Add export demo noise watermarking

libs/audiographer/audiographer/general/demo_noise.h

@@ -0,0 +1,46 @@
+#ifndef AUDIOGRAPHER_DEMO_NOISE_H
+#define AUDIOGRAPHER_DEMO_NOISE_H
+
+#include "audiographer/visibility.h"
+#include "audiographer/sink.h"
+#include "audiographer/types.h"
+#include "audiographer/utils/listed_source.h"
+
+namespace AudioGrapher
+{
+
+/// Noise injector
+class LIBAUDIOGRAPHER_API DemoNoiseAdder
+  : public ListedSource<float>
+  , public Sink<float>
+  , public Throwing<>
+{
+public:
+	/// Constructor. \n RT safe
+	DemoNoiseAdder (unsigned int channels);
+	~DemoNoiseAdder ();
+
+	void init (samplecnt_t max_samples, samplecnt_t interval, samplecnt_t duration, float level);
+
+	void process (ProcessContext<float> const& ctx);
+	using Sink<float>::process;
+
+private:
+	float*       _data_out;
+	samplecnt_t  _data_out_size;
+
+	unsigned int _channels;
+	samplecnt_t  _interval;
+	samplecnt_t  _duration;
+	float        _level;
+	samplecnt_t  _pos;
+
+	/* Park-Miller-Carta */
+	uint32_t randi ();
+	float    randf () { return (randi () / 1073741824.f) - 1.f; }
+	uint32_t _rseed;
+};
+
+} // namespace
+
+#endif

libs/audiographer/src/general/demo_noise.cc

@@ -0,0 +1,116 @@
+/*
+ * 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 "audiographer/general/demo_noise.h"
+#include "ardour/dB.h"
+
+using namespace AudioGrapher;
+
+DemoNoiseAdder::DemoNoiseAdder (unsigned int channels)
+  : _data_out (0)
+  , _data_out_size (0)
+	, _channels (channels)
+	, _interval (48000 * 20)
+	, _duration (48000)
+	, _level    (.1) //  -20dBFS
+	, _pos      (48000 * 5)
+	, _rseed (1)
+{
+}
+
+DemoNoiseAdder::~DemoNoiseAdder ()
+{
+	delete[] _data_out;
+}
+
+void
+DemoNoiseAdder::init (samplecnt_t max_samples, samplecnt_t interval, samplecnt_t duration, float level)
+{
+	if (max_samples > _data_out_size) {
+		delete[] _data_out;
+		_data_out = new float[max_samples];
+		_data_out_size = max_samples;
+	}
+
+	if (_duration <= 0) {
+		_duration = 48000;
+	}
+	if (duration > interval) {
+		_duration = std::min ((samplecnt_t)48000, interval / 5);
+	} else {
+		_duration = duration;
+	}
+
+	_interval = interval;
+	_level = dB_to_coefficient (level);
+	_pos = interval / 5 + duration;
+}
+
+void
+DemoNoiseAdder::process (ProcessContext<float> const& ctx)
+{
+	const samplecnt_t n_samples = ctx.samples_per_channel ();
+
+	if (throw_level (ThrowStrict) && ctx.channels () != _channels) {
+		throw Exception (*this, boost::str (boost::format ("Wrong channel count given to process(), %1% instead of %2%") % ctx.channels () % _channels));
+	}
+	if (throw_level (ThrowProcess) && ctx.samples () > _data_out_size) {
+		throw Exception (*this, boost::str (boost::format ("Too many samples given to process(), %1% instead of %2%") % ctx.samples () % _data_out_size));
+	}
+
+	if (_pos + n_samples > _duration) {
+		_pos -= n_samples;
+		ListedSource<float>::output (ctx);
+		return;
+	}
+
+	assert (ctx.samples () % ctx.channels () == 0);
+	assert (ctx.samples () == n_samples * _channels);
+
+	memcpy (_data_out, ctx.data (), sizeof (float) * n_samples * _channels);
+
+	// TODO: optimize, single loop
+	float* d = _data_out;
+	for (samplecnt_t s = 0; s < n_samples; ++s) {
+		for (unsigned int c = 0; c < _channels; ++c, ++d) {
+			if (_pos <= _duration) {
+				*d += _level * randf ();
+			}
+		}
+		if (--_pos == 0) {
+			_pos += _interval;
+			break;
+		}
+	}
+
+	ProcessContext<float> ctx_out (ctx, _data_out);
+	this->output (ctx_out);
+}
+
+inline uint32_t
+DemoNoiseAdder::randi ()
+{
+  // 31bit Park-Miller-Carta Pseudo-Random Number Generator
+  uint32_t hi, lo;
+  lo = 16807 * (_rseed & 0xffff);
+  hi = 16807 * (_rseed >> 16);
+  lo += (hi & 0x7fff) << 16;
+  lo += hi >> 15;
+  lo = (lo & 0x7fffffff) + (lo >> 31);
+  return (_rseed = lo);
+}

libs/audiographer/wscript

@@ -65,6 +65,7 @@ def build(bld):
         'src/debug_utils.cc',
         'src/general/analyser.cc',
         'src/general/broadcast_info.cc',
+        'src/general/demo_noise.cc',
         'src/general/loudness_reader.cc',
         'src/general/normalizer.cc'
         ]