decoder/modplug: Add "loop_count" parameter

The "loop_count" configuration parameter allows the user to set how
many times a module with backward loops shall loop. "0" (the default)
means a module is not allowed to use backward loops at all. "-1"
enables inifinite looping.

NEWS

@@ -18,6 +18,7 @@ ver 0.18 (2012/??/??)
   - opus: new decoder plugin for the Opus codec
   - vorbis: skip 16 bit quantisation, provide float samples
   - mikmod: add "loop" configuration parameter
+  - modplug: add "loop_count" configuration parameter
   - mp4ff: obsolete plugin removed
 * encoder:
   - opus: new encoder plugin for the Opus codec

doc/user.xml

@@ -1000,6 +1000,37 @@ systemctl start mpd.socket</programlisting>
         </informaltable>
       </section>
 
+      <section>
+        <title><varname>modplug</varname></title>
+
+        <para>
+          Module player based on MODPlug.
+        </para>
+
+        <informaltable>
+          <tgroup cols="2">
+            <thead>
+              <row>
+                <entry>Setting</entry>
+                <entry>Description</entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>
+                  <varname>loop_count</varname>
+                </entry>
+                <entry>
+                  Number of times to loop the module if it uses backward loops.
+                  Default is <parameter>0</parameter> which prevents looping.
+                  <parameter>-1</parameter> loops forever.
+                </entry>
+              </row>
+            </tbody>
+          </tgroup>
+        </informaltable>
+      </section>
+
       <section>
         <title><varname>wildmidi</varname></title>
 

src/decoder/ModplugDecoderPlugin.cxx

@@ -22,6 +22,7 @@
 #include "DecoderAPI.hxx"
 #include "InputStream.hxx"
 #include "tag/TagHandler.hxx"
+#include "system/FatalError.hxx"
 #include "util/Domain.hxx"
 #include "Log.hxx"
 
@@ -38,6 +39,19 @@ static constexpr size_t MODPLUG_PREALLOC_BLOCK = 256 * 1024;
 static constexpr size_t MODPLUG_READ_BLOCK = 128 * 1024;
 static constexpr input_stream::offset_type MODPLUG_FILE_LIMIT = 100 * 1024 * 1024;
 
+static int modplug_loop_count;
+
+static bool
+modplug_decoder_init(const config_param &param)
+{
+	modplug_loop_count = param.GetBlockValue("loop_count", 0);
+	if (modplug_loop_count < -1)
+		FormatFatalError("Invalid loop count in line %d: %i",
+				 param.line, modplug_loop_count);
+
+	return true;
+}
+
 static GByteArray *
 mod_loadfile(struct decoder *decoder, struct input_stream *is)
 {
@@ -114,6 +128,7 @@ mod_decode(struct decoder *decoder, struct input_stream *is)
 	settings.mChannels = 2;
 	settings.mBits = 16;
 	settings.mFrequency = 44100;
+	settings.mLoopCount = modplug_loop_count;
 	/* insert more setting changes here */
 	ModPlug_SetSettings(&settings);
 
@@ -192,7 +207,7 @@ static const char *const mod_suffixes[] = {
 
 const struct decoder_plugin modplug_decoder_plugin = {
 	"modplug",
-	nullptr,
+	modplug_decoder_init,
 	nullptr,
 	mod_decode,
 	nullptr,