Emeric Vigier | 2f62582 | 2012-08-06 11:09:52 -0400 | [diff] [blame] | 1 | // Copyright (C) 2001,2002,2004 Federico Montesino Pouzols <fedemp@altern.org>. |
| 2 | // |
| 3 | // This program is free software; you can redistribute it and/or modify |
| 4 | // it under the terms of the GNU General Public License as published by |
| 5 | // the Free Software Foundation; either version 2 of the License, or |
| 6 | // (at your option) any later version. |
| 7 | // |
| 8 | // This program is distributed in the hope that it will be useful, |
| 9 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | // GNU General Public License for more details. |
| 12 | // |
| 13 | // You should have received a copy of the GNU General Public License |
| 14 | // along with this program; if not, write to the Free Software |
| 15 | // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 16 | // |
| 17 | // As a special exception, you may use this file as part of a free software |
| 18 | // library without restriction. Specifically, if other files instantiate |
| 19 | // templates or use macros or inline functions from this file, or you compile |
| 20 | // this file and link it with other files to produce an executable, this |
| 21 | // file does not by itself cause the resulting executable to be covered by |
| 22 | // the GNU General Public License. This exception does not however |
| 23 | // invalidate any other reasons why the executable file might be covered by |
| 24 | // the GNU General Public License. |
| 25 | // |
| 26 | // This exception applies only to the code released under the name GNU |
| 27 | // ccRTP. If you copy code from other releases into a copy of GNU |
| 28 | // ccRTP, as the General Public License permits, the exception does |
| 29 | // not apply to the code that you add in this way. To avoid misleading |
| 30 | // anyone as to the status of such modified files, you must delete |
| 31 | // this exception notice from them. |
| 32 | // |
| 33 | // If you write modifications of your own for GNU ccRTP, it is your choice |
| 34 | // whether to permit this exception to apply to your modifications. |
| 35 | // If you do not wish that, delete this exception notice. |
| 36 | // |
| 37 | |
| 38 | /** |
| 39 | * @file ioqueue.h |
| 40 | * |
| 41 | * @short Generic RTP input/output queues. |
| 42 | **/ |
| 43 | |
| 44 | #ifndef CCXX_RTP_IOQUEUE_H_ |
| 45 | #define CCXX_RTP_IOQUEUE_H_ |
| 46 | |
| 47 | #include <ccrtp/iqueue.h> |
| 48 | #include <ccrtp/oqueue.h> |
| 49 | |
| 50 | #ifdef CCXX_NAMESPACES |
| 51 | namespace ost { |
| 52 | #endif |
| 53 | |
| 54 | /** |
| 55 | * @defgroup ioqueue Generic RTP input/output queues. |
| 56 | * @{ |
| 57 | **/ |
| 58 | |
| 59 | /** |
| 60 | * @class RTPDataQueue |
| 61 | * |
| 62 | * A packet queue handler for building different kinds of RTP protocol |
| 63 | * systems. The queue manages both incoming and outgoing RTP packets, |
| 64 | * as well as synchronization and transmission/reception timers. By |
| 65 | * making the queue handler a seperate base class it becomes possible |
| 66 | * to define RTP classes for RTP profiles and sessions of different |
| 67 | * types. |
| 68 | * |
| 69 | * Outgoing packets are sent via the OutgoingDataQueue::putData method. |
| 70 | * |
| 71 | * Incoming packets can be retrieved via IncomingDataQueue::getData |
| 72 | * method. |
| 73 | * |
| 74 | * @author David Sugar <dyfet@ostel.com> |
| 75 | * @short RTP data queue handler. |
| 76 | */ |
| 77 | class __EXPORT RTPDataQueue : |
| 78 | public IncomingDataQueue, |
| 79 | public OutgoingDataQueue |
| 80 | { |
| 81 | public: |
| 82 | /** |
| 83 | * @enum Tos rtp.h cc++/rtp.h |
| 84 | * @short Type of network service the application uses. |
| 85 | * |
| 86 | * If the application uses enhanced network service, for |
| 87 | * instance Integrated Services or Differentiated Services, it |
| 88 | * <em>has not</em> to ensure fair competition with TCP, |
| 89 | * provided that the requested service is actually being |
| 90 | * delivered. Whenever the application uses best-effort |
| 91 | * service or the requested enhanced service is not actually |
| 92 | * being delivered, it <em>has</em> to ensure fair competition |
| 93 | * with TCP. By default, best-effot is assumed. |
| 94 | * |
| 95 | * @note Although not required, RTP packets are always sent on |
| 96 | * top of UDP segments. No other underlying transport protocol |
| 97 | * is supported at present. |
| 98 | * |
