output: new output plugin "ffado"

Using libffado, to play on firewire audio devices.

Warning: this plugin was not tested successfully.  I just couldn't
keep libffado2 from crashing.  Use at your own risk.

For details, see my Debian bug reports:

  http://bugs.debian.org/601657
  http://bugs.debian.org/601659

2 files changed, 348 insertions, 0 deletions

diff --git a/src/output/ffado_output_plugin.c b/src/output/ffado_output_plugin.c
new file mode 100644
index 000000000..588957d26
--- /dev/null
+++ b/src/output/ffado_output_plugin.c
@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) 2003-2010 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.
+ */
+
+/*
+ * Warning: this plugin was not tested successfully.  I just couldn't
+ * keep libffado2 from crashing.  Use at your own risk.
+ *
+ * For details, see my Debian bug reports:
+ *
+ *   http://bugs.debian.org/601657
+ *   http://bugs.debian.org/601659
+ *   http://bugs.debian.org/601663
+ *
+ */
+
+#include "config.h"
+#include "output_api.h"
+#include "timer.h"
+
+#include <glib.h>
+#include <assert.h>
+
+#include <libffado/ffado.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "ffado"
+
+enum {
+	MAX_STREAMS = 8,
+};
+
+struct mpd_ffado_stream {
+	/** libffado's stream number */
+	int number;
+
+	float *buffer;
+};
+
+struct mpd_ffado_device {
+	char *device_name;
+	int verbose;
+	unsigned period_size, nb_buffers;
+
+	ffado_device_t *dev;
+
+	/**
+	 * The current sample position inside the stream buffers.  New
+	 * samples get appended at this position on all streams at the
+	 * same time.  When the buffers are full
+	 * (buffer_position==period_size),
+	 * ffado_streaming_transfer_playback_buffers() gets called to
+	 * hand them over to libffado.
+	 */
+	unsigned buffer_position;
+
+	/**
+	 * The number of streams which are really used by MPD.
+	 */
+	int num_streams;
+	struct mpd_ffado_stream streams[MAX_STREAMS];
+};
+
+static inline GQuark
+ffado_output_quark(void)
+{
+	return g_quark_from_static_string("ffado_output");
+}
+
+static void *
+ffado_init(G_GNUC_UNUSED const struct audio_format *audio_format,
+	   const struct config_param *param,
+	   GError **error_r)
+{
+	g_debug("using libffado version %s, API=%d",
+		ffado_get_version(), ffado_get_api_version());
+
+	struct mpd_ffado_device *fd = g_new(struct mpd_ffado_device, 1);
+	fd->device_name = config_dup_block_string(param, "device", NULL);
+	fd->verbose = config_get_block_unsigned(param, "verbose", 0);
+
+	fd->period_size = config_get_block_unsigned(param, "period_size",
+						    1024);
+	if (fd->period_size == 0 || fd->period_size > 1024 * 1024) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "invalid period_size setting");
+		return false;
+	}
+
+	fd->nb_buffers = config_get_block_unsigned(param, "nb_buffers", 3);
+	if (fd->nb_buffers == 0 || fd->nb_buffers > 1024) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "invalid nb_buffers setting");
+		return false;
+	}
+
+	return fd;
+}
+
+static void
+ffado_finish(void *data)
+{
+	struct mpd_ffado_device *fd = data;
+
+	g_free(fd->device_name);
+	g_free(fd);
+}
+
+static bool
+ffado_configure_stream(ffado_device_t *dev, struct mpd_ffado_stream *stream,
+		       GError **error_r)
+{
+	char *buffer = (char *)stream->buffer;
+	if (ffado_streaming_set_playback_stream_buffer(dev, stream->number,
+						       buffer) != 0) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "failed to configure stream buffer");
+		return false;
+	}
+
+	if (ffado_streaming_playback_stream_onoff(dev, stream->number,
+						  1) != 0) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "failed to disable stream");
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+ffado_configure(struct mpd_ffado_device *fd, struct audio_format *audio_format,
+		GError **error_r)
+{
+	assert(fd != NULL);
+	assert(fd->dev != NULL);
+	assert(audio_format->channels <= MAX_STREAMS);
+
+	if (ffado_streaming_set_audio_datatype(fd->dev,
+					       ffado_audio_datatype_float) != 0) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "ffado_streaming_set_audio_datatype() failed");
+		return false;
+	}
+
+	int num_streams = ffado_streaming_get_nb_playback_streams(fd->dev);
+	if (num_streams < 0) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "ffado_streaming_get_nb_playback_streams() failed");
+		return false;
+	}
+
+	g_debug("there are %d playback streams", num_streams);
+
+	fd->num_streams = 0;
+	for (int i = 0; i < num_streams; ++i) {
+		char name[256];
+		ffado_streaming_get_playback_stream_name(fd->dev, i, name,
+							 sizeof(name) - 1);
+
+		ffado_streaming_stream_type type =
+			ffado_streaming_get_playback_stream_type(fd->dev, i);
+		if (type != ffado_stream_type_audio) {
+			g_debug("stream %d name='%s': not an audio stream",
+				i, name);
+			continue;
+		}
+
+		if (fd->num_streams >= audio_format->channels) {
