Add PIXEL_FORMAT_I422.

media/base/video_types.h

 // Copyright 2015 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_TYPES_H_
 #define MEDIA_BASE_VIDEO_TYPES_H_
 
 #include <string>
 
 #include "build/build_config.h"
@@ skipping 43 matching lines @@
   PIXEL_FORMAT_YUV444P9 = 20,
   PIXEL_FORMAT_YUV444P10 = 21,
 
   PIXEL_FORMAT_YUV420P12 = 22,
   PIXEL_FORMAT_YUV422P12 = 23,
   PIXEL_FORMAT_YUV444P12 = 24,
 
   PIXEL_FORMAT_Y8 = 25,   // single 8bpp plane.
   PIXEL_FORMAT_Y16 = 26,  // single 16bpp plane.
 
+  PIXEL_FORMAT_I422 =

[wuchengli, 2016/12/14 08:16:53]

I prefer PIXEL_FORMAT_YU16 to be consistent with PIXEL_FORMAT_YV16. Let's see
what media OWNER think about the naming.

[jcliang, 2016/12/14 08:25:41]

I followed the naming of libyuv which lists YU16 as an alias to I422. Not sure
what the best naming is here...

+      27,  // 16bpp YUV planar 1x1 Y, 2x2 UV samples, a.k.a. YU16.

[wuchengli, 2016/12/14 08:16:53]

This should be 2x1 UV samples.

[jcliang, 2016/12/14 08:25:41]

Done.

+
   // Please update UMA histogram enumeration when adding new formats here.
   PIXEL_FORMAT_MAX =
-      PIXEL_FORMAT_Y16,  // Must always be equal to largest entry logged.
+      PIXEL_FORMAT_I422,  // Must always be equal to largest entry logged.
 };
 
 // Color space or color range used for the pixels.
 // Logged to UMA, so never reuse values. Leave gaps if necessary.
 enum ColorSpace {
   COLOR_SPACE_UNSPECIFIED = 0,  // In general this is Rec601.
   // The JPEG color space is the combination of Rec.601 and full range colors
   // (aka pc range colors).
   COLOR_SPACE_JPEG = 1,
   COLOR_SPACE_HD_REC709 = 2,  // Rec709 "HD" color space.
   COLOR_SPACE_SD_REC601 = 3,  // Rec601 "SD" color space.
   COLOR_SPACE_MAX = COLOR_SPACE_SD_REC601,
 };
 
 // Returns the name of a Format as a string.
 MEDIA_EXPORT std::string VideoPixelFormatToString(VideoPixelFormat format);
 
 // Returns true if |format| is a YUV format with multiple planes.
 MEDIA_EXPORT bool IsYuvPlanar(VideoPixelFormat format);
 
 // Returns true if |format| has no Alpha channel (hence is always opaque).
 MEDIA_EXPORT bool IsOpaque(VideoPixelFormat format);
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_TYPES_H_