diff --git a/src/codec/video/VideoDecoderFFmpegHW.cpp b/src/codec/video/VideoDecoderFFmpegHW.cpp
index 715a1de4..a7498bf0 100644
--- a/src/codec/video/VideoDecoderFFmpegHW.cpp
+++ b/src/codec/video/VideoDecoderFFmpegHW.cpp
@@ -1,8 +1,8 @@
 /******************************************************************************
-    QtAV:  Media play library based on Qt and FFmpeg
-    Copyright (C) 2013-2015 Wang Bin <wbsecg1@gmail.com>
+    QtAV:  Multimedia framework based on Qt and FFmpeg
+    Copyright (C) 2012-2016 Wang Bin <wbsecg1@gmail.com>
 
-*   This file is part of QtAV
+*   This file is part of QtAV (from 2013)
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
@@ -114,6 +114,7 @@ bool VideoDecoderFFmpegHWPrivate::prepare()
 {
     //// From vlc begin
     codec_ctx->thread_safe_callbacks = true; //?
+    codec_ctx->thread_count = threads;
 #ifdef _MSC_VER
 #pragma warning(disable:4065) //vc: switch has default but no case
 #endif //_MSC_VER
@@ -225,8 +226,9 @@ VideoDecoderFFmpegHW::VideoDecoderFFmpegHW(VideoDecoderFFmpegHWPrivate &d):
                 .arg(tr("Not implemented for all codecs"))
                 .arg(tr("OptimizedCopy: copy from USWC memory optimized by SSE4.1"))
                 .arg(tr("GenericCopy: slowest. Generic cpu copy")));
-    setProperty("detail_threads", QString("%1\n%2\n%3")
+    setProperty("detail_threads", QString("%1\n%2\n%3\n%4")
                 .arg(tr("Number of decoding threads. Set before open. Maybe no effect for some decoders"))
+                .arg(tr("Multithread decoding may crash"))
                 .arg(tr("0: auto"))
                 .arg(tr("1: single thread decoding")));
     Q_UNUSED(QObject::tr("ZeroCopy"));
diff --git a/src/codec/video/VideoDecoderFFmpegHW.h b/src/codec/video/VideoDecoderFFmpegHW.h
index 957f1349..28383ecd 100644
--- a/src/codec/video/VideoDecoderFFmpegHW.h
+++ b/src/codec/video/VideoDecoderFFmpegHW.h
@@ -1,8 +1,8 @@
 /******************************************************************************
-    QtAV:  Media play library based on Qt and FFmpeg
-    Copyright (C) 2013-2015 Wang Bin <wbsecg1@gmail.com>
+    QtAV:  Multimedia framework based on Qt and FFmpeg
+    Copyright (C) 2012-2016 Wang Bin <wbsecg1@gmail.com>
 
-*   This file is part of QtAV
+*   This file is part of QtAV (from 2013)
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
diff --git a/src/codec/video/VideoDecoderFFmpegHW_p.h b/src/codec/video/VideoDecoderFFmpegHW_p.h
index 28cf768d..3ee84c04 100644
--- a/src/codec/video/VideoDecoderFFmpegHW_p.h
+++ b/src/codec/video/VideoDecoderFFmpegHW_p.h
@@ -1,8 +1,8 @@
 /******************************************************************************
-    QtAV:  Media play library based on Qt and FFmpeg
-    Copyright (C) 2013-2015 Wang Bin <wbsecg1@gmail.com>
+    QtAV:  Multimedia framework based on Qt and FFmpeg
+    Copyright (C) 2012-2016 Wang Bin <wbsecg1@gmail.com>
 
-*   This file is part of QtAV
+*   This file is part of QtAV (from 2013)
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
@@ -83,7 +83,7 @@ public:
     int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
 
     QString description;
-    int threads;
+    int threads; // multithread decoding may crash for some decoders (dxva, videotoolbox)
     // false for not intel gpu. my test result is intel gpu is supper fast and lower cpu usage if use optimized uswc copy. but nv is worse.
     // TODO: flag enable, disable, auto
     VideoDecoderFFmpegHW::CopyMode copy_mode;