1 files changed, 543 insertions, 0 deletions
diff --git a/src/output/jack_output_plugin.c b/src/output/jack_output_plugin.c
new file mode 100644
index 000000000..fba921e04
--- /dev/null
+++ b/src/output/jack_output_plugin.c
@@ -0,0 +1,543 @@
+/*
+ * Copyright (C) 2003-2009 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 "output_api.h"
+#include "config.h"
+
+#include <assert.h>
+
+#include <glib.h>
+#include <jack/jack.h>
+#include <jack/types.h>
+#include <jack/ringbuffer.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "jack"
+
+static const size_t sample_size = sizeof(jack_default_audio_sample_t);
+
+static const char *const port_names[2] = {
+	"left", "right",
+};
+
+struct jack_data {
+	const char *name;
+
+	/* configuration */
+	char *output_ports[2];
+	size_t ringbuffer_size;
+
+	/* the current audio format */
+	struct audio_format audio_format;
+
+	/* jack library stuff */
+	jack_port_t *ports[2];
+	jack_client_t *client;
+	jack_ringbuffer_t *ringbuffer[2];
+
+	bool shutdown;
+
+	/**
+	 * While this flag is set, the "process" callback generates
+	 * silence.
+	 */
+	bool pause;
+};
+
+/**
+ * The quark used for GError.domain.
+ */
+static inline GQuark
+jack_output_quark(void)
+{
+	return g_quark_from_static_string("jack_output");
+}
+
+static int
+mpd_jack_process(jack_nframes_t nframes, void *arg)
+{
+	struct jack_data *jd = (struct jack_data *) arg;
+	jack_default_audio_sample_t *out;
+	size_t available;
+
+	if (nframes <= 0)
+		return 0;
+
+	if (jd->pause) {
+		/* generate silence while MPD is paused */
+
+		for (unsigned i = 0; i < G_N_ELEMENTS(jd->ringbuffer); ++i) {
+			out = jack_port_get_buffer(jd->ports[i], nframes);
+
+			for (jack_nframes_t f = 0; f < nframes; ++f)
+				out[f] = 0.0;
+		}
+
+		return 0;
+	}
+
+	for (unsigned i = 0; i < G_N_ELEMENTS(jd->ringbuffer); ++i) {
+		available = jack_ringbuffer_read_space(jd->ringbuffer[i]);
+		assert(available % sample_size == 0);
+		available /= sample_size;
+		if (available > nframes)
+			available = nframes;
+
+		out = jack_port_get_buffer(jd->ports[i], nframes);
+		jack_ringbuffer_read(jd->ringbuffer[i],
+				     (char *)out, available * sample_size);
+
+		while (available < nframes)
+			/* ringbuffer underrun, fill with silence */
+			out[available++] = 0.0;
+	}
+
+	return 0;
+}
+
+static void
+mpd_jack_shutdown(void *arg)
+{
+	struct jack_data *jd = (struct jack_data *) arg;
+	jd->shutdown = true;
+}
+
+static void
+set_audioformat(struct jack_data *jd, struct audio_format *audio_format)
+{
+	audio_format->sample_rate = jack_get_sample_rate(jd->client);
+	audio_format->channels = 2;
+
+	if (audio_format->bits != 16 && audio_format->bits != 24)
+		audio_format->bits = 24;
+}
+
+static void
+mpd_jack_error(const char *msg)
+{
+	g_warning("%s", msg);
+}
+
+#ifdef HAVE_JACK_SET_INFO_FUNCTION
+static void
+mpd_jack_info(const char *msg)
+{
+	g_message("%s", msg);
+}
+#endif
+
+/**
+ * Disconnect the JACK client.
+ */
+static void
+mpd_jack_disconnect(struct jack_data *jd)
+{
+	assert(jd != NULL);
+	assert(jd->client != NULL);
+
+	jack_deactivate(jd->client);
+	jack_client_close(jd->client);
+	jd->client = NULL;
+}
+
+/**
+ * Connect the JACK client and performs some basic setup
+ * (e.g. register callbacks).
