X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/bd8895a87731c72190ea2012f36583f796d4181a..0e2b222fc14b8f890fab644118cf0f43abbe450a:/lib/mixer.c

diff --git a/lib/mixer.c b/lib/mixer.c
index f674d68..ee88fbb 100644
--- a/lib/mixer.c
+++ b/lib/mixer.c
@@ -17,82 +17,100 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  * USA
  */
+/** @file lib/mixer.c
+ * @brief Mixer support
+ */
 
 #include <config.h>
 #include "types.h"
 
-#include <stdio.h>
-#include <string.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <stddef.h>
-#include <sys/ioctl.h>
-
 #include "configuration.h"
 #include "mixer.h"
 #include "log.h"
-#include "syscalls.h"
+#include "mem.h"
+
+/** @brief Whether lack of volume support has been reported yet */
+static int none_reported;
+
+/** @brief Get/set volume stub if volume control is not supported */
+static int none_get_set(int attribute((unused)) *left,
+			int attribute((unused)) *right) {
+  if(!none_reported) {
+    error(0, "don't know how to get/set volume with this api");
+    none_reported = 1;
+  }
+  return -1;
+}
+
+/** @brief Stub mixer control */
+static const struct mixer mixer_none = {
+  -1,
+  none_get_set,
+  none_get_set,
+  "",
+  ""
+};
 
+/** @brief Table of mixer definitions */
 static const struct mixer *mixers[] = {
 #if HAVE_SYS_SOUNDCARD_H
-  &mixer_oss
+  &mixer_oss,
+#endif
+#if HAVE_ALSA_ASOUNDLIB_H
+  &mixer_alsa,
 #endif
+  &mixer_none				/* make sure array is never empty */
 };
 
+/** @brief Number of mixer definitions */
 #define NMIXERS (sizeof mixers / sizeof *mixers)
 
+/** @brief Find the mixer definition */
 static const struct mixer *find_mixer(int api) {
   size_t n;
 
+  if(api == -1)
+    api = config->api;
   for(n = 0; n < NMIXERS; ++n)
     if(mixers[n]->api == api)
       return mixers[n];
-  return 0;
+  return &mixer_none;
 }
 
-int mixer_valid_channel(int api, const char *c) {
-  const struct mixer *const m = find_mixer(api);
-
-  return m ? m->validate_channel(c) : 1;
-}
-
-int mixer_valid_device(int api, const char *d) {
-  const struct mixer *const m = find_mixer(api);
-
-  return m ? m->validate_device(d) : 1;
-}
-
-int mixer_control(int *left, int *right, int set) {
-  const struct mixer *const m = find_mixer(config->api);
-
-  if(m) {
-    if(set)
-      return m->set(left, right);
-    else
-      return m->get(left, right);
-  } else {
-    static int reported;
-
-    if(!reported) {
-      error(0, "don't know how to get/set volume with this api");
-      reported = 1;
-    }
-    return -1;
-  }
-}
-
-const char *mixer_default_device(int api) {
+/** @brief Return true if we know how to drive the mixer
+ * @param api Sound api or -1 for default
+ * @return true if suppored, false otherwise
+ */
+int mixer_supported(int api) {
   const struct mixer *const m = find_mixer(api);
-
-  return m ? m->device : "";
+  return m != &mixer_none;
 }
 
-const char *mixer_default_channel(int api) {
+/** @brief Get/set volume
+ * @param api Sound api or -1 for default
+ * @param left Left channel level, 0-100
+ * @param right Right channel level, 0-100
+ * @param set Set volume if non-0
+ * @return 0 on success, non-0 on error
+ *
+ * If getting the volume then @p left and @p right are filled in.
+ *
+ * If setting the volume then the target levels are read from @p left and
+ * @p right, and the actual level set is stored in them.
+ */
+int mixer_control(int api, int *left, int *right, int set) {
   const struct mixer *const m = find_mixer(api);
 
-  return m ? m->channel : "";
+  /* We impose defaults bizarrely late, but this has the advantage of
+   * not making everything depend on sound libraries */
+  if(!config->mixer)
+    config->mixer = xstrdup(m->device);
+  if(!config->channel)
+    config->channel = xstrdup(m->channel);
+  if(set)
+    return m->set(left, right);
+  else
+    return m->get(left, right);
 }
 
 /*