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      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);
     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