Interface with webrtc through encoded frames

remoting/protocol/webrtc_video_encoder.cc

+// Copyright 2016 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 "remoting/protocol/webrtc_video_encoder.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/synchronization/lock.h"
+
+namespace remoting {
+
+WebRtcVideoEncoder::WebRtcVideoEncoder(webrtc::VideoCodecType codec)
+    : state_(kUninitialized), video_codec_type_(codec) {
+  VLOG(1) << "video codecType " << video_codec_type_;
+}
+
+WebRtcVideoEncoder::~WebRtcVideoEncoder() {}
+
+int32_t WebRtcVideoEncoder::InitEncode(const webrtc::VideoCodec* codec_settings,
+                                       int32_t number_of_cores,
+                                       size_t max_payload_size) {
+  base::AutoLock lock(lock_);
+  DCHECK(codec_settings);
+  VLOG(1) << "video codecType " << codec_settings->codecType << " width "
+          << codec_settings->width << " height " << codec_settings->height
+          << " startBitrate " << codec_settings->startBitrate << " maxBitrate "
+          << codec_settings->maxBitrate << " minBitrate "
+          << codec_settings->minBitrate << " targetBitrate "
+          << codec_settings->targetBitrate << " maxFramerate "
+          << codec_settings->maxFramerate;
+
+  int streamCount = codec_settings->numberOfSimulcastStreams;
+  // Validate request is to support a single stream.
+  if (streamCount > 1) {
+    for (int i = 0; i < streamCount; ++i) {
+      if (codec_settings->simulcastStream[i].maxBitrate != 0) {
+        LOG(ERROR) << "Simulcast unsupported";
+        return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
+      }
+    }
+  }
+  target_bitrate_ = codec_settings->startBitrate;
+  state_ = kInitialized;
+  return WEBRTC_VIDEO_CODEC_OK;
+}
+
+int32_t WebRtcVideoEncoder::RegisterEncodeCompleteCallback(
+    webrtc::EncodedImageCallback* callback) {
+  base::AutoLock lock(lock_);
+  DCHECK(callback);
+  encoded_callback_ = callback;
+  return WEBRTC_VIDEO_CODEC_OK;
+}
+
+int32_t WebRtcVideoEncoder::Release() {
+  base::AutoLock lock(lock_);
+  encoded_callback_ = nullptr;
+  return WEBRTC_VIDEO_CODEC_OK;
+}
+
+int32_t WebRtcVideoEncoder::Encode(
+    const webrtc::VideoFrame& frame,
+    const webrtc::CodecSpecificInfo* codec_specific_info,
+    const std::vector<webrtc::FrameType>* frame_types) {
+  if (!key_frame_request_.is_null())
+    key_frame_request_.Run();
+  return WEBRTC_VIDEO_CODEC_OK;
+}
+
+int32_t WebRtcVideoEncoder::SetChannelParameters(uint32_t packet_loss,
+                                                 int64_t rtt) {
+  VLOG(1) << "WebRtcVideoEncoder::SetChannelParameters "
+          << "loss:RTT " << packet_loss << ":" << rtt;
+  // Unused right now.
+  return WEBRTC_VIDEO_CODEC_OK;
+}
+
+int32_t WebRtcVideoEncoder::SetRates(uint32_t bitrate, uint32_t framerate) {
+  VLOG(1) << "WebRtcVideoEncoder::SetRates bitrate:framerate " << bitrate << ":"
+          << framerate;
+  target_bitrate_ = bitrate;
+  // framerate is not expected to be valid given we never report captured
+  // frames
+  return WEBRTC_VIDEO_CODEC_OK;
+}
+
+int WebRtcVideoEncoder::SendEncodedFrame(int64_t capture_timestamp_ms,
+                                         std::unique_ptr<VideoPacket> frame) {
+  uint8_t* buffer =
+      reinterpret_cast<uint8_t*>(const_cast<char*>(frame->data().data()));
+  size_t buffer_size = frame->data().size();
+  base::AutoLock lock(lock_);
+  if (state_ == kUninitialized) {
+    LOG(ERROR) << "encoder interface uninitialized";
+    return -1;
+  }
+
+  webrtc::EncodedImage encoded_image(buffer, buffer_size, buffer_size);
+  encoded_image._encodedWidth = frame->format().screen_width();
+  encoded_image._encodedHeight = frame->format().screen_height();
+  encoded_image._completeFrame = true;
+  encoded_image._frameType =
+      frame->key_frame() ? webrtc::kVideoFrameKey : webrtc::kVideoFrameDelta;
