| /* | 
 |  *  Copyright (c) 2012 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. | 
 |  */ | 
 |  | 
 | #ifndef COMMON_TYPES_H_ | 
 | #define COMMON_TYPES_H_ | 
 |  | 
 | #include <stddef.h> | 
 | #include <string.h> | 
 | #include <string> | 
 | #include <vector> | 
 |  | 
 | #include "api/array_view.h" | 
 | #include "api/optional.h" | 
 | // TODO(sprang): Remove this include when all usage includes it directly. | 
 | #include "api/video/video_bitrate_allocation.h" | 
 | #include "rtc_base/checks.h" | 
 | #include "rtc_base/deprecation.h" | 
 | #include "typedefs.h"  // NOLINT(build/include) | 
 |  | 
 | #if defined(_MSC_VER) | 
 | // Disable "new behavior: elements of array will be default initialized" | 
 | // warning. Affects OverUseDetectorOptions. | 
 | #pragma warning(disable : 4351) | 
 | #endif | 
 |  | 
 | #ifndef NULL | 
 | #define NULL 0 | 
 | #endif | 
 |  | 
 | #define RTP_PAYLOAD_NAME_SIZE 32u | 
 |  | 
 | #if defined(WEBRTC_WIN) || defined(WIN32) | 
 | // Compares two strings without regard to case. | 
 | #define STR_CASE_CMP(s1, s2) ::_stricmp(s1, s2) | 
 | // Compares characters of two strings without regard to case. | 
 | #define STR_NCASE_CMP(s1, s2, n) ::_strnicmp(s1, s2, n) | 
 | #else | 
 | #define STR_CASE_CMP(s1, s2) ::strcasecmp(s1, s2) | 
 | #define STR_NCASE_CMP(s1, s2, n) ::strncasecmp(s1, s2, n) | 
 | #endif | 
 |  | 
 | namespace webrtc { | 
 |  | 
 | enum FrameType { | 
 |   kEmptyFrame = 0, | 
 |   kAudioFrameSpeech = 1, | 
 |   kAudioFrameCN = 2, | 
 |   kVideoFrameKey = 3, | 
 |   kVideoFrameDelta = 4, | 
 | }; | 
 |  | 
 | // Statistics for an RTCP channel | 
 | struct RtcpStatistics { | 
 |   RtcpStatistics() | 
 |       : fraction_lost(0), | 
 |         packets_lost(0), | 
 |         extended_highest_sequence_number(0), | 
 |         jitter(0) {} | 
 |  | 
 |   uint8_t fraction_lost; | 
 |   union { | 
 |     int32_t packets_lost;  // Defined as a 24 bit signed integer in RTCP | 
 |     RTC_DEPRECATED uint32_t cumulative_lost; | 
 |   }; | 
 |   union { | 
 |     uint32_t extended_highest_sequence_number; | 
 |     RTC_DEPRECATED uint32_t extended_max_sequence_number; | 
 |   }; | 
 |   uint32_t jitter; | 
 | }; | 
 |  | 
 | class RtcpStatisticsCallback { | 
 |  public: | 
 |   virtual ~RtcpStatisticsCallback() {} | 
 |  | 
 |   virtual void StatisticsUpdated(const RtcpStatistics& statistics, | 
 |                                  uint32_t ssrc) = 0; | 
 |   virtual void CNameChanged(const char* cname, uint32_t ssrc) = 0; | 
 | }; | 
 |  | 
 | // Statistics for RTCP packet types. | 
 | struct RtcpPacketTypeCounter { | 
 |   RtcpPacketTypeCounter() | 
 |       : first_packet_time_ms(-1), | 
 |         nack_packets(0), | 
 |         fir_packets(0), | 
 |         pli_packets(0), | 
 |         nack_requests(0), | 
 |         unique_nack_requests(0) {} | 
 |  | 
 |   void Add(const RtcpPacketTypeCounter& other) { | 
 |     nack_packets += other.nack_packets; | 
 |     fir_packets += other.fir_packets; | 
 |     pli_packets += other.pli_packets; | 
 |     nack_requests += other.nack_requests; | 
 |     unique_nack_requests += other.unique_nack_requests; | 
 |     if (other.first_packet_time_ms != -1 && | 
 |         (other.first_packet_time_ms < first_packet_time_ms || | 
 |          first_packet_time_ms == -1)) { | 
 |       // Use oldest time. | 
 |       first_packet_time_ms = other.first_packet_time_ms; | 
 |     } | 
 |   } | 
 |  | 
 |   void Subtract(const RtcpPacketTypeCounter& other) { | 
 |     nack_packets -= other.nack_packets; | 
 |     fir_packets -= other.fir_packets; | 
 |     pli_packets -= other.pli_packets; | 
