[timidity-talk] [patch] Add libao plugin options support to ao_a.c

[Yair K <ce...@gm...>]

Hi,

The patch below allows timidity to specify libao plugin options. This le=
ts  =

the libao backend have similiar functionality to other backends (like  =

specifying different output devices - 'timidity -Od -o /dev/dsp2' and  =

'TIMIDITY_LIBAO_OPTS=3D"dsp=3D/dev/dsp2" timidity -OO -o oss' will both =
try to  =

use /dev/dsp2). It should also provide an ability not yet available in  =

timidity - using remote hosts for nas or esd output.
A doc on libao options is at: http://www.xiph.org/ao/doc/drivers.html , =
 =

but it is best to check the libao sources as the doc has a few errors an=
d  =

omissions.

Yours,
	Yair K.

--- timidity/ao_a.c	2004-04-12 20:44:03.000000000 +0300
+++ timidity/ao_a.c	2006-09-02 13:57:03.699576000 +0300
@@ -38,6 +38,8 @@
  #include "playmidi.h"
  #include "miditrace.h"

+static void safe_ao_append_option(ao_option **options, const char *key,=
  =

const char *value);
+static void ao_set_options(int driver_id, ao_option **options);
  static int open_output(void); /* 0=3Dsuccess, 1=3Dwarning, -1=3Dfatal =
error */
  static void close_output(void);
  static int output_data(char *buf, int32 nbytes);
@@ -62,6 +64,87 @@
  static ao_device *ao_device_ctx;
  static ao_sample_format ao_sample_format_ctx;

+static void safe_ao_append_option(ao_option **options, const char *key,=
  =

const char *value)
+{
+ if (ao_append_option(options, key, value) =3D=3D 1) return;
+ else {
+   ctl->cmsg(CMSG_FATAL, VERB_NORMAL,
+                "Fatal error: ao_append_option has failed to allocate  =

memory");
+ #ifdef ABORT_AT_FATAL
+    abort();
+ #endif /* ABORT_AT_FATAL */
+    safe_exit(10);
+    /*NOTREACHED*/
+ }
+}
+
+/* ao_set_options - set options for libao's plugins.
+ * First, it translates a few of TiMidity's defaults into libao's.
+ * Second, it allows the user to pass options via $TIMIDITY_LIBAO_OPTS.=

+ *
+ * TIMIDITY_LIBAO_OPTS should have "key=3Dvalue" pairs, multiple pairs =
are
+ * seperated by commas. e.g. "use_mmap=3D1,dev=3Ddefault". Three import=
ant  =

notes:
+ * 1. Spaces are not clipped, so "dsp =3D /dev/dsp2" will be passed as
+ * "dsp " (key) and " /dev/dsp" (value), which is not valid.
+ * 2. If nothing is present after the "=3D" in the pair, a NULL is
+ * used as the value. "host=3D,buf_size=3D8192" will be passed as "host=
" =3D  =

"NULL"
+ * and "buf_size" =3D "8192".
+ * 3. Later options have precedence over previous ones in libao.
+ * "dsp=3D/dev/dsp2,dsp=3D/dev/dsp" will check only for /dev/dsp in the=
 oss  =

plugin.
+ */
+static void ao_set_options(int driver_id, ao_option **options)
+{
+  #define SUBDELIM '=3D'
+  const char delim =3D ',';
+
+  char *opt_string =3D getenv ("TIMIDITY_LIBAO_OPTS");
+  char *token, *value;
+
+  char *driver_name =3D NULL;
+
+  /* We can't rely on dpm.name, because the interface might have been
+   * selected by ao_default_driver (when dpm.name =3D=3D NULL)
+   */
+  driver_name=3Dao_driver_info(driver_id)->short_name;
+
+  /* We check for each plugin, since some parameters can have a differe=
nt
+   * correct values in different plugins (e.g. "sun"'s dev vs. "alsa09"=
's  =

dev).
+   * and/or different ways of setting them in timidity.
+   */
+  if (!strcmp(driver_name, "alsa09")) {
+      const char *env_pcm_name =3D getenv ("TIMIDITY_PCM_NAME");
+      if (env_pcm_name !=3D NULL) safe_ao_append_option(options, "dev",=
  =

env_pcm_name);
+  } else if (!strcmp(driver_name, "alsa")) {
+    const char *env_pcm_name =3D getenv ("TIMIDITY_PCM_NAME");
+    const char *env_sound_card =3D getenv ("TIMIDITY_SOUND_CARD");
+    if (env_sound_card !=3D NULL) safe_ao_append_option(options, "card"=
,  =

env_sound_card);
+    if (env_pcm_name !=3D NULL) safe_ao_append_option(options, "dev",  =

env_pcm_name);
+  }
+  #ifdef OSS_DEVICE
+  else if (!strcmp(driver_name, "oss")) {
+    safe_ao_append_option(options, "dsp", OSS_DEVICE);
+  }
+  #endif
+
+  if (opt_string =3D=3D NULL) return;
+
+  token=3Dstrtok(opt_string, &delim);
+  while (token !=3D NULL)
+  {
+    value=3Dstrchr(token, SUBDELIM);
+    if ((value =3D=3D NULL) || (value =3D=3D token)) goto next;
+    *value=3D'\0';
+    safe_ao_append_option(options, token, value+1);
+    /* value+1 is always defined since the string is NULL-terminated an=
d
+     * strchr returns either NULL or a pointer before the NULL in the  =

string.
+     */
+
+    next:
+       token=3Dstrtok(NULL, &delim);
+  }
+  #undef SUBDELIM
+}
+
  void show_ao_device_info(FILE *fp)
  {
    int driver_count;
@@ -92,6 +175,7 @@
  static int open_output(void)
  {
    int driver_id;
+  ao_option *options =3D NULL;

    ao_initialize();

@@ -131,11 +215,15 @@
    if (ao_sample_format_ctx.bits =3D=3D 0)
      ao_sample_format_ctx.bits =3D 8;

-  if ((ao_device_ctx =3D ao_open_live(driver_id, &ao_sample_format_ctx,=
  =

NULL /* no options */)) =3D=3D NULL) {
+  ao_set_options(driver_id, &options);
+
+  if ((ao_device_ctx =3D ao_open_live(driver_id, &ao_sample_format_ctx,=
  =

options)) =3D=3D NULL) {
      ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "%s: %s",
  	      dpm.name, strerror(errno));
+    ao_free_options(options);
      return -1;
    }
+  ao_free_options(options);
    return 0;
  }
-- =

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