OLD | NEW |
(Empty) | |
| 1 // Copyright 2016 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 MEDIA_FILTERS_PIPELINE_CONTROLLER_H_ |
| 6 #define MEDIA_FILTERS_PIPELINE_CONTROLLER_H_ |
| 7 |
| 8 #include "base/callback.h" |
| 9 #include "base/macros.h" |
| 10 #include "base/memory/weak_ptr.h" |
| 11 #include "base/time/time.h" |
| 12 #include "media/base/media_export.h" |
| 13 #include "media/base/pipeline.h" |
| 14 #include "media/base/renderer.h" |
| 15 |
| 16 namespace media { |
| 17 |
| 18 class ChunkDemuxer; |
| 19 class Demuxer; |
| 20 |
| 21 // PipelineController wraps a Pipeline to expose the one-at-a-time operations |
| 22 // (Seek(), Suspend(), and Resume()) with a simpler API. Internally it tracks |
| 23 // pending operations and dispatches them when possible. Duplicate requests |
| 24 // (such as seeking twice to the same time) may be elided. |
| 25 // |
| 26 // TODO(sandersd): |
| 27 // - Expose an operation that restarts via suspend+resume. |
| 28 // - Block invalid calls after an error occurs. |
| 29 class MEDIA_EXPORT PipelineController |
| 30 : public base::SupportsWeakPtr<PipelineController> { |
| 31 public: |
| 32 enum class State { |
| 33 CREATED, |
| 34 STARTING, |
| 35 PLAYING, |
| 36 SEEKING, |
| 37 SUSPENDING, |
| 38 SUSPENDED, |
| 39 RESUMING, |
| 40 }; |
| 41 |
| 42 typedef base::Callback<scoped_ptr<Renderer>(void)> RendererFactoryCB; |
| 43 typedef base::Callback<void(bool time_updated)> SeekedCB; |
| 44 typedef base::Callback<void()> SuspendedCB; |
| 45 |
| 46 PipelineController(Pipeline* pipeline, |
| 47 const RendererFactoryCB& renderer_factory_cb, |
| 48 const SeekedCB& seeked_cb, |
| 49 const SuspendedCB& suspended_cb, |
| 50 const PipelineStatusCB& error_cb); |
| 51 ~PipelineController(); |
| 52 |
| 53 // Start |pipeline_|. If provided, |chunk_demuxer| will be stored and |
| 54 // StartWaitingForSeek()/CancelPendingSeek() will be issued to it as |
| 55 // necessary. When |is_streaming| is true, Resume() will always start at the |
| 56 // beginning of the stream, rather than attempting to seek to the current |
| 57 // time. Other parameters are just passed directly to pipeline_.Start(). |
| 58 void Start(ChunkDemuxer* chunk_demuxer, |
| 59 Demuxer* demuxer, |
| 60 bool is_streaming, |
| 61 const base::Closure& ended_cb, |
| 62 const PipelineMetadataCB& metadata_cb, |
| 63 const BufferingStateCB& buffering_state_cb, |
| 64 const base::Closure& duration_change_cb, |
| 65 const AddTextTrackCB& add_text_track_cb, |
| 66 const base::Closure& waiting_for_decryption_key_cb); |
| 67 |
| 68 void Seek(base::TimeDelta time, bool time_updated); |
| 69 void Suspend(); |
| 70 void Resume(); |
| 71 |
| 72 // Returns true if the current state is stable. This means that |state_| is |
| 73 // PLAYING and there are no pending operations. Requests are processed |
| 74 // immediately when the state is stable, otherwise they are queued. |
| 75 // (Exception: Resume() is processed immediately while suspended.) |
| 76 bool IsStable(); |
| 77 |
| 78 // Returns true if |pipeline_| is suspended. |
| 79 bool IsSuspended(); |
| 80 |
| 81 private: |
| 82 // Attempts to make progress from the current state to the target state. |
| 83 void Dispatch(); |
| 84 |
| 85 // PipelineStaus callback that also carries the target state. |
| 86 void OnPipelineStatus(State state, PipelineStatus pipeline_status); |
| 87 |
| 88 // The Pipeline we are managing state for. |
| 89 Pipeline* pipeline_ = nullptr; |
| 90 |
| 91 // Factory for Renderers, used for Start() and Resume(). |
| 92 RendererFactoryCB renderer_factory_cb_; |
| 93 |
| 94 // Called after seeks (which includes Start()) upon reaching a stable state. |
| 95 // Multiple seeks result in only one callback if no stable state occurs |
| 96 // between them. |
| 97 SeekedCB seeked_cb_; |
| 98 |
| 99 // Called immediately when |pipeline_| completes a suspend operation. |
| 100 SuspendedCB suspended_cb_; |
| 101 |
| 102 // Called immediately when any operation on |pipeline_| results in an error. |
| 103 PipelineStatusCB error_cb_; |
| 104 |
| 105 // State for handling StartWaitingForSeek()/CancelPendingSeek(). |
| 106 ChunkDemuxer* chunk_demuxer_ = nullptr; |
| 107 bool waiting_for_seek_ = false; |
| 108 |
| 109 // When true, Resume() will start at time zero instead of seeking to the |
| 110 // current time. |
| 111 bool is_streaming_ = false; |
| 112 |
| 113 // Tracks the current state of |pipeline_|. |
| 114 State state_ = State::CREATED; |
| 115 |
| 116 // Indicates that a seek has occurred. When set, a seeked callback will be |
| 117 // issued at the next stable state. |
| 118 bool pending_seeked_ = false; |
| 119 |
| 120 // Indicates that time has been changed by a seek, which will be reported at |
| 121 // the next seeked callback. |
| 122 bool pending_time_update_ = false; |
| 123 |
| 124 // The target time of the active seek; valid while SEEKING or RESUMING. |
| 125 base::TimeDelta seek_time_; |
| 126 |
| 127 // Target state which we will work to achieve. |pending_seek_time_| is only |
| 128 // valid when |pending_seek_| is true. |
| 129 bool pending_seek_ = false; |
| 130 base::TimeDelta pending_seek_time_; |
| 131 bool pending_suspend_ = false; |
| 132 bool pending_resume_ = false; |
| 133 |
| 134 DISALLOW_COPY_AND_ASSIGN(PipelineController); |
| 135 }; |
| 136 |
| 137 } // namespace media |
| 138 |
| 139 #endif // MEDIA_FILTERS_PIPELINE_CONTROLLER_H_ |
OLD | NEW |