 |     nack_requests -= other.nack_requests; | 
 |     unique_nack_requests -= other.unique_nack_requests; | 
 |     if (other.first_packet_time_ms != -1 && | 
 |         (other.first_packet_time_ms > first_packet_time_ms || | 
 |          first_packet_time_ms == -1)) { | 
 |       // Use youngest time. | 
 |       first_packet_time_ms = other.first_packet_time_ms; | 
 |     } | 
 |   } | 
 |  | 
 |   int64_t TimeSinceFirstPacketInMs(int64_t now_ms) const { | 
 |     return (first_packet_time_ms == -1) ? -1 : (now_ms - first_packet_time_ms); | 
 |   } | 
 |  | 
 |   int UniqueNackRequestsInPercent() const { | 
 |     if (nack_requests == 0) { | 
 |       return 0; | 
 |     } | 
 |     return static_cast<int>((unique_nack_requests * 100.0f / nack_requests) + | 
 |                             0.5f); | 
 |   } | 
 |  | 
 |   int64_t first_packet_time_ms;   // Time when first packet is sent/received. | 
 |   uint32_t nack_packets;          // Number of RTCP NACK packets. | 
 |   uint32_t fir_packets;           // Number of RTCP FIR packets. | 
 |   uint32_t pli_packets;           // Number of RTCP PLI packets. | 
 |   uint32_t nack_requests;         // Number of NACKed RTP packets. | 
 |   uint32_t unique_nack_requests;  // Number of unique NACKed RTP packets. | 
 | }; | 
 |  | 
 | class RtcpPacketTypeCounterObserver { | 
 |  public: | 
 |   virtual ~RtcpPacketTypeCounterObserver() {} | 
 |   virtual void RtcpPacketTypesCounterUpdated( | 
 |       uint32_t ssrc, | 
 |       const RtcpPacketTypeCounter& packet_counter) = 0; | 
 | }; | 
 |  | 
 | // Callback, used to notify an observer whenever new rates have been estimated. | 
 | class BitrateStatisticsObserver { | 
 |  public: | 
 |   virtual ~BitrateStatisticsObserver() {} | 
 |  | 
 |   virtual void Notify(uint32_t total_bitrate_bps, | 
 |                       uint32_t retransmit_bitrate_bps, | 
 |                       uint32_t ssrc) = 0; | 
 | }; | 
 |  | 
 | struct FrameCounts { | 
 |   FrameCounts() : key_frames(0), delta_frames(0) {} | 
 |   int key_frames; | 
 |   int delta_frames; | 
 | }; | 
 |  | 
 | // Callback, used to notify an observer whenever frame counts have been updated. | 
 | class FrameCountObserver { | 
 |  public: | 
 |   virtual ~FrameCountObserver() {} | 
 |   virtual void FrameCountUpdated(const FrameCounts& frame_counts, | 
 |                                  uint32_t ssrc) = 0; | 
 | }; | 
 |  | 
 | // Callback, used to notify an observer whenever the send-side delay is updated. | 
 | class SendSideDelayObserver { | 
 |  public: | 
 |   virtual ~SendSideDelayObserver() {} | 
 |   virtual void SendSideDelayUpdated(int avg_delay_ms, | 
 |                                     int max_delay_ms, | 
 |                                     uint32_t ssrc) = 0; | 
 | }; | 
 |  | 
 | // Callback, used to notify an observer whenever a packet is sent to the | 
 | // transport. | 
 | // TODO(asapersson): This class will remove the need for SendSideDelayObserver. | 
 | // Remove SendSideDelayObserver once possible. | 
 | class SendPacketObserver { | 
 |  public: | 
 |   virtual ~SendPacketObserver() {} | 
 |   virtual void OnSendPacket(uint16_t packet_id, | 
 |                             int64_t capture_time_ms, | 
 |                             uint32_t ssrc) = 0; | 
 | }; | 
 |  | 
 | // Callback, used to notify an observer when the overhead per packet | 
 | // has changed. | 
 | class OverheadObserver { | 
 |  public: | 
 |   virtual ~OverheadObserver() = default; | 
 |   virtual void OnOverheadChanged(size_t overhead_bytes_per_packet) = 0; | 
 | }; | 
 |  | 
 | // ================================================================== | 
