mediaiosource.h

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#pragma once
 
 
#include <promeki/config.h>
#if PROMEKI_ENABLE_PROAV
#include <promeki/namespace.h>
#include <promeki/error.h>
#include <promeki/frame.h>
#include <promeki/framenumber.h>
#include <promeki/framecount.h>
#include <promeki/mediadesc.h>
#include <promeki/mediaioport.h>
#include <promeki/mediaio.h>
#include <promeki/mediaioreadcache.h>
 
PROMEKI_NAMESPACE_BEGIN
 
class MediaIO;
class MediaIOPortGroup;
class MediaIOCommand;
class MediaIORequest;
 
class MediaIOSource : public MediaIOPort {
                PROMEKI_OBJECT(MediaIOSource, MediaIOPort)
                friend class MediaIO;
                friend class MediaIOPortGroup;
        public:
                MediaIOSource(MediaIOPortGroup *group, int index, const String &name = String());
 
                ~MediaIOSource() override;
 
                Role role() const override { return MediaIOPort::Source; }
 
                // ---- Capacity / status ----
 
                bool frameAvailable() const;
 
                int readyReads() const;
 
                int pendingReads() const;
 
                int prefetchDepth() const { return _readCache.depth(); }
 
                void setPrefetchDepth(int n);
 
                // ---- Format negotiation ----
 
                Error proposeOutput(const MediaDesc &requested, MediaDesc *achievable,
                                    MediaConfig *configDelta = nullptr) const;
 
                // ---- Read API ----
 
                MediaIORequest readFrame();
 
                size_t cancelPending();
 
                // ---- Navigation (forwards to the port group) ----
 
                double rate() const;
 
                void setRate(double r);
 
                FrameNumber currentFrame() const;
 
                MediaIORequest seekToFrame(const FrameNumber &frameNumber,
                                           MediaIOSeekMode mode = MediaIO_SeekDefault);
 
                // ---- Signal ----
 
                PROMEKI_SIGNAL(frameReady);
 
        private:
                MediaIOReadCache _readCache{this};
                // True once a caller has explicitly set the prefetch
                // depth via @ref setPrefetchDepth — silences the
                // post-open re-apply of the backend's
                // @c defaultPrefetchDepth so the user override sticks.
                bool             _prefetchDepthExplicit = false;
};
 
PROMEKI_NAMESPACE_END
 
#endif // PROMEKI_ENABLE_PROAV