# Video stats Overview of collected statistics for [VideoSendStream] and [VideoReceiveStream]. ## VideoSendStream [VideoSendStream::Stats] for a sending stream can be gathered via `VideoSendStream::GetStats()`. Some statistics are collected per RTP stream (see [StreamStats]) and can be of `StreamType`: `kMedia`, `kRtx`, `kFlexfec`. Multiple `StreamStats` objects are for example present if simulcast is used (multiple `kMedia` objects) or if RTX or FlexFEC is negotiated. ### SendStatisticsProxy `VideoSendStream` owns a [SendStatisticsProxy] which implements `VideoStreamEncoderObserver`, `RtcpStatisticsCallback`, `ReportBlockDataObserver`, `RtcpPacketTypeCounterObserver`, `StreamDataCountersCallback`, `BitrateStatisticsObserver`, `FrameCountObserver`, `SendSideDelayObserver` and holds a `VideoSendStream::Stats` object. `SendStatisticsProxy` is called via these interfaces by different components (e.g. `RtpRtcp` module) to update stats. #### StreamStats * `type` - kMedia, kRtx or kFlexfec. * `referenced_media_ssrc` - only present for type kRtx/kFlexfec. The SSRC for the kMedia stream that retransmissions or FEC is performed for. Updated when a frame has been encoded, `VideoStreamEncoder::OnEncodedImage`. * `frames_encoded `- total number of encoded frames. * `encode_frame_rate` - number of encoded frames during the last second. * `width` - width of last encoded frame [[rtcoutboundrtpstreamstats-framewidth]]. * `height` - height of last encoded frame [[rtcoutboundrtpstreamstats-frameheight]]. * `total_encode_time_ms` - total encode time for encoded frames. * `qp_sum` - sum of quantizer values of encoded frames [[rtcoutboundrtpstreamstats-qpsum]]. * `frame_counts` - total number of encoded key/delta frames [[rtcoutboundrtpstreamstats-keyframesencoded]]. Updated when a RTP packet is transmitted to the network, `RtpSenderEgress::SendPacket`. * `rtp_stats` - total number of sent bytes/packets. * `total_bitrate_bps` - total bitrate sent in bits per second (over a one second window). * `retransmit_bitrate_bps` - total retransmit bitrate sent in bits per second (over a one second window). * `avg_delay_ms` - average capture-to-send delay for sent packets (over a one second window). * `max_delay_ms` - maximum capture-to-send delay for sent packets (over a one second window). * `total_packet_send_delay_ms` - total capture-to-send delay for sent packets [[rtcoutboundrtpstreamstats-totalpacketsenddelay]]. Updated when an incoming RTCP packet is parsed, `RTCPReceiver::ParseCompoundPacket`. * `rtcp_packet_type_counts` - total number of received NACK/FIR/PLI packets [rtcoutboundrtpstreamstats-[nackcount], [fircount], [plicount]]. Updated when a RTCP report block packet is received, `RTCPReceiver::TriggerCallbacksFromRtcpPacket`. * `rtcp_stats` - RTCP report block data. * `report_block_data` - RTCP report block data. #### Stats * `std::map substreams` - StreamStats mapped per SSRC. Updated when a frame is received from the source, `VideoStreamEncoder::OnFrame`. * `frames` - total number of frames fed to VideoStreamEncoder. * `input_frame_rate` - number of frames fed to VideoStreamEncoder during the last second. * `frames_dropped_by_congestion_window` - total number of dropped frames due to congestion window pushback. * `frames_dropped_by_encoder_queue` - total number of dropped frames due to that the encoder is blocked. Updated if a frame from the source is dropped, `VideoStreamEncoder::OnDiscardedFrame`. * `frames_dropped_by_capturer` - total number dropped frames by the source. Updated if a frame is dropped by `FrameDropper`, `VideoStreamEncoder::MaybeEncodeVideoFrame`. * `frames_dropped_by_rate_limiter` - total number of dropped frames to avoid bitrate overuse. Updated (if changed) before a frame is passed to the encoder, `VideoStreamEncoder::EncodeVideoFrame`. * `encoder_implementation_name` - name of encoder implementation [[rtcoutboundrtpstreamstats-encoderimplementation]]. Updated after a frame has been encoded, `VideoStreamEncoder::OnEncodedImage`. * `frames_encoded `- total number of encoded frames [[rtcoutboundrtpstreamstats-framesencoded]]. * `encode_frame_rate` - number of encoded frames during the last second [[rtcoutboundrtpstreamstats-framespersecond]]. * `total_encoded_bytes_target` - total target frame size in bytes [[rtcoutboundrtpstreamstats-totalencodedbytestarget]]. * `huge_frames_sent` - total number of huge frames sent [[rtcoutboundrtpstreamstats-hugeframessent]]. * `media_bitrate_bps` - the actual bitrate the encoder is producing. * `avg_encode_time_ms` - average encode time for encoded frames. * `total_encode_time_ms` - total encode time for encoded frames [[rtcoutboundrtpstreamstats-totalencodetime]]. * `frames_dropped_by_encoder`- total number of dropped frames by the encoder. Adaptation stats. * `bw_limited_resolution` - shows if resolution is limited due to restricted bandwidth. * `cpu_limited_resolution` - shows if resolution is limited due to cpu. * `bw_limited_framerate` - shows if framerate is limited due to restricted bandwidth. * `cpu_limited_framerate` - shows if framerate is limited due to cpu. * `quality_limitation_reason` - current