ARTPSource.cpp revision a979ad6739d573b3823b0fe7321f554ef5544753 
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#include "ARTPSource.h"
18
19#include "AAMRAssembler.h"
20#include "AAVCAssembler.h"
21#include "AH263Assembler.h"
22#include "AMPEG4AudioAssembler.h"
23#include "AMPEG4ElementaryAssembler.h"
24#include "ASessionDescription.h"
25
26#include <media/stagefright/foundation/ABuffer.h>
27#include <media/stagefright/foundation/ADebug.h>
28#include <media/stagefright/foundation/AMessage.h>
29
30#define BE_VERBOSE      0
31
32namespace android {
33
34static const uint32_t kSourceID = 0xdeadbeef;
35
36ARTPSource::ARTPSource(
37        uint32_t id,
38        const sp<ASessionDescription> &sessionDesc, size_t index,
39        const sp<AMessage> &notify)
40    : mID(id),
41      mHighestSeqNumber(0),
42      mNumBuffersReceived(0),
43      mNumTimes(0),
44      mLastNTPTime(0),
45      mLastNTPTimeUpdateUs(0),
46      mIssueFIRRequests(false),
47      mLastFIRRequestUs(-1),
48      mNextFIRSeqNo((rand() * 256.0) / RAND_MAX) {
49    unsigned long PT;
50    AString desc;
51    AString params;
52    sessionDesc->getFormatType(index, &PT, &desc, &params);
53
54    if (!strncmp(desc.c_str(), "H264/", 5)) {
55        mAssembler = new AAVCAssembler(notify);
56        mIssueFIRRequests = true;
57    } else if (!strncmp(desc.c_str(), "MP4A-LATM/", 10)) {
58        mAssembler = new AMPEG4AudioAssembler(notify);
59    } else if (!strncmp(desc.c_str(), "H263-1998/", 10)
60            || !strncmp(desc.c_str(), "H263-2000/", 10)) {
61        mAssembler = new AH263Assembler(notify);
62        mIssueFIRRequests = true;
63    } else if (!strncmp(desc.c_str(), "AMR/", 4)) {
64        mAssembler = new AAMRAssembler(notify, false /* isWide */, params);
65    } else  if (!strncmp(desc.c_str(), "AMR-WB/", 7)) {
66        mAssembler = new AAMRAssembler(notify, true /* isWide */, params);
67    } else if (!strncmp(desc.c_str(), "MP4V-ES/", 8)) {
68        mAssembler = new AMPEG4ElementaryAssembler(notify);
69        mIssueFIRRequests = true;
70    } else {
71        TRESPASS();
72    }
73}
74
75static uint32_t AbsDiff(uint32_t seq1, uint32_t seq2) {
76    return seq1 > seq2 ? seq1 - seq2 : seq2 - seq1;
77}
78
79void ARTPSource::processRTPPacket(const sp<ABuffer> &buffer) {
80    if (queuePacket(buffer)
81            && mNumTimes == 2
82            && mAssembler != NULL) {
83        mAssembler->onPacketReceived(this);
84    }
85
86    dump();
87}
88
89void ARTPSource::timeUpdate(uint32_t rtpTime, uint64_t ntpTime) {
90#if BE_VERBOSE
91    LOG(VERBOSE) << "timeUpdate";
92#endif
93
94    mLastNTPTime = ntpTime;
95    mLastNTPTimeUpdateUs = ALooper::GetNowUs();
96
97    if (mNumTimes == 2) {
98        mNTPTime[0] = mNTPTime[1];
99        mRTPTime[0] = mRTPTime[1];
100        mNumTimes = 1;
101    }
102    mNTPTime[mNumTimes] = ntpTime;
103    mRTPTime[mNumTimes++] = rtpTime;
104
105    if (timeEstablished()) {
106        for (List<sp<ABuffer> >::iterator it = mQueue.begin();
107             it != mQueue.end(); ++it) {
108            sp<AMessage> meta = (*it)->meta();
109
110            uint32_t rtpTime;
111            CHECK(meta->findInt32("rtp-time", (int32_t *)&rtpTime));
112
113            meta->setInt64("ntp-time", RTP2NTP(rtpTime));
114        }
115    }
116}
117
118bool ARTPSource::queuePacket(const sp<ABuffer> &buffer) {
119    uint32_t seqNum = (uint32_t)buffer->int32Data();
120
121    if (mNumTimes == 2) {
122        sp<AMessage> meta = buffer->meta();
123
124        uint32_t rtpTime;
125        CHECK(meta->findInt32("rtp-time", (int32_t *)&rtpTime));
126
127        meta->setInt64("ntp-time", RTP2NTP(rtpTime));
128    }
129
130    if (mNumBuffersReceived++ == 0) {
131        mHighestSeqNumber = seqNum;
132        mQueue.push_back(buffer);
133        return true;
134    }
135
136    // Only the lower 16-bit of the sequence numbers are transmitted,
137    // derive the high-order bits by choosing the candidate closest
138    // to the highest sequence number (extended to 32 bits) received so far.