 | // Voice specific types | 
 | // ================================================================== | 
 |  | 
 | // Each codec supported can be described by this structure. | 
 | struct CodecInst { | 
 |   int pltype; | 
 |   char plname[RTP_PAYLOAD_NAME_SIZE]; | 
 |   int plfreq; | 
 |   int pacsize; | 
 |   size_t channels; | 
 |   int rate;  // bits/sec unlike {start,min,max}Bitrate elsewhere in this file! | 
 |  | 
 |   bool operator==(const CodecInst& other) const { | 
 |     return pltype == other.pltype && | 
 |            (STR_CASE_CMP(plname, other.plname) == 0) && | 
 |            plfreq == other.plfreq && pacsize == other.pacsize && | 
 |            channels == other.channels && rate == other.rate; | 
 |   } | 
 |  | 
 |   bool operator!=(const CodecInst& other) const { return !(*this == other); } | 
 | }; | 
 |  | 
 | // RTP | 
 | enum { kRtpCsrcSize = 15 };  // RFC 3550 page 13 | 
 |  | 
 | // NETEQ statistics. | 
 | struct NetworkStatistics { | 
 |   // current jitter buffer size in ms | 
 |   uint16_t currentBufferSize; | 
 |   // preferred (optimal) buffer size in ms | 
 |   uint16_t preferredBufferSize; | 
 |   // adding extra delay due to "peaky jitter" | 
 |   bool jitterPeaksFound; | 
 |   // Stats below correspond to similarly-named fields in the WebRTC stats spec. | 
 |   // https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamtrackstats | 
 |   uint64_t totalSamplesReceived; | 
 |   uint64_t concealedSamples; | 
 |   uint64_t concealmentEvents; | 
 |   uint64_t jitterBufferDelayMs; | 
 |   // Stats below DO NOT correspond directly to anything in the WebRTC stats | 
 |   // Loss rate (network + late); fraction between 0 and 1, scaled to Q14. | 
 |   uint16_t currentPacketLossRate; | 
 |   // Late loss rate; fraction between 0 and 1, scaled to Q14. | 
 |   union { | 
 |     RTC_DEPRECATED uint16_t currentDiscardRate; | 
 |   }; | 
 |   // fraction (of original stream) of synthesized audio inserted through | 
 |   // expansion (in Q14) | 
 |   uint16_t currentExpandRate; | 
 |   // fraction (of original stream) of synthesized speech inserted through | 
 |   // expansion (in Q14) | 
 |   uint16_t currentSpeechExpandRate; | 
 |   // fraction of synthesized speech inserted through pre-emptive expansion | 
 |   // (in Q14) | 
 |   uint16_t currentPreemptiveRate; | 
 |   // fraction of data removed through acceleration (in Q14) | 
 |   uint16_t currentAccelerateRate; | 
 |   // fraction of data coming from secondary decoding (in Q14) | 
 |   uint16_t currentSecondaryDecodedRate; | 
 |   // Fraction of secondary data, including FEC and RED, that is discarded (in | 
 |   // Q14). Discarding of secondary data can be caused by the reception of the | 
 |   // primary data, obsoleting the secondary data. It can also be caused by early | 
 |   // or late arrival of secondary data. | 
 |   uint16_t currentSecondaryDiscardedRate; | 
 |   // clock-drift in parts-per-million (negative or positive) | 
 |   int32_t clockDriftPPM; | 
 |   // average packet waiting time in the jitter buffer (ms) | 
 |   int meanWaitingTimeMs; | 
 |   // median packet waiting time in the jitter buffer (ms) | 
 |   int medianWaitingTimeMs; | 
 |   // min packet waiting time in the jitter buffer (ms) | 
 |   int minWaitingTimeMs; | 
 |   // max packet waiting time in the jitter buffer (ms) | 
 |   int maxWaitingTimeMs; | 
 |   // added samples in off mode due to packet loss | 
 |   size_t addedSamples; | 
 | }; | 
 |  | 
 | // Statistics for calls to AudioCodingModule::PlayoutData10Ms(). | 
 | struct AudioDecodingCallStats { | 
