New class AdaptedVideoTrackSource.

webrtc/media/base/adaptedvideotracksource.cc

+/*
+ *  Copyright (c) 2016 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/media/base/adaptedvideotracksource.h"
+
+namespace rtc {
+
+AdaptedVideoTrackSource::AdaptedVideoTrackSource() {
+  thread_checker_.DetachFromThread();
+}
+
+bool AdaptedVideoTrackSource::GetStats(Stats* stats) {
+  rtc::CritScope lock(&stats_crit_);
+
+  if (!stats_) {
+    return false;
+  }
+
+  *stats = *stats_;
+  return true;
+}
+
+void AdaptedVideoTrackSource::OnFrame(const cricket::VideoFrame& frame) {
+  rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer(
+      frame.video_frame_buffer());
+  /* Note that this is a "best effort" approach to
+     wants.rotation_applied; apply_rotation_ can change from false to
+     true between the check of apply_rotation() and the call to
+     broadcaster_.OnFrame(), in which case we generate a frame with
+     pending rotation despite some sink with wants.rotation_applied ==
+     true was just added. The VideoBroadcaster enforces
+     synchronization for us in this case, by not passing the frame on
+     to sinks which don't want it. */
+  if (apply_rotation() &&
+      frame.rotation() != webrtc::kVideoRotation_0 &&
+      !buffer->native_handle()) {
+    /* Apply pending rotation. */
+    broadcaster_.OnFrame(cricket::WebRtcVideoFrame(
+        webrtc::I420Buffer::Rotate(buffer, frame.rotation()),
+        webrtc::kVideoRotation_0, frame.timestamp_us()));
+  } else {
+    broadcaster_.OnFrame(frame);
+  }
+}
+
+void AdaptedVideoTrackSource::AddOrUpdateSink(
+    rtc::VideoSinkInterface<cricket::VideoFrame>* sink,
+    const rtc::VideoSinkWants& wants) {
+  RTC_DCHECK(thread_checker_.CalledOnValidThread());
+
+  broadcaster_.AddOrUpdateSink(sink, wants);
+  OnSinkWantsChanged(broadcaster_.wants());
+}
+
+void AdaptedVideoTrackSource::RemoveSink(
+    rtc::VideoSinkInterface<cricket::VideoFrame>* sink) {
+  RTC_DCHECK(thread_checker_.CalledOnValidThread());
+
+  broadcaster_.RemoveSink(sink);
+  OnSinkWantsChanged(broadcaster_.wants());
+}
+
+bool AdaptedVideoTrackSource::apply_rotation() {
+  return broadcaster_.wants().rotation_applied;
+}
+
+void AdaptedVideoTrackSource::OnSinkWantsChanged(
+    const rtc::VideoSinkWants& wants) {
+  RTC_DCHECK(thread_checker_.CalledOnValidThread());
+  video_adapter_.OnResolutionRequest(wants.max_pixel_count,
+                                     wants.max_pixel_count_step_up);
+}
+
+bool AdaptedVideoTrackSource::AdaptFrame(int width,
+                                         int height,
+                                         int64_t time_us,
+                                         int* out_width,
+                                         int* out_height,
+                                         int* crop_width,
+                                         int* crop_height,
+                                         int* crop_x,
+                                         int* crop_y) {
+  {
+    rtc::CritScope lock(&stats_crit_);
+    stats_ = rtc::Optional<Stats>({width, height});
+  }
+
+  if (!broadcaster_.frame_wanted()) {
+    return false;
+  }
+
+  if (!video_adapter_.AdaptFrameResolution(
+          width, height, time_us * rtc::kNumNanosecsPerMicrosec,
+          crop_width, crop_height, out_width, out_height)) {
+    // VideoAdapter dropped the frame.
+    return false;
+  }
+
+  *crop_x = (width - *crop_width) / 2;
+  *crop_y = (height - *crop_height) / 2;
+  return true;
+}
+
+}  // namespace rtc