decoder/ffmpeg: move code to lib/ffmpeg/Time.hxx

src/lib/ffmpeg/Time.hxx

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2003-2014 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_FFMPEG_TIME_HXX
+#define MPD_FFMPEG_TIME_HXX
+
+#include "Chrono.hxx"
+#include "Compiler.h"
+
+extern "C" {
+#include <libavutil/avutil.h>
+#include <libavutil/mathematics.h>
+}
+
+#include <assert.h>
+#include <stdint.h>
+
+/* suppress the ffmpeg compatibility macro */
+#ifdef SampleFormat
+#undef SampleFormat
+#endif
+
+gcc_const
+static inline double
+FfmpegTimeToDouble(int64_t t, const AVRational time_base)
+{
+	assert(t != (int64_t)AV_NOPTS_VALUE);
+
+	return (double)av_rescale_q(t, time_base, (AVRational){1, 1024})
+		/ (double)1024;
+}
+
+template<typename Ratio>
+static inline constexpr AVRational
+RatioToAVRational()
+{
+	return { Ratio::num, Ratio::den };
+}
+
+gcc_const
+static inline int64_t
+ToFfmpegTime(SongTime t, const AVRational time_base)
+{
+	return av_rescale_q(t.count(),
+			    RatioToAVRational<SongTime::period>(),
+			    time_base);
+}
+
+/**
+ * Replace #AV_NOPTS_VALUE with the given fallback.
+ */
+static constexpr int64_t
+FfmpegTimestampFallback(int64_t t, int64_t fallback)
+{
+	return gcc_likely(t != int64_t(AV_NOPTS_VALUE))
+		? t
+		: fallback;
+}
+
+#endif