 |   AudioDecodingCallStats() | 
 |       : calls_to_silence_generator(0), | 
 |         calls_to_neteq(0), | 
 |         decoded_normal(0), | 
 |         decoded_plc(0), | 
 |         decoded_cng(0), | 
 |         decoded_plc_cng(0), | 
 |         decoded_muted_output(0) {} | 
 |  | 
 |   int calls_to_silence_generator;  // Number of calls where silence generated, | 
 |                                    // and NetEq was disengaged from decoding. | 
 |   int calls_to_neteq;              // Number of calls to NetEq. | 
 |   int decoded_normal;  // Number of calls where audio RTP packet decoded. | 
 |   int decoded_plc;     // Number of calls resulted in PLC. | 
 |   int decoded_cng;  // Number of calls where comfort noise generated due to DTX. | 
 |   int decoded_plc_cng;  // Number of calls resulted where PLC faded to CNG. | 
 |   int decoded_muted_output;  // Number of calls returning a muted state output. | 
 | }; | 
 |  | 
 | // ================================================================== | 
 | // Video specific types | 
 | // ================================================================== | 
 |  | 
 | // TODO(nisse): Delete, and switch to fourcc values everywhere? | 
 | // Supported video types. | 
 | enum class VideoType { | 
 |   kUnknown, | 
 |   kI420, | 
 |   kIYUV, | 
 |   kRGB24, | 
 |   kABGR, | 
 |   kARGB, | 
 |   kARGB4444, | 
 |   kRGB565, | 
 |   kARGB1555, | 
 |   kYUY2, | 
 |   kYV12, | 
 |   kUYVY, | 
 |   kMJPEG, | 
 |   kNV21, | 
 |   kNV12, | 
 |   kBGRA, | 
 | }; | 
 |  | 
 | // Video codec | 
 | enum VideoCodecComplexity { | 
 |   kComplexityNormal = 0, | 
 |   kComplexityHigh = 1, | 
 |   kComplexityHigher = 2, | 
 |   kComplexityMax = 3 | 
 | }; | 
 |  | 
 | // VP8 specific | 
 | struct VideoCodecVP8 { | 
 |   bool operator==(const VideoCodecVP8& other) const; | 
 |   bool operator!=(const VideoCodecVP8& other) const { | 
 |     return !(*this == other); | 
 |   } | 
 |   VideoCodecComplexity complexity; | 
 |   unsigned char numberOfTemporalLayers; | 
 |   bool denoisingOn; | 
 |   bool automaticResizeOn; | 
 |   bool frameDroppingOn; | 
 |   int keyFrameInterval; | 
 | }; | 
 |  | 
 | enum class InterLayerPredMode { | 
 |   kOn,       // Allow inter-layer prediction for all frames. | 
 |              // Frame of low spatial layer can be used for | 
 |              // prediction of next spatial layer frame. | 
 |   kOff,      // Encoder produces independent spatial layers. | 
 |   kOnKeyPic  // Allow inter-layer prediction only for frames | 
 |              // within key picture. | 
 | }; | 
 |  | 
 | // VP9 specific. | 
 | struct VideoCodecVP9 { | 
 |   bool operator==(const VideoCodecVP9& other) const; | 
 |   bool operator!=(const VideoCodecVP9& other) const { | 
 |     return !(*this == other); | 
 |   } | 
 |   VideoCodecComplexity complexity; | 
 |   unsigned char numberOfTemporalLayers; | 
 |   bool denoisingOn; | 
 |   bool frameDroppingOn; | 
 |   int keyFrameInterval; | 
 |   bool adaptiveQpMode; | 
 |   bool automaticResizeOn; | 
 |   unsigned char numberOfSpatialLayers; | 
 |   bool flexibleMode; | 
 |   InterLayerPredMode interLayerPred; | 
 | }; | 
 |  | 
 | // TODO(magjed): Move this and other H264 related classes out to their own file. | 
 | namespace H264 { | 
 |  | 
 | enum Profile { | 
 |   kProfileConstrainedBaseline, | 
 |   kProfileBaseline, | 
 |   kProfileMain, | 
 |   kProfileConstrainedHigh, | 
 |   kProfileHigh, | 
 | }; | 
 |  | 
 | }  // namespace H264 | 
 |  | 
 | // H264 specific. | 
 | struct VideoCodecH264 { | 
 |   bool operator==(const VideoCodecH264& other) const; | 
 |   bool operator!=(const VideoCodecH264& other) const { | 
