forked from livekit/livekit
-
Notifications
You must be signed in to change notification settings - Fork 0
/
rtpmunger.go
367 lines (303 loc) · 9.73 KB
/
rtpmunger.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
// Copyright 2023 LiveKit, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package sfu
import (
"fmt"
"github.com/livekit/protocol/logger"
"github.com/livekit/livekit-server/pkg/sfu/buffer"
"github.com/livekit/livekit-server/pkg/sfu/utils"
)
// RTPMunger
type SequenceNumberOrdering int
const (
SequenceNumberOrderingContiguous SequenceNumberOrdering = iota
SequenceNumberOrderingOutOfOrder
SequenceNumberOrderingGap
SequenceNumberOrderingDuplicate
)
const (
RtxGateWindow = 2000
)
type TranslationParamsRTP struct {
snOrdering SequenceNumberOrdering
extSequenceNumber uint64
extTimestamp uint64
}
type SnTs struct {
extSequenceNumber uint64
extTimestamp uint64
}
// ----------------------------------------------------------------------
type RTPMungerState struct {
ExtLastSN uint64
ExtSecondLastSN uint64
ExtLastTS uint64
ExtSecondLastTS uint64
LastMarker bool
SecondLastMarker bool
}
func (r RTPMungerState) String() string {
return fmt.Sprintf(
"RTPMungerState{extLastSN: %d, extSecondLastSN: %d, extLastTS: %d, extSecondLastTS: %d, lastMarker: %v, secondLastMarker: %v)",
r.ExtLastSN, r.ExtSecondLastSN,
r.ExtLastTS, r.ExtSecondLastTS,
r.LastMarker, r.SecondLastMarker,
)
}
// ----------------------------------------------------------------------
type RTPMunger struct {
logger logger.Logger
extHighestIncomingSN uint64
snRangeMap *utils.RangeMap[uint64, uint64]
extLastSN uint64
extSecondLastSN uint64
snOffset uint64
extLastTS uint64
extSecondLastTS uint64
tsOffset uint64
pinnedTSOffset uint64
lastMarker bool
secondLastMarker bool
extRtxGateSn uint64
isInRtxGateRegion bool
}
func NewRTPMunger(logger logger.Logger) *RTPMunger {
return &RTPMunger{
logger: logger,
snRangeMap: utils.NewRangeMap[uint64, uint64](100),
}
}
func (r *RTPMunger) DebugInfo() map[string]interface{} {
return map[string]interface{}{
"ExtHighestIncomingSN": r.extHighestIncomingSN,
"ExtLastSN": r.extLastSN,
"ExtSecondLastSN": r.extSecondLastSN,
"SNOffset": r.snOffset,
"ExtLastTS": r.extLastTS,
"ExtSecondLastTS": r.extSecondLastTS,
"TSOffset": r.tsOffset,
"PinnedTSOffset": r.pinnedTSOffset,
"LastMarker": r.lastMarker,
"SecondLastMarker": r.secondLastMarker,
}
}
func (r *RTPMunger) GetLast() RTPMungerState {
return RTPMungerState{
ExtLastSN: r.extLastSN,
ExtSecondLastSN: r.extSecondLastSN,
ExtLastTS: r.extLastTS,
ExtSecondLastTS: r.extSecondLastTS,
LastMarker: r.lastMarker,
SecondLastMarker: r.secondLastMarker,
}
}
func (r *RTPMunger) GetPinnedTSOffset() uint64 {
return r.pinnedTSOffset
}
func (r *RTPMunger) SeedLast(state RTPMungerState) {
r.extLastSN = state.ExtLastSN
r.extSecondLastSN = state.ExtSecondLastSN
r.extLastTS = state.ExtLastTS
r.extSecondLastTS = state.ExtSecondLastTS
r.lastMarker = state.LastMarker
r.secondLastMarker = state.SecondLastMarker
}
