Use cached Key frames to avoid browser seek

media/base/android/media_decoder_job.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_ANDROID_MEDIA_DECODER_JOB_H_
 #define MEDIA_BASE_ANDROID_MEDIA_DECODER_JOB_H_
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "media/base/android/demuxer_stream_player_params.h"
 #include "media/base/android/media_codec_bridge.h"
 #include "ui/gl/android/scoped_java_surface.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace media {
 
 class MediaDrmBridge;
 
 // Class for managing all the decoding tasks. Each decoding task will be posted
 // onto the same thread. The thread will be stopped once Stop() is called.
 // Data is stored in 2 chunks. When new data arrives, it is always stored in
 // an inactive chunk. And when the current active chunk becomes empty, a new
 // data request will be sent to the renderer.
 class MediaDecoderJob {
  public:
+  // Return value when Decode() is called.
+  enum MediaDecoderJobStatus {
+    STATUS_SUCCESS,
+    STATUS_KEY_FRAME_REQUIRED,
+    STATUS_FAILURE,
+  };
+
   struct Deleter {
     inline void operator()(MediaDecoderJob* ptr) const { ptr->Release(); }
   };
 
   // Callback when a decoder job finishes its work. Args: whether decode
   // finished successfully, current presentation time, max presentation time.
   // If the current presentation time is equal to kNoTimestamp(), the decoder
   // job skipped rendering of the decoded output and the callback target should
   // ignore the timestamps provided.
   typedef base::Callback<void(MediaCodecStatus, base::TimeDelta,
@@ skipping 10 matching lines @@
   // Called by MediaSourcePlayer when more data for this object has arrived.
   void OnDataReceived(const DemuxerData& data);
 
   // Prefetch so we know the decoder job has data when we call Decode().
   // |prefetch_cb| - Run when prefetching has completed.
   void Prefetch(const base::Closure& prefetch_cb);
 
   // Called by MediaSourcePlayer to decode some data.
   // |callback| - Run when decode operation has completed.
   //
-  // Returns true if the next decode was started and |callback| will be
-  // called when the decode operation is complete.
-  // Returns false if |media_codec_bridge_| cannot be created; |callback| is
-  // ignored and will not be called.
-  bool Decode(base::TimeTicks start_time_ticks,
-              base::TimeDelta start_presentation_timestamp,
-              const DecoderCallback& callback);
+  // Returns STATUS_SUCCESS on success, or STATUS_FAILURE on failure, or
+  // STATUS_KEY_FRAME_REQUIRED if a browser seek is required.

[wolenetz, 2015/02/04 21:07:23]

nit: retain comment around |callback| usage

[qinmin, 2015/02/04 23:11:23]

Done.

+  MediaDecoderJobStatus Decode(base::TimeTicks start_time_ticks,
+                               base::TimeDelta start_presentation_timestamp,
+                               const DecoderCallback& callback);
 
   // Called to stop the last Decode() early.
   // If the decoder is in the process of decoding the next frame, then
   // this method will just allow the decode to complete as normal. If
   // this object is waiting for a data request to complete, then this method
   // will wait for the data to arrive and then call the |callback|
   // passed to Decode() with a status of MEDIA_CODEC_ABORT. This ensures that
   // the |callback| passed to Decode() is always called and the status
   // reflects whether data was actually decoded or the decode terminated early.
   void StopDecode();
@@ skipping 48 matching lines @@
   // Returns true if the "time to render" needs to be computed for frames in
   // this decoder job.
   virtual bool ComputeTimeToRender() const = 0;
 
   // Gets MediaCrypto object from |drm_bridge_|.
   base::android::ScopedJavaLocalRef<jobject> GetMediaCrypto();
 
   // Releases the |media_codec_bridge_|.
   void ReleaseMediaCodecBridge();
 
+  // Sets the current frame to a previously cached key frame. Returns true if
+  // a key frame is found, or false otherwise.
+  // TODO(qinmin): add UMA to study the cache hit ratio for key frames.
+  bool SetCurrentFrameToPreviouslyCachedKeyFrame();
+
   MediaDrmBridge* drm_bridge() { return drm_bridge_; }
 
   void set_is_content_encrypted(bool is_content_encrypted) {
     is_content_encrypted_ = is_content_encrypted;
   }
 
+  virtual bool is_video() { return false; }
   bool need_to_reconfig_decoder_job_;
 
   scoped_ptr<MediaCodecBridge> media_codec_bridge_;
 
  private:
   friend class MediaSourcePlayerTest;
 
   // Causes this instance to be deleted on the thread it is bound to.
   void Release();
 
@@ skipping 51 matching lines @@
 
   // Requests new data for the current chunk if it runs out of data.
   void RequestCurrentChunkIfEmpty();
 
   // Initializes |received_data_| and |access_unit_index_|.
   void InitializeReceivedData();
 
   // Called when the decoder is completely drained and is ready to be released.
   void OnDecoderDrained();
 
-  // Creates |media_codec_bridge_| for decoding purpose. Returns true if it is
-  // created, or false otherwise.
-  bool CreateMediaCodecBridge();
-
-  // Called when an access unit is consumed by the decoder. |is_config_change|
-  // indicates whether the current access unit is a config change. If it is
-  // true, the next access unit is guarateed to be an I-frame.
-  virtual void CurrentDataConsumed(bool is_config_change) {}
+  // Creates |media_codec_bridge_| for decoding purpose.
+  // Returns STATUS_SUCCESS on success, or STATUS_FAILURE on failure, or
+  // STATUS_KEY_FRAME_REQUIRED if a browser seek is required.
+  MediaDecoderJobStatus CreateMediaCodecBridge();
 
   // Implemented by the child class to create |media_codec_bridge_| for a
-  // particular stream. Returns true if it is created, or false otherwise.
-  virtual bool CreateMediaCodecBridgeInternal() = 0;
+  // particular stream.
+  // Returns STATUS_SUCCESS on success, or STATUS_FAILURE on failure, or
+  // STATUS_KEY_FRAME_REQUIRED if a browser seek is required.
+  virtual MediaDecoderJobStatus CreateMediaCodecBridgeInternal() = 0;
 
   // Returns true if the |configs| doesn't match the current demuxer configs
   // the decoder job has.
   virtual bool AreDemuxerConfigsChanged(
       const DemuxerConfigs& configs) const = 0;
 
   // Returns true if |media_codec_bridge_| needs to be reconfigured for the
   // new DemuxerConfigs, or false otherwise.
   virtual bool IsCodecReconfigureNeeded(const DemuxerConfigs& configs) const;
 
@@ skipping 109 matching lines @@
   // This access unit is passed to the decoder during config changes to drain
   // the decoder.
   AccessUnit eos_unit_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MediaDecoderJob);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_ANDROID_MEDIA_DECODER_JOB_H_