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_GROUP_H_ 18 19 #define MEDIA_BUFFER_GROUP_H_ 20 21 #include <media/stagefright/MediaBuffer.h> 22 #include <utils/Errors.h> 23 #include <utils/threads.h> 24 25 namespace android { 26 27 class MediaBuffer; 28 class MetaData; 29 30 class MediaBufferGroup : public MediaBufferObserver { 31 public: 32 MediaBufferGroup(size_t growthLimit = 0); 33 34 // create a media buffer group with preallocated buffers 35 MediaBufferGroup(size_t buffers, size_t buffer_size, size_t growthLimit = 0); 36 37 ~MediaBufferGroup(); 38 39 void add_buffer(MediaBuffer *buffer); 40 41 bool has_buffers(); 42 43 // If nonBlocking is false, it blocks until a buffer is available and 44 // passes it to the caller in *buffer, while returning OK. 45 // The returned buffer will have a reference count of 1. 46 // If nonBlocking is true and a buffer is not immediately available, 47 // buffer is set to NULL and it returns WOULD_BLOCK. 48 // If requestedSize is 0, any free MediaBuffer will be returned. 49 // If requestedSize is > 0, the returned MediaBuffer should have buffer 50 // size of at least requstedSize. 51 status_t acquire_buffer( 52 MediaBuffer **buffer, bool nonBlocking = false, size_t requestedSize = 0); 53 buffers()54 size_t buffers() const { return mBuffers.size(); } 55 56 // If buffer is nullptr, have acquire_buffer() check for remote release. 57 virtual void signalBufferReturned(MediaBuffer *buffer); 58 59 private: 60 friend class MediaBuffer; 61 62 Mutex mLock; 63 Condition mCondition; 64 size_t mGrowthLimit; // Do not automatically grow group larger than this. 65 std::list<MediaBuffer *> mBuffers; 66 67 MediaBufferGroup(const MediaBufferGroup &); 68 MediaBufferGroup &operator=(const MediaBufferGroup &); 69 }; 70 71 } // namespace android 72 73 #endif // MEDIA_BUFFER_GROUP_H_ 74