reason for limiting resolution and/or framerate [[rtcoutboundrtpstreamstats-qualitylimitationreason]]. * `quality_limitation_durations_ms` - total time spent in quality limitation state [[rtcoutboundrtpstreamstats-qualitylimitationdurations]]. * `quality_limitation_resolution_changes` - total number of times that resolution has changed due to quality limitation [[rtcoutboundrtpstreamstats-qualitylimitationresolutionchanges]]. * `number_of_cpu_adapt_changes` - total number of times resolution/framerate has changed due to cpu limitation. * `number_of_quality_adapt_changes` - total number of times resolution/framerate has changed due to quality limitation. Updated when the encoder is configured, `VideoStreamEncoder::ReconfigureEncoder`. * `content_type` - configured content type (UNSPECIFIED/SCREENSHARE). Updated when the available bitrate changes, `VideoSendStreamImpl::OnBitrateUpdated`. * `target_media_bitrate_bps` - the bitrate the encoder is configured to use. * `suspended` - shows if video is suspended due to zero target bitrate. ## VideoReceiveStream [VideoReceiveStream::Stats] for a receiving stream can be gathered via `VideoReceiveStream::GetStats()`. ### ReceiveStatisticsProxy `VideoReceiveStream` owns a [ReceiveStatisticsProxy] which implements `VideoStreamBufferControllerStatsObserver`, `RtcpCnameCallback`, `RtcpPacketTypeCounterObserver`, `CallStatsObserver` and holds a `VideoReceiveStream::Stats` object. `ReceiveStatisticsProxy` is called via these interfaces by different components (e.g. `RtpRtcp` module) to update stats. #### Stats * `current_payload_type` - current payload type. * `ssrc` - configured SSRC for the received stream. Updated when a complete frame is received, `FrameBuffer::InsertFrame`. * `frame_counts` - total number of key/delta frames received [[rtcinboundrtpstreamstats-keyframesdecoded]]. * `network_frame_rate` - number of frames received during the last second. Updated when a frame is ready for decoding, `FrameBuffer::GetNextFrame`. From `VCMTiming`: * `jitter_buffer_ms` - jitter delay in ms: this is the delay added to handle network jitter * `max_decode_ms` - the 95th percentile observed decode time within a time window (10 sec). * `render_delay_ms` - render delay in ms. * `min_playout_delay_ms` - minimum playout delay in ms. * `target_delay_ms` - target playout delay in ms. Max(`min_playout_delay_ms`, `jitter_delay_ms` + `max_decode_ms` + `render_delay_ms`). * `current_delay_ms` - actual playout delay in ms. * `jitter_buffer_delay_seconds` - total jitter buffer delay in seconds: this is the time spent waiting in the jitter buffer [[rtcinboundrtpstreamstats-jitterbufferdelay]]. * `jitter_buffer_emitted_count` - total number of frames that have come out from the jitter buffer [[rtcinboundrtpstreamstats-jitterbufferemittedcount]]. Updated (if changed) after a frame is passed to the decoder, `VCMGenericDecoder::Decode`. * `decoder_implementation_name` - name of decoder implementation [[rtcinboundrtpstreamstats-decoderimplementation]]. Updated when a frame is ready for decoding, `FrameBuffer::GetNextFrame`. * `timing_frame_info` - timestamps for a full lifetime of a frame. * `first_frame_received_to_decoded_ms` - initial decoding latency between the first arrived frame and the first decoded frame. * `frames_dropped` - total number of dropped frames prior to decoding or if the system is too slow [[rtcreceivedrtpstreamstats-framesdropped]]. Updated after a frame has been decoded, `VCMDecodedFrameCallback::Decoded`. * `frames_decoded` - total number of decoded frames [[rtcinboundrtpstreamstats-framesdecoded]]. * `decode_frame_rate` - number of decoded frames during the last second [[rtcinboundrtpstreamstats-framespersecond]]. * `decode_ms` - time to decode last frame in ms. * `total_decode_time_ms` - total decode time for decoded frames [[rtcinboundrtpstreamstats-totaldecodetime]]. * `qp_sum` - sum of quantizer values of decoded frames [[rtcinboundrtpstreamstats-qpsum]]. * `content_type` - content type (UNSPECIFIED/SCREENSHARE). * `interframe_delay_max_ms` - max inter-frame delay within a time window between decoded frames. Updated before a frame is sent to the renderer, `VideoReceiveStream2::OnFrame`. * `frames_rendered` - total number of rendered frames. * `render_frame_rate` - number of rendered frames during the last second. * `width` - width of last frame fed to renderer [[rtcinboundrtpstreamstats-framewidth]]. * `height` - height of last frame fed to renderer [[rtcinboundrtpstreamstats-frameheight]]. * `estimated_playout_ntp_timestamp_ms` - estimated playout NTP timestamp [[rtcinboundrtpstreamstats-estimatedplayouttimestamp]]. * `sync_offset_ms` - NTP timestamp difference between the last played out audio and video frame. * `freeze_count` - total number of detected freezes. * `pause_count` - total number of detected pauses. * `total_freezes_duration_ms` - total duration of freezes in ms. * `total_pauses_duration_ms` - total duration of pauses in ms. * `total_inter_frame_delay` - sum of inter-frame delay in seconds between rendered frames [[rtcinboundrtpstreamstats-totalinterframedelay]]. * `total_squared_inter_frame_delay` - sum