[vorbis-dev] libao AU driver

William T. Mahan wtm2 at duke.edu
Tue May 8 20:32:30 PDT 2001


Hi,

I noticed there was some discussion on this list about the desire
for ogg123 to support output to stdout via Sun's .au file format, so
I decided to give implementing an AU driver for libao a shot.  Here
is my first attempt.

To test the driver:
        * Apply the patch below (against ao in CVS)
        * Copy the attached ao_au.c into ao/src
        * Run ao/autogen.sh, compile, and install
        * Test: e.g. ogg123 -d au -o file:- | play -t au -

This is my first patch to libao, so any comments or suggestions
would be appreciated.  Thanks to Stan Seibert for the raw
output driver, which I used as an example.  I hope someone
finds this driver useful.

Regards,
Wil Mahan

Index: doc/DRIVERS
===================================================================
RCS file: /usr/local/cvsroot/ao/doc/DRIVERS,v
retrieving revision 1.3
diff -u -r1.3 DRIVERS
--- doc/DRIVERS	2001/05/06 00:13:58	1.3
+++ doc/DRIVERS	2001/05/09 01:39:18
@@ -72,6 +72,15 @@
                 big-endian order, and "little" for little-endian order. By
                 default this is "native".

+au
+--
+Sun audio file output.  Writes an au file from the audio
+data you output.
+	Option keys:
+		"file" - Sets the output file.  Use "-" to
+		write to stdout.  By default this is
+		"output.au".
+
 ADDING NEW DRIVERS

 [To be written. - Stan]
Index: include/ao/ao.h
===================================================================
RCS file: /usr/local/cvsroot/ao/include/ao/ao.h,v
retrieving revision 1.12
diff -u -r1.12 ao.h
--- include/ao/ao.h	2001/05/06 00:13:59	1.12
+++ include/ao/ao.h	2001/05/09 01:39:18
@@ -76,6 +76,7 @@
 #define AO_NULL     0
 #define AO_WAV      1
 #define AO_RAW	    2
+#define AO_AU       3

 /* --- Functions --- */

Index: src/Makefile.am
===================================================================
RCS file: /usr/local/cvsroot/ao/src/Makefile.am,v
retrieving revision 1.5
diff -u -r1.5 Makefile.am
--- src/Makefile.am	2001/05/06 00:13:59	1.5
+++ src/Makefile.am	2001/05/09 01:39:18
@@ -7,7 +7,7 @@

 lib_LTLIBRARIES = libao.la

-libao_la_SOURCES = audio_out.c ao_raw.c ao_wav.c ao_null.c
+libao_la_SOURCES = audio_out.c ao_au.c ao_raw.c ao_wav.c ao_null.c
 libao_la_LDFLAGS = -version-info @LIB_CURRENT@:@LIB_REVISION@:@LIB_AGE@

Index: src/audio_out.c
===================================================================
RCS file: /usr/local/cvsroot/ao/src/audio_out.c,v
retrieving revision 1.14
diff -u -r1.14 audio_out.c
--- src/audio_out.c	2001/05/06 00:13:59	1.14
+++ src/audio_out.c	2001/05/09 01:39:18
@@ -56,6 +56,7 @@
 extern ao_functions_t ao_null;
 extern ao_functions_t ao_wav;
 extern ao_functions_t ao_raw;
+extern ao_functions_t ao_au;

 driver_tree_t *driver_head = NULL;

@@ -99,6 +100,7 @@
         driver_tree_t *dnull;
         driver_tree_t *dwav;
         driver_tree_t *draw;
+	driver_tree_t *dau;
         driver_tree_t *plugin;
         driver_tree_t *driver;
         DIR *plugindir;
@@ -109,7 +111,7 @@
         char fullpath[FILENAME_MAX];

         if (driver_head == NULL) {
-		/* insert the null and wav drivers into the tree */
+		/* insert the null, wav, raw, and au drivers into the tree */
                 dnull = (driver_tree_t *)malloc(sizeof(driver_tree_t));
                 dnull->functions = &ao_null;
                 dnull->handle = NULL;
@@ -119,13 +121,17 @@
                 draw = (driver_tree_t *)malloc(sizeof(driver_tree_t));
                 draw->functions = &ao_raw;
                 draw->handle = NULL;
+		dau = (driver_tree_t *)malloc(sizeof(driver_tree_t));
+		dau->functions = &ao_au;
+		dau->handle = NULL;

                 dnull->next = dwav;
                 dwav->next = draw;
-		draw->next = NULL;
+		draw->next = dau;
+		dau->next = NULL;

                 driver_head = dnull;
-		driver = draw;
+		driver = dau;

                 /* now insert any plugins we find */
                 plugindir = opendir(AO_PLUGIN_PATH);
@@ -157,7 +163,7 @@
         if (!driver_head) return;

         /* unload and free all the plugins */
-	driver = driver->next->next->next;  /* Skip null, wav, and raw driver */
+	driver = driver->next->next->next->next; /* Skip null, wav, raw, and au drivers */
         while (driver) {
                 if (driver->functions) free(driver->functions);
                 if (driver->handle) dlclose(driver->handle);


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<UL>
<LI>TEXT/PLAIN attachment: ao_au.c
</UL>
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