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      1 /*
      2  * Copyright (C) 2018 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_BASE_H_
     18 
     19 #define MEDIA_SOURCE_BASE_H_
     20 
     21 #include <sys/types.h>
     22 
     23 #include <binder/IMemory.h>
     24 #include <binder/MemoryDealer.h>
     25 #include <media/stagefright/MediaErrors.h>
     26 #include <media/stagefright/MetaData.h>
     27 #include <utils/Log.h>
     28 #include <utils/RefBase.h>
     29 #include <utils/Vector.h>
     30 
     31 namespace android {
     32 
     33 class MediaBufferBase;
     34 
     35 class SourceBaseAllocTracker {
     36 public:
     37     SourceBaseAllocTracker() {
     38         ALOGD("sourcebase allocated: %p", this);
     39     }
     40     virtual ~SourceBaseAllocTracker() {
     41         ALOGD("sourcebase freed: %p", this);
     42     }
     43 };
     44 
     45 struct MediaTrack
     46 //    : public SourceBaseAllocTracker
     47 {
     48     MediaTrack();
     49 
     50     // To be called before any other methods on this object, except
     51     // getFormat().
     52     virtual status_t start(MetaDataBase *params = NULL) = 0;
     53 
     54     // Any blocking read call returns immediately with a result of NO_INIT.
     55     // It is an error to call any methods other than start after this call
     56     // returns. Any buffers the object may be holding onto at the time of
     57     // the stop() call are released.
     58     // Also, it is imperative that any buffers output by this object and
     59     // held onto by callers be released before a call to stop() !!!
     60     virtual status_t stop() = 0;
     61 
     62     // Returns the format of the data output by this media track.
     63     virtual status_t getFormat(MetaDataBase& format) = 0;
     64 
     65     // Options that modify read() behaviour. The default is to
     66     // a) not request a seek
     67     // b) not be late, i.e. lateness_us = 0
     68     struct ReadOptions {
     69         enum SeekMode : int32_t {
     70             SEEK_PREVIOUS_SYNC,
     71             SEEK_NEXT_SYNC,
     72             SEEK_CLOSEST_SYNC,
     73             SEEK_CLOSEST,
     74             SEEK_FRAME_INDEX,
     75         };
     76 
     77         ReadOptions();
     78 
     79         // Reset everything back to defaults.
     80         void reset();
     81 
     82         void setSeekTo(int64_t time_us, SeekMode mode = SEEK_CLOSEST_SYNC);
     83         void clearSeekTo();
     84         bool getSeekTo(int64_t *time_us, SeekMode *mode) const;
     85 
     86         void setNonBlocking();
     87         void clearNonBlocking();
     88         bool getNonBlocking() const;
     89 
     90         // Used to clear all non-persistent options for multiple buffer reads.
     91         void clearNonPersistent() {
     92             clearSeekTo();
     93         }
     94 
     95     private:
     96         enum Options {
     97             kSeekTo_Option      = 1,
     98         };
     99 
    100         uint32_t mOptions;
    101         int64_t mSeekTimeUs;
    102         SeekMode mSeekMode;
    103         bool mNonBlocking;
    104     } __attribute__((packed)); // sent through Binder
    105 
    106     // Returns a new buffer of data. Call blocks until a
    107     // buffer is available, an error is encountered of the end of the stream
    108     // is reached.
    109     // End of stream is signalled by a result of ERROR_END_OF_STREAM.
    110     // A result of INFO_FORMAT_CHANGED indicates that the format of this
    111     // MediaSource has changed mid-stream, the client can continue reading
    112     // but should be prepared for buffers of the new configuration.
    113     virtual status_t read(
    114             MediaBufferBase **buffer, const ReadOptions *options = NULL) = 0;
    115 
    116     virtual ~MediaTrack();
    117 
    118 private:
    119     MediaTrack(const MediaTrack &);
    120     MediaTrack &operator=(const MediaTrack &);
    121 };
    122 
    123 }  // namespace android
    124 
    125 #endif  // MEDIA_SOURCE_BASE_H_
    126