MediaCodecPlayer implementation - stage 7 (DRM)

media/base/android/media_codec_player.h

 // Copyright 2015 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_CODEC_PLAYER_H_
 #define MEDIA_BASE_ANDROID_MEDIA_CODEC_PLAYER_H_
 
 #include "base/android/scoped_java_ref.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread.h"
 #include "base/time/default_tick_clock.h"
 #include "media/base/android/demuxer_android.h"
+#include "media/base/android/media_drm_bridge.h"
 #include "media/base/android/media_player_android.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/media_export.h"
 #include "media/base/time_delta_interpolator.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gl/android/scoped_java_surface.h"
 
 // The MediaCodecPlayer class implements the media player by using Android's
 // MediaCodec. It differs from MediaSourcePlayer in that it removes most
 // processing away from the UI thread: it uses a dedicated Media thread to
@@ skipping 204 matching lines @@
  private:
   // The state machine states.
   enum PlayerState {
     kStatePaused,
     kStateWaitingForConfig,
     kStateWaitingForPermission,
     kStatePrefetching,
     kStatePlaying,
     kStateStopping,
     kStateWaitingForSurface,
+    kStateWaitingForKey,
+    kStateWaitingForCrypto,

[xhwang, 2015/09/30 18:07:53]

nit: Crypto can mean a lot of things while MediaCrypto is a concrete Android API
object. Can we make it clearer to name this kStateWaitingForMediaCrypto

[Tima Vaisburd, 2015/09/30 23:00:50]

Done.

     kStateWaitingForSeek,
     kStateError,

[xhwang, 2015/09/30 18:07:53]

nit: We still prefer MACRO_STYLE to kConstantNaming style for enums:
https://www.chromium.org/developers/coding-style

[Tima Vaisburd, 2015/09/30 23:00:50]

I found the corresponding line. Thank you.
I have to say though that I have already changed the MACRO_STYLE to kConstStyle
everywhere by one reviewer request. If I have to change everywhere again, let it
be a separate CL.

[xhwang, 2015/10/01 00:04:39]

A separate CL will be great.

   };
 
   enum StartStatus {
     kStartOk = 0,
     kStartBrowserSeekRequired,
+    kStartCryptoRequired,
     kStartFailed,
   };
 
   // Cached values for the manager.
   struct MediaMetadata {
     base::TimeDelta duration;
     gfx::Size video_size;
   };
 
   // Information about current seek in progress.
@@ skipping 21 matching lines @@
 
   // Callback from manager
   void OnPermissionDecided(bool granted);
 
   // Callbacks from decoders
   void RequestDemuxerData(DemuxerStream::Type stream_type);
   void OnPrefetchDone();
   void OnPrerollDone();
   void OnDecoderDrained(DemuxerStream::Type type);
   void OnStopDone(DemuxerStream::Type type);
+  void OnKeyRequired(DemuxerStream::Type type);

[xhwang, 2015/09/30 18:07:54]

nit: OnWaitingForDecryptionKey()?

[Tima Vaisburd, 2015/09/30 23:00:50]

Renamed to OnMissingKeyReported(). As I mentioned before, I feel easily confused
when using "waiting" in a name of an event, tried to make it something that
"happened".

[xhwang, 2015/10/01 00:04:40]

That makes sense. Can we kinda consolidate this name and the variable name
|key_request_posted_|?

[Tima Vaisburd, 2015/10/01 00:51:20]

s/key_request_posted_/missing_key_reported_/

   void OnError();
   void OnStarvation(DemuxerStream::Type stream_type);
   void OnTimeIntervalUpdate(DemuxerStream::Type stream_type,
                             base::TimeDelta now_playing,
                             base::TimeDelta last_buffered,
                             bool postpone);
 
   // Callbacks from video decoder
   void OnVideoCodecCreated();
   void OnVideoResolutionChanged(const gfx::Size& size);
 
+  // Callbacks from DRM

[xhwang, 2015/09/30 18:07:54]

nit: I would s/DRM/CDM :)

[Tima Vaisburd, 2015/09/30 23:00:50]

Done.

Mmm... does CDM stand for Content Decryption Module and DRM for Digital Right
Management?

[xhwang, 2015/10/01 00:04:39]

Yeah. In chromium/EME we don't say DRM. The only reason we have it in some
places is MediaDrm/MediaDrmBridge.

+  void OnMediaCryptoReady(MediaDrmBridge::JavaObjectPtr media_crypto,
+                          bool needs_protected_surface);
+  void OnKeyAdded();
+  void OnCdmUnset();
+
   // Operations called from the state machine.
   void SetState(PlayerState new_state);
   void SetPendingStart(bool need_to_start);
   bool HasPendingStart() const;
   void SetPendingSeek(base::TimeDelta timestamp);
   base::TimeDelta GetPendingSeek() const;
   bool HasVideo() const;
   bool HasAudio() const;
   void SetDemuxerConfigs(const DemuxerConfigs& configs);
   void RequestPlayPermission();
@@ skipping 27 matching lines @@
   scoped_ptr<MediaCodecAudioDecoder> audio_decoder_;
   scoped_ptr<MediaCodecVideoDecoder> video_decoder_;
 
   // The state of the state machine.
   PlayerState state_;
 
   // Notification callbacks, they call MediaPlayerManager.
   base::Closure request_resources_cb_;
   TimeUpdateCallback time_update_cb_;
   base::Closure completion_cb_;
+  base::Closure key_required_cb_;

[xhwang, 2015/09/30 18:07:54]

nit: This is more commonly called |waiting_for_decryption_key_cb|: 

https://code.google.com/p/chromium/codesearch#search/&q=waiting_for_decryptio...

This is also more consistent with the kStateWaitingForKey state.

[Tima Vaisburd, 2015/09/30 23:00:50]

Done.

   SeekDoneCallback seek_done_cb_;
   ErrorCallback error_cb_;
 
   // A callback that updates metadata cache and calls the manager.
   MetadataChangedCallback metadata_changed_cb_;
 
   // We call the base class' AttachListener() and DetachListener() methods on UI
   // thread with these callbacks.
   base::Closure attach_listener_cb_;
   base::Closure detach_listener_cb_;
@@ skipping 22 matching lines @@
 
   // Configuration data for the manager, accessed on the UI thread.
   MediaMetadata metadata_cache_;
 
   // Cached current time, accessed on UI thread.
   base::TimeDelta current_time_cache_;
 
   // For testing only.
   DecodersTimeCallback decoders_time_cb_;
 
+  // DRM
+  MediaDrmBridge::JavaObjectPtr media_crypto_;
+
+  MediaDrmBridge* drm_bridge_;
+  int cdm_registration_id_;
+
+  // The flag is set when the player receives the error from decoder that the
+  // decoder needs a new encryption key. Cleared on starting the playback.

[xhwang, 2015/09/30 18:07:53]

s/encryption/decryption

[Tima Vaisburd, 2015/09/30 23:00:50]

Done.

+  bool key_is_required_;

[xhwang, 2015/09/30 18:07:53]

What's the relation between this and state_ == kStateWaitingForKey?

[Tima Vaisburd, 2015/09/30 21:24:51]

My intention was to set the |key_is_required_| every time we receive a
corresponding error from decoder, but to enter the waiting state during the
restart process (I check it after Prefetch).

+
+  // The flag is set after the new encryption key is added to MediaDrm. Cleared
+  // on starting the playback.
+  bool key_is_added_;
+
   base::WeakPtr<MediaCodecPlayer> media_weak_this_;
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<MediaCodecPlayer> media_weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaCodecPlayer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_ANDROID_MEDIA_CODEC_PLAYER_H_