media/cast/cast_defines.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_CAST_CAST_DEFINES_H_
   6 #define MEDIA_CAST_CAST_DEFINES_H_
   7
   8 #include <stdint.h>
   9
  10 #include <map>
  11 #include <set>
  12
  13 #include "base/basictypes.h"
  14 #include "base/compiler_specific.h"
  15 #include "base/logging.h"
  16 #include "base/time/time.h"
  17 #include "media/cast/transport/cast_transport_config.h"
  18
  19 namespace media {
  20 namespace cast {
  21
  22 const int64 kDontShowTimeoutMs = 33;
  23 const float kDefaultCongestionControlBackOff = 0.875f;
  24 const uint32 kVideoFrequency = 90000;
  25 const int64 kSkippedFramesCheckPeriodkMs = 10000;
  26 const uint32 kStartFrameId = UINT32_C(0xffffffff);
  27
  28 // Number of skipped frames threshold in fps (as configured) per period above.
  29 const int kSkippedFramesThreshold = 3;
  30 const size_t kMaxIpPacketSize = 1500;
  31 const int kStartRttMs = 20;
  32 const int64 kCastMessageUpdateIntervalMs = 33;
  33 const int64 kNackRepeatIntervalMs = 30;
  34
  35 enum CastInitializationStatus {
  36   STATUS_AUDIO_UNINITIALIZED,
  37   STATUS_VIDEO_UNINITIALIZED,
  38   STATUS_AUDIO_INITIALIZED,
  39   STATUS_VIDEO_INITIALIZED,
  40   STATUS_INVALID_CAST_ENVIRONMENT,
  41   STATUS_INVALID_CRYPTO_CONFIGURATION,
  42   STATUS_UNSUPPORTED_AUDIO_CODEC,
  43   STATUS_UNSUPPORTED_VIDEO_CODEC,
  44   STATUS_INVALID_AUDIO_CONFIGURATION,
  45   STATUS_INVALID_VIDEO_CONFIGURATION,
  46   STATUS_GPU_ACCELERATION_NOT_SUPPORTED,
  47   STATUS_GPU_ACCELERATION_ERROR,
  48 };
  49
  50 enum DefaultSettings {
  51   kDefaultAudioEncoderBitrate = 0,  // This means "auto," and may mean VBR.
  52   kDefaultAudioSamplingRate = 48000,
  53   kDefaultMaxQp = 56,
  54   kDefaultMinQp = 4,
  55   kDefaultMaxFrameRate = 30,
  56   kDefaultNumberOfVideoBuffers = 1,
  57   kDefaultRtcpIntervalMs = 500,
  58   kDefaultRtpHistoryMs = 1000,
  59   kDefaultRtpMaxDelayMs = 100,
  60 };
  61
  62 enum PacketType {
  63   kNewPacket,
  64   kNewPacketCompletingFrame,
  65   kDuplicatePacket,
  66   kTooOldPacket,
  67 };
  68
  69 const uint16 kRtcpCastAllPacketsLost = 0xffff;
  70
  71 const size_t kMinLengthOfRtcp = 8;
  72
  73 // Basic RTP header + cast header.
  74 const size_t kMinLengthOfRtp = 12 + 6;
  75
  76 // Each uint16 represents one packet id within a cast frame.
  77 typedef std::set<uint16> PacketIdSet;
  78 // Each uint8 represents one cast frame.
  79 typedef std::map<uint8, PacketIdSet> MissingFramesAndPacketsMap;
  80
  81 // TODO(pwestin): Re-factor the functions bellow into a class with static
  82 // methods.
  83
  84 // January 1970, in NTP seconds.
  85 // Network Time Protocol (NTP), which is in seconds relative to 0h UTC on
  86 // 1 January 1900.
  87 static const int64 kUnixEpochInNtpSeconds = INT64_C(2208988800);
  88
  89 // Magic fractional unit. Used to convert time (in microseconds) to/from
  90 // fractional NTP seconds.
  91 static const double kMagicFractionalUnit = 4.294967296E3;
  92
  93 // The maximum number of Cast receiver events to keep in history for the
  94 // purpose of sending the events through RTCP.
  95 // The number chosen should be more than the number of events that can be
  96 // stored in a RTCP packet.
