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.
5 #ifndef MEDIA_CAST_CAST_DEFINES_H_
6 #define MEDIA_CAST_CAST_DEFINES_H_
14 #include "base/basictypes.h"
15 #include "base/compiler_specific.h"
16 #include "base/logging.h"
17 #include "base/time/time.h"
18 #include "media/cast/net/cast_transport_config.h"
23 const int64 kDontShowTimeoutMs
= 33;
24 const float kDefaultCongestionControlBackOff
= 0.875f
;
25 const uint32 kVideoFrequency
= 90000;
26 const uint32 kStartFrameId
= UINT32_C(0xffffffff);
28 // This is an important system-wide constant. This limits how much history the
29 // implementation must retain in order to process the acknowledgements of past
31 // This value is carefully choosen such that it fits in the 8-bits range for
32 // frame IDs. It is also less than half of the full 8-bits range such that we
33 // can handle wrap around and compare two frame IDs.
34 const int kMaxUnackedFrames
= 120;
36 const int64 kCastMessageUpdateIntervalMs
= 33;
37 const int64 kNackRepeatIntervalMs
= 30;
39 // Success/in-progress/failure status codes bubbled up to clients via
40 // StatusChangeCallbacks.
41 enum OperationalStatus
{
42 // Client should not send frames yet (sender), or should not expect to receive
43 // frames yet (receiver).
46 // Client may now send or receive frames.
49 // Codec is being re-initialized. Client may continue sending frames, but
50 // some may be ignored/dropped until a transition back to STATUS_INITIALIZED.
51 STATUS_CODEC_REINIT_PENDING
,
53 // Session has halted due to invalid configuration.
54 STATUS_INVALID_CONFIGURATION
,
56 // Session has halted due to an unsupported codec.
57 STATUS_UNSUPPORTED_CODEC
,
59 // Session has halted due to a codec initialization failure. Note that this
60 // can be reported after STATUS_INITIALIZED/STATUS_CODEC_REINIT_PENDING if the
61 // codec was re-initialized during the session.
62 STATUS_CODEC_INIT_FAILED
,
64 // Session has halted due to a codec runtime failure.
65 STATUS_CODEC_RUNTIME_ERROR
,
68 enum DefaultSettings
{
69 kDefaultAudioEncoderBitrate
= 0, // This means "auto," and may mean VBR.
70 kDefaultAudioSamplingRate
= 48000,
73 kDefaultMaxFrameRate
= 30,
74 kDefaultNumberOfVideoBuffers
= 1,
75 kDefaultRtcpIntervalMs
= 500,
76 kDefaultRtpHistoryMs
= 1000,
77 kDefaultRtpMaxDelayMs
= 100,
82 kNewPacketCompletingFrame
,
87 // kRtcpCastAllPacketsLost is used in PacketIDSet and
88 // on the wire to mean that ALL packets for a particular
90 const uint16 kRtcpCastAllPacketsLost
= 0xffff;
92 // kRtcpCastLastPacket is used in PacketIDSet to ask for
93 // the last packet of a frame to be retransmitted.
94 const uint16 kRtcpCastLastPacket
= 0xfffe;
96 const size_t kMinLengthOfRtcp
= 8;
98 // Basic RTP header + cast header.
99 const size_t kMinLengthOfRtp
= 12 + 6;
101 // Each uint16 represents one packet id within a cast frame.
102 // Can also contain kRtcpCastAllPacketsLost and kRtcpCastLastPacket.
103 typedef std::set
<uint16
> PacketIdSet
;
104 // Each uint8 represents one cast frame.
105 typedef std::map
<uint8
, PacketIdSet
> MissingFramesAndPacketsMap
;
107 // TODO(pwestin): Re-factor the functions bellow into a class with static
110 // January 1970, in NTP seconds.
111 // Network Time Protocol (NTP), which is in seconds relative to 0h UTC on
113 static const int64 kUnixEpochInNtpSeconds
= INT64_C(2208988800);
115 // Magic fractional unit. Used to convert time (in microseconds) to/from
116 // fractional NTP seconds.
117 static const double kMagicFractionalUnit
= 4.294967296E3
;
119 // The maximum number of Cast receiver events to keep in history for the
120 // purpose of sending the events through RTCP.
121 // The number chosen should be more than the number of events that can be
122 // stored in a RTCP packet.