| 99 | * @todo implement fair competition with tcp |
| 100 | **/ |
| 101 | typedef enum { |
| 102 | tosBestEffort, ///< Best-effort network service |
| 103 | tosEnhanced ///< Enhanced network service |
| 104 | } Tos; |
| 105 | |
| 106 | /** |
| 107 | * Specify the kind of service the application expects to use. |
| 108 | * |
| 109 | * @param tos type of service the application expects to use |
| 110 | * |
| 111 | * @note If enhanced service is specified but packet loss is |
| 112 | * high (the requested service does not appear to actually be |
| 113 | * delivered) ccRTP defaults to best-effort suitable |
| 114 | * behaviour: guarantee fair competition with TCP. |
| 115 | * |
| 116 | * @todo Implement fair competition with tcp |
| 117 | **/ |
| 118 | inline void |
| 119 | setTypeOfService(Tos tos) |
| 120 | { typeOfService = tos; } |
| 121 | |
| 122 | /** |
| 123 | * Enable packet queue processing in the stack. This method |
| 124 | * will not any thread of execution. |
| 125 | **/ |
| 126 | inline void enableStack() |
| 127 | { dataServiceActive = true; } |
| 128 | |
| 129 | /** |
| 130 | * Disable packet queue processing in the stack. |
| 131 | **/ |
| 132 | inline void disableStack() |
| 133 | { dataServiceActive = false; } |
| 134 | |
| 135 | /** |
| 136 | * Get active connection state flag. |
| 137 | * |
| 138 | * @return true if connection "active". |
| 139 | */ |
| 140 | inline bool |
| 141 | isActive() const |
| 142 | { return dataServiceActive; } |
| 143 | |
| 144 | /** |
| 145 | * Get the timestamp that should be given for a packet whose |
| 146 | * payload sampling instant corresponds to the current system |
| 147 | * time. |
| 148 | * |
| 149 | * The timestamp applications should provide for each packet |
| 150 | * represents the sampling instant of its payload and should |
| 151 | * not be a reading of the system clock. Nevertheless, the |
| 152 | * internal operation of the RTP stack relies on the accuracy |
| 153 | * of the provided timestamp, since several computations |
| 154 | * assume that there is a certain degree of correspondence |
| 155 | * between the timestamp and the system clock. |
| 156 | * |
| 157 | * It is recommended that applications use this method in |
| 158 | * order to <em>periodically adjust the RTP timestamp</em>. |
| 159 | * |
| 160 | * In particular, it is advisable getting the timestamp |
| 161 | * corresponding to the first sampling instant or any instant |
| 162 | * after a period of inactivity through a call to this method. |
| 163 | * |
| 164 | * Applications should use the nominal sampling or |
| 165 | * any other value provided by the coder in order to compute |
| 166 | * the next timestamps with minimum computational requirement. |
| 167 | * |
| 168 | * For instance, an application using an RTP profile that |
| 169 | * specifies a fixed sampling rate of 8 Khz with eight bits |
| 170 | * per sample, continuously transmitting audio blocks 80 |
| 171 | * octets long, would transmit 100 packets every |
| 172 | * second. Every packet would carry a timestamp 80 units |
| 173 | * greater than the previous one. So, the first timestamp |
| 174 | * would be obtained from this method, whereas the following |
| 175 | * ones would be computed adding 80 every time. Also the |
| 176 | * timestamp should be increased for every block whether |
| 177 | * it is put in the queue or dropped. |
| 178 | * |
| 179 | * The aforementioned increment can be obtained from the |
| 180 | * RTPDataQueue::getTimestampIncrement() method rather than |
| 181 | * computing it by hand in the application. |
| 182 | * |
| 183 | * @note Frame based applications must follow a specific |
| 184 | * timestamping method, probably specified in a profile. |
| 185 | * |
| 186 | * @note You should take into account that by default ccRTP |
| 187 | * assumes that the application begins sampling at the queue |
| 188 | * creation time. Moreover, the first sampling instant is |
| 189 | * assigned a "user visible" timestamp of 0, although the RTP |
| 190 | * stack will then add internally a ramdom offset unknown to |
| 191 | * the application. That is to say, the application may count |
| 192 | * samples from 0 in order to get the timestamp for the next |
| 193 | * packet, provided that the first sampling instant is the |
| 194 | * same as the queue creation time. Nevertheless, this |
| 195 | * simpler way of starting will not be as accurate as it would |
| 196 | * be if the application got at least the first timestamp |