func (r *RTPMunger) SetLastSnTs(extPkt *buffer.ExtPacket) {
r.extHighestIncomingSN = extPkt.ExtSequenceNumber - 1
r.extLastSN = extPkt.ExtSequenceNumber
r.extSecondLastSN = r.extLastSN - 1
r.snRangeMap.ClearAndResetValue(extPkt.ExtSequenceNumber, 0)
r.updateSnOffset()
r.extLastTS = extPkt.ExtTimestamp
r.extSecondLastTS = extPkt.ExtTimestamp
r.tsOffset = 0
r.pinnedTSOffset = r.tsOffset
}
func (r *RTPMunger) UpdateSnTsOffsets(extPkt *buffer.ExtPacket, snAdjust uint64, tsAdjust uint64) {
r.extHighestIncomingSN = extPkt.ExtSequenceNumber - 1
r.snRangeMap.ClearAndResetValue(extPkt.ExtSequenceNumber, extPkt.ExtSequenceNumber-r.extLastSN-snAdjust)
r.updateSnOffset()
r.tsOffset = extPkt.ExtTimestamp - r.extLastTS - tsAdjust
r.pinnedTSOffset = r.tsOffset
}
func (r *RTPMunger) PacketDropped(extPkt *buffer.ExtPacket) {
if r.extHighestIncomingSN != extPkt.ExtSequenceNumber {
return
}
snOffset, err := r.snRangeMap.GetValue(extPkt.ExtSequenceNumber)
if err == nil {
outSN := extPkt.ExtSequenceNumber - snOffset
if outSN != r.extLastSN {
r.logger.Warnw("last outgoing sequence number mismatch", nil, "expected", r.extLastSN, "got", outSN)
}
}
if r.extLastSN == r.extSecondLastSN {
r.logger.Warnw("cannot roll back on drop", nil, "extLastSN", r.extLastSN, "secondLastSN", r.extSecondLastSN)
}
if err := r.snRangeMap.ExcludeRange(r.extHighestIncomingSN, r.extHighestIncomingSN+1); err != nil {
r.logger.Errorw("could not exclude range", err, "sn", r.extHighestIncomingSN)
}
r.extLastSN = r.extSecondLastSN
r.updateSnOffset()
r.extLastTS = r.extSecondLastTS
r.lastMarker = r.secondLastMarker
}
func (r *RTPMunger) UpdateAndGetSnTs(extPkt *buffer.ExtPacket, marker bool) (TranslationParamsRTP, error) {
diff := int64(extPkt.ExtSequenceNumber - r.extHighestIncomingSN)
if (diff == 1 && len(extPkt.Packet.Payload) != 0) || diff > 1 {
// in-order - either contiguous packet with payload OR packet following a gap, may or may not have payload
r.extHighestIncomingSN = extPkt.ExtSequenceNumber
ordering := SequenceNumberOrderingContiguous
if diff > 1 {
ordering = SequenceNumberOrderingGap
}
extMungedSN := extPkt.ExtSequenceNumber - r.snOffset
extMungedTS := extPkt.ExtTimestamp - r.tsOffset
r.extSecondLastSN = r.extLastSN
r.extLastSN = extMungedSN
r.extSecondLastTS = r.extLastTS
r.extLastTS = extMungedTS
r.secondLastMarker = r.lastMarker
r.lastMarker = marker
if extPkt.KeyFrame {
r.extRtxGateSn = extMungedSN
r.isInRtxGateRegion = true
}
if r.isInRtxGateRegion && (extMungedSN-r.extRtxGateSn) > RtxGateWindow {
r.isInRtxGateRegion = false
}
return TranslationParamsRTP{
snOrdering: ordering,
extSequenceNumber: extMungedSN,
extTimestamp: extMungedTS,
}, nil
}
if diff < 0 {
// out-of-order, look up sequence number offset cache
snOffset, err := r.snRangeMap.GetValue(extPkt.ExtSequenceNumber)
if err != nil {
return TranslationParamsRTP{
snOrdering: SequenceNumberOrderingOutOfOrder,
}, ErrOutOfOrderSequenceNumberCacheMiss
}
extSequenceNumber := extPkt.ExtSequenceNumber - snOffset
if extSequenceNumber >= r.extLastSN {
