Bug#460503: sox: play(1) doesn't work without libsox-fmt-ao

[Morita Sho]

I have made a patch.
This patch allows play(1) to determine audio device to use at run-time.

Actually, this patch changes behavior of set_device function.
What changes is:
  * To use audio device only when it is available,
    add this for each one.
      if (sox_find_format("name", sox_false)) {
        ...
        return;
      }

  * To try next device if previous one is unavailable,
    replace
      #elif
    with
      #endif
      #if

After the patch applied,
play(1) works correctly while at least one of
libsox-fmt-alsa, libsox-fmt-ao or libsox-fmt-oss is installed.

I hope this helps.

--
Morita Sho <[EMAIL PROTECTED]>

--- sox-14.0.0/src/sox.c.orig	2007-09-07 05:47:20.000000000 +0900
+++ sox-14.0.0/src/sox.c	2008-01-13 18:11:06.000000000 +0900
@@ -372,25 +372,37 @@
 {
 #ifdef HAVE_LIBAO
   if (!recording) {
-    f->filetype = "ao";
+    if (sox_find_format("ao", sox_false)) {
+      f->filetype = "ao";
+      f->filename = xstrdup("default");
+      return;
+    }
+  }
+#endif
+#if defined(HAVE_ALSA)
+  if (sox_find_format("alsa", sox_false)) {
+    f->filetype = "alsa";
     f->filename = xstrdup("default");
     return;
   }
 #endif
-#if defined(HAVE_ALSA)
-  f->filetype = "alsa";
-  f->filename = xstrdup("default");
-#elif defined(HAVE_SYS_SOUNDCARD_H) || defined(HAVE_MACHINE_SOUNDCARD_H)
-  f->filetype = "ossdsp";
-  f->filename = xstrdup("/dev/dsp");
-#elif defined(HAVE_SYS_AUDIOIO_H) || defined(HAVE_SUN_AUDIOIO_H)
-  char *device = getenv("AUDIODEV");
-  f->filetype = "sunau";
-  f->filename = xstrdup(device ? device : "/dev/audio");
-#else
+#if defined(HAVE_SYS_SOUNDCARD_H) || defined(HAVE_MACHINE_SOUNDCARD_H)
+  if (sox_find_format("ossdsp", sox_false)) {
+    f->filetype = "ossdsp";
+    f->filename = xstrdup("/dev/dsp");
+    return;
+  }
+#endif
+#if defined(HAVE_SYS_AUDIOIO_H) || defined(HAVE_SUN_AUDIOIO_H)
+  if (sox_find_format("sunau", sox_false)) {
+    char *device = getenv("AUDIODEV");
+    f->filetype = "sunau";
+    f->filename = xstrdup(device ? device : "/dev/audio");
+    return;
+  }
+#endif
   sox_fail("Sorry, there is no default audio device configured");
   exit(1);
-#endif
 }
 
 static void set_replay_gain(char const * comment, file_t f)