of squared inter-frame delays in seconds between rendered frames [[rtcinboundrtpstreamstats-totalsquaredinterframedelay]]. `ReceiveStatisticsImpl::OnRtpPacket` is updated for received RTP packets. From `ReceiveStatistics`: * `total_bitrate_bps` - incoming bitrate in bps. * `rtp_stats` - RTP statistics for the received stream. Updated when a RTCP packet is sent, `RTCPSender::ComputeCompoundRTCPPacket`. * `rtcp_packet_type_counts` - total number of sent NACK/FIR/PLI packets [rtcinboundrtpstreamstats-[nackcount], [fircount], [plicount]]. [VideoSendStream]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/call/video_send_stream.h [VideoSendStream::Stats]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/call/video_send_stream.h?q=VideoSendStream::Stats [StreamStats]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/call/video_send_stream.h?q=VideoSendStream::StreamStats [SendStatisticsProxy]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/video/send_statistics_proxy.h [rtcoutboundrtpstreamstats-framewidth]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-framewidth [rtcoutboundrtpstreamstats-frameheight]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-frameheight [rtcoutboundrtpstreamstats-qpsum]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-qpsum [rtcoutboundrtpstreamstats-keyframesencoded]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-keyframesencoded [rtcoutboundrtpstreamstats-totalpacketsenddelay]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-totalpacketsenddelay [nackcount]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-nackcount [fircount]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-fircount [plicount]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-plicount [rtcoutboundrtpstreamstats-encoderimplementation]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-encoderimplementation [rtcoutboundrtpstreamstats-framesencoded]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-framesencoded [rtcoutboundrtpstreamstats-framespersecond]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-framespersecond [rtcoutboundrtpstreamstats-totalencodedbytestarget]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-totalencodedbytestarget [rtcoutboundrtpstreamstats-hugeframessent]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-hugeframessent [rtcoutboundrtpstreamstats-totalencodetime]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-totalencodetime [rtcoutboundrtpstreamstats-qualitylimitationreason]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-qualitylimitationreason [rtcoutboundrtpstreamstats-qualitylimitationdurations]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-qualitylimitationdurations [rtcoutboundrtpstreamstats-qualitylimitationresolutionchanges]: https://w3c.github.io/webrtc-stats/#dom-rtcoutboundrtpstreamstats-qualitylimitationresolutionchanges [VideoReceiveStream]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/call/video_receive_stream.h [VideoReceiveStream::Stats]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/call/video_receive_stream.h?q=VideoReceiveStream::Stats [ReceiveStatisticsProxy]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/webrtc/video/receive_statistics_proxy.h [rtcinboundrtpstreamstats-keyframesdecoded]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-keyframesdecoded [rtcinboundrtpstreamstats-jitterbufferdelay]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-jitterbufferdelay [rtcinboundrtpstreamstats-jitterbufferemittedcount]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-jitterbufferemittedcount [rtcinboundrtpstreamstats-decoderimplementation]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-decoderimplementation [rtcreceivedrtpstreamstats-framesdropped]: https://www.w3.org/TR/webrtc-stats/#dom-rtcreceivedrtpstreamstats-framesdropped [rtcinboundrtpstreamstats-framesdecoded]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-framesdecoded [rtcinboundrtpstreamstats-framespersecond]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-framespersecond [rtcinboundrtpstreamstats-totaldecodetime]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-totaldecodetime [rtcinboundrtpstreamstats-qpsum]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-qpsum [rtcinboundrtpstreamstats-totalinterframedelay]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-totalinterframedelay [rtcinboundrtpstreamstats-totalsquaredinterframedelay]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-totalsquaredinterframedelay [rtcinboundrtpstreamstats-estimatedplayouttimestamp]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-estimatedplayouttimestamp [rtcinboundrtpstreamstats-framewidth]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-framewidth [rtcinboundrtpstreamstats-frameheight]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-frameheight [nackcount]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-nackcount [fircount]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-fircount [plicount]: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-plicount