player/Thread: add option "mixramp_analyzer"

src/pcm/MixRampGlue.cxx

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2003-2021 The Music Player Daemon Project
+ * http://www.musicpd.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 "MixRampGlue.hxx"
+#include "MixRampAnalyzer.hxx"
+#include "AudioFormat.hxx"
+#include "MusicPipe.hxx"
+#include "MusicChunk.hxx"
+#include "util/Compiler.h"
+
+#include <stdio.h>
+
+static std::string
+StartToString(const MixRampArray &a) noexcept
+{
+	std::string s;
+
+	MixRampItem last{};
+	for (const auto &i : a) {
+		if (i.time < FloatDuration{} || i == last)
+			continue;
+
+		char buffer[64];
+		sprintf(buffer, "%.2f %.2f;", i.volume, i.time.count());
+		last = i;
+
+		s.append(buffer);
+	}
+
+	return s;
+}
+
+static std::string
+EndToString(const MixRampArray &a, FloatDuration total_time) noexcept
+{
+	std::string s;
+
+	MixRampItem last{};
+	for (const auto &i : a) {
+		if (i.time < FloatDuration{} || i == last)
+			continue;
+
+		char buffer[64];
+		sprintf(buffer, "%.2f %.2f;",
+			i.volume, (total_time - i.time).count());
+		last = i;
+
+		s.append(buffer);
+	}
+
+	return s;
+}
+
+static std::string
+ToString(const MixRampData &mr, FloatDuration total_time,
+	 MixRampDirection direction) noexcept
+{
+	switch (direction) {
+	case MixRampDirection::START:
+		return StartToString(mr.start);
+
+	case MixRampDirection::END:
+		return EndToString(mr.end, total_time);
+	}
+
+	gcc_unreachable();
+}
+
+std::string
+AnalyzeMixRamp(const MusicPipe &pipe, const AudioFormat &audio_format,
+	       MixRampDirection direction) noexcept
+{
+	if (audio_format.sample_rate != ReplayGainAnalyzer::SAMPLE_RATE ||
+	    audio_format.channels != ReplayGainAnalyzer::CHANNELS ||
+	    audio_format.format != SampleFormat::FLOAT)
+		// TODO: auto-convert
+		return {};
+
+	const auto *chunk = pipe.Peek();
+	if (chunk == nullptr)
+		return {};
+
+	MixRampAnalyzer a;
+	do {
+		a.Process(ConstBuffer<ReplayGainAnalyzer::Frame>::FromVoid({chunk->data, chunk->length}));
+	} while ((chunk = chunk->next.get()) != nullptr);
+
+	return ToString(a.GetResult(), a.GetTime(), direction);
+}

src/pcm/MixRampGlue.hxx

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2003-2021 The Music Player Daemon Project
+ * http://www.musicpd.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.
+ */
+
+#pragma once
+
+#include <string>
+
+struct AudioFormat;
+class MusicPipe;
+
+enum class MixRampDirection {
+	START, END
+};
+
+[[gnu::pure]]
+std::string
+AnalyzeMixRamp(const MusicPipe &pipe, const AudioFormat &audio_format,
+	       MixRampDirection direction) noexcept;

src/pcm/meson.build

@@ -49,6 +49,7 @@ pcm_sources = [
   'AudioCompress/compress.c',
   'ReplayGainAnalyzer.cxx',
   'MixRampAnalyzer.cxx',
+  'MixRampGlue.cxx',
 ]
 
 libsamplerate_dep = dependency('samplerate', version: '>= 0.1.3', required: get_option('libsamplerate'))