From d58b85b8ae8cd890f9e188c60faf165f5b8d733f Mon Sep 17 00:00:00 2001
From: Emery Hemingway <ehmry@posteo.net>
Date: Wed, 10 Jul 2019 14:06:56 +0200
Subject: [PATCH] Restore original mp3_audio_sink

Use the version written against the traditional audio streams.
---
 src/mp3_audio_sink/component.cc | 65 +++++++++++++++++++++++++--------
 1 file changed, 50 insertions(+), 15 deletions(-)

diff --git a/src/mp3_audio_sink/component.cc b/src/mp3_audio_sink/component.cc
index 56dddae1b..f089e4163 100644
--- a/src/mp3_audio_sink/component.cc
+++ b/src/mp3_audio_sink/component.cc
@@ -14,6 +14,7 @@
 /*
  * TODO:
  * - Metadata report
+ * - Configure the mpg123 volume control and equalizer
  * - Optimize buffer sizes
  */
 
@@ -21,7 +22,7 @@
 #include <gems/magic_ring_buffer.h>
 #include <os/static_root.h>
 #include <libc/component.h>
-#include <audio/source.h>
+#include <audio_out_session/connection.h>
 #include <terminal_session/connection.h>
 #include <base/attached_rom_dataspace.h>
 #include <base/attached_ram_dataspace.h>
@@ -57,7 +58,7 @@ namespace Mp3_audio_sink {
 }
 
 
-struct Mp3_audio_sink::Decoder : Audio::Source
+struct Mp3_audio_sink::Decoder
 {
 	template <typename FUNC>
 	static void for_each_channel(FUNC const &func) {
@@ -67,7 +68,9 @@ struct Mp3_audio_sink::Decoder : Audio::Source
 
 	Attached_rom_dataspace _config_rom { _env, "config" };
 
-	Audio::Stereo_out _stereo_out { _env, *this };
+	Audio_out::Connection _out_left  { _env, "left",  true, true };
+	Audio_out::Connection _out_right { _env, "right", false, false };
+	Audio_out::Connection *_out[NUM_CHANNELS];
 
 	void die_mpg123(mpg123_handle *mh, char const *msg)
 	{
@@ -146,7 +149,7 @@ struct Mp3_audio_sink::Decoder : Audio::Source
 		return value;
 	}
 
-	bool fill(float *left, float *right, Genode::size_t samples) override;
+	void submit_audio();
 
 	/**
 	 * Process client data, blocks until all data is consumed.
@@ -170,7 +173,7 @@ struct Mp3_audio_sink::Decoder : Audio::Source
 
 				while (_pcm.write_avail() < samples) {
 					/* submit audio blocks for packet allocation */
-					_env.ep().wait_and_dispatch_one_io_signal();
+					submit_audio();
 				}
 
 				Genode::memcpy(_pcm.write_addr(), audio, bytes);
@@ -184,6 +187,9 @@ struct Mp3_audio_sink::Decoder : Audio::Source
 		});
 	}
 
+	Io_signal_handler<Decoder> _progress_handler {
+		_env.ep(), *this, &Decoder::submit_audio };
+
 	Signal_handler<Decoder> _config_handler {
 		_env.ep(), *this, &Decoder::_handle_config };
 
@@ -212,28 +218,57 @@ struct Mp3_audio_sink::Decoder : Audio::Source
 
 	Decoder(Genode::Env &env) : _env(env)
 	{
+		_out[LEFT]  = &_out_left;
+		_out[RIGHT] = &_out_right;
+		_out_left.progress_sigh(_progress_handler);
 		_config_rom.sigh(_config_handler);
 		_handle_config();
 	}
 };
 
 
-bool Mp3_audio_sink::Decoder::fill(float *left,
-                                   float *right,
-                                   Genode::size_t samples)
+void Mp3_audio_sink::Decoder::submit_audio()
 {
 	using namespace Audio_out;
 
-	if (_pcm.read_avail() < samples*2) return false;
+	enum { STEREO_PERIOD = Audio_out::PERIOD*NUM_CHANNELS };
 
-	float const *buf = _pcm.read_addr();
-	for (unsigned i = 0; i < samples; ++i) {
-	 	 left[i] = buf[(i<<1)|0];
-		right[i] = buf[(i<<1)|1];
+	if (_out_left.stream()->empty()) {
+		for_each_channel([&] (int const c) {
+			_out[c]->start(); });
+		log("Audio_out streams started");
 	}
 
-	_pcm.drain(samples*2);
-	return true;
+	while (_pcm.read_avail() > STEREO_PERIOD) {
+		Audio_out::Packet *p[NUM_CHANNELS];
+
+		while (true) {
+			try { p[LEFT] = _out[LEFT]->stream()->alloc(); break; }
+			catch (Audio_out::Stream::Alloc_failed) {
+				_out[LEFT]->wait_for_alloc(); }
+		}
+
+		unsigned const ppos = _out[LEFT]->stream()->packet_position(p[LEFT]);
+		p[RIGHT] = _out[RIGHT]->stream()->get(ppos);
+
+		float const *content = _pcm.read_addr();
+
+		/* copy channel contents into sessions */
+		for (unsigned i = 0; i < STEREO_PERIOD; i += NUM_CHANNELS) {
+			for_each_channel([&] (int const c) {
+				p[c]->content()[i/NUM_CHANNELS] = content[i+c]; });
+		}
+
+		for_each_channel([&] (int const c) {
+			 _out[c]->submit(p[c]); });
+		_pcm.drain(STEREO_PERIOD);
+	}
+
+	if (_out_left.stream()->empty()) {
+		log("Audio_out queue underrun, stopping stream");
+		for_each_channel([&] (int const c) {
+			_out[c]->stop(); });
+	}
 }