Break out API to create readables from files

libs/ardour/ardour/readable.h

@@ -25,11 +25,15 @@
 
 namespace ARDOUR {
 
+class Session;
+
 class LIBARDOUR_API Readable {
-  public:
+public:
-	Readable () {}
 	virtual ~Readable() {}
 
+	static std::vector<boost::shared_ptr<Readable> >
+		load (Session&, std::string const&);
+
 	virtual samplecnt_t read (Sample*, samplepos_t pos, samplecnt_t cnt, int channel) const = 0;
 	virtual samplecnt_t readable_length() const = 0;
 	virtual uint32_t  n_channels () const = 0;

libs/ardour/convolver.cc

@@ -24,6 +24,7 @@
 #include "ardour/audioengine.h"
 #include "ardour/audiofilesource.h"
 #include "ardour/convolver.h"
+#include "ardour/readable.h"
 #include "ardour/session.h"
 #include "ardour/srcfilesource.h"
 #include "ardour/source_factory.h"
@@ -48,44 +49,18 @@ Convolver::Convolver (
 	, _offset (0)
 	, _configured (false)
 {
-	ARDOUR::SoundFileInfo sf_info;
+	_readables = Readable::load (_session, path);
-	std::string error_msg;
-
-	if (!AudioFileSource::get_soundfile_info (path, sf_info, error_msg)) {
-		PBD::error << string_compose(_("Convolver: cannot open IR \"%1\": %2"), path, error_msg) << endmsg;
-		throw failed_constructor ();
-	}
-
-	if (sf_info.length > 0x1000000 /*2^24*/) {
-		PBD::error << string_compose(_("Convolver: IR \"%1\" file too long."), path) << endmsg;
-		throw failed_constructor ();
-	}
-
-	for (unsigned int n = 0; n < sf_info.channels; ++n) {
-		try {
-			boost::shared_ptr<AudioFileSource> afs;
-			afs = boost::dynamic_pointer_cast<AudioFileSource> (
-					SourceFactory::createExternal (DataType::AUDIO, _session,
-						path, n,
-						Source::Flag (ARDOUR::AudioFileSource::NoPeakFile), false));
-
-			if (afs->sample_rate() != _session.nominal_sample_rate()) {
-				boost::shared_ptr<SrcFileSource> sfs (new SrcFileSource(_session, afs, ARDOUR::SrcBest));
-				_readables.push_back(sfs);
-			} else {
-				_readables.push_back (afs);
-			}
-		} catch (failed_constructor& err) {
-			PBD::error << string_compose(_("Convolver: Could not open IR \"%1\"."), path) << endmsg;
-			throw failed_constructor ();
-		}
-	}
 
 	if (_readables.empty ()) {
 		PBD::error << string_compose (_("Convolver: IR \"%1\" no usable audio-channels sound."), path) << endmsg;
 		throw failed_constructor ();
 	}
 
+	if (_readables[0]->readable_length () > 0x1000000 /*2^24*/) {
+		PBD::error << string_compose(_("Convolver: IR \"%1\" file too long."), path) << endmsg;
+		throw failed_constructor ();
+	}
+
 	AudioEngine::instance ()->BufferSizeChanged.connect_same_thread (*this, boost::bind (&Convolver::reconfigure, this));
 
 	reconfigure ();

libs/ardour/readable.cc

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2020 Robin Gareus <robin@gareus.org>
+ *
+ * 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 program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <vector>
+
+#include "pbd/error.h"
+
+#include "ardour/audiofilesource.h"
+#include "ardour/readable.h"
+#include "ardour/session.h"
+#include "ardour/srcfilesource.h"
+#include "ardour/source_factory.h"
+
+#include "pbd/i18n.h"
+
+using namespace ARDOUR;
+
+std::vector<boost::shared_ptr<Readable> >
+Readable::load (Session& session, std::string const& path)
+{
+	std::vector<boost::shared_ptr<Readable> > readables;
+
+	ARDOUR::SoundFileInfo sf_info;
+	std::string error_msg;
+
+	if (!AudioFileSource::get_soundfile_info (path, sf_info, error_msg)) {
+		PBD::error << string_compose(_("Cannot open File \"%1\": %2"), path, error_msg) << endmsg;
+		throw failed_constructor ();
+	}
+
+	for (unsigned int n = 0; n < sf_info.channels; ++n) {
+		try {
+			boost::shared_ptr<AudioFileSource> afs;
+			afs = boost::dynamic_pointer_cast<AudioFileSource> (
+					SourceFactory::createExternal (DataType::AUDIO, session,
+						path, n,
+						Source::Flag (ARDOUR::AudioFileSource::NoPeakFile), false));
+
+			if (afs->sample_rate() != session.nominal_sample_rate()) {
+				boost::shared_ptr<SrcFileSource> sfs (new SrcFileSource(session, afs, ARDOUR::SrcBest));
+				readables.push_back(sfs);
+			} else {
+				readables.push_back (afs);
+			}
+		} catch (failed_constructor& err) {
+			PBD::error << string_compose(_("Could not read file \"%1\"."), path) << endmsg;
+			throw failed_constructor ();
+		}
+	}
+	return readables;
+}

libs/ardour/wscript

@@ -181,6 +181,7 @@ libardour_sources = [
         'progress.cc',
         'quantize.cc',
         'rc_configuration.cc',
+        'readable.cc',
         'readonly_control.cc',
         'raw_midi_parser.cc',
         'recent_sessions.cc',