MediaBuffer.h revision 96e92b58b7e9647b4c7c2f54b62a1b357ab06b66 
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 <media/stagefright/foundation/MediaBufferBase.h>
22
23#include <pthread.h>
24
25#include <utils/Errors.h>
26#include <utils/RefBase.h>
27
28namespace android {
29
30struct ABuffer;
31class GraphicBuffer;
32class MediaBuffer;
33class MediaBufferObserver;
34class MetaData;
35
36class MediaBufferObserver {
37public:
38    MediaBufferObserver() {}
39    virtual ~MediaBufferObserver() {}
40
41    virtual void signalBufferReturned(MediaBuffer *buffer) = 0;
42
43private:
44    MediaBufferObserver(const MediaBufferObserver &);
45    MediaBufferObserver &operator=(const MediaBufferObserver &);
46};
47
48class MediaBuffer : public MediaBufferBase {
49public:
50    // The underlying data remains the responsibility of the caller!
51    MediaBuffer(void *data, size_t size);
52
53    MediaBuffer(size_t size);
54
55    MediaBuffer(const sp<GraphicBuffer>& graphicBuffer);
56
57    MediaBuffer(const sp<ABuffer> &buffer);
58
59    // Decrements the reference count and returns the buffer to its
60    // associated MediaBufferGroup if the reference count drops to 0.
61    virtual void release();
62
63    // Increments the reference count.
64    virtual void add_ref();
65
66    void *data() const;
67    size_t size() const;
68
69    size_t range_offset() const;
70    size_t range_length() const;
71
72    void set_range(size_t offset, size_t length);
73
74    sp<GraphicBuffer> graphicBuffer() const;
75
76    sp<MetaData> meta_data();
77
78    // Clears meta data and resets the range to the full extent.
79    void reset();
80
81    void setObserver(MediaBufferObserver *group);
82
83    // Returns a clone of this MediaBuffer increasing its reference count.
84    // The clone references the same data but has its own range and
85    // MetaData.
86    MediaBuffer *clone();
87
88    int refcount() const;
89
90protected:
91    virtual ~MediaBuffer();
92
93private:
94    friend class MediaBufferGroup;
95    friend class OMXDecoder;
96
97    // For use by OMXDecoder, reference count must be 1, drop reference
98    // count to 0 without signalling the observer.
99    void claim();
100
101    MediaBufferObserver *mObserver;
102    MediaBuffer *mNextBuffer;
103    int mRefCount;
104
105    void *mData;
106    size_t mSize, mRangeOffset, mRangeLength;
107    sp<GraphicBuffer> mGraphicBuffer;
108    sp<ABuffer> mBuffer;
109
110    bool mOwnsData;
111
112    sp<MetaData> mMetaData;
113
114    MediaBuffer *mOriginal;
115
116    void setNextBuffer(MediaBuffer *buffer);
117    MediaBuffer *nextBuffer();
118
119    MediaBuffer(const MediaBuffer &);
120    MediaBuffer &operator=(const MediaBuffer &);
121};
122
123}  // namespace android
124
125#endif  // MEDIA_BUFFER_H_
126