decoder/dsdiff: add option "lsbitfirst"

Defaults to "no", which fixes the noise problems.

doc/user.xml

@@ -742,6 +742,29 @@ cd mpd-version</programlisting>
         <para>
           Decodes DFF files containing DSDIFF data (e.g. SACD rips).
         </para>
+
+        <informaltable>
+          <tgroup cols="2">
+            <thead>
+              <row>
+                <entry>Setting</entry>
+                <entry>Description</entry>
+              </row>
+            </thead>
+            <tbody>
+              <row>
+                <entry>
+                  <varname>lsbitfirst</varname>
+                  <parameter>yes|no</parameter>
+                </entry>
+                <entry>
+                  Decode the least significant bit first.  Default is
+                  "no".
+                </entry>
+              </row>
+            </tbody>
+          </tgroup>
+        </informaltable>
       </section>
 
       <section>

src/decoder/dsdiff_decoder_plugin.c

@@ -54,6 +54,15 @@ struct dsdiff_metadata {
 	unsigned sample_rate, channels;
 };
 
+static bool lsbitfirst;
+
+static bool
+dsdiff_init(const struct config_param *param)
+{
+	lsbitfirst = config_get_block_bool(param, "lsbitfirst", false);
+	return true;
+}
+
 static bool
 dsdiff_id_equals(const struct dsdiff_id *id, const char *s)
 {
@@ -356,7 +365,7 @@ dsdiff_decode_chunk(struct decoder *decoder, struct input_stream *is,
 		for (unsigned c = 0; c < channels; ++c)
 			dsd2pcm_translate(dsd2pcm[c], now_frames,
 					  buffer + c, channels,
-					  true, f_buffer + c, channels);
+					  lsbitfirst, f_buffer + c, channels);
 
 		/* convert to integer and submit to the decoder API */
 
@@ -485,6 +494,7 @@ static const char *const dsdiff_mime_types[] = {
 
 const struct decoder_plugin dsdiff_decoder_plugin = {
 	.name = "dsdiff",
+	.init = dsdiff_init,
 	.stream_decode = dsdiff_stream_decode,
 	.stream_tag = dsdiff_stream_tag,
 	.suffixes = dsdiff_suffixes,