139
140    uint32_t seq1 = seqNum | (mHighestSeqNumber & 0xffff0000);
141    uint32_t seq2 = seqNum | ((mHighestSeqNumber & 0xffff0000) + 0x10000);
142    uint32_t seq3 = seqNum | ((mHighestSeqNumber & 0xffff0000) - 0x10000);
143    uint32_t diff1 = AbsDiff(seq1, mHighestSeqNumber);
144    uint32_t diff2 = AbsDiff(seq2, mHighestSeqNumber);
145    uint32_t diff3 = AbsDiff(seq3, mHighestSeqNumber);
146
147    if (diff1 < diff2) {
148        if (diff1 < diff3) {
149            // diff1 < diff2 ^ diff1 < diff3
150            seqNum = seq1;
151        } else {
152            // diff3 <= diff1 < diff2
153            seqNum = seq3;
154        }
155    } else if (diff2 < diff3) {
156        // diff2 <= diff1 ^ diff2 < diff3
157        seqNum = seq2;
158    } else {
159        // diff3 <= diff2 <= diff1
160        seqNum = seq3;
161    }
162
163    if (seqNum > mHighestSeqNumber) {
164        mHighestSeqNumber = seqNum;
165    }
166
167    buffer->setInt32Data(seqNum);
168
169    List<sp<ABuffer> >::iterator it = mQueue.begin();
170    while (it != mQueue.end() && (uint32_t)(*it)->int32Data() < seqNum) {
171        ++it;
172    }
173
174    if (it != mQueue.end() && (uint32_t)(*it)->int32Data() == seqNum) {
175        LOG(WARNING) << "Discarding duplicate buffer";
176        return false;
177    }
178
179    mQueue.insert(it, buffer);
180
181    return true;
182}
183
184void ARTPSource::dump() const {
185    if ((mNumBuffersReceived % 128) != 0) {
186        return;
187    }
188
189#if 0
190    if (mAssembler == NULL) {
191        char tmp[20];
192        sprintf(tmp, "0x%08x", mID);
193
194        int32_t numMissing = 0;
195
196        if (!mQueue.empty()) {
197            List<sp<ABuffer> >::const_iterator it = mQueue.begin();
198            uint32_t expectedSeqNum = (uint32_t)(*it)->int32Data();
199            ++expectedSeqNum;
200            ++it;
201
202            for (; it != mQueue.end(); ++it) {
203                uint32_t seqNum = (uint32_t)(*it)->int32Data();
204                CHECK_GE(seqNum, expectedSeqNum);
205
206                if (seqNum != expectedSeqNum) {
207                    numMissing += seqNum - expectedSeqNum;
208                    expectedSeqNum = seqNum;
209                }
210
211                ++expectedSeqNum;
212            }
213        }
214
215        LOG(VERBOSE) << "[" << tmp << "] Missing " << numMissing
216             << " / " << (mNumBuffersReceived + numMissing) << " packets. ("
217             << (100.0 * numMissing / (mNumBuffersReceived + numMissing))
218             << " %%)";
219    }
220#endif
221
222#if 0
223    AString out;
224
225    out.append(tmp);
226    out.append(" [");
227
228    List<sp<ABuffer> >::const_iterator it = mQueue.begin();
229    while (it != mQueue.end()) {
230        uint32_t start = (uint32_t)(*it)->int32Data();
231
232        out.append(start);
233
234        ++it;
235        uint32_t expected = start + 1;
236
237        while (it != mQueue.end()) {
238            uint32_t seqNum = (uint32_t)(*it)->int32Data();
239
240            if (seqNum != expected) {
241                if (expected > start + 1) {
242                    out.append("-");
243                    out.append(expected - 1);
244                }
245                out.append(", ");
246                break;
247            }
248
249            ++it;
250            ++expected;
251        }
252
253        if (it == mQueue.end()) {
254            if (expected > start + 1) {
255                out.append("-");
256                out.append(expected - 1);
257            }
258        }
259    }
260
261    out.append("]");
262
263    LOG(VERBOSE) << out;
264#endif
265}
266
267uint64_t ARTPSource::RTP2NTP(uint32_t rtpTime) const {
268    CHECK_EQ(mNumTimes, 2u);
269
270    return mNTPTime[0] + (double)(mNTPTime[1] - mNTPTime[0])
271            * ((double)rtpTime - (double)mRTPTime[0])
272            / (double)(mRTPTime[1] - mRTPTime[0]);
273}
274
275void ARTPSource::byeReceived() {
276    mAssembler->onByeReceived();
277}
278
279void ARTPSource::addFIR(const sp<ABuffer> &buffer) {
280    if (!mIssueFIRRequests) {
281        return;
282    }
283
284    int64_t nowUs = ALooper::GetNowUs();
285    if (mLastFIRRequestUs >= 0 && mLastFIRRequestUs + 5000000ll > nowUs) {
286        // Send FIR requests at most every 5 secs.