// should not happen, just being paranoid
r.logger.Errorw(
"unexpected packet ordering", nil,
"extIncomingSN", extPkt.ExtSequenceNumber,
"extHighestIncomingSN", r.extHighestIncomingSN,
"extLastSN", r.extLastSN,
"snOffsetIncoming", snOffset,
"snOffsetHighest", r.snOffset,
)
return TranslationParamsRTP{
snOrdering: SequenceNumberOrderingOutOfOrder,
}, ErrOutOfOrderSequenceNumberCacheMiss
}
return TranslationParamsRTP{
snOrdering: SequenceNumberOrderingOutOfOrder,
extSequenceNumber: extSequenceNumber,
extTimestamp: extPkt.ExtTimestamp - r.tsOffset,
}, nil
}
// if padding only packet, can be dropped and sequence number adjusted, if contiguous
if diff == 1 {
r.extHighestIncomingSN = extPkt.ExtSequenceNumber
if err := r.snRangeMap.ExcludeRange(r.extHighestIncomingSN, r.extHighestIncomingSN+1); err != nil {
r.logger.Errorw("could not exclude range", err, "sn", r.extHighestIncomingSN)
}
r.updateSnOffset()
return TranslationParamsRTP{
snOrdering: SequenceNumberOrderingContiguous,
}, ErrPaddingOnlyPacket
}
// can get duplicate packet due to FEC
return TranslationParamsRTP{
snOrdering: SequenceNumberOrderingDuplicate,
}, ErrDuplicatePacket
}
func (r *RTPMunger) FilterRTX(nacks []uint16) []uint16 {
if !r.isInRtxGateRegion {
return nacks
}
filtered := make([]uint16, 0, len(nacks))
for _, sn := range nacks {
if (sn - uint16(r.extRtxGateSn)) < (1 << 15) {
filtered = append(filtered, sn)
}
}
return filtered
}
func (r *RTPMunger) UpdateAndGetPaddingSnTs(num int, clockRate uint32, frameRate uint32, forceMarker bool, extRtpTimestamp uint64) ([]SnTs, error) {
if num == 0 {
return nil, nil
}
useLastTSForFirst := false
tsOffset := 0
if !r.lastMarker {
if !forceMarker {
return nil, ErrPaddingNotOnFrameBoundary
}
// if forcing frame end, use timestamp of latest received frame for the first one
useLastTSForFirst = true
tsOffset = 1
}
extLastSN := r.extLastSN
extLastTS := r.extLastTS
vals := make([]SnTs, num)
for i := 0; i < num; i++ {
extLastSN++
vals[i].extSequenceNumber = extLastSN
if frameRate != 0 {
if useLastTSForFirst && i == 0 {
vals[i].extTimestamp = r.extLastTS
} else {
ets := extRtpTimestamp + uint64(((uint32(i+1-tsOffset)*clockRate)+frameRate-1)/frameRate)
if int64(ets-extLastTS) <= 0 {
ets = extLastTS + 1
}
extLastTS = ets
vals[i].extTimestamp = ets
}
} else {
vals[i].extTimestamp = r.extLastTS
}
}
r.extSecondLastSN = extLastSN - 1
r.extLastSN = extLastSN
r.snRangeMap.DecValue(r.extHighestIncomingSN, uint64(num))
r.updateSnOffset()
if len(vals) == 1 {
r.extSecondLastTS = r.extLastTS
} else {
r.extSecondLastTS = vals[len(vals)-2].extTimestamp
}
r.tsOffset -= extLastTS - r.extLastTS
r.extLastTS = extLastTS
if forceMarker {
r.lastMarker = true
}
return vals, nil
}
func (r *RTPMunger) IsOnFrameBoundary() bool {
return r.lastMarker
}
func (r *RTPMunger) updateSnOffset() {
snOffset, err := r.snRangeMap.GetValue(r.extHighestIncomingSN + 1)
if err != nil {
r.logger.Errorw("could not get sequence number offset", err)
}
r.snOffset = snOffset
}