1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 //#define LOG_NDEBUG 0
18 #define LOG_TAG "ARTPSource"
19 #include <utils/Log.h>
20
21 #include "ARTPSource.h"
22
23 #include "AAMRAssembler.h"
24 #include "AAVCAssembler.h"
25 #include "AH263Assembler.h"
26 #include "AMPEG2TSAssembler.h"
27 #include "AMPEG4AudioAssembler.h"
28 #include "AMPEG4ElementaryAssembler.h"
29 #include "ARawAudioAssembler.h"
30 #include "ASessionDescription.h"
31
32 #include <media/stagefright/foundation/ABuffer.h>
33 #include <media/stagefright/foundation/ADebug.h>
34 #include <media/stagefright/foundation/AMessage.h>
35
36 namespace android {
37
38 static const uint32_t kSourceID = 0xdeadbeef;
39
ARTPSource(uint32_t id,const sp<ASessionDescription> & sessionDesc,size_t index,const sp<AMessage> & notify)40 ARTPSource::ARTPSource(
41 uint32_t id,
42 const sp<ASessionDescription> &sessionDesc, size_t index,
43 const sp<AMessage> ¬ify)
44 : mID(id),
45 mHighestSeqNumber(0),
46 mNumBuffersReceived(0),
47 mLastNTPTime(0),
48 mLastNTPTimeUpdateUs(0),
49 mIssueFIRRequests(false),
50 mLastFIRRequestUs(-1),
51 mNextFIRSeqNo((rand() * 256.0) / RAND_MAX),
52 mNotify(notify) {
53 unsigned long PT;
54 AString desc;
55 AString params;
56 sessionDesc->getFormatType(index, &PT, &desc, ¶ms);
57
58 if (!strncmp(desc.c_str(), "H264/", 5)) {
59 mAssembler = new AAVCAssembler(notify);
60 mIssueFIRRequests = true;
61 } else if (!strncmp(desc.c_str(), "MP4A-LATM/", 10)) {
62 mAssembler = new AMPEG4AudioAssembler(notify, params);
63 } else if (!strncmp(desc.c_str(), "H263-1998/", 10)
64 || !strncmp(desc.c_str(), "H263-2000/", 10)) {
65 mAssembler = new AH263Assembler(notify);
66 mIssueFIRRequests = true;
67 } else if (!strncmp(desc.c_str(), "AMR/", 4)) {
68 mAssembler = new AAMRAssembler(notify, false /* isWide */, params);
69 } else if (!strncmp(desc.c_str(), "AMR-WB/", 7)) {
70 mAssembler = new AAMRAssembler(notify, true /* isWide */, params);
71 } else if (!strncmp(desc.c_str(), "MP4V-ES/", 8)
72 || !strncasecmp(desc.c_str(), "mpeg4-generic/", 14)) {
73 mAssembler = new AMPEG4ElementaryAssembler(notify, desc, params);
74 mIssueFIRRequests = true;
75 } else if (ARawAudioAssembler::Supports(desc.c_str())) {
76 mAssembler = new ARawAudioAssembler(notify, desc.c_str(), params);
77 } else if (!strncasecmp(desc.c_str(), "MP2T/", 5)) {
78 mAssembler = new AMPEG2TSAssembler(notify, desc.c_str(), params);
79 } else {
80 TRESPASS();
81 }
82 }
83
AbsDiff(uint32_t seq1,uint32_t seq2)84 static uint32_t AbsDiff(uint32_t seq1, uint32_t seq2) {
85 return seq1 > seq2 ? seq1 - seq2 : seq2 - seq1;
86 }
87
processRTPPacket(const sp<ABuffer> & buffer)88 void ARTPSource::processRTPPacket(const sp<ABuffer> &buffer) {
89 if (queuePacket(buffer) && mAssembler != NULL) {
90 mAssembler->onPacketReceived(this);
91 }
92 }
93
timeUpdate(uint32_t rtpTime,uint64_t ntpTime)94 void ARTPSource::timeUpdate(uint32_t rtpTime, uint64_t ntpTime) {
95 mLastNTPTime = ntpTime;
96 mLastNTPTimeUpdateUs = ALooper::GetNowUs();
97
98 sp<AMessage> notify = mNotify->dup();
99 notify->setInt32("time-update", true);
100 notify->setInt32("rtp-time", rtpTime);
101 notify->setInt64("ntp-time", ntpTime);
102 notify->post();
103 }
104
queuePacket(const sp<ABuffer> & buffer)105 bool ARTPSource::queuePacket(const sp<ABuffer> &buffer) {
106 uint32_t seqNum = (uint32_t)buffer->int32Data();
107
108 if (mNumBuffersReceived++ == 0) {
109 mHighestSeqNumber = seqNum;
110 mQueue.push_back(buffer);
111 return true;
112 }
113
114 // Only the lower 16-bit of the sequence numbers are transmitted,
115 // derive the high-order bits by choosing the candidate closest
116 // to the highest sequence number (extended to 32 bits) received so far.
