LUMIERA.clone/src/proc/play/timings.hpp

145 lines
4.6 KiB
C++

/*
TIMINGS.hpp - timing specifications for a frame quantised data stream
Copyright (C) Lumiera.org
2011, Hermann Vosseler <Ichthyostega@web.de>
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file timings.hpp
** How to define a timing specification or constraint.
** A timing spec is used to anchor a data stream with relation to a time axis or frame grid.
** There are two kinds of timing specs:
** - nominal timing specifications relate to the nominal time values
** of the frames in a data stream, i.e. the "should be" time values.
** These might be values derived from a timecode or just values in
** in relation to the timeline axis, but without any connection to
** the real wall clock time
** - actual timing specifications are always connected or related to
** an external time source, typically just wall clock time. For example,
** actual timing specs dictate the constraints for real time frame
** delivery to an external output connection.
**
** @todo WIP-WIP-WIP 8/2011
** @see output-slot.hpp ////TODO
*/
#ifndef PROC_PLAY_TIMINGS_H
#define PROC_PLAY_TIMINGS_H
#include "lib/error.hpp"
//#include "lib/handle.hpp"
#include "lib/time/timevalue.hpp"
//#include "proc/engine/buffer-provider.hpp"
//#include "lib/iter-source.hpp"
//#include "lib/sync.hpp"
//#include <boost/noncopyable.hpp>
//#include <string>
//#include <vector>
#include <tr1/memory>
//#include <boost/scoped_ptr.hpp>
namespace lib {
namespace time{
class Quantiser;
typedef std::tr1::shared_ptr<const Quantiser> PQuant;
}}
namespace proc {
namespace play {
using lib::time::FrameRate;
using lib::time::TimeValue;
using lib::time::Duration;
using lib::time::Offset;
using lib::time::Time;
//using std::string;
//using std::vector;
//using std::tr1::shared_ptr;
//using boost::scoped_ptr;
enum PlaybackUrgency {
ASAP,
NICE,
TIMEBOUND
};
/*****************************************************************************
* Generic frame timing specification. Defines the expected delivery interval,
* optionally also the expected quality-of-service
*
* @note copyable value class
*
* @todo write type comment
* /////////////////////////////////////////////////////////////////TODO: WIP seems to become some kind of abstracted Grid representation!
*/
class Timings
{
lib::time::PQuant grid_;
public:
PlaybackUrgency playbackUrgency;
Duration outputLatency;
Timings (FrameRate fps);
// default copy acceptable
TimeValue getOrigin() const;
Offset getFrameOffsetAt (TimeValue refPoint) const;
Duration getFrameDurationAt (TimeValue refPoint) const;
Duration getFrameDurationAt (int64_t refFrameNr) const;
/** the frame spacing and duration remains constant for some time...
* @param startPoint looking from that time point into future
* @return duration after this starting point, where it's safe
* to assume unaltered frame dimensions */
Duration constantFrameTimingsInterval (TimeValue startPoint) const;
/** for scheduled time of delivery, which is signalled
* by \code playbackUrgency == TIMEBOUND \endcode
* @return wall clock time to expect delivery of data corresponding
* to \link #getOrigin time axis origin \endlink
* @note for other playback urgencies \c Time::NEVER
*/
Time getTimeDue() const;
/** number of jobs to be planned and scheduled in one sway.
* The continuous planning of additional frame calculation jobs
* for playback or rendering proceeds in chunks of jobs
* controlled by this chunk size.
*/
uint getPlanningChunkSize() const;
//////////////TODO further accessor functions here
Timings constrainedBy (Timings additionalConditions);
};
}} // namespace proc::play
#endif