DataSource.h revision fbe7fcfe818b6f68e352c7c450d4fe15a543b801 
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 DATA_SOURCE_H_
18
19#define DATA_SOURCE_H_
20
21#include <sys/types.h>
22
23#include <media/stagefright/MediaErrors.h>
24#include <utils/Errors.h>
25#include <utils/KeyedVector.h>
26#include <utils/List.h>
27#include <utils/RefBase.h>
28#include <utils/threads.h>
29#include <drm/DrmManagerClient.h>
30
31namespace android {
32
33struct AMessage;
34struct AString;
35class  IDataSource;
36struct IMediaHTTPService;
37class String8;
38struct HTTPBase;
39
40class DataSource : public RefBase {
41public:
42    enum Flags {
43        kWantsPrefetching      = 1,
44        kStreamedFromLocalHost = 2,
45        kIsCachingDataSource   = 4,
46        kIsHTTPBasedSource     = 8,
47    };
48
49    static sp<DataSource> CreateFromURI(
50            const sp<IMediaHTTPService> &httpService,
51            const char *uri,
52            const KeyedVector<String8, String8> *headers = NULL,
53            String8 *contentType = NULL,
54            HTTPBase *httpSource = NULL);
55
56    static sp<DataSource> CreateMediaHTTP(const sp<IMediaHTTPService> &httpService);
57    static sp<DataSource> CreateFromIDataSource(const sp<IDataSource> &source);
58
59    DataSource() {}
60
61    virtual status_t initCheck() const = 0;
62
63    // Returns the number of bytes read, or -1 on failure. It's not an error if
64    // this returns zero; it just means the given offset is equal to, or
65    // beyond, the end of the source.
66    virtual ssize_t readAt(off64_t offset, void *data, size_t size) = 0;
67
68    // Convenience methods:
69    bool getUInt16(off64_t offset, uint16_t *x);
70    bool getUInt24(off64_t offset, uint32_t *x); // 3 byte int, returned as a 32-bit int
71    bool getUInt32(off64_t offset, uint32_t *x);
72    bool getUInt64(off64_t offset, uint64_t *x);
73
74    // May return ERROR_UNSUPPORTED.
75    virtual status_t getSize(off64_t *size);
76
77    virtual uint32_t flags() {
78        return 0;
79    }
80
81    virtual status_t reconnectAtOffset(off64_t offset) {
82        return ERROR_UNSUPPORTED;
83    }
84
85    ////////////////////////////////////////////////////////////////////////////
86
87    bool sniff(String8 *mimeType, float *confidence, sp<AMessage> *meta);
88
89    // The sniffer can optionally fill in "meta" with an AMessage containing
90    // a dictionary of values that helps the corresponding extractor initialize
91    // its state without duplicating effort already exerted by the sniffer.
92    typedef bool (*SnifferFunc)(
93            const sp<DataSource> &source, String8 *mimeType,
94            float *confidence, sp<AMessage> *meta);
95
96    static void RegisterDefaultSniffers();
97
98    // for DRM
99    virtual sp<DecryptHandle> DrmInitialization(const char *mime = NULL) {
100        return NULL;
101    }
102    virtual void getDrmInfo(sp<DecryptHandle> &handle, DrmManagerClient **client) {};
103
104    virtual String8 getUri() {
105        return String8();
106    }
107
108    virtual String8 getMIMEType() const;
109
110    virtual void close() {};
111
112protected:
113    virtual ~DataSource() {}
114
115private:
116    static Mutex gSnifferMutex;
117    static List<SnifferFunc> gSniffers;
118    static bool gSniffersRegistered;
119
120    static void RegisterSniffer_l(SnifferFunc func);
121
122    DataSource(const DataSource &);
123    DataSource &operator=(const DataSource &);
124};
125
126}  // namespace android
127
128#endif  // DATA_SOURCE_H_
129