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 #include "media/cast/net/rtp_sender/rtp_sender.h"
6
7 #include "base/logging.h"
8 #include "base/rand_util.h"
9 #include "media/cast/cast_defines.h"
10 #include "media/cast/net/pacing/paced_sender.h"
11 #include "media/cast/rtcp/rtcp_defines.h"
12 #include "net/base/big_endian.h"
13
14 namespace media {
15 namespace cast {
16
RtpSender(scoped_refptr<CastEnvironment> cast_environment,const AudioSenderConfig * audio_config,const VideoSenderConfig * video_config,PacedPacketSender * transport)17 RtpSender::RtpSender(scoped_refptr<CastEnvironment> cast_environment,
18 const AudioSenderConfig* audio_config,
19 const VideoSenderConfig* video_config,
20 PacedPacketSender* transport)
21 : cast_environment_(cast_environment),
22 config_(),
23 transport_(transport) {
24 // Store generic cast config and create packetizer config.
25 DCHECK(audio_config || video_config) << "Invalid argument";
26 if (audio_config) {
27 storage_.reset(new PacketStorage(cast_environment->Clock(),
28 audio_config->rtp_history_ms));
29 config_.audio = true;
30 config_.ssrc = audio_config->sender_ssrc;
31 config_.payload_type = audio_config->rtp_payload_type;
32 config_.frequency = audio_config->frequency;
33 config_.audio_codec = audio_config->codec;
34 } else {
35 storage_.reset(new PacketStorage(cast_environment->Clock(),
36 video_config->rtp_history_ms));
37 config_.audio = false;
38 config_.ssrc = video_config->sender_ssrc;
39 config_.payload_type = video_config->rtp_payload_type;
40 config_.frequency = kVideoFrequency;
41 config_.video_codec = video_config->codec;
42 }
43 // Randomly set start values.
44 config_.sequence_number = base::RandInt(0, 65535);
45 config_.rtp_timestamp = base::RandInt(0, 65535);
46 config_.rtp_timestamp += base::RandInt(0, 65535) << 16;
47 packetizer_.reset(new RtpPacketizer(transport, storage_.get(), config_));
48 }
49
~RtpSender()50 RtpSender::~RtpSender() {}
51
IncomingEncodedVideoFrame(const EncodedVideoFrame * video_frame,const base::TimeTicks & capture_time)52 void RtpSender::IncomingEncodedVideoFrame(const EncodedVideoFrame* video_frame,
53 const base::TimeTicks& capture_time) {
54 packetizer_->IncomingEncodedVideoFrame(video_frame, capture_time);
55 }
56
IncomingEncodedAudioFrame(const EncodedAudioFrame * audio_frame,const base::TimeTicks & recorded_time)57 void RtpSender::IncomingEncodedAudioFrame(const EncodedAudioFrame* audio_frame,
58 const base::TimeTicks& recorded_time) {
59 packetizer_->IncomingEncodedAudioFrame(audio_frame, recorded_time);
60 }
61
ResendPackets(const MissingFramesAndPacketsMap & missing_frames_and_packets)62 void RtpSender::ResendPackets(
63 const MissingFramesAndPacketsMap& missing_frames_and_packets) {
64 // Iterate over all frames in the list.
65 for (MissingFramesAndPacketsMap::const_iterator it =
66 missing_frames_and_packets.begin();
67 it != missing_frames_and_packets.end(); ++it) {
68 PacketList packets_to_resend;
69 uint8 frame_id = it->first;
70 const PacketIdSet& packets_set = it->second;
71 bool success = false;
72
73 if (packets_set.empty()) {
74 VLOG(1) << "Missing all packets in frame " << static_cast<int>(frame_id);
75
76 uint16 packet_id = 0;
77 do {
78 // Get packet from storage.
79 success = storage_->GetPacket(frame_id, packet_id, &packets_to_resend);
80
81 // Resend packet to the network.
82 if (success) {
83 VLOG(1) << "Resend " << static_cast<int>(frame_id)
84 << ":" << packet_id;
85 // Set a unique incremental sequence number for every packet.
86 Packet& packet = packets_to_resend.back();
87 UpdateSequenceNumber(&packet);
88 // Set the size as correspond to each frame.
89 ++packet_id;
90 }
91 } while (success);
92 } else {
93 // Iterate over all of the packets in the frame.
94 for (PacketIdSet::const_iterator set_it = packets_set.begin();
95 set_it != packets_set.end(); ++set_it) {
96 uint16 packet_id = *set_it;
97 success = storage_->GetPacket(frame_id, packet_id, &packets_to_resend);
98
99 // Resend packet to the network.
100 if (success) {
101 VLOG(1) << "Resend " << static_cast<int>(frame_id)
102 << ":" << packet_id;
103 Packet& packet = packets_to_resend.back();
104 UpdateSequenceNumber(&packet);
105 }
106 }
107 }
108 transport_->ResendPackets(packets_to_resend);
109 }
110 }
111
UpdateSequenceNumber(Packet * packet)112 void RtpSender::UpdateSequenceNumber(Packet* packet) {
113 uint16 new_sequence_number = packetizer_->NextSequenceNumber();
114 int index = 2;
115 (*packet)[index] = (static_cast<uint8>(new_sequence_number));
116 (*packet)[index + 1] =(static_cast<uint8>(new_sequence_number >> 8));
117 }
118
RtpStatistics(const base::TimeTicks & now,RtcpSenderInfo * sender_info)119 void RtpSender::RtpStatistics(const base::TimeTicks& now,
120 RtcpSenderInfo* sender_info) {
121 // The timestamp of this Rtcp packet should be estimated as the timestamp of
122 // the frame being captured at this moment. We are calculating that
123 // timestamp as the last frame's timestamp + the time since the last frame
124 // was captured.
125 uint32 ntp_seconds = 0;
126 uint32 ntp_fraction = 0;
127 ConvertTimeTicksToNtp(now, &ntp_seconds, &ntp_fraction);
128 sender_info->ntp_seconds = ntp_seconds;
129 sender_info->ntp_fraction = ntp_fraction;
130
131 base::TimeTicks time_sent;
132 uint32 rtp_timestamp;
133 if (packetizer_->LastSentTimestamp(&time_sent, &rtp_timestamp)) {
134 base::TimeDelta time_since_last_send = now - time_sent;
135 sender_info->rtp_timestamp = rtp_timestamp +
136 time_since_last_send.InMilliseconds() * (config_.frequency / 1000);
137 } else {
138 sender_info->rtp_timestamp = 0;
139 }
140 sender_info->send_packet_count = packetizer_->send_packets_count();
141 sender_info->send_octet_count = packetizer_->send_octet_count();
142 }
143
144 } // namespace cast
145 } // namespace media
146