1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
// Copyright (c) 2012 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_FILTERS_DECRYPTING_AUDIO_DECODER_H_
#define MEDIA_FILTERS_DECRYPTING_AUDIO_DECODER_H_
#include "base/callback.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "media/base/audio_decoder.h"
#include "media/base/decryptor.h"
#include "media/base/demuxer_stream.h"
namespace base {
class SingleThreadTaskRunner;
}
namespace media {
class AudioTimestampHelper;
class DecoderBuffer;
class Decryptor;
class MediaLog;
// Decryptor-based AudioDecoder implementation that can decrypt and decode
// encrypted audio buffers and return decrypted and decompressed audio frames.
// All public APIs and callbacks are trampolined to the |task_runner_| so
// that no locks are required for thread safety.
class MEDIA_EXPORT DecryptingAudioDecoder : public AudioDecoder {
public:
DecryptingAudioDecoder(
const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
const scoped_refptr<MediaLog>& media_log,
const SetDecryptorReadyCB& set_decryptor_ready_cb,
const base::Closure& waiting_for_decryption_key_cb);
~DecryptingAudioDecoder() override;
// AudioDecoder implementation.
std::string GetDisplayName() const override;
void Initialize(const AudioDecoderConfig& config,
const InitCB& init_cb,
const OutputCB& output_cb) override;
void Decode(const scoped_refptr<DecoderBuffer>& buffer,
const DecodeCB& decode_cb) override;
void Reset(const base::Closure& closure) override;
private:
// For a detailed state diagram please see this link: http://goo.gl/8jAok
// TODO(xhwang): Add a ASCII state diagram in this file after this class
// stabilizes.
// TODO(xhwang): Update this diagram for DecryptingAudioDecoder.
enum State {
kUninitialized = 0,
kDecryptorRequested,
kPendingDecoderInit,
kIdle,
kPendingDecode,
kWaitingForKey,
kDecodeFinished,
kError
};
// Callback for DecryptorHost::RequestDecryptor(). |decryptor_attached_cb| is
// called when the decryptor has been completely attached to the pipeline.
void SetDecryptor(Decryptor* decryptor,
const DecryptorAttachedCB& decryptor_attached_cb);
// Initializes the audio decoder on the |decryptor_| with |config_|.
void InitializeDecoder();
// Callback for Decryptor::InitializeAudioDecoder() during initialization.
void FinishInitialization(bool success);
void DecodePendingBuffer();
// Callback for Decryptor::DecryptAndDecodeAudio().
void DeliverFrame(int buffer_size,
Decryptor::Status status,
const Decryptor::AudioFrames& frames);
// Callback for the |decryptor_| to notify this object that a new key has been
// added.
void OnKeyAdded();
// Resets decoder and calls |reset_cb_|.
void DoReset();
// Sets timestamps for |frames| and then passes them to |output_cb_|.
void ProcessDecodedFrames(const Decryptor::AudioFrames& frames);
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
scoped_refptr<MediaLog> media_log_;
State state_;
InitCB init_cb_;
OutputCB output_cb_;
DecodeCB decode_cb_;
base::Closure reset_cb_;
base::Closure waiting_for_decryption_key_cb_;
// The current decoder configuration.
AudioDecoderConfig config_;
// Callback to request/cancel decryptor creation notification.
SetDecryptorReadyCB set_decryptor_ready_cb_;
Decryptor* decryptor_;
// The buffer that needs decrypting/decoding.
scoped_refptr<media::DecoderBuffer> pending_buffer_to_decode_;
// Indicates the situation where new key is added during pending decode
// (in other words, this variable can only be set in state kPendingDecode).
// If this variable is true and kNoKey is returned then we need to try
// decrypting/decoding again in case the newly added key is the correct
// decryption key.
bool key_added_while_decode_pending_;
scoped_ptr<AudioTimestampHelper> timestamp_helper_;
base::WeakPtr<DecryptingAudioDecoder> weak_this_;
base::WeakPtrFactory<DecryptingAudioDecoder> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(DecryptingAudioDecoder);
};
} // namespace media
#endif // MEDIA_FILTERS_DECRYPTING_AUDIO_DECODER_H_
|