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VideoStreamFactory.h (4235B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
      6 
      7 #ifndef VideoStreamFactory_h
      8 #define VideoStreamFactory_h
      9 
     10 #include "CodecConfig.h"
     11 #include "mozilla/Atomics.h"
     12 #include "mozilla/EventTargetCapability.h"
     13 #include "mozilla/gfx/Point.h"
     14 #include "video/config/video_encoder_config.h"
     15 
     16 namespace webrtc {
     17 class VideoFrame;
     18 }
     19 
     20 namespace mozilla {
     21 
     22 // Factory class for VideoStreams... vie_encoder.cc will call this to
     23 // reconfigure.
     24 class VideoStreamFactory
     25    : public webrtc::VideoEncoderConfig::VideoStreamFactoryInterface {
     26 public:
     27  struct ResolutionAndBitrateLimits {
     28    int resolution_in_mb;
     29    int min_bitrate_bps;
     30    int start_bitrate_bps;
     31    int max_bitrate_bps;
     32  };
     33 
     34  static ResolutionAndBitrateLimits GetLimitsFor(gfx::IntSize aSize,
     35                                                 int aCapBps = 0);
     36 
     37  VideoStreamFactory(VideoCodecConfig aConfig, int aMinBitrate,
     38                     int aStartBitrate, int aPrefMaxBitrate,
     39                     int aNegotiatedMaxBitrate)
     40      : mMaxFramerateForAllStreams(std::numeric_limits<unsigned int>::max()),
     41        mCodecConfig(std::forward<VideoCodecConfig>(aConfig)),
     42        mMinBitrate(aMinBitrate),
     43        mStartBitrate(aStartBitrate),
     44        mPrefMaxBitrate(aPrefMaxBitrate),
     45        mNegotiatedMaxBitrate(aNegotiatedMaxBitrate) {}
     46 
     47  // This gets called off-main thread and may hold internal webrtc.org
     48  // locks. May *NOT* lock the conduit's mutex, to avoid deadlocks.
     49  std::vector<webrtc::VideoStream> CreateEncoderStreams(
     50      const webrtc::FieldTrialsView& field_trials, int aWidth, int aHeight,
     51      const webrtc::VideoEncoderConfig& aConfig) override
     52      MOZ_EXCLUDES(mEncodeQueue);
     53 
     54  // Called right before CreateEncoderStreams with info about the encoder
     55  // instance used.
     56  void SetEncoderInfo(const webrtc::VideoEncoder::EncoderInfo& aInfo) override
     57      MOZ_EXCLUDES(mEncodeQueue);
     58 
     59  /**
     60   * Called by CreateEncoderStreams and
     61   * WebrtcVideoConduit::OnControlConfigChange to set VideoStream.max_framerate.
     62   */
     63  void SelectResolutionAndMaxFramerate(
     64      gfx::IntSize aSize, const VideoCodecConfig::Encoding& aEncoding,
     65      webrtc::VideoStream& aVideoStream) MOZ_REQUIRES(mEncodeQueue);
     66 
     67  /**
     68   * Function to select and change the encoding resolution based on incoming
     69   * frame size and current available bandwidth.
     70   * @param aSize: dimensions of the frame
     71   */
     72  void SelectMaxFramerateForAllStreams(gfx::IntSize aSize);
     73 
     74 private:
     75  /**
     76   * Function to calculate a scaled down width and height based on
     77   * scaleDownByResolution, maxFS, and max pixel count settings.
     78   * @param aSize current frame size
     79   * @param aScaleDownByResolution value to scale width and height down by.
     80   * @return a gfx:IntSize containing  width and height to use. These may match
     81   *         the aSize passed in if no scaling was needed.
     82   */
     83  gfx::IntSize CalculateScaledResolution(gfx::IntSize aSize,
     84                                         double aScaleDownByResolution)
     85      MOZ_REQUIRES(mEncodeQueue);
     86 
     87  /**
     88   * Function to select and change the encoding frame rate based on incoming
     89   * frame rate, current frame size and max-mbps setting.
     90   * @param aOldFramerate current framerate
     91   * @param aSendingSize size of frames being sent
     92   * @return new framerate meeting max-mbps requriements based on frame size
     93   */
     94  unsigned int SelectFrameRate(unsigned int aOldFramerate, gfx::IntSize aSize);
     95 
     96  // The framerate we're currently sending at.
     97  Atomic<unsigned int> mMaxFramerateForAllStreams;
     98 
     99  Maybe<EventTargetCapability<nsISerialEventTarget>> mEncodeQueue;
    100  Maybe<int> mRequestedResolutionAlignment MOZ_GUARDED_BY(mEncodeQueue);
    101 
    102  // The current send codec config, containing simulcast layer configs.
    103  const VideoCodecConfig mCodecConfig;
    104 
    105  // Bitrate limits in bps.
    106  const int mMinBitrate = 0;
    107  const int mStartBitrate = 0;
    108  const int mPrefMaxBitrate = 0;
    109  const int mNegotiatedMaxBitrate = 0;
    110 };
    111 
    112 }  // namespace mozilla
    113 
    114 #endif