decoder/pcm: add MIME type "audio/x-mpd-float"

NEWS

@@ -23,7 +23,7 @@ ver 0.20 (not yet released)
   - gme: add option "accuracy"
   - mad: reduce memory usage while scanning tags
   - mpcdec: read the bit rate
-  - pcm: support audio/L16 (RFC 2586)
+  - pcm: support audio/L16 (RFC 2586) and audio/x-mpd-float
 * playlist
   - cue: don't skip pregap
   - embcue: fix last track

doc/user.xml

@@ -1944,7 +1944,9 @@ buffer_size: 16384</programlisting>
         <para>
           Read raw PCM samples.  It understands the "audio/L16" MIME
           type with parameters "rate" and "channels" according to RFC
-          2586.
+          2586.  It also understands the
+          <application>MPD</application>-specific MIME type
+          "audio/x-mpd-float".
         </para>
       </section>
 

src/decoder/plugins/PcmDecoderPlugin.cxx

@@ -45,11 +45,16 @@ pcm_stream_decode(Decoder &decoder, InputStream &is)
 
 	const bool l16 = mime != nullptr &&
 		GetMimeTypeBase(mime) == "audio/L16";
-	if (l16) {
+	const bool is_float = mime != nullptr &&
+		GetMimeTypeBase(mime) == "audio/x-mpd-float";
+	if (l16 || is_float) {
 		audio_format.sample_rate = 0;
 		audio_format.channels = 1;
 	}
 
+	if (is_float)
+		audio_format.format = SampleFormat::FLOAT;
+
 	{
 		const auto mime_parameters = ParseMimeTypeParameters(mime);
 		Error error;
@@ -154,6 +159,9 @@ static const char *const pcm_mime_types[] = {
 	/* RFC 2586 */
 	"audio/L16",
 
+	/* MPD-specific: float32 native-endian */
+	"audio/x-mpd-float",
+
 	/* for streams obtained by the cdio_paranoia input plugin */
 	"audio/x-mpd-cdda-pcm",