Add a Read Only Memory Audio Source

This will come in handy for FIR, or short samples in combination
with a Lua convolution processor.

3 files changed, 105 insertions, 0 deletions

diff --git a/libs/ardour/ardour/audiorom.h b/libs/ardour/ardour/audiorom.h
new file mode 100644
index 0000000000..605e12dfa7
--- /dev/null
+++ b/libs/ardour/ardour/audiorom.h
@@ -0,0 +1,50 @@
+/*
+ * 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.
+ */
+
+#ifndef __ardour_audio_rom_h__
+#define __ardour_audio_rom_h__
+
+#include "ardour/libardour_visibility.h"
+#include "ardour/readable.h"
+#include "ardour/types.h"
+
+namespace ARDOUR {
+
+class Session;
+
+class LIBARDOUR_API AudioRom : public Readable
+{
+public:
+	static boost::shared_ptr<AudioRom> new_rom (Sample*, size_t);
+	~AudioRom();
+
+	samplecnt_t read (Sample*, samplepos_t pos, samplecnt_t cnt, int channel) const;
+	samplecnt_t readable_length() const { return _size; }
+	uint32_t  n_channels () const { return 1; }
+
+private:
+	AudioRom (Sample*, size_t);
+	AudioRom (AudioRom const&);
+
+	Sample*     _rom;
+	samplecnt_t _size;
+};
+
+}
+
+#endif /* __ardour_readable_h__ */
diff --git a/libs/ardour/audiorom.cc b/libs/ardour/audiorom.cc
new file mode 100644
index 0000000000..4550ecf7f5
--- /dev/null
+++ b/libs/ardour/audiorom.cc
@@ -0,0 +1,54 @@
+/*
+ * 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 "pbd/failed_constructor.h"
+#include "ardour/audiorom.h"
+
+using namespace ARDOUR;
+
+AudioRom::AudioRom (Sample* rom, size_t size)
+	: _size (size)
+{
+	_rom = (Sample*) malloc (sizeof (Sample) * _size);
+	if (!_rom) {
+		throw failed_constructor ();
+	}
+	memcpy (_rom, rom, sizeof (Sample) * _size);
+}
+
+boost::shared_ptr<AudioRom>
+AudioRom::new_rom (Sample* rom, size_t size)
+{
+	return boost::shared_ptr<AudioRom> (new AudioRom (rom, size));
+}
+
+AudioRom::~AudioRom ()
+{
+	free (_rom);
+}
+
+samplecnt_t
+AudioRom::read (Sample* dst, samplepos_t pos, samplecnt_t cnt, int channel) const
+{
+	if (channel != 0 || pos >= _size) {
+		return 0;
+	}
+	samplecnt_t to_copy = std::min (cnt, _size - pos);
+	memcpy (dst, &_rom[pos], sizeof (Sample) * _size);
+	return to_copy;
+}
diff --git a/libs/ardour/wscript b/libs/ardour/wscript
index 8d6090d956..e03fbf65e4 100644
--- a/libs/ardour/wscript
+++ b/libs/ardour/wscript
@@ -38,6 +38,7 @@ libardour_sources = [
         'audiofile_tagger.cc',
         'audiofilesource.cc',
         'audioregion.cc',
+        'audiorom.cc',
         'audiosource.cc',
         'auditioner.cc',
         'automatable.cc',