--- /dev/null
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+// This header should only be used to simplify code where
+// threading is optional, not as a generic threading abstraction.
+
+#ifndef AVUTIL_THREAD_H
+#define AVUTIL_THREAD_H
+
+#include "config.h"
+
+#if HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS2THREADS
+
+#define USE_ATOMICS 0
+
+#if HAVE_PTHREADS
+#include <pthread.h>
+#elif HAVE_OS2THREADS
+#include "compat/os2threads.h"
+#else
+#include "compat/w32pthreads.h"
+#endif
+
+#define AVMutex pthread_mutex_t
+
+#define ff_mutex_init pthread_mutex_init
+#define ff_mutex_lock pthread_mutex_lock
+#define ff_mutex_unlock pthread_mutex_unlock
+#define ff_mutex_destroy pthread_mutex_destroy
+
+#else
+
+#define USE_ATOMICS 1
+
+#define AVMutex char
+
+#define ff_mutex_init(mutex, attr) (0)
+#define ff_mutex_lock(mutex) (0)
+#define ff_mutex_unlock(mutex) (0)
+#define ff_mutex_destroy(mutex) (0)
+
+#endif
+
+#endif /* AVUTIL_THREAD_H */