Make sure MediaStreamVideoSource support cropping.

content/renderer/media/webrtc/webrtc_video_capturer_adapter.cc

 // Copyright 2014 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 "content/renderer/media/webrtc/webrtc_video_capturer_adapter.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
+#include "base/memory/aligned_memory.h"
 #include "media/base/video_frame.h"
+#include "third_party/libyuv/include/libyuv/convert.h"
 
 namespace content {
 
 WebRtcVideoCapturerAdapter::WebRtcVideoCapturerAdapter(bool is_screencast)
     : is_screencast_(is_screencast),
-      running_(false) {
+      running_(false),
+      buffer_(NULL),
+      buffer_size_(0) {
 }
 
 WebRtcVideoCapturerAdapter::~WebRtcVideoCapturerAdapter() {
   DVLOG(3) << " WebRtcVideoCapturerAdapter::dtor";
+  base::AlignedFree(buffer_);
 }
 
 void WebRtcVideoCapturerAdapter::SetRequestedFormat(
     const media::VideoCaptureFormat& format) {
   DCHECK_EQ(media::PIXEL_FORMAT_I420, format.pixel_format);
   DVLOG(3) << "WebRtcVideoCapturerAdapter::SetRequestedFormat"
            << " w = " << format.frame_size.width()
            << " h = " << format.frame_size.height();
   cricket::VideoFormat supported_format(format.frame_size.width(),
                                         format.frame_size.height(),
@@ skipping 54 matching lines @@
   // Use the desired format as the best format.
   best_format->width = desired.width;
   best_format->height = desired.height;
   best_format->fourcc = cricket::FOURCC_I420;
   best_format->interval = desired.interval;
   return true;
 }
 
 void WebRtcVideoCapturerAdapter::OnFrameCaptured(
     const scoped_refptr<media::VideoFrame>& frame) {
-  DCHECK_EQ(media::VideoFrame::I420, frame->format());
+  DCHECK(media::VideoFrame::I420 == frame->format() ||
+         media::VideoFrame::YV12 == frame->format());
   if (first_frame_timestamp_ == media::kNoTimestamp())
     first_frame_timestamp_ = frame->GetTimestamp();
 
-  // Currently, |fourcc| is always I420.
   cricket::CapturedFrame captured_frame;
-  captured_frame.width = frame->coded_size().width();
-  captured_frame.height = frame->coded_size().height();
-  captured_frame.fourcc = cricket::FOURCC_I420;
+  captured_frame.width = frame->visible_rect().width();
+  captured_frame.height = frame->visible_rect().height();
   // cricket::CapturedFrame time is in nanoseconds.
   captured_frame.elapsed_time =
       (frame->GetTimestamp() - first_frame_timestamp_).InMicroseconds() *
       base::Time::kNanosecondsPerMicrosecond;
   captured_frame.time_stamp = frame->GetTimestamp().InMicroseconds() *
                               base::Time::kNanosecondsPerMicrosecond;
-  // TODO(sheu): we assume contiguous layout of image planes.
-  captured_frame.data = frame->data(0);
-  captured_frame.data_size =
-      media::VideoFrame::AllocationSize(frame->format(), frame->coded_size());
   captured_frame.pixel_height = 1;
   captured_frame.pixel_width = 1;
 
+  // TODO(perkj):
+  // Libjingle expects contiguous layout of image planes as input.
+  // The only format where that is true in Chrome is I420 where the
+  // coded_size == visible_rect().size().
+  if (frame->format() != media::VideoFrame::I420 ||
+      frame->coded_size() != frame->visible_rect().size()) {
+    // Cropping and or switching UV planes is needed.
+    UpdateI420Buffer(frame);
+    captured_frame.data = buffer_;
+    captured_frame.data_size = buffer_size_;
+    captured_frame.fourcc = cricket::FOURCC_I420;
+  } else {
+    captured_frame.fourcc = media::VideoFrame::I420 == frame->format() ?
+        cricket::FOURCC_I420 : cricket::FOURCC_YV12;
+    captured_frame.data = frame->data(0);
+    captured_frame.data_size =
+        media::VideoFrame::AllocationSize(frame->format(), frame->coded_size());
+  }
+
   // This signals to libJingle that a new VideoFrame is available.
   // libJingle have no assumptions on what thread this signal come from.
   SignalFrameCaptured(this, &captured_frame);
 }
 
+void WebRtcVideoCapturerAdapter::UpdateI420Buffer(
+    const scoped_refptr<media::VideoFrame>& src) {
+  const int src_width = src->coded_size().width();
+  const int src_height = src->coded_size().height();
+  const int dst_width = src->visible_rect().width();
+  const int dst_height = src->visible_rect().height();
+  DCHECK(src_width >= dst_width && src_height >= dst_height);
+
+  const int horiz_crop = src->visible_rect().x();
+  const int vert_crop = src->visible_rect().y();
+
+  const uint8* src_y = src->data(media::VideoFrame::kYPlane) +
+      (src_width * vert_crop + horiz_crop);
+  const int center = (src_width + 1) / 2;
+  const uint8* src_u = src->data(media::VideoFrame::kUPlane) +
+      (center * vert_crop + horiz_crop) / 2;
+  const uint8* src_v = src->data(media::VideoFrame::kVPlane) +
+      (center * vert_crop + horiz_crop) / 2;
+
+  const size_t dst_size =
+      media::VideoFrame::AllocationSize(src->format(),
+                                        src->visible_rect().size());
+
+  if (dst_size != buffer_size_) {
+    base::AlignedFree(buffer_);
+    buffer_ = reinterpret_cast<uint8*>(
+        base::AlignedAlloc(dst_size + media::VideoFrame::kFrameSizePadding,
+                           media::VideoFrame::kFrameAddressAlignment));
+    buffer_size_ = dst_size;
+  }
+
+  uint8* dst_y = buffer_;
+  const int dst_stride_y = dst_width;
+  uint8* dst_u = dst_y + dst_width * dst_height;
+  const int dst_halfwidth = (dst_width + 1) / 2;
+  const int dst_halfheight = (dst_height + 1) / 2;
+  uint8* dst_v = dst_u + dst_halfwidth * dst_halfheight;
+
+  libyuv::I420Copy(src_y,
+                   src->stride(media::VideoFrame::kYPlane),
+                   src_u,
+                   src->stride(media::VideoFrame::kUPlane),
+                   src_v,
+                   src->stride(media::VideoFrame::kVPlane),
+                   dst_y,
+                   dst_stride_y,
+                   dst_u,
+                   dst_halfwidth,
+                   dst_v,
+                   dst_halfwidth,
+                   dst_width,
+                   dst_height);
+}
+
 }  // namespace content