comparison cpack/dml/lib/dsp.pl @ 0:718306e29690 tip

commiting public release

+/* Part of DML (Digital Music Laboratory)
+	Copyright 2014-2015 Samer Abdallah, University of London
+	 
+	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.
+
+	You should have received a copy of the GNU General Public
+	License along with this library; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+:- module(dsp, 
+      [  spectrogram/2
+      ,  spectrogram/3
+      ,  spectrum/2
+      ,  sum/2
+      ]).
+
+:- use_module(library(semweb/rdf_db)).
+:- use_module(library(sandbox)).
+:- use_module(library(rdfutils)).
+:- use_module(library(memo)).
+:- use_module(library(mlserver)).
+
+:- set_prolog_flag(double_quotes,string).
+
+:- setting(specgram_dynamic_range,number,90,"Dynamic range in dB for spectrograms").
+
+spectrogram(URI,X) :-
+   rdf_text(URI,beets:path,P), 
+   X===specgrm( monofile(P), hanning(2048),512).
+
+:- volatile_memo spectrum(+atom,-ground).
+spectrum(URI,X) :-
+   spectrogram(URI,Y),
+   X1===sum(Y,2),
+   persist_item(X1,X).
+
+spectrogram(URI,Offset,Length) :-
+   setting(specgram_dynamic_range,DBs),
+   (  cp_audio:audio_file(URI,P,Fmt),
+      (  Fmt=just(aac) 
+      -> MSignal=sndfile(q(P),q(enc),q(aac))
+      ;  MSignal=sndfile(q(P))
+      )
+   ;  cp_audio:audio_link(URI,P,just(mp3)),
+      MSignal=mp3file(q(P))
+   ), !,
+   ?? (specgrm( taket(Length,dropt(Offset,mixdown(MSignal))), 
+                hanning(2048),512,"range",DBs,"offset",Offset); 
+       ylim([0,15])).
+
+sum(Items,Sum) :-
+   once(member(X,Items)),
+   D===numdims(X)+1,
+   Sum===sum(cellcat(D,cell(Items)),D).
+
+sandbox:safe_primitive(dsp:spectrogram(_,_,_)).