| 197 | * through getCurrentTimestamp. <em>We provide this option |
| 198 | * since ccRTP interface is evolving, but we admit that it is |
| 199 | * ugly, we could remove this option or even replace uint32 |
| 200 | * timestamps with a restrictively regulated object; |
| 201 | * suggestions are gladly welcomed</em> |
| 202 | **/ |
| 203 | uint32 |
| 204 | getCurrentTimestamp() const; |
| 205 | |
| 206 | /** |
| 207 | * Specify the bandwidth of the current session. |
| 208 | * |
| 209 | * @param bw bandwidth of the current session, in bits/s. |
| 210 | * |
| 211 | * @see AVPQueue::setControlBandwidth() |
| 212 | */ |
| 213 | void |
| 214 | setSessionBandwidth(uint32 bw) |
| 215 | { sessionBw = bw; } |
| 216 | |
| 217 | uint32 |
| 218 | getDefaultSessionBandwidth() const |
| 219 | { return defaultSessionBw; } |
| 220 | |
| 221 | uint32 |
| 222 | getSessionBandwidth() const |
| 223 | { return sessionBw; } |
| 224 | |
| 225 | /** |
| 226 | * Set the packet timeclock for synchronizing timestamps. |
| 227 | **/ |
| 228 | inline void |
| 229 | setTimeclock() |
| 230 | { timeclock.setTimer(); } |
| 231 | |
| 232 | /** |
| 233 | * Get the packet timeclock for synchronizing timestamps. |
| 234 | * |
| 235 | * @return runtime in milliseconds since last set. |
| 236 | */ |
| 237 | inline timeout_t |
| 238 | getTimeclock() const |
| 239 | { return timeclock.getElapsed(); } |
| 240 | |
| 241 | protected: |
| 242 | |
| 243 | /** |
| 244 | * Constructor. This will generate a random application SSRC |
| 245 | * identifier. |
| 246 | * |
| 247 | * @param size an estimation of the number of participants in |
| 248 | * the session |
| 249 | **/ |
| 250 | RTPDataQueue(uint32 size = defaultMembersHashSize); |
| 251 | |
| 252 | /** |
| 253 | * Using this constructor you can start a session with the |
| 254 | * given ssrc, instead of the usual randomly generated |
| 255 | * one. This is necessary when you need to initiate several |
| 256 | * sessions having the same SSRC identifier, for instance, to |
| 257 | * implement layered encoding, in which case each layer is |
| 258 | * managed through a different session but all sessions share |
| 259 | * the same SSRC identifier. |
| 260 | * |
| 261 | * @warning This doesn't seem to be a good solution |
| 262 | * |
| 263 | * @param ssrc Synchronization SouRCe identifier for this session |
| 264 | * @param size an estimation of the number of participants in the |
| 265 | * session |
| 266 | */ |
| 267 | RTPDataQueue(uint32* ssrc, uint32 size = defaultMembersHashSize); |
| 268 | |
| 269 | /** |
| 270 | * The queue destructor flushes the queue and stops all |
| 271 | * services. |
| 272 | */ |
| 273 | inline virtual |
| 274 | ~RTPDataQueue() |
| 275 | { endQueue(); } |
| 276 | |
| 277 | /** |
| 278 | * A plugin point for timer tick driven events. |
| 279 | */ |
| 280 | inline virtual void |
| 281 | timerTick() |
| 282 | { return; } |
| 283 | |
| 284 | void renewLocalSSRC() |
| 285 | {IncomingDataQueue::renewLocalSSRC();} |
| 286 | |
| 287 | private: |
| 288 | RTPDataQueue(const RTPDataQueue &o); |
| 289 | |
| 290 | RTPDataQueue& |
| 291 | operator=(const RTPDataQueue &o); |
| 292 | |
| 293 | /** |
| 294 | * Global queue initialization. |
| 295 | * |
| 296 | * @param localSSRC local 32-bit SSRC identifier |
| 297 | **/ |
| 298 | void |
| 299 | initQueue(); |
| 300 | |
| 301 | protected: |
| 302 | /** |
| 303 | * This method ends the queue. |
| 304 | */ |
| 305 | void |
| 306 | endQueue(); |
| 307 | |
| 308 | /** |
| 309 | * This function is used to check for and schedule against |
| 310 | * arriving packets based on the derived connection type. |
| 311 | * |
| 312 | * @return true if packet waiting for processing. |
| 313 | * @param number of microseconds to wait. |
| 314 | */ |
| 315 | virtual bool |
| 316 | isPendingData(microtimeout_t timeout) = 0; |
| 317 | |
| 318 | private: |
| 319 | // true if connection "active" |
| 320 | volatile bool dataServiceActive; |
| 321 | Tos typeOfService; |
| 322 | TimerPort timeclock; |
| 323 | /* RTP session bandwidth control */ |
| 324 | static const uint32 defaultSessionBw; |
| 325 | uint32 sessionBw; |
| 326 | |
| 327 | |
| 328 | }; |
| 329 | |
| 330 | /** @}*/ // ioqueue |
| 331 | |
| 332 | #ifdef CCXX_NAMESPACES |
| 333 | } |
| 334 | #endif |
| 335 | |
| 336 | #endif //CCXX_RTP_IOQUEUE_H_ |
| 337 | |
| 338 | /** EMACS ** |
| 339 | * Local variables: |
| 340 | * mode: c++ |
| 341 | * c-basic-offset: 8 |
| 342 | * End: |
| 343 | */ |