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 {
+
+// Class for handling legacy implementations of NativeToI420Buffer() and
+// adapting them into the new ToI420() function.
+class LegacyI420Wrapper : public I420BufferInterface {
+ public:
+  explicit LegacyI420Wrapper(rtc::scoped_refptr<VideoFrameBuffer> buffer)
+      : buffer_(buffer) {}
+
+  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::PixelFormat VideoFrameBuffer::Format() const {
+  return native_handle() ? PixelFormat::kNative : PixelFormat::kI420;
+}
+
+const uint8_t* VideoFrameBuffer::DataY() const {
+  return const_cast<VideoFrameBuffer*>(this)->ToI420()->DataY();
+}
+
+const uint8_t* VideoFrameBuffer::DataU() const {
+  return const_cast<VideoFrameBuffer*>(this)->ToI420()->DataU();
+}
+
+const uint8_t* VideoFrameBuffer::DataV() const {
+  return const_cast<VideoFrameBuffer*>(this)->ToI420()->DataV();
+}
+
+// Returns the number of bytes between successive rows for a given plane.
+int VideoFrameBuffer::StrideY() const {
+  return const_cast<VideoFrameBuffer*>(this)->ToI420()->StrideY();
+}
+
+int VideoFrameBuffer::StrideU() const {
+  return const_cast<VideoFrameBuffer*>(this)->ToI420()->StrideU();
+}
+
+int VideoFrameBuffer::StrideV() const {
+  return const_cast<VideoFrameBuffer*>(this)->ToI420()->StrideV();
+}
+
+void* VideoFrameBuffer::native_handle() const {
+  RTC_DCHECK(Format() != PixelFormat::kNative);
+  return nullptr;
+}
+
+rtc::scoped_refptr<VideoFrameBuffer> VideoFrameBuffer::NativeToI420Buffer() {
+  return ToI420();
+}
+
+rtc::scoped_refptr<I420BufferInterface> VideoFrameBuffer::ToI420() {
+  return new rtc::RefCountedObject<LegacyI420Wrapper>(NativeToI420Buffer());
+}
+
+rtc::scoped_refptr<I444BufferInterface> VideoFrameBuffer::ToI444() {
+  RTC_NOTREACHED();
+  return nullptr;
+}
+
+VideoFrameBuffer::PixelFormat I420BufferInterface::Format() const {
+  return PixelFormat::kI420;
+}
+
+rtc::scoped_refptr<I420BufferInterface> I420BufferInterface::ToI420() {
+  return this;
+}
+
+VideoFrameBuffer::PixelFormat I444BufferInterface::Format() const {
+  return PixelFormat::kI444;
+}
+
+rtc::scoped_refptr<I420BufferInterface> I444BufferInterface::ToI420() {
+  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;
+}
+
+rtc::scoped_refptr<I444BufferInterface> I444BufferInterface::ToI444() {
+  return this;
+}
+
+}  // namespace webrtc