Attempt to add opus support.

tagutils/opus.c

@@ -0,0 +1,59 @@
+//=========================================================================
+// FILENAME : tagutils-opus.c
+// DESCRIPTION  : Opus metadata reader
+//=========================================================================
+
+static int
+_get_opusfileinfo(char *filename, struct song_metadata *psong)
+{
+    OggOpusFile *opusfile;
+    const OpusTags *tags;
+    char **comment;
+    int *commentlen;
+    int j, e;
+
+
+    opusfile = op_open_file (filename, &e);
+    if(!opusfile)
+    {
+        DPRINTF(E_WARN, L_SCANNER,
+            "Error opening input file \"%s\": %s\n", filename, opus_strerror(e));
+        return -1;
+    }
+
+    DPRINTF(E_MAXDEBUG, L_SCANNER, "Processing file \"%s\"...\n", filename);
+
+    psong->song_length = op_pcm_total (opusfile, -1);
+    if (psong->song_length < 0)
+    {
+        DPRINTF(E_WARN, L_SCANNER,
+                "Unable to obtain length of %s\n", filename);
+        psong->song_length = 0;
+    } else
+        /* Sample rate is always 48k, so length in ms is just samples/48 */
+        psong->song_length /= 48;
+
+    /* Note that this gives only the first link's channel count. */
+    psong->channels = op_channel_count (opusfile, -1);
+
+    psong->samplerate = 48000;
+    psong->bitrate = op_bitrate (opusfile, -1);
+
+    tags = op_tags (opusfile, -1);
+
+    if (!tags)
+    {
+        DPRINTF(E_WARN, L_SCANNER, "Unable to obtain tags from %s\n",
+                filename);
+        return -1;
+    }
+
+    comment = tags->user_comments;
+    commentlen = tags->comment_lengths; 
+
+    for (j = 0; j < tags->comments; j++)
+        vc_scan (psong, *(comment++), *(commentlen++));
+
+    op_free (opusfile);
+    return 0;
+}