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 #include <media/stagefright/foundation/ADebug.h> 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 // Reads in "count" entries of type T into vector *x. 75 // Returns true if "count" entries can be read. 76 // If fewer than "count" entries can be read, return false. In this case, 77 // the output vector *x will still have those entries that were read. Call 78 // x->size() to obtain the number of entries read. 79 // The optional parameter chunkSize specifies how many entries should be 80 // read from the data source at one time into a temporary buffer. Increasing 81 // chunkSize can improve the performance at the cost of extra memory usage. 82 // The default value for chunkSize is set to read at least 4k bytes at a 83 // time, depending on sizeof(T). 84 template <typename T> 85 bool getVector(off64_t offset, Vector<T>* x, size_t count, 86 size_t chunkSize = (4095 / sizeof(T)) + 1); 87 88 // May return ERROR_UNSUPPORTED. 89 virtual status_t getSize(off64_t *size); 90 91 virtual uint32_t flags() { 92 return 0; 93 } 94 95 virtual String8 toString() { 96 return String8("<unspecified>"); 97 } 98 99 virtual status_t reconnectAtOffset(off64_t offset) { 100 return ERROR_UNSUPPORTED; 101 } 102 103 //////////////////////////////////////////////////////////////////////////// 104 105 bool sniff(String8 *mimeType, float *confidence, sp<AMessage> *meta); 106 107 // The sniffer can optionally fill in "meta" with an AMessage containing 108 // a dictionary of values that helps the corresponding extractor initialize 109 // its state without duplicating effort already exerted by the sniffer. 110 typedef bool (*SnifferFunc)( 111 const sp<DataSource> &source, String8 *mimeType, 112 float *confidence, sp<AMessage> *meta); 113 114 static void RegisterDefaultSniffers(); 115 116 // for DRM 117 virtual sp<DecryptHandle> DrmInitialization(const char *mime = NULL) { 118 return NULL; 119 } 120 virtual void getDrmInfo(sp<DecryptHandle> &handle, DrmManagerClient **client) {}; 121 122 virtual String8 getUri() { 123 return String8(); 124 } 125 126 virtual String8 getMIMEType() const; 127 128 virtual void close() {}; 129 130 protected: 131 virtual ~DataSource() {} 132 133 private: 134 static Mutex gSnifferMutex; 135 static List<SnifferFunc> gSniffers; 136 static bool gSniffersRegistered; 137 138 static void RegisterSniffer_l(SnifferFunc func); 139 140 DataSource(const DataSource &); 141 DataSource &operator=(const DataSource &); 142 }; 143 144 template <typename T> 145 bool DataSource::getVector(off64_t offset, Vector<T>* x, size_t count, 146 size_t chunkSize) 147 { 148 x->clear(); 149 if (chunkSize == 0) { 150 return false; 151 } 152 if (count == 0) { 153 return true; 154 } 155 156 T tmp[chunkSize]; 157 ssize_t numBytesRead; 158 size_t numBytesPerChunk = chunkSize * sizeof(T); 159 size_t i; 160 161 for (i = 0; i + chunkSize < count; i += chunkSize) { 162 // This loops is executed when more than chunkSize records need to be 163 // read. 164 numBytesRead = this->readAt(offset, (void*)&tmp, numBytesPerChunk); 165 if (numBytesRead == -1) { // If readAt() returns -1, there is an error. 166 return false; 167 } 168 if (numBytesRead < numBytesPerChunk) { 169 // This case is triggered when the stream ends before the whole 170 // chunk is read. 171 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T)); 172 return false; 173 } 174 x->appendArray(tmp, chunkSize); 175 offset += numBytesPerChunk; 176 } 177 178 // There are (count - i) more records to read. 179 // Right now, (count - i) <= chunkSize. 180 // We do the same thing as above, but with chunkSize replaced by count - i. 181 numBytesRead = this->readAt(offset, (void*)&tmp, (count - i) * sizeof(T)); 182 if (numBytesRead == -1) { 183 return false; 184 } 185 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T)); 186 return x->size() == count; 187 } 188 189 } // namespace android 190 191 #endif // DATA_SOURCE_H_ 192
