1 /*
2  *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef PC_JITTER_BUFFER_DELAY_H_
12 #define PC_JITTER_BUFFER_DELAY_H_
13 
14 #include <stdint.h>
15 
16 #include "absl/types/optional.h"
17 #include "media/base/delayable.h"
18 #include "pc/jitter_buffer_delay_interface.h"
19 #include "rtc_base/thread.h"
20 
21 namespace webrtc {
22 
23 // JitterBufferDelay converts delay from seconds to milliseconds for the
24 // underlying media channel. It also handles cases when user sets delay before
25 // the start of media_channel by caching its request. Note, this class is not
26 // thread safe. Its thread safe version is defined in
27 // pc/jitter_buffer_delay_proxy.h
28 class JitterBufferDelay : public JitterBufferDelayInterface {
29  public:
30   // Must be called on signaling thread.
31   explicit JitterBufferDelay(rtc::Thread* worker_thread);
32 
33   void OnStart(cricket::Delayable* media_channel, uint32_t ssrc) override;
34 
35   void OnStop() override;
36 
37   void Set(absl::optional<double> delay_seconds) override;
38 
39  private:
40   // Throughout webrtc source, sometimes it is also called as |main_thread_|.
41   rtc::Thread* const signaling_thread_;
42   rtc::Thread* const worker_thread_;
43   // Media channel and ssrc together uniqely identify audio stream.
44   cricket::Delayable* media_channel_ = nullptr;
45   absl::optional<uint32_t> ssrc_;
46   absl::optional<double> cached_delay_seconds_;
47 };
48 
49 }  // namespace webrtc
50 
51 #endif  // PC_JITTER_BUFFER_DELAY_H_
52