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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 #ifndef CHROMECAST_MEDIA_CMA_BACKEND_MEDIA_COMPONENT_DEVICE_H_ | |
6 #define CHROMECAST_MEDIA_CMA_BACKEND_MEDIA_COMPONENT_DEVICE_H_ | |
7 | |
8 #include <string> | |
9 | |
10 #include "base/basictypes.h" | |
11 #include "base/callback.h" | |
12 #include "base/macros.h" | |
13 #include "base/memory/ref_counted.h" | |
14 #include "base/threading/non_thread_safe.h" | |
15 #include "base/time/time.h" | |
16 | |
17 namespace chromecast { | |
18 namespace media { | |
19 class DecoderBufferBase; | |
20 class DecryptContext; | |
21 | |
22 // MediaComponentDevice - | |
23 // | |
24 // State machine: | |
25 // -------------- kRunning <--- | |
26 // | ^ | | |
27 // v | | | |
28 // kUninitialized <--> kIdle -------------- | | |
29 // ^ | | | |
30 // | v | | |
31 // -------------- kPaused <---- | |
32 // {any state} --> kError | |
33 // kError --> kUninitialized | |
34 // | |
35 // Notes: | |
36 // - Hardware resources are acquired when transitioning from the | |
37 // |kUninitialized| state to the |kIdle| state. | |
38 // - Buffers can be pushed only in the kRunning or kPaused states. | |
39 // - The end of stream is signaled through a special buffer. | |
40 // Once the end of stream buffer is fed, no other buffer | |
41 // can be fed until the FSM goes through the kIdle state again. | |
42 // - In both kPaused and kRunning states, frames can be fed. | |
43 // However, frames are possibly rendered only in the kRunning state. | |
44 // - In the kRunning state, frames are rendered according to the clock rate. | |
45 // - All the hardware resources must be released in the |kError| state. | |
46 // | |
47 class MediaComponentDevice | |
48 : NON_EXPORTED_BASE(public base::NonThreadSafe) { | |
49 public: | |
50 enum State { | |
51 kStateUninitialized, | |
52 kStateIdle, | |
53 kStateRunning, | |
54 kStatePaused, | |
55 kStateError, | |
56 }; | |
57 | |
58 enum FrameStatus { | |
59 kFrameSuccess, | |
60 kFrameFailed, | |
61 kFramePending, | |
62 }; | |
63 typedef base::Callback<void(FrameStatus)> FrameStatusCB; | |
64 | |
65 struct Client { | |
66 Client(); | |
67 ~Client(); | |
68 | |
69 // Invoked when playback reaches the end of stream. | |
70 base::Closure eos_cb; | |
71 }; | |
72 | |
73 // The statistics are computed since the media component left the idle state. | |
74 // For video, a sample is defined as a frame. | |
75 struct Statistics { | |
76 uint64 decoded_bytes; | |
77 uint64 decoded_samples; | |
78 uint64 dropped_samples; | |
79 }; | |
80 | |
81 // Returns whether or not transitioning from |state1| to |state2| is valid. | |
82 static bool IsValidStateTransition(State state1, State state2); | |
83 | |
84 // Returns string representation of state (for logging) | |
85 static std::string StateToString(const State& state); | |
86 | |
87 MediaComponentDevice(); | |
88 virtual ~MediaComponentDevice(); | |
89 | |
90 // Register |client| as the media event handler. | |
91 virtual void SetClient(const Client& client) = 0; | |
92 | |
93 // Changes the state and performs any necessary transitions. | |
94 // Returns true when successful. | |
95 virtual bool SetState(State new_state) = 0; | |
96 | |
97 // Returns the current state of the media component. | |
98 virtual State GetState() const = 0; | |
99 | |
100 // Sets the time where rendering should start. | |
101 // Return true when successful. | |
102 // Can only be invoked in state kStateIdle. | |
103 virtual bool SetStartPts(base::TimeDelta time) = 0; | |
104 | |
105 // Pushes a frame. | |
106 // |completion_cb| is only invoked if the returned value is |kFramePending|. | |
107 // In this specific case, no additional frame can be pushed before | |
108 // |completion_cb| is invoked. | |
109 // Note: |completion_cb| cannot be invoked with |kFramePending|. | |
110 // Note: pushing the pending frame should be aborted when the state goes back | |
111 // to kStateIdle. |completion_cb| is not invoked in that case. | |
112 virtual FrameStatus PushFrame( | |
113 const scoped_refptr<DecryptContext>& decrypt_context, | |
114 const scoped_refptr<DecoderBufferBase>& buffer, | |
115 const FrameStatusCB& completion_cb) = 0; | |
116 | |
117 // Returns the rendering time of the latest rendered sample. | |
118 // Can be invoked only in states kStateRunning or kStatePaused. | |
119 // Returns |kNoTimestamp()| if the playback time cannot be retrieved. | |
120 virtual base::TimeDelta GetRenderingTime() const = 0; | |
121 | |
122 // Returns the pipeline latency: i.e. the amount of data | |
123 // in the pipeline that have not been rendered yet. | |
124 // Returns |kNoTimestamp()| if the latency is not available. | |
125 virtual base::TimeDelta GetRenderingDelay() const = 0; | |
126 | |
127 // Returns the playback statistics. Statistics are computed since the media | |
128 // component left the idle state. | |
129 // Returns true when successful. | |
130 // Can only be invoked in state kStateRunning. | |
131 virtual bool GetStatistics(Statistics* stats) const = 0; | |
132 | |
133 private: | |
134 DISALLOW_COPY_AND_ASSIGN(MediaComponentDevice); | |
135 }; | |
136 | |
137 } // namespace media | |
138 } // namespace chromecast | |
139 | |
140 #endif // CHROMECAST_MEDIA_CMA_BACKEND_MEDIA_COMPONENT_DEVICE_H_ | |
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