123 static const size_t kReceiverRtcpEventHistorySize
= 512;
125 inline bool IsNewerFrameId(uint32 frame_id
, uint32 prev_frame_id
) {
126 return (frame_id
!= prev_frame_id
) &&
127 static_cast<uint32
>(frame_id
- prev_frame_id
) < 0x80000000;
130 inline bool IsNewerRtpTimestamp(uint32 timestamp
, uint32 prev_timestamp
) {
131 return (timestamp
!= prev_timestamp
) &&
132 static_cast<uint32
>(timestamp
- prev_timestamp
) < 0x80000000;
135 inline bool IsOlderFrameId(uint32 frame_id
, uint32 prev_frame_id
) {
136 return (frame_id
== prev_frame_id
) || IsNewerFrameId(prev_frame_id
, frame_id
);
139 inline bool IsNewerPacketId(uint16 packet_id
, uint16 prev_packet_id
) {
140 return (packet_id
!= prev_packet_id
) &&
141 static_cast<uint16
>(packet_id
- prev_packet_id
) < 0x8000;
144 inline bool IsNewerSequenceNumber(uint16 sequence_number
,
145 uint16 prev_sequence_number
) {
146 // Same function as IsNewerPacketId just different data and name.
147 return IsNewerPacketId(sequence_number
, prev_sequence_number
);
150 // Create a NTP diff from seconds and fractions of seconds; delay_fraction is
151 // fractions of a second where 0x80000000 is half a second.
152 inline uint32
ConvertToNtpDiff(uint32 delay_seconds
, uint32 delay_fraction
) {
153 return ((delay_seconds
& 0x0000FFFF) << 16) +
154 ((delay_fraction
& 0xFFFF0000) >> 16);
157 inline base::TimeDelta
ConvertFromNtpDiff(uint32 ntp_delay
) {
158 uint32 delay_ms
= (ntp_delay
& 0x0000ffff) * 1000;
160 delay_ms
+= ((ntp_delay
& 0xffff0000) >> 16) * 1000;
161 return base::TimeDelta::FromMilliseconds(delay_ms
);
164 inline void ConvertTimeToFractions(int64 ntp_time_us
,
167 DCHECK_GE(ntp_time_us
, 0) << "Time must NOT be negative";
168 const int64 seconds_component
=
169 ntp_time_us
/ base::Time::kMicrosecondsPerSecond
;
170 // NTP time will overflow in the year 2036. Also, make sure unit tests don't
171 // regress and use an origin past the year 2036. If this overflows here, the
172 // inverse calculation fails to compute the correct TimeTicks value, throwing
173 // off the entire system.
174 DCHECK_LT(seconds_component
, INT64_C(4263431296))
175 << "One year left to fix the NTP year 2036 wrap-around issue!";
176 *seconds
= static_cast<uint32
>(seconds_component
);
177 *fractions
= static_cast<uint32
>(
178 (ntp_time_us
% base::Time::kMicrosecondsPerSecond
) *
179 kMagicFractionalUnit
);
182 inline void ConvertTimeTicksToNtp(const base::TimeTicks
& time
,
184 uint32
* ntp_fractions
) {
185 base::TimeDelta elapsed_since_unix_epoch
=
186 time
- base::TimeTicks::UnixEpoch();
189 elapsed_since_unix_epoch
.InMicroseconds() +
190 (kUnixEpochInNtpSeconds
* base::Time::kMicrosecondsPerSecond
);
192 ConvertTimeToFractions(ntp_time_us
, ntp_seconds
, ntp_fractions
);
195 inline base::TimeTicks
ConvertNtpToTimeTicks(uint32 ntp_seconds
,
196 uint32 ntp_fractions
) {
197 // We need to ceil() here because the calculation of |fractions| in
198 // ConvertTimeToFractions() effectively does a floor().
199 int64 ntp_time_us
= ntp_seconds
* base::Time::kMicrosecondsPerSecond
+
200 static_cast<int64
>(std::ceil(ntp_fractions
/ kMagicFractionalUnit
));
202 base::TimeDelta elapsed_since_unix_epoch
= base::TimeDelta::FromMicroseconds(
204 (kUnixEpochInNtpSeconds
* base::Time::kMicrosecondsPerSecond
));
205 return base::TimeTicks::UnixEpoch() + elapsed_since_unix_epoch
;
208 inline base::TimeDelta
RtpDeltaToTimeDelta(int64 rtp_delta
, int rtp_timebase
) {
209 DCHECK_GT(rtp_timebase
, 0);
210 return rtp_delta
* base::TimeDelta::FromSeconds(1) / rtp_timebase
;
213 inline int64
TimeDeltaToRtpDelta(base::TimeDelta delta
, int rtp_timebase
) {
214 DCHECK_GT(rtp_timebase
, 0);
215 return delta
* rtp_timebase
/ base::TimeDelta::FromSeconds(1);
221 #endif // MEDIA_CAST_CAST_DEFINES_H_