 |     return !(*this == other); | 
 |   } | 
 |   bool frameDroppingOn; | 
 |   int keyFrameInterval; | 
 |   // These are NULL/0 if not externally negotiated. | 
 |   const uint8_t* spsData; | 
 |   size_t spsLen; | 
 |   const uint8_t* ppsData; | 
 |   size_t ppsLen; | 
 |   H264::Profile profile; | 
 | }; | 
 |  | 
 | // Video codec types | 
 | enum VideoCodecType { | 
 |   kVideoCodecVP8, | 
 |   kVideoCodecVP9, | 
 |   kVideoCodecH264, | 
 |   kVideoCodecI420, | 
 |   kVideoCodecRED, | 
 |   kVideoCodecULPFEC, | 
 |   kVideoCodecFlexfec, | 
 |   kVideoCodecGeneric, | 
 |   kVideoCodecMultiplex, | 
 |   kVideoCodecUnknown | 
 | }; | 
 |  | 
 | // Translates from name of codec to codec type and vice versa. | 
 | const char* CodecTypeToPayloadString(VideoCodecType type); | 
 | VideoCodecType PayloadStringToCodecType(const std::string& name); | 
 |  | 
 | union VideoCodecUnion { | 
 |   VideoCodecVP8 VP8; | 
 |   VideoCodecVP9 VP9; | 
 |   VideoCodecH264 H264; | 
 | }; | 
 |  | 
 | struct SpatialLayer { | 
 |   bool operator==(const SpatialLayer& other) const; | 
 |   bool operator!=(const SpatialLayer& other) const { return !(*this == other); } | 
 |  | 
 |   unsigned short width; | 
 |   unsigned short height; | 
 |   unsigned char numberOfTemporalLayers; | 
 |   unsigned int maxBitrate;     // kilobits/sec. | 
 |   unsigned int targetBitrate;  // kilobits/sec. | 
 |   unsigned int minBitrate;     // kilobits/sec. | 
 |   unsigned int qpMax;          // minimum quality | 
 |   bool active;                 // encoded and sent. | 
 | }; | 
 |  | 
 | // Simulcast is when the same stream is encoded multiple times with different | 
 | // settings such as resolution. | 
 | typedef SpatialLayer SimulcastStream; | 
 |  | 
 | enum VideoCodecMode { kRealtimeVideo, kScreensharing }; | 
 |  | 
 | // Common video codec properties | 
 | class VideoCodec { | 
 |  public: | 
 |   VideoCodec(); | 
 |  | 
 |   // Public variables. TODO(hta): Make them private with accessors. | 
 |   VideoCodecType codecType; | 
 |   unsigned char plType; | 
 |  | 
 |   unsigned short width; | 
 |   unsigned short height; | 
 |  | 
 |   unsigned int startBitrate;   // kilobits/sec. | 
 |   unsigned int maxBitrate;     // kilobits/sec. | 
 |   unsigned int minBitrate;     // kilobits/sec. | 
 |   unsigned int targetBitrate;  // kilobits/sec. | 
 |  | 
 |   uint32_t maxFramerate; | 
 |  | 
 |   // This enables/disables encoding and sending when there aren't multiple | 
 |   // simulcast streams,by allocating 0 bitrate if inactive. | 
 |   bool active; | 
 |  | 
 |   unsigned int qpMax; | 
 |   unsigned char numberOfSimulcastStreams; | 
 |   SimulcastStream simulcastStream[kMaxSimulcastStreams]; | 
 |   SpatialLayer spatialLayers[kMaxSpatialLayers]; | 
 |  | 
 |   VideoCodecMode mode; | 
 |   bool expect_encode_from_texture; | 
 |  | 
 |   // Timing frames configuration. There is delay of delay_ms between two | 
 |   // consequent timing frames, excluding outliers. Frame is always made a | 
 |   // timing frame if it's at least outlier_ratio in percent of "ideal" average | 
 |   // frame given bitrate and framerate, i.e. if it's bigger than | 
 |   // |outlier_ratio / 100.0 * bitrate_bps / fps| in bits. This way, timing | 
 |   // frames will not be sent too often usually. Yet large frames will always | 
 |   // have timing information for debug purposes because they are more likely to | 
 |   // cause extra delays. | 
 |   struct TimingFrameTriggerThresholds { | 
 |     int64_t delay_ms; | 
 |     uint16_t outlier_ratio_percent; | 
 |   } timing_frame_thresholds; | 
 |  | 
