1 files changed, 74 insertions, 0 deletions
diff --git a/chromium/third_party/blink/renderer/modules/peerconnection/rtc_encoded_video_underlying_source.cc b/chromium/third_party/blink/renderer/modules/peerconnection/rtc_encoded_video_underlying_source.cc
new file mode 100644
index 00000000000..a459e4112b2
--- /dev/null
+++ b/chromium/third_party/blink/renderer/modules/peerconnection/rtc_encoded_video_underlying_source.cc
@@ -0,0 +1,74 @@
+// Copyright 2020 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 "third_party/blink/renderer/modules/peerconnection/rtc_encoded_video_underlying_source.h"
+
+#include "third_party/blink/renderer/bindings/core/v8/v8_throw_dom_exception.h"
+#include "third_party/blink/renderer/core/streams/readable_stream_default_controller_with_script_scope.h"
+#include "third_party/blink/renderer/modules/peerconnection/rtc_encoded_video_frame.h"
+#include "third_party/blink/renderer/platform/bindings/exception_code.h"
+#include "third_party/blink/renderer/platform/bindings/exception_state.h"
+#include "third_party/webrtc/api/frame_transformer_interface.h"
+
+namespace blink {
+
+// Frames should not be queued at all. We allow queuing a few frames to deal
+// with transient slowdowns. Specified as a negative number of frames since
+// queuing is reported by the stream controller as a negative desired size.
+const int RTCEncodedVideoUnderlyingSource::kMinQueueDesiredSize = -60;
+
+RTCEncodedVideoUnderlyingSource::RTCEncodedVideoUnderlyingSource(
+    ScriptState* script_state,
+    base::OnceClosure disconnect_callback)
+    : UnderlyingSourceBase(script_state),
+      script_state_(script_state),
+      disconnect_callback_(std::move(disconnect_callback)) {
+  DCHECK(disconnect_callback_);
+}
+
+ScriptPromise RTCEncodedVideoUnderlyingSource::pull(ScriptState* script_state) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  // WebRTC is a push source without backpressure support, so nothing to do
+  // here.
+  return ScriptPromise::CastUndefined(script_state);
+}
+
+ScriptPromise RTCEncodedVideoUnderlyingSource::Cancel(ScriptState* script_state,
+                                                      ScriptValue reason) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  if (disconnect_callback_)
+    std::move(disconnect_callback_).Run();
+  return ScriptPromise::CastUndefined(script_state);
+}
+
+void RTCEncodedVideoUnderlyingSource::Trace(Visitor* visitor) {
+  visitor->Trace(script_state_);
+  UnderlyingSourceBase::Trace(visitor);
+}
+
+void RTCEncodedVideoUnderlyingSource::OnFrameFromSource(
+    std::unique_ptr<webrtc::TransformableVideoFrameInterface> webrtc_frame) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  // If the source is canceled or there are too many queued frames,
+  // drop the new frame.
+  if (!disconnect_callback_ || !Controller() ||
+      Controller()->DesiredSize() <= kMinQueueDesiredSize) {
+    return;
+  }
+
+  RTCEncodedVideoFrame* encoded_frame =
+      MakeGarbageCollected<RTCEncodedVideoFrame>(std::move(webrtc_frame));
+  Controller()->Enqueue(encoded_frame);
+}
+
+void RTCEncodedVideoUnderlyingSource::Close() {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  if (disconnect_callback_)
+    std::move(disconnect_callback_).Run();
+
+  if (Controller())
+    Controller()->Close();
+}
+
+}  // namespace blink