Video Capture: extract storage info from pixel format in VideoCaptureFormat.

media/base/video_capture_types.h

Index: media/base/video_capture_types.h
diff --git a/media/base/video_capture_types.h b/media/base/video_capture_types.h
index 8483a2dd42f5cb03015dffda309f08efdae20727..2f777b073f9d6f0ab06471949edb4dd94c736d6a 100644
--- a/media/base/video_capture_types.h
+++ b/media/base/video_capture_types.h
@@ -18,6 +18,7 @@ namespace media {
 typedef int VideoCaptureSessionId;
 
 // Color formats from camera. This list is sorted in order of preference.
+// TODO(mcasas): Consider if this list can be merged with media::Format.
 enum VideoPixelFormat {
   PIXEL_FORMAT_I420,
   PIXEL_FORMAT_YV12,
@@ -29,12 +30,19 @@ enum VideoPixelFormat {
   PIXEL_FORMAT_RGB32,
   PIXEL_FORMAT_ARGB,
   PIXEL_FORMAT_MJPEG,
-  PIXEL_FORMAT_TEXTURE,  // Capture format as a GL texture.
-  PIXEL_FORMAT_GPUMEMORYBUFFER,
   PIXEL_FORMAT_UNKNOWN,  // Color format not set.
   PIXEL_FORMAT_MAX,
 };
 
+// Storage type for the pixels. In principle, all combinations of Storage and
+// Format are possible, though some are very typical, such as texture + ARGB,
+// and others are only available if the platform allows it e.g. GpuMemoryBuffer.
+enum VideoPixelStorage {
+  PIXEL_STORAGE_CPU,
+  PIXEL_STORAGE_TEXTURE,
+  PIXEL_STORAGE_GPUMEMORYBUFFER,
+};
+
 // Policies for capture devices that have source content that varies in size.
 // It is up to the implementation how the captured content will be transformed
 // (e.g., scaling and/or letterboxing) in order to produce video frames that
@@ -70,9 +78,15 @@ struct MEDIA_EXPORT VideoCaptureFormat {
   VideoCaptureFormat(const gfx::Size& frame_size,
                      float frame_rate,
                      VideoPixelFormat pixel_format);
+  VideoCaptureFormat(const gfx::Size& frame_size,
+                     float frame_rate,
+                     VideoPixelFormat pixel_format,
+                     VideoPixelStorage pixel_storage);
 
+  // TODO(mcasas): Remove this method http://crbug.com/501134.
   std::string ToString() const;
   static std::string PixelFormatToString(VideoPixelFormat format);
+  static std::string PixelStorageToString(VideoPixelStorage storage);
 
   // Returns the required buffer size to hold an image of a given
   // VideoCaptureFormat with no padding and tightly packed.
@@ -91,6 +105,7 @@ struct MEDIA_EXPORT VideoCaptureFormat {
   gfx::Size frame_size;
   float frame_rate;
   VideoPixelFormat pixel_format;
+  VideoPixelStorage pixel_storage;

[miu, 2015/06/23 22:58:15]

Should this extra field be added in
content/common/media/video_capture_messages.h (where the IPC struct is
declared)?

[mcasas, 2015/06/23 23:24:43]

I don't understand, VideoPixelStorage is not
sent to Render process, stays local to Browser.

[miu, 2015/06/23 23:35:55]

I meant: There's a declaration of the VideoCaptureFormat struct.  I believe it's
used in the IPC messages sent from renderer to browser to start/resume the video
capture.

[mcasas, 2015/06/24 00:16:39]

Oh yes, media_param_traits.cc, good catch, thanks.

 };
 
 typedef std::vector<VideoCaptureFormat> VideoCaptureFormats;