MediaSource.h revision d35bd5fb4e09c2cd8608497c279cbb2ef9c3a029
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_SOURCE_H_ 18 19#define MEDIA_SOURCE_H_ 20 21#include <sys/types.h> 22 23#include <media/stagefright/MediaErrors.h> 24#include <utils/RefBase.h> 25 26namespace android { 27 28class MediaBuffer; 29class MetaData; 30 31struct MediaSource : public RefBase { 32 MediaSource(); 33 34 // To be called before any other methods on this object, except 35 // getFormat(). 36 virtual status_t start(MetaData *params = NULL) = 0; 37 38 // Any blocking read call returns immediately with a result of NO_INIT. 39 // It is an error to call any methods other than start after this call 40 // returns. Any buffers the object may be holding onto at the time of 41 // the stop() call are released. 42 // Also, it is imperative that any buffers output by this object and 43 // held onto by callers be released before a call to stop() !!! 44 virtual status_t stop() = 0; 45 46 // Returns the format of the data output by this media source. 47 virtual sp<MetaData> getFormat() = 0; 48 49 struct ReadOptions; 50 51 // Returns a new buffer of data. Call blocks until a 52 // buffer is available, an error is encountered of the end of the stream 53 // is reached. 54 // End of stream is signalled by a result of ERROR_END_OF_STREAM. 55 // A result of INFO_FORMAT_CHANGED indicates that the format of this 56 // MediaSource has changed mid-stream, the client can continue reading 57 // but should be prepared for buffers of the new configuration. 58 virtual status_t read( 59 MediaBuffer **buffer, const ReadOptions *options = NULL) = 0; 60 61 // Options that modify read() behaviour. The default is to 62 // a) not request a seek 63 // b) not be late, i.e. lateness_us = 0 64 struct ReadOptions { 65 ReadOptions(); 66 67 // Reset everything back to defaults. 68 void reset(); 69 70 void setSeekTo(int64_t time_us); 71 void clearSeekTo(); 72 bool getSeekTo(int64_t *time_us) const; 73 74 void setLateBy(int64_t lateness_us); 75 int64_t getLateBy() const; 76 77 private: 78 enum Options { 79 kSeekTo_Option = 1, 80 }; 81 82 uint32_t mOptions; 83 int64_t mSeekTimeUs; 84 int64_t mLatenessUs; 85 }; 86 87 // Causes this source to suspend pulling data from its upstream source 88 // until a subsequent read-with-seek. Currently only supported by 89 // OMXCodec. 90 virtual status_t pause() { 91 return ERROR_UNSUPPORTED; 92 } 93 94protected: 95 virtual ~MediaSource(); 96 97private: 98 MediaSource(const MediaSource &); 99 MediaSource &operator=(const MediaSource &); 100}; 101 102} // namespace android 103 104#endif // MEDIA_SOURCE_H_ 105