X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/f845e711f93952805f2773900d64a499e293b270..a1bedb6db8934e6788075a1e1cda001356cf1d8b:/lib/mixer.c

diff --git a/lib/mixer.c b/lib/mixer.c
index 5ef30a2..58d9e60 100644
--- a/lib/mixer.c
+++ b/lib/mixer.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of DisOrder
- * Copyright (C) 2004 Richard Kettlewell
+ * Copyright (C) 2007 Richard Kettlewell
  *
  * 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
@@ -17,98 +17,89 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  * USA
  */
+/** @file lib/mixer.c
+ * @brief Mixer support
+ */
 
 #include <config.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 "types.h"
 
 #include "configuration.h"
 #include "mixer.h"
 #include "log.h"
-#include "syscalls.h"
+#include "mem.h"
 
-#if HAVE_SYS_SOUNDCARD_H
-#include <sys/soundcard.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,
+  "",
+  ""
+};
 
-/* documentation does not match implementation! */
-#ifndef SOUND_MIXER_READ
-# define SOUND_MIXER_READ(x) MIXER_READ(x)
+/** @brief Table of mixer definitions */
+static const struct mixer *mixers[] = {
+#if HAVE_SYS_SOUNDCARD_H
+  &mixer_oss,
 #endif
-#ifndef SOUND_MIXER_WRITE
-# define SOUND_MIXER_WRITE(x) MIXER_WRITE(x)
+#if HAVE_ALSA_ASOUNDLIB_H
+  &mixer_alsa,
 #endif
+  &mixer_none				/* make sure array is never empty */
+};
 
-static const char *channels[] = SOUND_DEVICE_NAMES;
+/** @brief Number of mixer definitions */
+#define NMIXERS (sizeof mixers / sizeof *mixers)
 
-int mixer_channel(const char *c) {
-  unsigned n;
-  
-  if(!c[strspn(c, "0123456789")])
-    return atoi(c);
-  else {
-    for(n = 0; n < sizeof channels / sizeof *channels; ++n)
-      if(!strcmp(channels[n], c))
-	return n;
-    return -1;
-  }
-}
+/** @brief Find the mixer definition */
+static const struct mixer *find_mixer(int api) {
+  size_t n;
 
-int mixer_control(int *left, int *right, int set) {
-  int fd, ch, r;
-    
-  if(config->mixer
-     && config->channel
-     && (ch = mixer_channel(config->channel)) != -1) {
-    if((fd = open(config->mixer, O_RDWR, 0)) < 0) {
-      error(errno, "error opening %s", config->mixer);
-      return -1;
-    }
-    if(set) {
-      r = (*left & 0xff) + (*right & 0xff) * 256;
-      if(ioctl(fd, SOUND_MIXER_WRITE(ch), &r) == -1) {
-	error(errno, "error changing %s channel %s",
-	      config->mixer, config->channel);
-	xclose(fd);
-	return -1;
-      }
-    }
-    if(ioctl(fd, SOUND_MIXER_READ(ch), &r) == -1) {
-      error(errno, "error reading %s channel %s",
-	    config->mixer, config->channel);
-      xclose(fd);
-      return -1;
-    }
-    *left = r & 0xff;
-    *right = (r >> 8) & 0xff;
-    xclose(fd);
-    return 0;
-  } else
-    return -1;
-}
-#else
-int mixer_channel(const char attribute((unused)) *c) {
-  return 0;
+  for(n = 0; n < NMIXERS; ++n)
+    if(mixers[n]->api == api)
+      return mixers[n];
+  return &mixer_none;
 }
 
-int mixer_control(int attribute((unused)) *left, 
-		  int attribute((unused)) *right,
-		  int attribute((unused)) set) {
-  static int reported;
+/** @brief Get/set volume
+ * @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 *left, int *right, int set) {
+  const struct mixer *const m = find_mixer(config->api);
 
-  if(!reported) {
-    error(0, "don't know how to set volume on this platform");
-    reported = 1;
-  }
-  return -1;
+  /* 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);
 }
-#endif
 
 /*
 Local Variables: