Add support for multiple pixel formats in VideoFrameBuffer

webrtc/api/video/video_frame_buffer.cc

+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/api/video/video_frame_buffer.h"
+
+#include "libyuv/convert_from.h"
+#include "webrtc/api/video/i420_buffer.h"
+#include "webrtc/base/checks.h"
+
+namespace webrtc {
+
+namespace {
+
+// TODO(magjed): Remove this class. It is only used for providing a default
+// implementation of ToI420() until external clients are updated. ToI420() will
+// then be made pure virtual. This adapter adapts a VideoFrameBuffer (which is
+// expected to be in I420 format) to the PlanarYuvBuffer interface. The reason
+// this is needed is because of the return type mismatch in NativeToI420Buffer
+// (returns VideoFrameBuffer) vs ToI420 (returns PlanarYuvBuffer).
+class PlanarYuvBufferAdapter : public PlanarYuvBuffer {
+ public:
+  explicit PlanarYuvBufferAdapter(rtc::scoped_refptr<VideoFrameBuffer> buffer)
+      : buffer_(buffer) {}
+
+  Type type() const override { return Type::kI420; }
+
+  int width() const override { return buffer_->width(); }
+  int height() const override { return buffer_->height(); }
+
+  const uint8_t* DataY() const override { return buffer_->DataY(); }
+  const uint8_t* DataU() const override { return buffer_->DataU(); }
+  const uint8_t* DataV() const override { return buffer_->DataV(); }
+
+  int StrideY() const override { return buffer_->StrideY(); }
+  int StrideU() const override { return buffer_->StrideU(); }
+  int StrideV() const override { return buffer_->StrideV(); }
+
+ private:
+  rtc::scoped_refptr<VideoFrameBuffer> buffer_;
+};
+
+}  // namespace
+
+// TODO(magjed): The default implementations in VideoFrameBuffer are provided in
+// order to support the deprecated interface until external clients are updated.
+// Remove once done.
+VideoFrameBuffer::Type VideoFrameBuffer::type() const {
+  return native_handle() ? Type::kNative : Type::kI420;
+}
+
+const uint8_t* VideoFrameBuffer::DataY() const {
+  return const_cast<VideoFrameBuffer*>(this)->GetI420()->DataY();
+}
+
+const uint8_t* VideoFrameBuffer::DataU() const {
+  return const_cast<VideoFrameBuffer*>(this)->GetI420()->DataU();
+}
+
+const uint8_t* VideoFrameBuffer::DataV() const {
+  return const_cast<VideoFrameBuffer*>(this)->GetI420()->DataV();
+}
+
+// Returns the number of bytes between successive rows for a given plane.
+int VideoFrameBuffer::StrideY() const {
+  return const_cast<VideoFrameBuffer*>(this)->GetI420()->StrideY();
+}
+
+int VideoFrameBuffer::StrideU() const {
+  return const_cast<VideoFrameBuffer*>(this)->GetI420()->StrideU();
+}
+
+int VideoFrameBuffer::StrideV() const {
+  return const_cast<VideoFrameBuffer*>(this)->GetI420()->StrideV();
+}
+
+void* VideoFrameBuffer::native_handle() const {
+  RTC_DCHECK(type() != Type::kNative);
+  return nullptr;
+}
+
+rtc::scoped_refptr<VideoFrameBuffer> VideoFrameBuffer::NativeToI420Buffer() {
+  return ToI420();
+}
+
+rtc::scoped_refptr<PlanarYuvBuffer> VideoFrameBuffer::ToI420() {
+  return new rtc::RefCountedObject<PlanarYuvBufferAdapter>(
+      NativeToI420Buffer());
+}
+
+rtc::scoped_refptr<PlanarYuvBuffer> VideoFrameBuffer::GetI420() {
+  RTC_CHECK(type() == Type::kI420);
+  // TODO(magjed): static_cast to PlanarYuvBuffer instead once external clients
+  // are updated.
+  return new rtc::RefCountedObject<PlanarYuvBufferAdapter>(this);
+}
+
+rtc::scoped_refptr<PlanarYuvBuffer> VideoFrameBuffer::GetI444() {
+  RTC_CHECK(type() == Type::kI444);
+  return static_cast<PlanarYuvBuffer*>(this);
+}
+
+rtc::scoped_refptr<PlanarYuvBuffer> PlanarYuvBuffer::ToI420() {
+  switch (type()) {
+    case Type::kI420:
+      return this;
+    case Type::kI444: {
+      rtc::scoped_refptr<I420Buffer> i420_buffer =
+          I420Buffer::Create(width(), height());
+      libyuv::I420ToI444(DataY(), StrideY(), DataU(), StrideU(), DataV(),
+                         StrideV(), i420_buffer->MutableDataY(),
+                         i420_buffer->StrideY(), i420_buffer->MutableDataU(),
+                         i420_buffer->StrideU(), i420_buffer->MutableDataV(),
+                         i420_buffer->StrideV(), width(), height());
+      return i420_buffer;
+    }
+    default:
+      RTC_NOTREACHED();
+      return nullptr;
+  }
+}
+
+int PlanarYuvBuffer::ChromaWidth() const {
+  switch (type()) {
+    case Type::kI420:
+      return (width() + 1) / 2;
+    case Type::kI444:
+      return width();
+    default:
+      RTC_NOTREACHED();
+      return 0;
+  }
+}
+
+int PlanarYuvBuffer::ChromaHeight() const {
+  switch (type()) {
+    case Type::kI420:
+      return (height() + 1) / 2;
+    case Type::kI444:
+      return height();
+    default:
+      RTC_NOTREACHED();
+      return 0;
+  }
+}
+
+}  // namespace webrtc