| // Copyright (C) 2001,2002,2004 Federico Montesino Pouzols <fedemp@altern.org>. |
| // |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License as published by |
| // the Free Software Foundation; either version 2 of the License, or |
| // (at your option) any later version. |
| // |
| // This program is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| // |
| // You should have received a copy of the GNU General Public License |
| // along with this program; if not, write to the Free Software |
| // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| // |
| // As a special exception, you may use this file as part of a free software |
| // library without restriction. Specifically, if other files instantiate |
| // templates or use macros or inline functions from this file, or you compile |
| // this file and link it with other files to produce an executable, this |
| // file does not by itself cause the resulting executable to be covered by |
| // the GNU General Public License. This exception does not however |
| // invalidate any other reasons why the executable file might be covered by |
| // the GNU General Public License. |
| // |
| // This exception applies only to the code released under the name GNU |
| // ccRTP. If you copy code from other releases into a copy of GNU |
| // ccRTP, as the General Public License permits, the exception does |
| // not apply to the code that you add in this way. To avoid misleading |
| // anyone as to the status of such modified files, you must delete |
| // this exception notice from them. |
| // |
| // If you write modifications of your own for GNU ccRTP, it is your choice |
| // whether to permit this exception to apply to your modifications. |
| // If you do not wish that, delete this exception notice. |
| // |
| |
| /** |
| * @file ioqueue.h |
| * |
| * @short Generic RTP input/output queues. |
| **/ |
| |
| #ifndef CCXX_RTP_IOQUEUE_H_ |
| #define CCXX_RTP_IOQUEUE_H_ |
| |
| #include <ccrtp/iqueue.h> |
| #include <ccrtp/oqueue.h> |
| |
| NAMESPACE_COMMONCPP |
| |
| /** |
| * @defgroup ioqueue Generic RTP input/output queues. |
| * @{ |
| **/ |
| |
| /** |
| * @class RTPDataQueue |
| * |
| * A packet queue handler for building different kinds of RTP protocol |
| * systems. The queue manages both incoming and outgoing RTP packets, |
| * as well as synchronization and transmission/reception timers. By |
| * making the queue handler a seperate base class it becomes possible |
| * to define RTP classes for RTP profiles and sessions of different |
| * types. |
| * |
| * Outgoing packets are sent via the OutgoingDataQueue::putData method. |
| * |
| * Incoming packets can be retrieved via IncomingDataQueue::getData |
| * method. |
| * |
| * @author David Sugar <dyfet@ostel.com> |
| * @short RTP data queue handler. |
| */ |
| class __EXPORT RTPDataQueue : |
| public IncomingDataQueue, |
| public OutgoingDataQueue |
| { |
| public: |
| /** |
| * @enum Tos rtp.h cc++/rtp.h |
| * @short Type of network service the application uses. |
| * |
| * If the application uses enhanced network service, for |
| * instance Integrated Services or Differentiated Services, it |
| * <em>has not</em> to ensure fair competition with TCP, |
| * provided that the requested service is actually being |
| * delivered. Whenever the application uses best-effort |
| * service or the requested enhanced service is not actually |
| * being delivered, it <em>has</em> to ensure fair competition |
| * with TCP. By default, best-effot is assumed. |
| * |
| * @note Although not required, RTP packets are always sent on |
| * top of UDP segments. No other underlying transport protocol |
| * is supported at present. |
| * |
| * @todo implement fair competition with tcp |
| **/ |
| typedef enum { |
| tosBestEffort, ///< Best-effort network service |
| tosEnhanced ///< Enhanced network service |
| } Tos; |
| |
| /** |
| * Specify the kind of service the application expects to use. |
| * |
| * @param tos type of service the application expects to use |
| * |
| * @note If enhanced service is specified but packet loss is |
| * high (the requested service does not appear to actually be |
| * delivered) ccRTP defaults to best-effort suitable |
| * behaviour: guarantee fair competition with TCP. |
| * |
| * @todo Implement fair competition with tcp |
| **/ |
| inline void |
| setTypeOfService(Tos tos) |
| { typeOfService = tos; } |
| |
| /** |
| * Enable packet queue processing in the stack. This method |
| * will not any thread of execution. |
| **/ |
| inline void enableStack() |
| { dataServiceActive = true; } |
| |
| /** |
| * Disable packet queue processing in the stack. |
| **/ |
| inline void disableStack() |
| { dataServiceActive = false; } |
| |
| /** |
| * Get active connection state flag. |
| * |
| * @return true if connection "active". |
| */ |
| inline bool |
| isActive() const |
| { return dataServiceActive; } |
| |
| /** |
| * Get the timestamp that should be given for a packet whose |
| * payload sampling instant corresponds to the current system |
| * time. |
| * |
| * The timestamp applications should provide for each packet |
| * represents the sampling instant of its payload and should |
| * not be a reading of the system clock. Nevertheless, the |
| * internal operation of the RTP stack relies on the accuracy |
| * of the provided timestamp, since several computations |
| * assume that there is a certain degree of correspondence |
| * between the timestamp and the system clock. |
| * |
| * It is recommended that applications use this method in |
