added mixer

1 files changed, 83 insertions, 0 deletions

diff --git a/apps/mixer.c b/apps/mixer.c
new file mode 100644
index 0000000..1e3287f
--- /dev/null
+++ b/apps/mixer.c
@@ -0,0 +1,83 @@
+/*
+ *  dolmetschctl
+ *
+ *
+ *  Copyright (C) 2015 Christian Pointner <equinox@spreadspace.org>
+ *
+ *  This file is part of dolmetschctl.
+ *
+ *  dolmetschctl 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 3 of the License, or
+ *  any later version.
+ *
+ *  dolmetschctl 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 dolmetschctl. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <error.h>
+#include <poll.h>
+#include <assert.h>
+
+#include "mixer.h"
+
+
+int mixer_init(mixer_t* m, const char* name, const char* device)
+{
+  assert(m != NULL);
+
+  m->name_ = name;
+  m->output_ = NULL;
+  int ret = snd_rawmidi_open(NULL, &(m->output_), device, SND_RAWMIDI_NONBLOCK);
+  if(ret < 0) {
+    error(0, 0, "MIXER: cannot open midi port '%s': %s", device, snd_strerror(ret));
+    return ret;
+  }
+
+  return 0;
+}
+
+int mixer_get_poll_fd_count(mixer_t* m)
+{
+  return snd_rawmidi_poll_descriptors_count(m->output_);
+}
+
+int mixer_get_poll_fds(mixer_t* m, struct pollfd *pfds, int npfds)
+{
+  return snd_rawmidi_poll_descriptors(m->output_, pfds, npfds);
+}
+
+int mixer_handle_revents(mixer_t* m, struct pollfd *pfds, int npfds)
+{
+  int err;
+  unsigned short revents;
+  if((err = snd_rawmidi_poll_descriptors_revents(m->output_, pfds, npfds, &revents)) < 0) {
+    error(0, 0, "MIXER: cannot get poll events: %s", snd_strerror(errno));
+    return -1;
+  }
+  if(pfds[0].revents & (POLLERR | POLLHUP | POLLNVAL)) {
+    error(0, 0, "MIXER: got POLLERR, POLLHUP or POLLNVAL");
+    return -1;
+  }
+  if(!(revents & POLLOUT))
+    return 0;
+
+  u_int8_t buf[3] = { 0xB0, 0x00, 0x02 };
+  int ret = snd_rawmidi_write(m->output_, buf, sizeof(buf));
+  if(ret == -EAGAIN)
+    return 0;
+  if(ret < 0) {
+    error(0, 0, "MIXER: cannot write to midi port: %s", snd_strerror(ret));
+    return -1;
+  }
+
+  return 0;
+}