+  encoded_image.capture_time_ms_ = capture_timestamp_ms;
+  encoded_image._timeStamp = static_cast<uint32_t>(capture_timestamp_ms * 90);
+
+  webrtc::CodecSpecificInfo codec_specific_info;
+  memset(&codec_specific_info, 0, sizeof(codec_specific_info));
+  codec_specific_info.codecType = webrtc::kVideoCodecVP8;
+
+  webrtc::RTPFragmentationHeader header;
+  memset(&header, 0, sizeof(header));
+
+  codec_specific_info.codecSpecific.VP8.simulcastIdx = 0;
+  codec_specific_info.codecSpecific.VP8.temporalIdx = webrtc::kNoTemporalIdx;
+  codec_specific_info.codecSpecific.VP8.tl0PicIdx = webrtc::kNoTl0PicIdx;
+  codec_specific_info.codecSpecific.VP8.pictureId = webrtc::kNoPictureId;
+
+  header.VerifyAndAllocateFragmentationHeader(1);
+  header.fragmentationOffset[0] = 0;
+  header.fragmentationLength[0] = buffer_size;
+  header.fragmentationPlType[0] = 0;
+  header.fragmentationTimeDiff[0] = 0;
+
+  int result =
+      encoded_callback_->Encoded(encoded_image, &codec_specific_info, &header);
+  if (result < 0) {
+    LOG(ERROR) << "Encoded callback failed: " << result;
+  } else if (result > 0) {
+    VLOG(1) << "Drop request from webrtc";
+  }
+  return result;
+}
+
+void WebRtcVideoEncoder::SetKeyFrameRequestCallback(
+    const base::Closure& key_frame_request) {
+  key_frame_request_ = key_frame_request;
+}
+
+WebRtcVideoEncoderFactory::WebRtcVideoEncoderFactory() {
+  // TODO(isheriff): These do not really affect anything internally
+  // in webrtc.
+  codecs_.push_back(cricket::WebRtcVideoEncoderFactory::VideoCodec(
+      webrtc::kVideoCodecVP8, "VP8", 1280, 720, 30));
+}
+
+WebRtcVideoEncoderFactory::~WebRtcVideoEncoderFactory() {
+  DCHECK(encoders_.empty());
+}
+
+webrtc::VideoEncoder* WebRtcVideoEncoderFactory::CreateVideoEncoder(
+    webrtc::VideoCodecType type) {
+  VLOG(2) << "WebRtcVideoEncoderFactory::CreateVideoEncoder " << type;
+  DCHECK(type == webrtc::kVideoCodecVP8);
+  WebRtcVideoEncoder* encoder = new WebRtcVideoEncoder(type);
+  encoder->SetKeyFrameRequestCallback(key_frame_request_);
+  VLOG(1) << "Created " << encoder;
+  encoders_.push_back(base::WrapUnique(encoder));
+  return encoder;
+}
+
+const std::vector<cricket::WebRtcVideoEncoderFactory::VideoCodec>&
+WebRtcVideoEncoderFactory::codecs() const {
+  VLOG(2) << "WebRtcVideoEncoderFactory::codecs";
+  return codecs_;
+}
+
+bool WebRtcVideoEncoderFactory::EncoderTypeHasInternalSource(
+    webrtc::VideoCodecType type) const {
+  VLOG(2) << "WebRtcVideoEncoderFactory::EncoderTypeHasInternalSource";
+  return true;
+}
+
+void WebRtcVideoEncoderFactory::DestroyVideoEncoder(
+    webrtc::VideoEncoder* encoder) {
+  VLOG(2) << "WebRtcVideoEncoderFactory::DestroyVideoEncoder";
+  if (encoder == nullptr) {
+    LOG(ERROR) << "Attempting to destroy null encoder";
+    return;
+  }
+  for (auto pos = encoders_.begin(); pos != encoders_.end(); ++pos) {
+    if ((*pos).get() == encoder) {
+      encoders_.erase(pos);
+      return;
+    }
+  }
+  DCHECK(false) << "Asked to remove encoder not owned by factory";
+}
+
+int WebRtcVideoEncoderFactory::SendEncodedFrame(
+    int64_t capture_timestamp_ms,
+    std::unique_ptr<VideoPacket> frame) {
+  if (encoders_.size() != 1) {
+    LOG(ERROR) << "Unexpected number of encoders " << encoders_.size();
+    return -1;
+  }
+  return encoders_.front()->SendEncodedFrame(capture_timestamp_ms,
+                                             std::move(frame));
+}
+
+void WebRtcVideoEncoderFactory::SetKeyFrameRequestCallback(
+    const base::Closure& key_frame_request) {
+  key_frame_request_ = key_frame_request;
+  if (encoders_.size() == 1) {
+    encoders_.front()->SetKeyFrameRequestCallback(key_frame_request);
+  } else {
+    LOG(ERROR) << "Dropping key frame request callback with unexpected"
+                  " number of encoders"
+               << encoders_.size();
+  }
+}
+
+}  // namespace remoting