diff --git a/media/base/video_frame_converter_internals.cc b/media/base/video_frame_converter_internals.cc
--- a/media/base/video_frame_converter_internals.cc
+++ b/media/base/video_frame_converter_internals.cc
@@ -254,15 +254,17 @@ void MergeUV(const VideoFrame& src_frame, VideoFrame& dest_frame) {
   DCHECK(dest_frame.format() == PIXEL_FORMAT_NV12 ||
          dest_frame.format() == PIXEL_FORMAT_NV12A);
   DCHECK_EQ(src_frame.visible_rect().size(), dest_frame.visible_rect().size());
+  // Use ceil semantics to match VideoFrame::Rows/Columns and PlaneSizeInSamples
+  // so the entire allocated UV plane is written for odd visible dimensions.
   libyuv::MergeUVPlane(
       src_frame.visible_data(VideoFrame::Plane::kU),
       src_frame.stride(VideoFrame::Plane::kU),
       src_frame.visible_data(VideoFrame::Plane::kV),
       src_frame.stride(VideoFrame::Plane::kV),
       dest_frame.GetWritableVisibleData(VideoFrame::Plane::kUV),
       dest_frame.stride(VideoFrame::Plane::kUV),
-      dest_frame.visible_rect().width() / 2,
-      dest_frame.visible_rect().height() / 2);
+      (dest_frame.visible_rect().width() + 1) / 2,
+      (dest_frame.visible_rect().height() + 1) / 2);
 }

 void SplitUV(const VideoFrame& src_frame, VideoFrame& dest_frame) {