Fix DCHECKs in V4l2VideoDevice.

media/base/video_frame.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_VIDEO_FRAME_H_
 #define MEDIA_BASE_VIDEO_FRAME_H_
 
 #include <vector>
 
 #include "base/callback.h"
@@ skipping 201 matching lines @@
 
   // Returns the required allocation size for a (tightly packed) plane of the
   // given coded size and format.
   static size_t PlaneAllocationSize(Format format,
                                     size_t plane,
                                     const gfx::Size& coded_size);
 
   // Returns horizontal bits per pixel for given |plane| and |format|.
   static int PlaneHorizontalBitsPerPixel(Format format, size_t plane);
 
+  // Returns the number of bytes per row for the given plane, format, and width.
+  // This refers to the bytes representing frame data scanlines without stride
+  // padding.
+  static int RowBytes(size_t plane, Format format, int width);
+
   Format format() const { return format_; }
 
   const gfx::Size& coded_size() const { return coded_size_; }
   const gfx::Rect& visible_rect() const { return visible_rect_; }
   const gfx::Size& natural_size() const { return natural_size_; }
 
   int stride(size_t plane) const;
 
   // Returns the number of bytes per row and number of rows for a given plane.
   //
@@ skipping 45 matching lines @@
   // VideoFrame.
   // This method is thread safe. Both blink and compositor threads can call it.
   void UpdateReleaseSyncPoint(SyncPointClient* client);
 
   // Used to keep a running hash of seen frames.  Expects an initialized MD5
   // context.  Calls MD5Update with the context and the contents of the frame.
   void HashFrameForTesting(base::MD5Context* context);
 
  private:
   friend class base::RefCountedThreadSafe<VideoFrame>;
+
+  // Used to DCHECK() plane parameters.
+  static bool IsValidPlane(size_t plane, VideoFrame::Format format);

[kcwu, 2014/08/15 10:19:17]

It is not always used to DCHECK(), for instance, HashFrameForTesting

[wuchengli, 2014/08/18 07:08:13]

Updated the comments.

+
   // Clients must use the static CreateFrame() method to create a new frame.
   VideoFrame(Format format,
              const gfx::Size& coded_size,
              const gfx::Rect& visible_rect,
              const gfx::Size& natural_size,
              scoped_ptr<gpu::MailboxHolder> mailbox_holder,
              base::TimeDelta timestamp,
              bool end_of_stream);
   virtual ~VideoFrame();
 
   void AllocateYUV();
 
-  // Used to DCHECK() plane parameters.
-  bool IsValidPlane(size_t plane) const;
-
   // Frame format.
   const Format format_;
 
   // Width and height of the video frame, in pixels. This must include pixel
   // data for the whole image; i.e. for YUV formats with subsampled chroma
   // planes, in the case that the visible portion of the image does not line up
   // on a sample boundary, |coded_size_| must be rounded up appropriately and
   // the pixel data provided for the odd pixels.
   const gfx::Size coded_size_;
 
@@ skipping 36 matching lines @@
   uint32 release_sync_point_;
 
   const bool end_of_stream_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoFrame);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_FRAME_H_