decoder/Opus: read total time

Makefile.am

@@ -531,6 +531,7 @@ if HAVE_OPUS
 libdecoder_plugins_a_SOURCES += \
 	src/decoder/OggUtil.cxx \
 	src/decoder/OggUtil.hxx \
+	src/decoder/OggFind.cxx src/decoder/OggFind.hxx \
 	src/decoder/OpusReader.hxx \
 	src/decoder/OpusHead.hxx \
 	src/decoder/OpusHead.cxx \

src/decoder/OggFind.cxx

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "OggFind.hxx"
+#include "OggUtil.hxx"
+
+bool
+OggFindEOS(ogg_sync_state &oy, ogg_stream_state &os, ogg_packet &packet,
+	   decoder *decoder, input_stream *is)
+{
+	while (true) {
+		int r = ogg_stream_packetout(&os, &packet);
+		if (r == 0) {
+			if (!OggExpectPageIn(oy, os, decoder, is))
+				return false;
+
+			continue;
+		} else if (r > 0 && packet.e_o_s)
+			return true;
+	}
+}

src/decoder/OggFind.hxx

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_OGG_FIND_HXX
+#define MPD_OGG_FIND_HXX
+
+#include "check.h"
+
+#include <ogg/ogg.h>
+
+struct decoder;
+struct input_stream;
+
+/**
+ * Skip all pages/packets until an end-of-stream (EOS) packet for the
+ * specified stream is found.
+ *
+ * @return true if the EOS packet was found
+ */
+bool
+OggFindEOS(ogg_sync_state &oy, ogg_stream_state &os, ogg_packet &packet,
+	   decoder *decoder, input_stream *is);
+
+#endif

src/decoder/OpusDecoderPlugin.cxx

@@ -22,6 +22,7 @@
 #include "OpusHead.hxx"
 #include "OpusTags.hxx"
 #include "OggUtil.hxx"
+#include "OggFind.hxx"
 #include "decoder_api.h"
 #include "OggCodec.hxx"
 #include "audio_check.h"
@@ -290,6 +291,23 @@ mpd_opus_stream_decode(struct decoder *decoder,
 	ogg_sync_clear(&oy);
 }
 
+static bool
+SeekFindEOS(ogg_sync_state &oy, ogg_stream_state &os, ogg_packet &packet,
+	    decoder *decoder, input_stream *is)
+{
+	if (is->size > 0 && is->size - is->offset < 65536)
+		return OggFindEOS(oy, os, packet, decoder, is);
+
+	if (!input_stream_cheap_seeking(is))
+		return false;
+
+	ogg_sync_reset(&oy);
+
+	return input_stream_lock_seek(is, -65536, SEEK_END, nullptr) &&
+		OggExpectPageSeekIn(oy, os, decoder, is) &&
+		OggFindEOS(oy, os, packet, decoder, is);
+}
+
 static bool
 mpd_opus_scan_stream(struct input_stream *is,
 		     const struct tag_handler *handler, void *handler_ctx)
@@ -351,6 +369,10 @@ mpd_opus_scan_stream(struct input_stream *is,
 		}
 	}
 
+	if (packet.e_o_s || SeekFindEOS(oy, os, packet, nullptr, is))
+		tag_handler_invoke_duration(handler, handler_ctx,
+					    packet.granulepos / opus_sample_rate);
+
 	ogg_stream_clear(&os);
 	ogg_sync_clear(&oy);