117
118 uint32_t seq1 = seqNum | (mHighestSeqNumber & 0xffff0000);
119
120 // non-overflowing version of:
121 // uint32_t seq2 = seqNum | ((mHighestSeqNumber & 0xffff0000) + 0x10000);
122 uint32_t seq2 = seqNum | (((mHighestSeqNumber >> 16) + 1) << 16);
123
124 // non-underflowing version of:
125 // uint32_t seq2 = seqNum | ((mHighestSeqNumber & 0xffff0000) - 0x10000);
126 uint32_t seq3 = seqNum | ((((mHighestSeqNumber >> 16) | 0x10000) - 1) << 16);
127
128 uint32_t diff1 = AbsDiff(seq1, mHighestSeqNumber);
129 uint32_t diff2 = AbsDiff(seq2, mHighestSeqNumber);
130 uint32_t diff3 = AbsDiff(seq3, mHighestSeqNumber);
131
132 if (diff1 < diff2) {
133 if (diff1 < diff3) {
134 // diff1 < diff2 ^ diff1 < diff3
135 seqNum = seq1;
136 } else {
137 // diff3 <= diff1 < diff2
138 seqNum = seq3;
139 }
140 } else if (diff2 < diff3) {
141 // diff2 <= diff1 ^ diff2 < diff3
142 seqNum = seq2;
143 } else {
144 // diff3 <= diff2 <= diff1
145 seqNum = seq3;
146 }
147
148 if (seqNum > mHighestSeqNumber) {
149 mHighestSeqNumber = seqNum;
150 }
151
152 buffer->setInt32Data(seqNum);
153
154 List<sp<ABuffer> >::iterator it = mQueue.begin();
155 while (it != mQueue.end() && (uint32_t)(*it)->int32Data() < seqNum) {
156 ++it;
157 }
158
159 if (it != mQueue.end() && (uint32_t)(*it)->int32Data() == seqNum) {
160 ALOGW("Discarding duplicate buffer");
161 return false;
162 }
163
164 mQueue.insert(it, buffer);
165
166 return true;
167 }
168
byeReceived()169 void ARTPSource::byeReceived() {
170 mAssembler->onByeReceived();
171 }
172
addFIR(const sp<ABuffer> & buffer)173 void ARTPSource::addFIR(const sp<ABuffer> &buffer) {
174 if (!mIssueFIRRequests) {
175 return;
176 }
177
178 int64_t nowUs = ALooper::GetNowUs();
179 if (mLastFIRRequestUs >= 0 && mLastFIRRequestUs + 5000000ll > nowUs) {
180 // Send FIR requests at most every 5 secs.
181 return;
182 }
183
184 mLastFIRRequestUs = nowUs;
185
186 if (buffer->size() + 20 > buffer->capacity()) {
187 ALOGW("RTCP buffer too small to accomodate FIR.");
188 return;
189 }
190
191 uint8_t *data = buffer->data() + buffer->size();
192
193 data[0] = 0x80 | 4;
194 data[1] = 206; // PSFB
195 data[2] = 0;
196 data[3] = 4;
197 data[4] = kSourceID >> 24;
198 data[5] = (kSourceID >> 16) & 0xff;
199 data[6] = (kSourceID >> 8) & 0xff;
200 data[7] = kSourceID & 0xff;
201
202 data[8] = 0x00; // SSRC of media source (unused)
203 data[9] = 0x00;
204 data[10] = 0x00;
205 data[11] = 0x00;
206
207 data[12] = mID >> 24;
208 data[13] = (mID >> 16) & 0xff;
209 data[14] = (mID >> 8) & 0xff;
210 data[15] = mID & 0xff;
211
212 data[16] = mNextFIRSeqNo++; // Seq Nr.
213
214 data[17] = 0x00; // Reserved
215 data[18] = 0x00;
216 data[19] = 0x00;
217
218 buffer->setRange(buffer->offset(), buffer->size() + 20);
219
220 ALOGV("Added FIR request.");
221 }
222
addReceiverReport(const sp<ABuffer> & buffer)223 void ARTPSource::addReceiverReport(const sp<ABuffer> &buffer) {
224 if (buffer->size() + 32 > buffer->capacity()) {
225 ALOGW("RTCP buffer too small to accomodate RR.");
226 return;
227 }
228
229 uint8_t *data = buffer->data() + buffer->size();
230
231 data[0] = 0x80 | 1;
232 data[1] = 201; // RR
233 data[2] = 0;
234 data[3] = 7;
235 data[4] = kSourceID >> 24;
236 data[5] = (kSourceID >> 16) & 0xff;
237 data[6] = (kSourceID >> 8) & 0xff;
238 data[7] = kSourceID & 0xff;
239
240 data[8] = mID >> 24;
241 data[9] = (mID >> 16) & 0xff;
242 data[10] = (mID >> 8) & 0xff;
243 data[11] = mID & 0xff;
244
245 data[12] = 0x00; // fraction lost
246
247 data[13] = 0x00; // cumulative lost
248 data[14] = 0x00;
249 data[15] = 0x00;
250
251 data[16] = mHighestSeqNumber >> 24;
252 data[17] = (mHighestSeqNumber >> 16) & 0xff;
253 data[18] = (mHighestSeqNumber >> 8) & 0xff;
254 data[19] = mHighestSeqNumber & 0xff;
255
256 data[20] = 0x00; // Interarrival jitter
257 data[21] = 0x00;
258 data[22] = 0x00;
259 data[23] = 0x00;
260
261 uint32_t LSR = 0;
262 uint32_t DLSR = 0;
263 if (mLastNTPTime != 0) {
264 LSR = (mLastNTPTime >> 16) & 0xffffffff;
265
266 DLSR = (uint32_t)
267 ((ALooper::GetNowUs() - mLastNTPTimeUpdateUs) * 65536.0 / 1E6);
268 }
269
270 data[24] = LSR >> 24;
271 data[25] = (LSR >> 16) & 0xff;
272 data[26] = (LSR >> 8) & 0xff;
273 data[27] = LSR & 0xff;
274
275 data[28] = DLSR >> 24;
276 data[29] = (DLSR >> 16) & 0xff;
277 data[30] = (DLSR >> 8) & 0xff;
278 data[31] = DLSR & 0xff;
279
280 buffer->setRange(buffer->offset(), buffer->size() + 32);
281 }
282
283 } // namespace android
284
285
286