+ */
+static bool
+mpd_jack_connect(struct jack_data *jd, GError **error_r)
+{
+	assert(jd != NULL);
+
+	jd->shutdown = false;
+
+	if ((jd->client = jack_client_new(jd->name)) == NULL) {
+		g_set_error(error_r, jack_output_quark(), 0,
+			    "Failed to connect to JACK server");
+		return false;
+	}
+
+	jack_set_process_callback(jd->client, mpd_jack_process, jd);
+	jack_on_shutdown(jd->client, mpd_jack_shutdown, jd);
+
+	for (unsigned i = 0; i < G_N_ELEMENTS(jd->ports); ++i) {
+		jd->ports[i] = jack_port_register(jd->client, port_names[i],
+						  JACK_DEFAULT_AUDIO_TYPE,
+						  JackPortIsOutput, 0);
+		if (jd->ports[i] == NULL) {
+			g_set_error(error_r, jack_output_quark(), 0,
+				    "Cannot register output port \"%s\"",
+				    port_names[i]);
+			mpd_jack_disconnect(jd);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static bool
+mpd_jack_test_default_device(void)
+{
+	return true;
+}
+
+static void *
+mpd_jack_init(G_GNUC_UNUSED const struct audio_format *audio_format,
+	      const struct config_param *param, GError **error_r)
+{
+	struct jack_data *jd;
+	const char *value;
+
+	jd = g_new(struct jack_data, 1);
+	jd->name = config_get_block_string(param, "name", "mpd_jack");
+
+	g_debug("mpd_jack_init (pid=%d)", getpid());
+
+	value = config_get_block_string(param, "ports", NULL);
+	if (value != NULL) {
+		char **ports = g_strsplit(value, ",", 0);
+
+		if (ports[0] == NULL || ports[1] == NULL || ports[2] != NULL) {
+			g_set_error(error_r, jack_output_quark(), 0,
+				    "two port names expected in line %d",
+				    param->line);
+			return NULL;
+		}
+
+		jd->output_ports[0] = ports[0];
+		jd->output_ports[1] = ports[1];
+
+		g_free(ports);
+	} else {
+		jd->output_ports[0] = NULL;
+		jd->output_ports[1] = NULL;
+	}
+
+	jd->ringbuffer_size =
+		config_get_block_unsigned(param, "ringbuffer_size", 32768);
+
+	jack_set_error_function(mpd_jack_error);
+
+#ifdef HAVE_JACK_SET_INFO_FUNCTION
+	jack_set_info_function(mpd_jack_info);
+#endif
+
+	return jd;
+}
+
+static void
+mpd_jack_finish(void *data)
+{
+	struct jack_data *jd = data;
+
+	for (unsigned i = 0; i < G_N_ELEMENTS(jd->output_ports); ++i)
+		g_free(jd->output_ports[i]);
+
+	g_free(jd);
+}
+
+static bool
+mpd_jack_enable(void *data, GError **error_r)
+{
+	struct jack_data *jd = (struct jack_data *)data;
+
+	for (unsigned i = 0; i < G_N_ELEMENTS(jd->ringbuffer); ++i)
+		jd->ringbuffer[i] = NULL;
+
+	return mpd_jack_connect(jd, error_r);
+}
+
+static void
+mpd_jack_disable(void *data)
+{
+	struct jack_data *jd = (struct jack_data *)data;
+
+	if (jd->client != NULL)
+		mpd_jack_disconnect(jd);
+
+	for (unsigned i = 0; i < G_N_ELEMENTS(jd->ringbuffer); ++i) {
+		if (jd->ringbuffer[i] != NULL) {
+			jack_ringbuffer_free(jd->ringbuffer[i]);
+			jd->ringbuffer[i] = NULL;
+		}
+	}
+}
+
+/**
+ * Stops the playback on the JACK connection.
+ */
+static void
+mpd_jack_stop(struct jack_data *jd)
+{
+	assert(jd != NULL);
+
+	if (jd->client == NULL)
+		return;
+
+	if (jd->shutdown)
+		/* the connection has failed; close it */
+		mpd_jack_disconnect(jd);
+	else
+		/* the connection is alive: just stop playback */
+		jack_deactivate(jd->client);
+}
+
+static bool
+mpd_jack_start(struct jack_data *jd, GError **error_r)
+{
+	const char *output_ports[2], **jports;
+
+	if (jd->client == NULL && !mpd_jack_connect(jd, error_r))
+		return false;
+
+	/* allocate the ring buffers on the first open(); these
+	   persist until MPD exits.  It's too unsafe to delete them
+	   because we can never know when mpd_jack_process() gets
+	   called */
+	for (unsigned i = 0; i < G_N_ELEMENTS(jd->ringbuffer); ++i)
+		if (jd->ringbuffer[i] == NULL)
+			jd->ringbuffer[i] =
+				jack_ringbuffer_create(jd->ringbuffer_size);
+
+	if ( jack_activate(jd->client) ) {
+		g_set_error(error_r, jack_output_quark(), 0,
+			    "cannot activate client");
+		mpd_jack_stop(jd);
+		return false;
+	}
+
+	if (jd->output_ports[1] == NULL) {
+		/* no output ports were configured - ask libjack for
+		   defaults */
+		jports = jack_get_ports(jd->client, NULL, NULL,
+					JackPortIsPhysical | JackPortIsInput);
+		if (jports == NULL) {
+			g_set_error(error_r, jack_output_quark(), 0,
+				    "no ports found");
+			mpd_jack_stop(jd);
+			return false;
+		}
+
+		output_ports[0] = jports[0];
+		output_ports[1] = jports[1] != NULL ? jports[1] : jports[0];
