defined(max_length)
+      null.defined(last_tracks)
     then
       current_entries =
         null.case(
-          max_length,
+          last_tracks,
           entries,
-          fun (max_length) ->
-            list.rev(list.prefix(max_length - 1, list.rev(entries())))
-        )
-      entries :=
-        list.mapi(
-          fun (pos, entry) -> entry.{position=pos + 1},
-          [...current_entries, entry]
+          fun (last_tracks) ->
+            list.rev(list.prefix(last_tracks - 1, list.rev(entries())))
         )
+      entries := [...current_entries, entry]
       write(append=false, entries())
     else
       write(append=true, [entry])
     end
   end
 
-  source.on_track(s, handle_metadata)
+  s = metadata.deduplicate(using=deduplicate_using, s)
+  source.on_metadata(s, handle_metadata)
 end

src/libs/source.liq

@@ -27,11 +27,27 @@ def source.video(~id=null("source.video"), video) =
 end
 
 # Remove duplicate metadata in a track.
+# @param ~using Labels to use to compare the metadata. Defaults to all of them \
+#               when `null`.
 # @category Metadata
-def track.metadata.deduplicate(~id=null("track.metadata.deduplicate"), t) =
+def track.metadata.deduplicate(
+  ~id=null("track.metadata.deduplicate"),
+  ~using=null(),
+  t
+) =
   last_meta = ref([])
 
   def f(m) =
+    m =
+      if
+        null.defined(using)
+      then
+        using = null.get(using)
+        list.filter(fun (x) -> list.mem(fst(x), using), m)
+      else
+        m
+      end
+
     if
       m == last_meta()
     then
@@ -49,11 +65,16 @@ end
 
 # Remove duplicate metadata in a source.
 # @category Metadata
+# @param ~using Labels to use to compare the metadata. Defaults to all of them \
+#               when `null`.
 # @param ~id Source id
 # @param s source
-def metadata.deduplicate(~id=null("metadata.deduplicate"), s) =
+def metadata.deduplicate(~id=null("metadata.deduplicate"), ~using=null(), s) =
   tracks = source.tracks(s)
-  source(id=id, tracks.{metadata=track.metadata.deduplicate(tracks.metadata)})
+  source(
+    id=id,
+    tracks.{metadata=track.metadata.deduplicate(using=using, tracks.metadata)}
+  )
 end
 
 # Rewrite metadata on the fly using a function.

tests/streams/source-cue.liq

@@ -26,7 +26,26 @@ s =
     title="tit",
     performer="perf",
     file="bla.mp3",
-    max_length=2,
+    comment=
+      "this is a comment",
+    year=2023,
+    last_tracks=2,
+    map_metadata=
+      fun (m) ->
+        list.assoc.filter_map(
+          fun (x, y) ->
+            if
+              y == "title2"
+            then
+              (
+                x,
+                "title 2"
+              )
+            else
+              (x, y)
+            end,
+          m
+        ),
     create_cuefile,
     s
   )
@@ -39,6 +58,8 @@ FILE "bla.mp3" MP3
     TITLE "title1"
     PERFORMER "artist1"
     REM ALBUM "album1"
+    REM DATE 2021
+    ISRC bla
     INDEX 01 00:00:00
   TRACK 02 AUDIO
     TITLE "title2"
@@ -54,13 +75,15 @@ FILE "bla.mp3" MP3
 create_expected =
   'TITLE "tit"
 PERFORMER "perf"
+REM COMMENT "this is a comment"
+REM DATE 2023
 FILE "bla.mp3" MP3
-  TRACK 01 AUDIO
-    TITLE "title2"
+  TRACK 02 AUDIO
+    TITLE "title 2"
     PERFORMER "artist2"
     REM ALBUM "album2"
     INDEX 01 00:02:00
-  TRACK 02 AUDIO
+  TRACK 03 AUDIO
     TITLE "title3"
     PERFORMER "artist3"
     REM ALBUM "album3"
@@ -80,11 +103,23 @@ s =
         if
           track_pos() == 1 and source.time(s) == 0.
         then
-          f([("artist", "artist1"), ("album", "album1"), ("title", "title1")])
+          f([("artist", "artist1"), ("album", "album1"), ("title", "title1"), ("cue_year", "2021"), ("isrc", "bla")])
         elsif
           track_pos() == 2 and source.time(s) == 2.
         then
           f([("artist", "artist2"), ("album", "album2"), ("title", "title2")])
+        elsif
+          track_pos() == 2 and source.time(s) == 2.1
+        then
+          # This one should be deduplicated.
+          f(
+            [
+              ("artist", "artist2"),
+              ("album", "album2"),
+              ("title", "title2"),
+              ("foo", "bar")
+            ]
+          )
         elsif
           track_pos() == 3 and source.time(s) == 3.
         then