Extend media::VideoFrame to wrap CVPixelBuffer on OS X and iOS.

media/base/video_frame.cc

 // 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.
 
 #include "media/base/video_frame.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 260 matching lines @@
     // Data is accessible only via fds.
     frame->data_[i] = NULL;
     frame->strides_[i] = 0;
   }
 
   frame->no_longer_needed_cb_ = no_longer_needed_cb;
   return frame;
 }
 #endif
 
+#if defined(OS_MACOSX)
+// static
+scoped_refptr<VideoFrame> VideoFrame::WrapCVPixelBuffer(
+    CVPixelBufferRef cv_pixel_buffer,
+    base::TimeDelta timestamp) {
+  DCHECK(cv_pixel_buffer);
+  DCHECK(CFGetTypeID(cv_pixel_buffer) == CVPixelBufferGetTypeID());
+
+  OSType cv_format = CVPixelBufferGetPixelFormatType(cv_pixel_buffer);
+  Format format;
+  // There are very few compatible CV pixel formats, so just check each.
+  if (cv_format == kCVPixelFormatType_420YpCbCr8Planar) {
+    format = Format::I420;
+  } else if (cv_format == kCVPixelFormatType_444YpCbCr8) {
+    format = Format::YV24;
+  } else if (cv_format == '420v') {
+    // TODO(jfroy): Use kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange when the

[miu, 2014/08/25 18:39:35]

I've seen others solve this problem by using #ifdefs to define constants at the
top of the file based on the SDK version.  Meaning, when the SDK is too old, we
define the constants ourselves using those found in the newer SDK.  Example:

https://code.google.com/p/chromium/codesearch#chromium/src/base/mac/sdk_forwa...

[Robert Sesek, 2014/08/25 18:42:07]

There was already back-and-forth about this on the review. This is fine.

+    // minimum OS X and iOS SDKs permits it.
+    format = Format::NV12;
+  } else {
+    DLOG(ERROR) << "CVPixelBuffer format not supported: " << cv_format;
+    return NULL;
+  }
+
+  gfx::Size coded_size(CVImageBufferGetEncodedSize(cv_pixel_buffer));
+  gfx::Rect visible_rect(CVImageBufferGetCleanRect(cv_pixel_buffer));
+  gfx::Size natural_size(CVImageBufferGetDisplaySize(cv_pixel_buffer));
+
+  if (!IsValidConfig(format, coded_size, visible_rect, natural_size))
+    return NULL;
+
+  scoped_refptr<VideoFrame> frame(
+      new VideoFrame(format,
+                     coded_size,
+                     visible_rect,
+                     natural_size,
+                     scoped_ptr<gpu::MailboxHolder>(),
+                     timestamp,
+                     false));
+
+  frame->cv_pixel_buffer_.reset(cv_pixel_buffer, base::scoped_policy::RETAIN);
+  return frame;
+}
+#endif
+
 // static
 scoped_refptr<VideoFrame> VideoFrame::WrapExternalYuvData(
     Format format,
     const gfx::Size& coded_size,
     const gfx::Rect& visible_rect,
     const gfx::Size& natural_size,
     int32 y_stride,
     int32 u_stride,
     int32 v_stride,
     uint8* y_data,
@@ skipping 559 matching lines @@
     client->WaitSyncPoint(release_sync_point_);
   release_sync_point_ = client->InsertSyncPoint();
 }
 
 #if defined(OS_POSIX)
 int VideoFrame::dmabuf_fd(size_t plane) const {
   return dmabuf_fds_[plane].get();
 }
 #endif
 
+#if defined(OS_MACOSX)
+CVPixelBufferRef VideoFrame::cv_pixel_buffer() const {
+  return cv_pixel_buffer_.get();
+}
+#endif
+
 void VideoFrame::HashFrameForTesting(base::MD5Context* context) {
   for (int plane = 0; plane < kMaxPlanes; ++plane) {
     if (!IsValidPlane(plane, format_))
       break;
     for (int row = 0; row < rows(plane); ++row) {
       base::MD5Update(context, base::StringPiece(
           reinterpret_cast<char*>(data(plane) + stride(plane) * row),
           row_bytes(plane)));
     }
   }
 }
 
 }  // namespace media