  97 static const size_t kReceiverRtcpEventHistorySize = 512;
  98
  99 inline bool IsNewerFrameId(uint32 frame_id, uint32 prev_frame_id) {
 100   return (frame_id != prev_frame_id) &&
 101          static_cast<uint32>(frame_id - prev_frame_id) < 0x80000000;
 102 }
 103
 104 inline bool IsNewerRtpTimestamp(uint32 timestamp, uint32 prev_timestamp) {
 105   return (timestamp != prev_timestamp) &&
 106          static_cast<uint32>(timestamp - prev_timestamp) < 0x80000000;
 107 }
 108
 109 inline bool IsOlderFrameId(uint32 frame_id, uint32 prev_frame_id) {
 110   return (frame_id == prev_frame_id) || IsNewerFrameId(prev_frame_id, frame_id);
 111 }
 112
 113 inline bool IsNewerPacketId(uint16 packet_id, uint16 prev_packet_id) {
 114   return (packet_id != prev_packet_id) &&
 115          static_cast<uint16>(packet_id - prev_packet_id) < 0x8000;
 116 }
 117
 118 inline bool IsNewerSequenceNumber(uint16 sequence_number,
 119                                   uint16 prev_sequence_number) {
 120   // Same function as IsNewerPacketId just different data and name.
 121   return IsNewerPacketId(sequence_number, prev_sequence_number);
 122 }
 123
 124 // Create a NTP diff from seconds and fractions of seconds; delay_fraction is
 125 // fractions of a second where 0x80000000 is half a second.
 126 inline uint32 ConvertToNtpDiff(uint32 delay_seconds, uint32 delay_fraction) {
 127   return ((delay_seconds & 0x0000FFFF) << 16) +
 128          ((delay_fraction & 0xFFFF0000) >> 16);
 129 }
 130
 131 inline base::TimeDelta ConvertFromNtpDiff(uint32 ntp_delay) {
 132   uint32 delay_ms = (ntp_delay & 0x0000ffff) * 1000;
 133   delay_ms >>= 16;
 134   delay_ms += ((ntp_delay & 0xffff0000) >> 16) * 1000;
 135   return base::TimeDelta::FromMilliseconds(delay_ms);
 136 }
 137
 138 inline void ConvertTimeToFractions(int64 ntp_time_us,
 139                                    uint32* seconds,
 140                                    uint32* fractions) {
 141   DCHECK_GE(ntp_time_us, 0) << "Time must NOT be negative";
 142   const int64 seconds_component =
 143       ntp_time_us / base::Time::kMicrosecondsPerSecond;
 144   // NTP time will overflow in the year 2036.  Also, make sure unit tests don't
 145   // regress and use an origin past the year 2036.  If this overflows here, the
 146   // inverse calculation fails to compute the correct TimeTicks value, throwing
 147   // off the entire system.
 148   DCHECK_LT(seconds_component, INT64_C(4263431296))
 149       << "One year left to fix the NTP year 2036 wrap-around issue!";
 150   *seconds = static_cast<uint32>(seconds_component);
 151   *fractions = static_cast<uint32>(
 152       (ntp_time_us % base::Time::kMicrosecondsPerSecond) *
 153           kMagicFractionalUnit);
 154 }
 155
 156 inline void ConvertTimeTicksToNtp(const base::TimeTicks& time,
 157                                   uint32* ntp_seconds,
 158                                   uint32* ntp_fractions) {
 159   base::TimeDelta elapsed_since_unix_epoch =
 160       time - base::TimeTicks::UnixEpoch();
 161
 162   int64 ntp_time_us =
 163       elapsed_since_unix_epoch.InMicroseconds() +
 164       (kUnixEpochInNtpSeconds * base::Time::kMicrosecondsPerSecond);
 165
 166   ConvertTimeToFractions(ntp_time_us, ntp_seconds, ntp_fractions);
 167 }
 168
 169 inline base::TimeTicks ConvertNtpToTimeTicks(uint32 ntp_seconds,
 170                                              uint32 ntp_fractions) {
 171   int64 ntp_time_us =
 172       static_cast<int64>(ntp_seconds) * base::Time::kMicrosecondsPerSecond +
 173       static_cast<int64>(ntp_fractions) / kMagicFractionalUnit;
 174
 175   base::TimeDelta elapsed_since_unix_epoch = base::TimeDelta::FromMicroseconds(
 176       ntp_time_us -
 177       (kUnixEpochInNtpSeconds * base::Time::kMicrosecondsPerSecond));
 178   return base::TimeTicks::UnixEpoch() + elapsed_since_unix_epoch;
 179 }
 180
 181 inline base::TimeDelta RtpDeltaToTimeDelta(int64 rtp_delta, int rtp_timebase) {
 182   DCHECK_GT(rtp_timebase, 0);
 183   return rtp_delta * base::TimeDelta::FromSeconds(1) / rtp_timebase;
 184 }
 185
 186 inline uint32 GetVideoRtpTimestamp(const base::TimeTicks& time_ticks) {
 187   base::TimeTicks zero_time;
 188   base::TimeDelta recorded_delta = time_ticks - zero_time;
 189   // Timestamp is in 90 KHz for video.
 190   return static_cast<uint32>(recorded_delta.InMilliseconds() * 90);
 191 }
 192
 193 }  // namespace cast
 194 }  // namespace media
 195
 196 #endif  // MEDIA_CAST_CAST_DEFINES_H_