1 /* 2 3 * Copyright (C) 2009 The Android Open Source Project 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 #ifndef MEDIA_SOURCE_H_ 19 20 #define MEDIA_SOURCE_H_ 21 22 #include <sys/types.h> 23 24 #include <media/stagefright/MediaErrors.h> 25 #include <media/stagefright/MetaData.h> 26 #include <utils/RefBase.h> 27 28 #include <media/MediaTrack.h> 29 30 namespace android { 31 32 class MediaBuffer; 33 34 struct MediaSource : public virtual RefBase { 35 MediaSource(); 36 37 // To be called before any other methods on this object, except 38 // getFormat(). 39 virtual status_t start(MetaData *params = NULL) = 0; 40 41 // Any blocking read call returns immediately with a result of NO_INIT. 42 // It is an error to call any methods other than start after this call 43 // returns. Any buffers the object may be holding onto at the time of 44 // the stop() call are released. 45 // Also, it is imperative that any buffers output by this object and 46 // held onto by callers be released before a call to stop() !!! 47 virtual status_t stop() = 0; 48 49 // Returns the format of the data output by this media source. 50 virtual sp<MetaData> getFormat() = 0; 51 52 // Options that modify read() behaviour. The default is to 53 // a) not request a seek 54 // b) not be late, i.e. lateness_us = 0 55 typedef MediaTrack::ReadOptions ReadOptions; 56 57 // Returns a new buffer of data. Call blocks until a 58 // buffer is available, an error is encountered of the end of the stream 59 // is reached. 60 // End of stream is signalled by a result of ERROR_END_OF_STREAM. 61 // A result of INFO_FORMAT_CHANGED indicates that the format of this 62 // MediaSource has changed mid-stream, the client can continue reading 63 // but should be prepared for buffers of the new configuration. 64 virtual status_t read( 65 MediaBufferBase **buffer, const ReadOptions *options = NULL) = 0; 66 67 // Causes this source to suspend pulling data from its upstream source 68 // until a subsequent read-with-seek. This is currently not supported 69 // as such by any source. E.g. MediaCodecSource does not suspend its 70 // upstream source, and instead discard upstream data while paused. 71 virtual status_t pause() { 72 return ERROR_UNSUPPORTED; 73 } 74 75 // The consumer of this media source requests the source stops sending 76 // buffers with timestamp larger than or equal to stopTimeUs. stopTimeUs 77 // must be in the same time base as the startTime passed in start(). If 78 // source does not support this request, ERROR_UNSUPPORTED will be returned. 79 // If stopTimeUs is invalid, BAD_VALUE will be returned. This could be 80 // called at any time even before source starts and it could be called 81 // multiple times. Setting stopTimeUs to be -1 will effectively cancel the stopTimeUs 82 // set previously. If stopTimeUs is larger than or equal to last buffer's timestamp, 83 // source will start to drop buffer when it gets a buffer with timestamp larger 84 // than or equal to stopTimeUs. If stopTimeUs is smaller than or equal to last 85 // buffer's timestamp, source will drop all the incoming buffers immediately. 86 // After setting stopTimeUs, source may still stop sending buffers with timestamp 87 // less than stopTimeUs if it is stopped by the consumer. 88 virtual status_t setStopTimeUs(int64_t /* stopTimeUs */) { 89 return ERROR_UNSUPPORTED; 90 } 91 92 protected: 93 virtual ~MediaSource(); 94 95 private: 96 MediaSource(const MediaSource &); 97 MediaSource &operator=(const MediaSource &); 98 }; 99 100 } // namespace android 101 102 #endif // MEDIA_SOURCE_H_ 103
