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(*****************************************************************************
Liquidsoap, a programmable audio stream generator.
Copyright 2003-2017 Savonet team
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details, fully stated in the COPYING
file at the root of the liquidsoap distribution.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*****************************************************************************)
let log = Dtools.Log.make ["decoder";"puremeta"]
exception Error
(** Parse next item:
* [[Int:]Int:]Int String String
* Int can be Float, and there can be more than hours. *)
let parse_item stream =
let rec ts_of_list d = function
| hd::tl -> hd*.d +. ts_of_list (d*.60.) tl
| [] -> 0.
in
let rec read_meta timestamp =
match Stream.next stream with
| Genlex.Kwd ":" -> read_meta timestamp
| Genlex.Int i -> read_meta (float i :: timestamp)
| Genlex.Float f -> read_meta (f :: timestamp)
| Genlex.String key ->
begin match Stream.next stream with
| Genlex.String value -> ts_of_list 1. timestamp, key, value
| _ -> raise Error
end
| _ -> raise Error
in
read_meta []
let parse_file filename =
let input = open_in filename in
let lexer = Genlex.make_lexer [":"] (Stream.of_channel input) in
let rec parse acc =
match try Some (parse_item lexer) with Stream.Failure -> None with
| Some i -> parse (i::acc)
| None -> List.rev acc
in
let data = parse [] in
close_in input ;
data
let empty = {Frame.audio=0;video=0;midi=0}
let file_deco filename =
let events = ref (parse_file filename) in
let t = ref 0. in
let size = Lazy.force Frame.size in
let fill frame =
let pos = Frame.position frame in
let duration = Frame.seconds_of_master (size-pos) in
let rec aux () =
match !events with
| (ts,k,v)::tl ->
if ts < !t+.duration then
let pos = Frame.master_of_seconds (ts -. !t) in
let meta = Hashtbl.create 1 in
Hashtbl.add meta k v ;
Frame.set_metadata frame pos meta ;
events := tl ;
aux ()
else
Frame.add_break frame size
| [] -> Frame.add_break frame pos
in
ignore (Frame.content_of_type frame pos empty) ;
aux () ;
t := !t +. Frame.seconds_of_master (Frame.position frame - pos) ;
-1 (* TODO remaining time *)
in
{ Decoder.
fill = fill ;
fseek = (fun _ -> 0);
close = ignore }
let () =
Decoder.file_decoders#register "META"
(fun ~metadata:_ filename kind ->
if Frame.type_has_kind empty kind then begin
ignore (parse_file filename) ;
Some (fun () -> file_deco filename)
end else
None)
|
