DataSource.h revision 377fce69297a0e5b7c3b266a7602b17146785635 
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;
34class String8;
35
36class DataSource : public RefBase {
37public:
38    enum Flags {
39        kWantsPrefetching      = 1,
40        kStreamedFromLocalHost = 2,
41        kIsCachingDataSource   = 4,
42        kIsHTTPBasedSource     = 8,
43    };
44
45    static sp<DataSource> CreateFromURI(
46            const char *uri,
47            const KeyedVector<String8, String8> *headers = NULL);
48
49    DataSource() {}
50
51    virtual status_t initCheck() const = 0;
52
53    virtual ssize_t readAt(off64_t offset, void *data, size_t size) = 0;
54
55    // Convenience methods:
56    bool getUInt16(off64_t offset, uint16_t *x);
57    bool getUInt24(off64_t offset, uint32_t *x); // 3 byte int, returned as a 32-bit int
58    bool getUInt32(off64_t offset, uint32_t *x);
59    bool getUInt64(off64_t offset, uint64_t *x);
60
61    // May return ERROR_UNSUPPORTED.
62    virtual status_t getSize(off64_t *size);
63
64    virtual uint32_t flags() {
65        return 0;
66    }
67
68    virtual status_t reconnectAtOffset(off64_t offset) {
69        return ERROR_UNSUPPORTED;
70    }
71
72    ////////////////////////////////////////////////////////////////////////////
73
74    bool sniff(String8 *mimeType, float *confidence, sp<AMessage> *meta);
75
76    // The sniffer can optionally fill in "meta" with an AMessage containing
77    // a dictionary of values that helps the corresponding extractor initialize
78    // its state without duplicating effort already exerted by the sniffer.
79    typedef bool (*SnifferFunc)(
80            const sp<DataSource> &source, String8 *mimeType,
81            float *confidence, sp<AMessage> *meta);
82
83    static void RegisterDefaultSniffers();
84
85    // for DRM
86    virtual sp<DecryptHandle> DrmInitialization(const char *mime = NULL) {
87        return NULL;
88    }
89    virtual void getDrmInfo(sp<DecryptHandle> &handle, DrmManagerClient **client) {};
90
91    virtual String8 getUri() {
92        return String8();
93    }
94
95    virtual String8 getMIMEType() const;
96
97protected:
98    virtual ~DataSource() {}
99
100private:
101    static Mutex gSnifferMutex;
102    static List<SnifferFunc> gSniffers;
103    static bool gSniffersRegistered;
104
105    static void RegisterSniffer_l(SnifferFunc func);
106
107    DataSource(const DataSource &);
108    DataSource &operator=(const DataSource &);
109};
110
111}  // namespace android
112
113#endif  // DATA_SOURCE_H_
114