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      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 
     31 namespace android {
     32 
     33 struct AMessage;
     34 struct AString;
     35 class  IDataSource;
     36 struct IMediaHTTPService;
     37 class String8;
     38 struct HTTPBase;
     39 
     40 class DataSource : public RefBase {
     41 public:
     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 protected:
    111     virtual ~DataSource() {}
    112 
    113 private:
    114     static Mutex gSnifferMutex;
    115     static List<SnifferFunc> gSniffers;
    116     static bool gSniffersRegistered;
    117 
    118     static void RegisterSniffer_l(SnifferFunc func);
    119 
    120     DataSource(const DataSource &);
    121     DataSource &operator=(const DataSource &);
    122 };
    123 
    124 }  // namespace android
    125 
    126 #endif  // DATA_SOURCE_H_
    127