1 // Copyright (c) 2012 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.
5 #ifndef MEDIA_FILTERS_DECRYPTING_AUDIO_DECODER_H_
6 #define MEDIA_FILTERS_DECRYPTING_AUDIO_DECODER_H_
8 #include "base/callback.h"
9 #include "base/memory/ref_counted.h"
10 #include "base/memory/scoped_ptr.h"
11 #include "base/memory/weak_ptr.h"
12 #include "base/time/time.h"
13 #include "media/base/audio_decoder.h"
14 #include "media/base/decryptor.h"
15 #include "media/base/demuxer_stream.h"
18 class SingleThreadTaskRunner;
23 class AudioTimestampHelper;
27 // Decryptor-based AudioDecoder implementation that can decrypt and decode
28 // encrypted audio buffers and return decrypted and decompressed audio frames.
29 // All public APIs and callbacks are trampolined to the |task_runner_| so
30 // that no locks are required for thread safety.
31 class MEDIA_EXPORT DecryptingAudioDecoder : public AudioDecoder {
33 // We do not currently have a way to let the Decryptor choose the output
34 // audio sample format and notify us of its choice. Therefore, we require all
35 // Decryptor implementations to decode audio into a fixed integer sample
36 // format designated by kSupportedBitsPerChannel.
37 // TODO(xhwang): Remove this restriction after http://crbug.com/169105 fixed.
38 static const int kSupportedBitsPerChannel;
40 DecryptingAudioDecoder(
41 const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
42 const SetDecryptorReadyCB& set_decryptor_ready_cb);
43 virtual ~DecryptingAudioDecoder();
45 // AudioDecoder implementation.
46 virtual std::string GetDisplayName() const OVERRIDE;
47 virtual void Initialize(const AudioDecoderConfig& config,
48 const PipelineStatusCB& status_cb,
49 const OutputCB& output_cb) OVERRIDE;
50 virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
51 const DecodeCB& decode_cb) OVERRIDE;
52 virtual void Reset(const base::Closure& closure) OVERRIDE;
55 // For a detailed state diagram please see this link: http://goo.gl/8jAok
56 // TODO(xhwang): Add a ASCII state diagram in this file after this class
58 // TODO(xhwang): Update this diagram for DecryptingAudioDecoder.
70 // Callback for DecryptorHost::RequestDecryptor(). |decryptor_attached_cb| is
71 // called when the decryptor has been completely attached to the pipeline.
72 void SetDecryptor(Decryptor* decryptor,
73 const DecryptorAttachedCB& decryptor_attached_cb);
75 // Initializes the audio decoder on the |decryptor_| with |config_|.
76 void InitializeDecoder();
78 // Callback for Decryptor::InitializeAudioDecoder() during initialization.
79 void FinishInitialization(bool success);
81 void DecodePendingBuffer();
83 // Callback for Decryptor::DecryptAndDecodeAudio().
84 void DeliverFrame(int buffer_size,
85 Decryptor::Status status,
86 const Decryptor::AudioBuffers& frames);
88 // Callback for the |decryptor_| to notify this object that a new key has been
92 // Resets decoder and calls |reset_cb_|.
95 // Sets timestamps for |frames| and then passes them to |output_cb_|.
96 void ProcessDecodedFrames(const Decryptor::AudioBuffers& frames);
98 scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
102 PipelineStatusCB init_cb_;
105 base::Closure reset_cb_;
107 // The current decoder configuration.
108 AudioDecoderConfig config_;
110 // Callback to request/cancel decryptor creation notification.
111 SetDecryptorReadyCB set_decryptor_ready_cb_;
113 Decryptor* decryptor_;
115 // The buffer that needs decrypting/decoding.
116 scoped_refptr<media::DecoderBuffer> pending_buffer_to_decode_;
118 // Indicates the situation where new key is added during pending decode
119 // (in other words, this variable can only be set in state kPendingDecode).
120 // If this variable is true and kNoKey is returned then we need to try
121 // decrypting/decoding again in case the newly added key is the correct
123 bool key_added_while_decode_pending_;
125 scoped_ptr<AudioTimestampHelper> timestamp_helper_;
127 // NOTE: Weak pointers must be invalidated before all other member variables.
128 base::WeakPtrFactory<DecryptingAudioDecoder> weak_factory_;
129 base::WeakPtr<DecryptingAudioDecoder> weak_this_;
131 DISALLOW_COPY_AND_ASSIGN(DecryptingAudioDecoder);
136 #endif // MEDIA_FILTERS_DECRYPTING_AUDIO_DECODER_H_