| * order to <em>periodically adjust the RTP timestamp</em>. |
| * |
| * In particular, it is advisable getting the timestamp |
| * corresponding to the first sampling instant or any instant |
| * after a period of inactivity through a call to this method. |
| * |
| * Applications should use the nominal sampling or |
| * any other value provided by the coder in order to compute |
| * the next timestamps with minimum computational requirement. |
| * |
| * For instance, an application using an RTP profile that |
| * specifies a fixed sampling rate of 8 Khz with eight bits |
| * per sample, continuously transmitting audio blocks 80 |
| * octets long, would transmit 100 packets every |
| * second. Every packet would carry a timestamp 80 units |
| * greater than the previous one. So, the first timestamp |
| * would be obtained from this method, whereas the following |
| * ones would be computed adding 80 every time. Also the |
| * timestamp should be increased for every block whether |
| * it is put in the queue or dropped. |
| * |
| * The aforementioned increment can be obtained from the |
| * RTPDataQueue::getTimestampIncrement() method rather than |
| * computing it by hand in the application. |
| * |
| * @note Frame based applications must follow a specific |
| * timestamping method, probably specified in a profile. |
| * |
| * @note You should take into account that by default ccRTP |
| * assumes that the application begins sampling at the queue |
| * creation time. Moreover, the first sampling instant is |
| * assigned a "user visible" timestamp of 0, although the RTP |
| * stack will then add internally a ramdom offset unknown to |
| * the application. That is to say, the application may count |
| * samples from 0 in order to get the timestamp for the next |
| * packet, provided that the first sampling instant is the |
| * same as the queue creation time. Nevertheless, this |
| * simpler way of starting will not be as accurate as it would |
| * be if the application got at least the first timestamp |
| * through getCurrentTimestamp. <em>We provide this option |
| * since ccRTP interface is evolving, but we admit that it is |
| * ugly, we could remove this option or even replace uint32 |
| * timestamps with a restrictively regulated object; |
| * suggestions are gladly welcomed</em> |
| **/ |
| uint32 |
| getCurrentTimestamp() const; |
| |
| /** |
| * Specify the bandwidth of the current session. |
| * |
| * @param bw bandwidth of the current session, in bits/s. |
| * |
| * @see AVPQueue::setControlBandwidth() |
| */ |
| void |
| setSessionBandwidth(uint32 bw) |
| { sessionBw = bw; } |
| |
| uint32 |
| getDefaultSessionBandwidth() const |
| { return defaultSessionBw; } |
| |
| uint32 |
| getSessionBandwidth() const |
| { return sessionBw; } |
| |
| /** |
| * Set the packet timeclock for synchronizing timestamps. |
| **/ |
| inline void |
| setTimeclock() |
| { timeclock.setTimer(); } |
| |
| /** |
| * Get the packet timeclock for synchronizing timestamps. |
| * |
| * @return runtime in milliseconds since last set. |
| */ |
| inline timeout_t |
| getTimeclock() const |
| { return timeclock.getElapsed(); } |
| |
| protected: |
| |
| /** |
| * Constructor. This will generate a random application SSRC |
| * identifier. |
| * |
| * @param size an estimation of the number of participants in |
| * the session |
| **/ |
| RTPDataQueue(uint32 size = defaultMembersHashSize); |
| |
| /** |
| * Using this constructor you can start a session with the |
| * given ssrc, instead of the usual randomly generated |
| * one. This is necessary when you need to initiate several |
| * sessions having the same SSRC identifier, for instance, to |
| * implement layered encoding, in which case each layer is |
| * managed through a different session but all sessions share |
| * the same SSRC identifier. |
| * |
| * @warning This doesn't seem to be a good solution |
| * |
| * @param ssrc Synchronization SouRCe identifier for this session |
| * @param size an estimation of the number of participants in the |
| * session |
| */ |
| RTPDataQueue(uint32* ssrc, uint32 size = defaultMembersHashSize); |
| |
| /** |
| * The queue destructor flushes the queue and stops all |
| * services. |
| */ |
| inline virtual |
| ~RTPDataQueue() |
| { endQueue(); } |
| |
| /** |
| * A plugin point for timer tick driven events. |
| */ |
| inline virtual void |
| timerTick() |
| { return; } |
| |
| void renewLocalSSRC() |
| {IncomingDataQueue::renewLocalSSRC();} |
| |
| private: |
| RTPDataQueue(const RTPDataQueue &o); |
| |
| RTPDataQueue& |
| operator=(const RTPDataQueue &o); |
| |
| /** |
| * Global queue initialization. |
| * |
| * @param localSSRC local 32-bit SSRC identifier |
| **/ |
| void |
| initQueue(); |
| |
| protected: |
| /** |
| * This method ends the queue. |
| */ |
| void |
| endQueue(); |
| |
| /** |
| * This function is used to check for and schedule against |
| * arriving packets based on the derived connection type. |
| * |
| * @return true if packet waiting for processing. |
| * @param number of microseconds to wait. |
| */ |
| virtual bool |
| isPendingData(microtimeout_t timeout) = 0; |
| |
| private: |
| // true if connection "active" |
| volatile bool dataServiceActive; |
| Tos typeOfService; |
| TimerPort timeclock; |
| /* RTP session bandwidth control */ |
| static const uint32 defaultSessionBw; |
| uint32 sessionBw; |
| |
| |
| }; |
| |
| /** @}*/ // ioqueue |
| |
| END_NAMESPACE |
| |
| #endif //CCXX_RTP_IOQUEUE_H_ |
| |
| /** EMACS ** |
| * Local variables: |
| * mode: c++ |
| * c-basic-offset: 8 |
| * End: |
| */ |