1 /*
2  * Copyright (C) 2009 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef MEDIA_BUFFER_H_
18 
19 #define MEDIA_BUFFER_H_
20 
21 #include <pthread.h>
22 
23 #include <utils/Errors.h>
24 #include <utils/RefBase.h>
25 
26 namespace android {
27 
28 struct ABuffer;
29 class GraphicBuffer;
30 class MediaBuffer;
31 class MediaBufferObserver;
32 class MetaData;
33 
34 class MediaBufferObserver {
35 public:
36     MediaBufferObserver() {}
37     virtual ~MediaBufferObserver() {}
38 
39     virtual void signalBufferReturned(MediaBuffer *buffer) = 0;
40 
41 private:
42     MediaBufferObserver(const MediaBufferObserver &);
43     MediaBufferObserver &operator=(const MediaBufferObserver &);
44 };
45 
46 class MediaBuffer {
47 public:
48     // The underlying data remains the responsibility of the caller!
49     MediaBuffer(void *data, size_t size);
50 
51     MediaBuffer(size_t size);
~OnInfoListener()52 
53     MediaBuffer(const sp<GraphicBuffer>& graphicBuffer);
54 
55     MediaBuffer(const sp<ABuffer> &buffer);
56 
57     // Decrements the reference count and returns the buffer to its
58     // associated MediaBufferGroup if the reference count drops to 0.
59     void release();
60 
61     // Increments the reference count.
62     void add_ref();
63 
64     void *data() const;
65     size_t size() const;
66 
67     size_t range_offset() const;
68     size_t range_length() const;
69 
70     void set_range(size_t offset, size_t length);
71 
72     sp<GraphicBuffer> graphicBuffer() const;
73 
74     sp<MetaData> meta_data();
75 
76     // Clears meta data and resets the range to the full extent.
77     void reset();
78 
79     void setObserver(MediaBufferObserver *group);
80 
81     // Returns a clone of this MediaBuffer increasing its reference count.
82     // The clone references the same data but has its own range and
83     // MetaData.
84     MediaBuffer *clone();
85 
86     int refcount() const;
87 
88 protected:
89     virtual ~MediaBuffer();
90 
91 private:
92     friend class MediaBufferGroup;
93     friend class OMXDecoder;
94 
95     // For use by OMXDecoder, reference count must be 1, drop reference
96     // count to 0 without signalling the observer.
97     void claim();
98 
99     MediaBufferObserver *mObserver;
100     MediaBuffer *mNextBuffer;
101     int mRefCount;
102 
103     void *mData;
104     size_t mSize, mRangeOffset, mRangeLength;
105     sp<GraphicBuffer> mGraphicBuffer;
106     sp<ABuffer> mBuffer;
107 
108     bool mOwnsData;
109 
110     sp<MetaData> mMetaData;
111 
112     MediaBuffer *mOriginal;
113 
114     void setNextBuffer(MediaBuffer *buffer);
115     MediaBuffer *nextBuffer();
116 
117     MediaBuffer(const MediaBuffer &);
118     MediaBuffer &operator=(const MediaBuffer &);
119 };
120 
121 }  // namespace android
122 
123 #endif  // MEDIA_BUFFER_H_
124