1 // Copyright 2014 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/sender/audio_sender.h"
6
7 #include "base/bind.h"
8 #include "base/logging.h"
9 #include "base/message_loop/message_loop.h"
10 #include "media/cast/cast_defines.h"
11 #include "media/cast/net/cast_transport_config.h"
12 #include "media/cast/sender/audio_encoder.h"
13
14 namespace media {
15 namespace cast {
16 namespace {
17
18 // TODO(miu): This should be specified in AudioSenderConfig, but currently it is
19 // fixed to 100 FPS (i.e., 10 ms per frame), and AudioEncoder assumes this as
20 // well.
21 const int kAudioFrameRate = 100;
22
23 } // namespace
24
AudioSender(scoped_refptr<CastEnvironment> cast_environment,const AudioSenderConfig & audio_config,CastTransportSender * const transport_sender)25 AudioSender::AudioSender(scoped_refptr<CastEnvironment> cast_environment,
26 const AudioSenderConfig& audio_config,
27 CastTransportSender* const transport_sender)
28 : FrameSender(
29 cast_environment,
30 true,
31 transport_sender,
32 base::TimeDelta::FromMilliseconds(audio_config.rtcp_interval),
33 audio_config.frequency,
34 audio_config.ssrc,
35 kAudioFrameRate,
36 audio_config.min_playout_delay,
37 audio_config.max_playout_delay,
38 NewFixedCongestionControl(audio_config.bitrate)),
39 samples_in_encoder_(0),
40 weak_factory_(this) {
41 cast_initialization_status_ = STATUS_AUDIO_UNINITIALIZED;
42 VLOG(1) << "max_unacked_frames " << max_unacked_frames_;
43 DCHECK_GT(max_unacked_frames_, 0);
44
45 if (!audio_config.use_external_encoder) {
46 audio_encoder_.reset(
47 new AudioEncoder(cast_environment,
48 audio_config.channels,
49 audio_config.frequency,
50 audio_config.bitrate,
51 audio_config.codec,
52 base::Bind(&AudioSender::OnEncodedAudioFrame,
53 weak_factory_.GetWeakPtr(),
54 audio_config.bitrate)));
55 cast_initialization_status_ = audio_encoder_->InitializationResult();
56 } else {
57 NOTREACHED(); // No support for external audio encoding.
58 cast_initialization_status_ = STATUS_AUDIO_UNINITIALIZED;
59 }
60
61 media::cast::CastTransportRtpConfig transport_config;
62 transport_config.ssrc = audio_config.ssrc;
63 transport_config.feedback_ssrc = audio_config.incoming_feedback_ssrc;
64 transport_config.rtp_payload_type = audio_config.rtp_payload_type;
65 transport_config.aes_key = audio_config.aes_key;
66 transport_config.aes_iv_mask = audio_config.aes_iv_mask;
67
68 transport_sender->InitializeAudio(
69 transport_config,
70 base::Bind(&AudioSender::OnReceivedCastFeedback,
71 weak_factory_.GetWeakPtr()),
72 base::Bind(&AudioSender::OnMeasuredRoundTripTime,
73 weak_factory_.GetWeakPtr()));
74 }
75
~AudioSender()76 AudioSender::~AudioSender() {}
77
InsertAudio(scoped_ptr<AudioBus> audio_bus,const base::TimeTicks & recorded_time)78 void AudioSender::InsertAudio(scoped_ptr<AudioBus> audio_bus,
79 const base::TimeTicks& recorded_time) {
80 DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
81 if (cast_initialization_status_ != STATUS_AUDIO_INITIALIZED) {
82 NOTREACHED();
83 return;
84 }
85 DCHECK(audio_encoder_.get()) << "Invalid internal state";
86
87 const base::TimeDelta next_frame_duration =
88 RtpDeltaToTimeDelta(audio_bus->frames(), rtp_timebase());
89 if (ShouldDropNextFrame(next_frame_duration))
90 return;
91
92 samples_in_encoder_ += audio_bus->frames();
93
94 audio_encoder_->InsertAudio(audio_bus.Pass(), recorded_time);
95 }
96
GetNumberOfFramesInEncoder() const97 int AudioSender::GetNumberOfFramesInEncoder() const {
98 // Note: It's possible for a partial frame to be in the encoder, but returning
99 // the floor() is good enough for the "design limit" check in FrameSender.
100 return samples_in_encoder_ / audio_encoder_->GetSamplesPerFrame();
101 }
102
GetInFlightMediaDuration() const103 base::TimeDelta AudioSender::GetInFlightMediaDuration() const {
104 const int samples_in_flight = samples_in_encoder_ +
105 GetUnacknowledgedFrameCount() * audio_encoder_->GetSamplesPerFrame();
106 return RtpDeltaToTimeDelta(samples_in_flight, rtp_timebase());
107 }
108
OnAck(uint32 frame_id)109 void AudioSender::OnAck(uint32 frame_id) {
110 }
111
OnEncodedAudioFrame(int encoder_bitrate,scoped_ptr<EncodedFrame> encoded_frame,int samples_skipped)112 void AudioSender::OnEncodedAudioFrame(
113 int encoder_bitrate,
114 scoped_ptr<EncodedFrame> encoded_frame,
115 int samples_skipped) {
116 DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
117
118 samples_in_encoder_ -= audio_encoder_->GetSamplesPerFrame() + samples_skipped;
119 DCHECK_GE(samples_in_encoder_, 0);
120
121 SendEncodedFrame(encoder_bitrate, encoded_frame.Pass());
122 }
123
124 } // namespace cast
125 } // namespace media
126