Cast: Print out AV sync in cast receiver if playing test video

media/cast/test/utility/barcode.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.
 
 // Routines for encoding and decoding a small number of bits into an image
 // in a way that is decodable even after scaling/encoding/cropping.
 //
 // The encoding is very simple:
 //
 //   ####    ####    ########    ####        ####    ####
@@ skipping 61 matching lines @@
   // Now replicate this one row into all rows in kYPlane.
   for (int row = 0; row < output_frame->rows(VideoFrame::kYPlane); row++) {
     memcpy(output_frame->data(VideoFrame::kYPlane) +
            output_frame->stride(VideoFrame::kYPlane) * row,
            &bytes.front(),
            row_bytes);
   }
   return true;
 }
 
-// Note that "output" is assumed to be the right size already. This
-// could be inferred from the data, but the decoding is more robust
-// if we can assume that we know how many bits we want.
-bool DecodeBarcode(const scoped_refptr<VideoFrame>& frame,
-                   std::vector<bool>* output) {
-  DCHECK(frame->format() == VideoFrame::YV12 ||
-         frame->format() == VideoFrame::YV16 ||
-         frame->format() == VideoFrame::I420 ||
-         frame->format() == VideoFrame::YV12J);
-  int min_row = std::max(0, frame->rows(VideoFrame::kYPlane) / 2 - 10);
-  int max_row = std::min(frame->rows(VideoFrame::kYPlane),
-                         frame->rows(VideoFrame::kYPlane) / 2 + 10);
-
+namespace {
+bool DecodeBarCodeRows(const scoped_refptr<VideoFrame>& frame,
+                       std::vector<bool>* output,
+                       int min_row,
+                       int max_row) {
   // Do a basic run-length encoding
   std::deque<int> runs;
   bool is_black = true;
   int length = 0;
   for (int pos = 0; pos < frame->row_bytes(VideoFrame::kYPlane); pos++) {
     float value = 0.0;
     for (int row = min_row; row < max_row; row++) {
       value += frame->data(VideoFrame::kYPlane)[
           frame->stride(VideoFrame::kYPlane) * row + pos];
     }
@@ skipping 39 matching lines @@
     if (valid) {
       // Decoding successful, return true
      return true;
     }
     runs.pop_front();
     runs.pop_front();
   }
   return false;
 }
 
+}  // namespace
+
+// Note that "output" is assumed to be the right size already. This
+// could be inferred from the data, but the decoding is more robust
+// if we can assume that we know how many bits we want.
+bool DecodeBarcode(const scoped_refptr<VideoFrame>& frame,
+                   std::vector<bool>* output) {
+  DCHECK(frame->format() == VideoFrame::YV12 ||
+         frame->format() == VideoFrame::YV16 ||
+         frame->format() == VideoFrame::I420 ||
+         frame->format() == VideoFrame::YV12J);
+  int rows = frame->rows(VideoFrame::kYPlane);
+  // Middle 10 lines
+  if (DecodeBarCodeRows(frame,
+                        output,
+                        std::max(0, rows / 2 - 5),
+                        std::min(rows, rows / 2 + 5))) {
+    return true;
+  }
+
+  // Top 5 lines
+  if (DecodeBarCodeRows(frame, output, 0, std::min(5, rows))) {
+    return true;
+  }
+
+  return false;
+}
+
 }  // namespace test
 }  // namespace cast
 }  // namespace media