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-rw-r--r--src/InputRegistry.cxx7
-rw-r--r--src/input/AlsaInputPlugin.cxx206
-rw-r--r--src/input/AlsaInputPlugin.hxx28
-rw-r--r--src/ls.cxx3
4 files changed, 244 insertions, 0 deletions
diff --git a/src/InputRegistry.cxx b/src/InputRegistry.cxx
index aa6c06ed1..ef4acb237 100644
--- a/src/InputRegistry.cxx
+++ b/src/InputRegistry.cxx
@@ -22,6 +22,10 @@
#include "util/Macros.hxx"
#include "input/FileInputPlugin.hxx"
+#ifdef HAVE_ALSA
+#include "input/AlsaInputPlugin.hxx"
+#endif
+
#ifdef ENABLE_ARCHIVE
#include "input/ArchiveInputPlugin.hxx"
#endif
@@ -48,6 +52,9 @@
const InputPlugin *const input_plugins[] = {
&input_plugin_file,
+#ifdef HAVE_ALSA
+ &input_plugin_alsa,
+#endif
#ifdef ENABLE_ARCHIVE
&input_plugin_archive,
#endif
diff --git a/src/input/AlsaInputPlugin.cxx b/src/input/AlsaInputPlugin.cxx
new file mode 100644
index 000000000..f014434c1
--- /dev/null
+++ b/src/input/AlsaInputPlugin.cxx
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2003-2013 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.
+ */
+
+/*
+ * ALSA code based on an example by Paul Davis released under GPL here:
+ * http://equalarea.com/paul/alsa-audio.html
+ * and one by Matthias Nagorni, also GPL, here:
+ * http://alsamodular.sourceforge.net/alsa_programming_howto.html
+ */
+
+#include "config.h"
+#include "AlsaInputPlugin.hxx"
+#include "InputPlugin.hxx"
+#include "InputStream.hxx"
+#include "util/Domain.hxx"
+#include "util/Error.hxx"
+#include "util/StringUtil.hxx"
+#include "Log.hxx"
+
+#include <alsa/asoundlib.h>
+
+static constexpr Domain alsa_input_domain("alsa");
+
+static constexpr const char *default_device = "hw:0,0";
+
+// this value chosen to balance between limiting latency and avoiding stutter
+static constexpr int max_frames_to_buffer = 64;
+
+// the following defaults are because the PcmDecoderPlugin forces CD format
+static constexpr snd_pcm_format_t default_format = SND_PCM_FORMAT_S16;
+static constexpr int default_channels = 2; // stereo
+static constexpr unsigned int default_rate = 44100; // cd quality
+
+struct AlsaInputStream {
+ InputStream base;
+ snd_pcm_t *capture_handle;
+ size_t frame_size;
+ size_t max_bytes_to_read;
+
+ AlsaInputStream(const char *uri, Mutex &mutex, Cond &cond,
+ snd_pcm_t *handle)
+ :base(input_plugin_alsa, uri, mutex, cond),
+ capture_handle(handle) {
+ frame_size = snd_pcm_format_width(default_format) / 8 * default_channels;
+ max_bytes_to_read = max_frames_to_buffer * frame_size;
+ base.mime = strdup("audio/x-mpd-cdda-pcm");
+ base.seekable = false;
+ base.size = -1;
+ base.ready = true;
+ }
+
+ ~AlsaInputStream() {
+ snd_pcm_close(capture_handle);
+ }
+};
+
+static InputStream *
+alsa_input_open(const char *uri, Mutex &mutex, Cond &cond, Error &error)
+{
+ int err;
+
+ // check uri is appropriate for alsa input
+ if (!StringStartsWith(uri, "alsa://"))
+ return nullptr;
+
+ const char *device = uri + 7;
+ if (device[0] == '\0')
+ device = default_device;
+
+ snd_pcm_t *capture_handle;
+ if ((err = snd_pcm_open(&capture_handle, device,
+ SND_PCM_STREAM_CAPTURE, 0)) < 0) {
+ error.Format(alsa_input_domain, "Failed to open device: %s (%s)", device, snd_strerror(err));
+ return nullptr;
+ }
+
+ snd_pcm_hw_params_t *hw_params;
+ if ((err = snd_pcm_hw_params_malloc(&hw_params)) < 0) {
+ error.Format(alsa_input_domain, "Cannot allocate hardware parameter structure (%s)", snd_strerror(err));
+ snd_pcm_close(capture_handle);
+ return nullptr;
+ }
+
+ if ((err = snd_pcm_hw_params_any(capture_handle, hw_params)) < 0) {
+ error.Format(alsa_input_domain, "Cannot initialize hardware parameter structure (%s)", snd_strerror(err));
+ snd_pcm_hw_params_free(hw_params);
+ snd_pcm_close(capture_handle);
+ return nullptr;