 |   bool operator==(const VideoCodec& other) const = delete; | 
 |   bool operator!=(const VideoCodec& other) const = delete; | 
 |  | 
 |   // Accessors for codec specific information. | 
 |   // There is a const version of each that returns a reference, | 
 |   // and a non-const version that returns a pointer, in order | 
 |   // to allow modification of the parameters. | 
 |   VideoCodecVP8* VP8(); | 
 |   const VideoCodecVP8& VP8() const; | 
 |   VideoCodecVP9* VP9(); | 
 |   const VideoCodecVP9& VP9() const; | 
 |   VideoCodecH264* H264(); | 
 |   const VideoCodecH264& H264() const; | 
 |  | 
 |  private: | 
 |   // TODO(hta): Consider replacing the union with a pointer type. | 
 |   // This will allow removing the VideoCodec* types from this file. | 
 |   VideoCodecUnion codec_specific_; | 
 | }; | 
 |  | 
 | // TODO(sprang): Remove this when downstream projects have been updated. | 
 | using BitrateAllocation = VideoBitrateAllocation; | 
 |  | 
 | // Bandwidth over-use detector options.  These are used to drive | 
 | // experimentation with bandwidth estimation parameters. | 
 | // See modules/remote_bitrate_estimator/overuse_detector.h | 
 | // TODO(terelius): This is only used in overuse_estimator.cc, and only in the | 
 | // default constructed state. Can we move the relevant variables into that | 
 | // class and delete this? See also disabled warning at line 27 | 
 | struct OverUseDetectorOptions { | 
 |   OverUseDetectorOptions() | 
 |       : initial_slope(8.0 / 512.0), | 
 |         initial_offset(0), | 
 |         initial_e(), | 
 |         initial_process_noise(), | 
 |         initial_avg_noise(0.0), | 
 |         initial_var_noise(50) { | 
 |     initial_e[0][0] = 100; | 
 |     initial_e[1][1] = 1e-1; | 
 |     initial_e[0][1] = initial_e[1][0] = 0; | 
 |     initial_process_noise[0] = 1e-13; | 
 |     initial_process_noise[1] = 1e-3; | 
 |   } | 
 |   double initial_slope; | 
 |   double initial_offset; | 
 |   double initial_e[2][2]; | 
 |   double initial_process_noise[2]; | 
 |   double initial_avg_noise; | 
 |   double initial_var_noise; | 
 | }; | 
 |  | 
 | // This structure will have the information about when packet is actually | 
 | // received by socket. | 
 | struct PacketTime { | 
 |   PacketTime() : timestamp(-1), not_before(-1) {} | 
 |   PacketTime(int64_t timestamp, int64_t not_before) | 
 |       : timestamp(timestamp), not_before(not_before) {} | 
 |  | 
 |   int64_t timestamp;   // Receive time after socket delivers the data. | 
 |   int64_t not_before;  // Earliest possible time the data could have arrived, | 
 |                        // indicating the potential error in the |timestamp| | 
 |                        // value,in case the system is busy. | 
 |                        // For example, the time of the last select() call. | 
 |                        // If unknown, this value will be set to zero. | 
 | }; | 
 |  | 
 | // Minimum and maximum playout delay values from capture to render. | 
 | // These are best effort values. | 
 | // | 
 | // A value < 0 indicates no change from previous valid value. | 
 | // | 
 | // min = max = 0 indicates that the receiver should try and render | 
 | // frame as soon as possible. | 
 | // | 
 | // min = x, max = y indicates that the receiver is free to adapt | 
 | // in the range (x, y) based on network jitter. | 
 | // | 
 | // Note: Given that this gets embedded in a union, it is up-to the owner to | 
 | // initialize these values. | 
 | struct PlayoutDelay { | 
 |   int min_ms; | 
 |   int max_ms; | 
 | }; | 
 |  | 
 | }  // namespace webrtc | 
 |  | 
 | #endif  // COMMON_TYPES_H_ |