input/cdio_paranoia: add setting "default_byte_order"

Allows big-endian users to configure the fallback byte order to
little-endian.  Without this setting, MPD assumes native byte order if
the CD drive can't decide.

NEWS

@@ -2,6 +2,7 @@ ver 0.18.2 (2013/??/??)
 * protocol:
   - "close" flushes the output buffer
 * input:
+  - cdio_paranoia: add setting "default_byte_order"
   - curl: fix bug with redirected streams
 * playlist:
   - pls: fix reversed song order

doc/user.xml

@@ -814,6 +814,30 @@ systemctl start mpd.socket</programlisting>
           simplest form <filename>cdda://</filename> plays the whole
           disc in the default drive.
         </para>
+
+        <informaltable>
+          <tgroup cols="2">
+            <thead>
+              <row>
+                <entry>Setting</entry>
+                <entry>Description</entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>
+                  <varname>default_bute_order</varname>
+                <parameter>little_endian|big_endian</parameter>
+                </entry>
+                <entry>
+                  If the CD drive does not specify a byte order, MPD
+                  assumes it is the CPU's native byte order.  This
+                  setting allows overriding this.
+                </entry>
+              </row>
+            </tbody>
+          </tgroup>
+        </informaltable>
       </section>
 
       <section>

src/input/CdioParanoiaInputPlugin.cxx

@@ -30,6 +30,8 @@
 #include "system/ByteOrder.hxx"
 #include "fs/AllocatedPath.hxx"
 #include "Log.hxx"
+#include "ConfigData.hxx"
+#include "ConfigError.hxx"
 
 #include <stdio.h>
 #include <stdint.h>
@@ -77,6 +79,28 @@ struct CdioParanoiaInputStream {
 
 static constexpr Domain cdio_domain("cdio");
 
+static bool default_reverse_endian;
+
+static bool
+input_cdio_init(const config_param &param, Error &error)
+{
+	const char *value = param.GetBlockValue("default_byte_order");
+	if (value != nullptr) {
+		if (strcmp(value, "little_endian") == 0)
+			default_reverse_endian = IsBigEndian();
+		else if (strcmp(value, "big_endian") == 0)
+			default_reverse_endian = IsLittleEndian();
+		else {
+			error.Format(config_domain, 0,
+				     "Unrecognized 'default_byte_order' setting: %s",
+				     value);
+			return false;
+		}
+	}
+
+	return true;
+}
+
 static void
 input_cdio_close(InputStream *is)
 {
@@ -196,7 +220,7 @@ input_cdio_open(const char *uri,
 	switch (data_bigendianp(i->drv)) {
 	case -1:
 		LogDebug(cdio_domain, "drive returns unknown audio data");
-		reverse_endian = false;
+		reverse_endian = default_reverse_endian;
 		break;
 
 	case 0:
@@ -363,7 +387,7 @@ input_cdio_eof(InputStream *is)
 
 const InputPlugin input_plugin_cdio_paranoia = {
 	"cdio_paranoia",
-	nullptr,
+	input_cdio_init,
 	nullptr,
 	input_cdio_open,
 	input_cdio_close,