ManageFrame

ManageFrameInternal

enum VideoCodecType {
  // There are various memset(..., 0, ...) calls in the code that rely on
  // kVideoCodecGeneric being zero.
  kVideoCodecGeneric = 0,
  kVideoCodecVP8,
  kVideoCodecVP9,
  kVideoCodecAV1,
  kVideoCodecH264,
  kVideoCodecMultiplex,
};
RtpFrameReferenceFinder::ReturnVector RtpFrameReferenceFinderImpl::ManageFrame(
    std::unique_ptr<RtpFrameObject> frame) {
  const RTPVideoHeader& video_header = frame->GetRtpVideoHeader();
  if (video_header.generic.has_value()) {
    return GetRefFinderAs<RtpGenericFrameRefFinder>().ManageFrame(
        std::move(frame), *video_header.generic);
  }
  switch (frame->codec_type()) {
    case kVideoCodecVP8: {
      const RTPVideoHeaderVP8& vp8_header =
          absl::get<RTPVideoHeaderVP8>(video_header.video_type_header);
      if (vp8_header.temporalIdx == kNoTemporalIdx ||
          vp8_header.tl0PicIdx == kNoTl0PicIdx) {
        if (vp8_header.pictureId == kNoPictureId) {
          return GetRefFinderAs<RtpSeqNumOnlyRefFinder>().ManageFrame(
              std::move(frame));
        }
        return GetRefFinderAs<RtpFrameIdOnlyRefFinder>().ManageFrame(
            std::move(frame), vp8_header.pictureId);
      }
      return GetRefFinderAs<RtpVp8RefFinder>().ManageFrame(std::move(frame));
    }
    case kVideoCodecVP9: {
      const RTPVideoHeaderVP9& vp9_header =
          absl::get<RTPVideoHeaderVP9>(video_header.video_type_header);
      if (vp9_header.temporal_idx == kNoTemporalIdx) {
        if (vp9_header.picture_id == kNoPictureId) {
          return GetRefFinderAs<RtpSeqNumOnlyRefFinder>().ManageFrame(
              std::move(frame));
        }
        return GetRefFinderAs<RtpFrameIdOnlyRefFinder>().ManageFrame(
            std::move(frame), vp9_header.picture_id);
      }
      return GetRefFinderAs<RtpVp9RefFinder>().ManageFrame(std::move(frame));
    }
    case kVideoCodecGeneric: {
      if (auto* generic_header = absl::get_if<RTPVideoHeaderLegacyGeneric>(
              &video_header.video_type_header)) {
        return GetRefFinderAs<RtpFrameIdOnlyRefFinder>().ManageFrame(
            std::move(frame), generic_header->picture_id);
      }
      return GetRefFinderAs<RtpSeqNumOnlyRefFinder>().ManageFrame(
          std::move(frame));
    }
    default: {
      return GetRefFinderAs<RtpSeqNumOnlyRefFinder>().ManageFrame(
          std::move(frame));
    }
  }
}

可见H264编码方式的话会跑到default项。。

ManageFrameVp8

temporalIdx SVC分层的时域 的索引值
il0PicIdx : 时域层的第0层的pictureId索引值
如果不开启vp8的svc分层，则il0PicIdx 不存在。默认不开启。

ManageFramePidOrSeqNum

正常，获取到vp8的参考帧。 kHandOff代表找到了参考帧。

再看ManageFrame

RetryStashedFrames 判断缓存的stashedframe是否有某个帧找到了参考帧。

RtpFrameReferenceFinder::ReturnVector RtpSeqNumOnlyRefFinder::ManageFrame(
    std::unique_ptr<RtpFrameObject> frame) {
  FrameDecision decision = ManageFrameInternal(frame.get());
  RtpFrameReferenceFinder::ReturnVector res;
  switch (decision) {
    case kStash:
      if (stashed_frames_.size() > kMaxStashedFrames)
        stashed_frames_.pop_back();
      stashed_frames_.push_front(std::move(frame));
      return res;
    case kHandOff:
      res.push_back(std::move(frame));
      RetryStashedFrames(res);
      return res;
    case kDrop:
      return res;
  }
  return res;
}
void RtpSeqNumOnlyRefFinder::RetryStashedFrames(
    RtpFrameReferenceFinder::ReturnVector& res) {
  bool complete_frame = false;
  do {
    complete_frame = false;
    for (auto frame_it = stashed_frames_.begin();
         frame_it != stashed_frames_.end();) {
      FrameDecision decision = ManageFrameInternal(frame_it->get());
      switch (decision) {
        case kStash:
          ++frame_it;
          break;
        case kHandOff:
          complete_frame = true;
          res.push_back(std::move(*frame_it));
          ABSL_FALLTHROUGH_INTENDED;
        case kDrop:
          frame_it = stashed_frames_.erase(frame_it);
      }
    }
  } while (complete_frame);
}