decoder/dsf: Allow up to DSD512. Enable DSD rates based on Fs=48kHz

NEWS

@@ -40,6 +40,7 @@ ver 0.19 (not yet released)
   - audiofile: support scanning remote files
   - audiofile: log libaudiofile errors
   - dsdiff, dsf: report bit rate
+  - dsf: support DSD512
   - sndfile: support scanning remote files
   - sndfile: support tags "comment", "album", "track", "genre"
   - mp4v2: support playback of MP4 files.

src/decoder/plugins/DsdLib.cxx

@@ -82,6 +82,25 @@ dsdlib_skip(Decoder *decoder, InputStream &is,
 	return decoder_skip(decoder, is, delta);
 }
 
+bool
+dsdlib_valid_freq(uint32_t samplefreq)
+{
+	switch (samplefreq) {
+	case 2822400: /* DSD64, 64xFs, Fs = 44.100kHz */
+	case 3072000: /* DSD64 with Fs = 48.000 kHz */
+	case 5644800:
+	case 6144000:
+	case 11289600:
+	case 12288000:
+	case 22579200:/* DSD512 */
+	case 24576000:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
 #ifdef HAVE_ID3TAG
 void
 dsdlib_tag_id3(InputStream &is,

src/decoder/plugins/DsdLib.hxx

@@ -66,6 +66,13 @@ bool
 dsdlib_skip(Decoder *decoder, InputStream &is,
 	    uint64_t delta);
 
+/**
+ * Check if the sample frequency is a valid DSD frequency.
+ **/
+gcc_const
+bool
+dsdlib_valid_freq(uint32_t samplefreq);
+
 /**
  * Add tags from ID3 tag. All tags commonly found in the ID3 tags of
  * DSF and DSDIFF files are imported

src/decoder/plugins/DsfDecoderPlugin.cxx

@@ -131,7 +131,7 @@ dsf_read_metadata(Decoder *decoder, InputStream &is,
 	if (dsf_fmt_chunk.version != 1 || dsf_fmt_chunk.formatid != 0
 	    || dsf_fmt_chunk.channeltype != 2
 	    || dsf_fmt_chunk.channelnum != 2
-	    || (samplefreq != 2822400 && samplefreq != 5644800))
+	    || (!dsdlib_valid_freq(samplefreq)))
 		return false;
 
 	uint32_t chblksize = FromLE32(dsf_fmt_chunk.block_size);