287        return;
288    }
289
290    mLastFIRRequestUs = nowUs;
291
292    if (buffer->size() + 20 > buffer->capacity()) {
293        LOG(WARNING) << "RTCP buffer too small to accomodate FIR.";
294        return;
295    }
296
297    uint8_t *data = buffer->data() + buffer->size();
298
299    data[0] = 0x80 | 4;
300    data[1] = 206;  // PSFB
301    data[2] = 0;
302    data[3] = 4;
303    data[4] = kSourceID >> 24;
304    data[5] = (kSourceID >> 16) & 0xff;
305    data[6] = (kSourceID >> 8) & 0xff;
306    data[7] = kSourceID & 0xff;
307
308    data[8] = 0x00;  // SSRC of media source (unused)
309    data[9] = 0x00;
310    data[10] = 0x00;
311    data[11] = 0x00;
312
313    data[12] = mID >> 24;
314    data[13] = (mID >> 16) & 0xff;
315    data[14] = (mID >> 8) & 0xff;
316    data[15] = mID & 0xff;
317
318    data[16] = mNextFIRSeqNo++;  // Seq Nr.
319
320    data[17] = 0x00;  // Reserved
321    data[18] = 0x00;
322    data[19] = 0x00;
323
324    buffer->setRange(buffer->offset(), buffer->size() + 20);
325
326    LOG(VERBOSE) << "Added FIR request.";
327}
328
329void ARTPSource::addReceiverReport(const sp<ABuffer> &buffer) {
330    if (buffer->size() + 32 > buffer->capacity()) {
331        LOG(WARNING) << "RTCP buffer too small to accomodate RR.";
332        return;
333    }
334
335    uint8_t *data = buffer->data() + buffer->size();
336
337    data[0] = 0x80 | 1;
338    data[1] = 201;  // RR
339    data[2] = 0;
340    data[3] = 7;
341    data[4] = kSourceID >> 24;
342    data[5] = (kSourceID >> 16) & 0xff;
343    data[6] = (kSourceID >> 8) & 0xff;
344    data[7] = kSourceID & 0xff;
345
346    data[8] = mID >> 24;
347    data[9] = (mID >> 16) & 0xff;
348    data[10] = (mID >> 8) & 0xff;
349    data[11] = mID & 0xff;
350
351    data[12] = 0x00;  // fraction lost
352
353    data[13] = 0x00;  // cumulative lost
354    data[14] = 0x00;
355    data[15] = 0x00;
356
357    data[16] = mHighestSeqNumber >> 24;
358    data[17] = (mHighestSeqNumber >> 16) & 0xff;
359    data[18] = (mHighestSeqNumber >> 8) & 0xff;
360    data[19] = mHighestSeqNumber & 0xff;
361
362    data[20] = 0x00;  // Interarrival jitter
363    data[21] = 0x00;
364    data[22] = 0x00;
365    data[23] = 0x00;
366
367    uint32_t LSR = 0;
368    uint32_t DLSR = 0;
369    if (mLastNTPTime != 0) {
370        LSR = (mLastNTPTime >> 16) & 0xffffffff;
371
372        DLSR = (uint32_t)
373            ((ALooper::GetNowUs() - mLastNTPTimeUpdateUs) * 65536.0 / 1E6);
374    }
375
376    data[24] = LSR >> 24;
377    data[25] = (LSR >> 16) & 0xff;
378    data[26] = (LSR >> 8) & 0xff;
379    data[27] = LSR & 0xff;
380
381    data[28] = DLSR >> 24;
382    data[29] = (DLSR >> 16) & 0xff;
383    data[30] = (DLSR >> 8) & 0xff;
384    data[31] = DLSR & 0xff;
385
386    buffer->setRange(buffer->offset(), buffer->size() + 32);
387}
388
389}  // namespace android
390
391
392