+ }
+
+ if ((err = snd_pcm_hw_params_set_access(capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
+ error.Format(alsa_input_domain, "Cannot set access type (%s)", snd_strerror (err));
+ snd_pcm_hw_params_free (hw_params);
+ snd_pcm_close(capture_handle);
+ return nullptr;
+ }
+
+ if ((err = snd_pcm_hw_params_set_format(capture_handle, hw_params, default_format)) < 0) {
+ snd_pcm_hw_params_free(hw_params);
+ snd_pcm_close(capture_handle);
+ error.Format(alsa_input_domain, "Cannot set sample format (%s)", snd_strerror (err));
+ return nullptr;
+ }
+
+ if ((err = snd_pcm_hw_params_set_channels(capture_handle, hw_params, default_channels)) < 0) {
+ snd_pcm_hw_params_free(hw_params);
+ snd_pcm_close(capture_handle);
+ error.Format(alsa_input_domain, "Cannot set channels (%s)", snd_strerror (err));
+ return nullptr;
+ }
+
+ if ((err = snd_pcm_hw_params_set_rate(capture_handle, hw_params, default_rate, 0)) < 0) {
+ snd_pcm_hw_params_free(hw_params);
+ snd_pcm_close(capture_handle);
+ error.Format(alsa_input_domain, "Cannot set sample rate (%s)", snd_strerror (err));
+ return nullptr;
+ }
+
+ if ((err = snd_pcm_hw_params(capture_handle, hw_params)) < 0) {
+ error.Format(alsa_input_domain, "Cannot set parameters (%s)", snd_strerror (err));
+ snd_pcm_hw_params_free(hw_params);
+ snd_pcm_close(capture_handle);
+ return nullptr;
+ }
+
+ snd_pcm_hw_params_free (hw_params);
+
+ // clear any data already in the PCM buffer
+ if ((err = snd_pcm_drop(capture_handle)) < 0) {
+ error.Format(alsa_input_domain, "Cannot clear PCM buffer (%s)", snd_strerror (err));
+ snd_pcm_hw_params_free(hw_params);
+ snd_pcm_close(capture_handle);
+ return nullptr;
+ }
+
+ AlsaInputStream *ais = new AlsaInputStream(uri, mutex, cond, capture_handle);
+ return &ais->base;
+}
+
+static void
+alsa_input_close(InputStream *is)
+{
+ AlsaInputStream *ais = (AlsaInputStream*) is;
+ delete ais;
+}
+
+static size_t
+alsa_input_read(InputStream *is, void *ptr, size_t size,
+ gcc_unused Error &error)
+{
+ AlsaInputStream *ais = (AlsaInputStream*) is;
+ int num_frames = max_frames_to_buffer;
+ if (size < ais->max_bytes_to_read)
+ // calculate number of whole frames that will fit in size bytes
+ num_frames = size / ais->frame_size;
+
+ int ret;
+ while ((ret = snd_pcm_readi(ais->capture_handle, ptr,
+ num_frames)) < 0) {
+ snd_pcm_prepare(ais->capture_handle);
+ LogDebug(alsa_input_domain, "Buffer Overrun");
+ }
+
+ size_t nbytes = ret == max_frames_to_buffer
+ ? ais->max_bytes_to_read
+ : ret * ais->frame_size;
+ is->offset += nbytes;
+ return nbytes;
+}
+
+static bool
+alsa_input_eof(gcc_unused InputStream *is)
+{
+ return false;
+};
+
+const struct InputPlugin input_plugin_alsa = {
+ .name = "alsa",
+ .init = nullptr,
+ .finish = nullptr,
+ .open = alsa_input_open,
+ .close = alsa_input_close,
+ .check = nullptr,
+ .update = nullptr,
+ .tag = nullptr,
+ .available = nullptr,
+ .read = alsa_input_read,
+ .eof = alsa_input_eof,
+ .seek = nullptr
+};
diff --git a/src/input/AlsaInputPlugin.hxx b/src/input/AlsaInputPlugin.hxx
new file mode 100644
index 000000000..ac9519588
--- /dev/null
+++ b/src/input/AlsaInputPlugin.hxx
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2003-2013 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.
+ */
+
+#ifndef MPD_ALSA_INPUT_PLUGIN_HXX
+#define MPD_ALSA_INPUT_PLUGIN_HXX
+
+#include "InputPlugin.hxx"
+
+extern const struct InputPlugin input_plugin_alsa;
+
+
+#endif
diff --git a/src/ls.cxx b/src/ls.cxx
index 117c8875b..8039cf1d8 100644
--- a/src/ls.cxx
+++ b/src/ls.cxx
@@ -55,6 +55,9 @@ static const char *remoteUrlPrefixes[] = {
#ifdef ENABLE_DESPOTIFY
"spt://",
#endif
+#ifdef HAVE_ALSA
+ "alsa://",
+#endif
NULL
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-04 14:56:54 +0000