+
+		g_debug("output_ports: %s %s", jports[0], jports[1]);
+	} else {
+		/* use the configured output ports */
+
+		output_ports[0] = jd->output_ports[0];
+		output_ports[1] = jd->output_ports[1];
+
+		jports = NULL;
+	}
+
+	for (unsigned i = 0; i < G_N_ELEMENTS(jd->ports); ++i) {
+		int ret;
+
+		ret = jack_connect(jd->client, jack_port_name(jd->ports[i]),
+				   output_ports[i]);
+		if (ret != 0) {
+			g_set_error(error_r, jack_output_quark(), 0,
+				    "Not a valid JACK port: %s",
+				    output_ports[i]);
+
+			if (jports != NULL)
+				free(jports);
+
+			mpd_jack_stop(jd);
+			return false;
+		}
+	}
+
+	if (jports != NULL)
+		free(jports);
+
+	return true;
+}
+
+static bool
+mpd_jack_open(void *data, struct audio_format *audio_format, GError **error_r)
+{
+	struct jack_data *jd = data;
+
+	assert(jd != NULL);
+
+	jd->pause = false;
+
+	if (!mpd_jack_start(jd, error_r))
+		return false;
+
+	set_audioformat(jd, audio_format);
+	jd->audio_format = *audio_format;
+
+	return true;
+}
+
+static void
+mpd_jack_close(G_GNUC_UNUSED void *data)
+{
+	struct jack_data *jd = data;
+
+	mpd_jack_stop(jd);
+}
+
+static inline jack_default_audio_sample_t
+sample_16_to_jack(int16_t sample)
+{
+	return sample / (jack_default_audio_sample_t)(1 << (16 - 1));
+}
+
+static void
+mpd_jack_write_samples_16(struct jack_data *jd, const int16_t *src,
+			  unsigned num_samples)
+{
+	jack_default_audio_sample_t sample;
+
+	while (num_samples-- > 0) {
+		sample = sample_16_to_jack(*src++);
+		jack_ringbuffer_write(jd->ringbuffer[0], (void*)&sample,
+				      sizeof(sample));
+
+		sample = sample_16_to_jack(*src++);
+		jack_ringbuffer_write(jd->ringbuffer[1], (void*)&sample,
+				      sizeof(sample));
+	}
+}
+
+static inline jack_default_audio_sample_t
+sample_24_to_jack(int32_t sample)
+{
+	return sample / (jack_default_audio_sample_t)(1 << (24 - 1));
+}
+
+static void
+mpd_jack_write_samples_24(struct jack_data *jd, const int32_t *src,
+			  unsigned num_samples)
+{
+	jack_default_audio_sample_t sample;
+
+	while (num_samples-- > 0) {
+		sample = sample_24_to_jack(*src++);
+		jack_ringbuffer_write(jd->ringbuffer[0], (void*)&sample,
+				      sizeof(sample));
+
+		sample = sample_24_to_jack(*src++);
+		jack_ringbuffer_write(jd->ringbuffer[1], (void*)&sample,
+				      sizeof(sample));
+	}
+}
+
+static void
+mpd_jack_write_samples(struct jack_data *jd, const void *src,
+		       unsigned num_samples)
+{
+	switch (jd->audio_format.bits) {
+	case 16:
+		mpd_jack_write_samples_16(jd, (const int16_t*)src,
+					  num_samples);
+		break;
+
+	case 24:
+		mpd_jack_write_samples_24(jd, (const int32_t*)src,
+					  num_samples);
+		break;
+
+	default:
+		assert(false);
+	}
+}
+
+static size_t
+mpd_jack_play(void *data, const void *chunk, size_t size, GError **error_r)
+{
+	struct jack_data *jd = data;
+	const size_t frame_size = audio_format_frame_size(&jd->audio_format);
+	size_t space = 0, space1;
+
+	jd->pause = false;
+
+	assert(size % frame_size == 0);
+	size /= frame_size;
+
+	while (true) {
+		if (jd->shutdown) {
+			g_set_error(error_r, jack_output_quark(), 0,
+				    "Refusing to play, because "
+				    "there is no client thread");
+			return 0;
+		}
+
+		space = jack_ringbuffer_write_space(jd->ringbuffer[0]);
+		space1 = jack_ringbuffer_write_space(jd->ringbuffer[1]);
+		if (space > space1)
+			/* send data symmetrically */
+			space = space1;
+
+		if (space >= frame_size)
+			break;
+
+		/* XXX do something more intelligent to
+		   synchronize */
+		g_usleep(1000);
+	}
+
+	space /= sample_size;
+	if (space < size)
+		size = space;
+
+	mpd_jack_write_samples(jd, chunk, size);
+	return size * frame_size;
+}
+
+static bool
+mpd_jack_pause(void *data)
+{
+	struct jack_data *jd = data;
+
+	if (jd->shutdown)
+		return false;
+
+	jd->pause = true;
+
+	/* due to a MPD API limitation, we have to sleep a little bit
+	   here, to avoid hogging the CPU */
+	g_usleep(50000);
+
+	return true;
+}
+
+const struct audio_output_plugin jack_output_plugin = {
+	.name = "jack",
+	.test_default_device = mpd_jack_test_default_device,
+	.init = mpd_jack_init,
+	.finish = mpd_jack_finish,
+	.enable = mpd_jack_enable,
+	.disable = mpd_jack_disable,
+	.open = mpd_jack_open,
+	.play = mpd_jack_play,
+	.pause = mpd_jack_pause,
+	.close = mpd_jack_close,
+};