Create AudioOutput singleton, from extracted BasebandProcessor code.

firmware/baseband/audio_output.cpp

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * 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, 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; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "audio_output.hpp"
+
+#include "portapack_shared_memory.hpp"
+
+#include "audio_dma.hpp"
+
+#include "message.hpp"
+
+#include <cstdint>
+#include <cstddef>
+
+void AudioOutput::configure(
+	const iir_biquad_config_t& hpf_config,
+	const iir_biquad_config_t& deemph_config,
+	const uint32_t squelch_threshold
+) {
+	hpf.configure(hpf_config);
+	deemph.configure(deemph_config);
+	squelch.set_threshold(squelch_threshold);
+}
+
+void AudioOutput::write(
+	const buffer_s16_t& audio
+) {
+	const auto audio_present_now = squelch.execute(audio);
+
+	hpf.execute_in_place(audio);
+	deemph.execute_in_place(audio);
+
+	static uint64_t audio_present_history = 0;
+	audio_present_history = (audio_present_history << 1) | (audio_present_now ? 1 : 0);
+	const bool audio_present = (audio_present_history != 0);
+	
+	if( audio_present ) {
+		i2s::i2s0::tx_unmute();
+	} else {
+		i2s::i2s0::tx_mute();
+		for(size_t i=0; i<audio.count; i++) {
+			audio.p[i] = 0;
+		}
+	}
+
+	fill_audio_buffer(audio);
+}
+
+void AudioOutput::fill_audio_buffer(const buffer_s16_t& audio) {
+	auto audio_buffer = audio::dma::tx_empty_buffer();
+	for(size_t i=0; i<audio_buffer.count; i++) {
+		audio_buffer.p[i].left = audio_buffer.p[i].right = audio.p[i];
+	}
+
+	feed_audio_stats(audio);
+}
+
+void AudioOutput::feed_audio_stats(const buffer_s16_t& audio) {
+	audio_stats.feed(
+		audio,
+		[](const AudioStatistics& statistics) {
+			const AudioStatisticsMessage audio_stats_message { statistics };
+			shared_memory.application_queue.push(audio_stats_message);
+		}
+	);
+}
+
+AudioOutput audio_output;