+			g_debug("stream %d name='%s': ignoring",
+				i, name);
+			continue;
+		}
+
+		g_debug("stream %d name='%s'", i, name);
+
+		struct mpd_ffado_stream *stream =
+			&fd->streams[fd->num_streams++];
+
+		stream->number = i;
+
+		/* allocated buffer is zeroed = silence */
+		stream->buffer = g_new0(float, fd->period_size);
+
+		if (!ffado_configure_stream(fd->dev, stream, error_r))
+			return false;
+	}
+
+	if (!audio_valid_channel_count(fd->num_streams)) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "invalid channel count from libffado: %u",
+			    audio_format->channels);
+		return false;
+	}
+
+	g_debug("configured %d audio streams", fd->num_streams);
+
+	if (ffado_streaming_prepare(fd->dev) != 0) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "ffado_streaming_prepare() failed");
+		return false;
+	}
+
+	if (ffado_streaming_start(fd->dev) != 0) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "ffado_streaming_start() failed");
+		return false;
+	}
+
+	audio_format->channels = fd->num_streams;
+	return true;
+}
+
+static bool
+ffado_open(void *data, struct audio_format *audio_format, GError **error_r)
+{
+	struct mpd_ffado_device *fd = data;
+
+	/* will be converted to floating point, choose best input
+	   format */
+	audio_format->format = SAMPLE_FORMAT_S24_P32;
+
+	ffado_device_info_t device_info;
+	memset(&device_info, 0, sizeof(device_info));
+	if (fd->device_name != NULL) {
+		device_info.nb_device_spec_strings = 1;
+		device_info.device_spec_strings = &fd->device_name;
+	}
+
+	ffado_options_t options;
+	memset(&options, 0, sizeof(options));
+	options.sample_rate = audio_format->sample_rate;
+	options.period_size = fd->period_size;
+	options.nb_buffers = fd->nb_buffers;
+	options.verbose = fd->verbose;
+
+	fd->dev = ffado_streaming_init(device_info, options);
+	if (fd->dev == NULL) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "ffado_streaming_init() failed");
+		return false;
+	}
+
+	if (!ffado_configure(fd, audio_format, error_r)) {
+		ffado_streaming_finish(fd->dev);
+
+		for (int i = 0; i < fd->num_streams; ++i) {
+			struct mpd_ffado_stream *stream = &fd->streams[i];
+			g_free(stream->buffer);
+		}
+
+		return false;
+	}
+
+	fd->buffer_position = 0;
+
+	return true;
+}
+
+static void
+ffado_close(void *data)
+{
+	struct mpd_ffado_device *fd = data;
+
+	ffado_streaming_stop(fd->dev);
+	ffado_streaming_finish(fd->dev);
+
+	for (int i = 0; i < fd->num_streams; ++i) {
+		struct mpd_ffado_stream *stream = &fd->streams[i];
+		g_free(stream->buffer);
+	}
+}
+
+static size_t
+ffado_play(void *data, const void *chunk, size_t size, GError **error_r)
+{
+	struct mpd_ffado_device *fd = data;
+
+	/* wait for prefious buffer to finish (if it was full) */
+
+	if (fd->buffer_position >= fd->period_size) {
+		switch (ffado_streaming_wait(fd->dev)) {
+		case ffado_wait_ok:
+		case ffado_wait_xrun:
+			break;
+
+		default:
+			g_set_error(error_r, ffado_output_quark(), 0,
+				    "ffado_streaming_wait() failed");
+			return 0;
+		}
+
+		fd->buffer_position = 0;
+	}
+
+	/* copy samples to stream buffers, non-interleaved */
+
+	const int32_t *p = chunk;
+	unsigned num_frames = size / sizeof(*p) / fd->num_streams;
+	if (num_frames > fd->period_size - fd->buffer_position)
+		num_frames = fd->period_size - fd->buffer_position;
+
+	for (unsigned i = num_frames; i > 0; --i) {
+		for (int stream = 0; stream < fd->num_streams; ++stream)
+			fd->streams[stream].buffer[fd->buffer_position] =
+				*p++ / (float)(1 << 23);
+		++fd->buffer_position;
+	}
+
+	/* if buffer full, transfer to device */
+
+	if (fd->buffer_position >= fd->period_size &&
+	    ffado_streaming_transfer_playback_buffers(fd->dev) != 0) {
+		g_set_error(error_r, ffado_output_quark(), 0,
+			    "ffado_streaming_transfer_playback_buffers() failed");
+		return 0;
+	}
+
+	return num_frames * sizeof(*p) * fd->num_streams;
+}
+
+const struct audio_output_plugin ffado_output_plugin = {
+	.name = "ffado",
+	.init = ffado_init,
+	.finish = ffado_finish,
+	.open = ffado_open,
+	.close = ffado_close,
+	.play = ffado_play,
+};
diff --git a/src/output_list.c b/src/output_list.c
index 0d1e70968..8238f581b 100644
--- a/src/output_list.c
+++ b/src/output_list.c
@@ -37,6 +37,7 @@ extern const struct audio_output_plugin jack_output_plugin;
 extern const struct audio_output_plugin httpd_output_plugin;
 extern const struct audio_output_plugin recorder_output_plugin;
 extern const struct audio_output_plugin winmm_output_plugin;
+extern const struct audio_output_plugin ffado_output_plugin;
 
 const struct audio_output_plugin *audio_output_plugins[] = {
 #ifdef HAVE_SHOUT
@@ -85,6 +86,9 @@ const struct audio_output_plugin *audio_output_plugins[] = {
 #ifdef ENABLE_WINMM_OUTPUT
 	&winmm_output_plugin,
 #endif
+#ifdef ENABLE_FFADO_OUTPUT
+	&ffado_output_plugin,
+#endif
 	NULL
 };