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#include <utils/Vector.h>
26
27namespace android {
28
29class MediaBuffer;
30class MetaData;
31
32struct MediaSource : public virtual RefBase {
33    MediaSource();
34
35    // To be called before any other methods on this object, except
36    // getFormat().
37    virtual status_t start(MetaData *params = NULL) = 0;
38
39    // Any blocking read call returns immediately with a result of NO_INIT.
40    // It is an error to call any methods other than start after this call
41    // returns. Any buffers the object may be holding onto at the time of
42    // the stop() call are released.
43    // Also, it is imperative that any buffers output by this object and
44    // held onto by callers be released before a call to stop() !!!
45    virtual status_t stop() = 0;
46
47    // Returns the format of the data output by this media source.
48    virtual sp<MetaData> getFormat() = 0;
49
50    struct ReadOptions;
51
52    // Returns a new buffer of data. Call blocks until a
53    // buffer is available, an error is encountered of the end of the stream
54    // is reached.
55    // End of stream is signalled by a result of ERROR_END_OF_STREAM.
56    // A result of INFO_FORMAT_CHANGED indicates that the format of this
57    // MediaSource has changed mid-stream, the client can continue reading
58    // but should be prepared for buffers of the new configuration.
59    virtual status_t read(
60            MediaBuffer **buffer, const ReadOptions *options = NULL) = 0;
61
62    // Options that modify read() behaviour. The default is to
63    // a) not request a seek
64    // b) not be late, i.e. lateness_us = 0
65    struct ReadOptions {
66        enum SeekMode {
67            SEEK_PREVIOUS_SYNC,
68            SEEK_NEXT_SYNC,
69            SEEK_CLOSEST_SYNC,
70            SEEK_CLOSEST,
71        };
72
73        ReadOptions();
74
75        // Reset everything back to defaults.
76        void reset();
77
78        void setSeekTo(int64_t time_us, SeekMode mode = SEEK_CLOSEST_SYNC);
79        void clearSeekTo();
80        bool getSeekTo(int64_t *time_us, SeekMode *mode) const;
81
82        void setLateBy(int64_t lateness_us);
83        int64_t getLateBy() const;
84
85        void setNonBlocking();
86        void clearNonBlocking();
87        bool getNonBlocking() const;
88
89    private:
90        enum Options {
91            kSeekTo_Option      = 1,
92        };
93
94        uint32_t mOptions;
95        int64_t mSeekTimeUs;
96        SeekMode mSeekMode;
97        int64_t mLatenessUs;
98        bool mNonBlocking;
99    };
100
101    // Causes this source to suspend pulling data from its upstream source
102    // until a subsequent read-with-seek. Currently only supported by
103    // OMXCodec.
104    virtual status_t pause() {
105        return ERROR_UNSUPPORTED;
106    }
107
108    // The consumer of this media source requests that the given buffers
109    // are to be returned exclusively in response to read calls.
110    // This will be called after a successful start() and before the
111    // first read() call.
112    // Callee assumes ownership of the buffers if no error is returned.
113    virtual status_t setBuffers(const Vector<MediaBuffer *> & /* buffers */) {
114        return ERROR_UNSUPPORTED;
115    }
116
117protected:
118    virtual ~MediaSource();
119
120private:
121    MediaSource(const MediaSource &);
122    MediaSource &operator=(const MediaSource &);
123};
124
125}  // namespace android
126
127#endif  // MEDIA_SOURCE_H_
128