FFMMedium.h

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/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
 
#ifndef META_OCEAN_MEDIA_FFM_MEDIUM_H
#define META_OCEAN_MEDIA_FFM_MEDIUM_H
 
#include "ocean/media/ffmpeg/FFmpeg.h"
 
#include "ocean/media/Medium.h"
 
// Forward declaration.
struct AVFormatContext;
 
namespace Ocean
{
 
namespace Media
{
 
namespace FFmpeg
{
 
/**
 * This is the base class for all FFmpeg mediums.
 * @ingroup mediaffm
 */
class FFMMedium : virtual public Medium
{
    public:
 
        /**
         * Returns whether the medium is started currently.
         * @see Medium::isStarted()
         */
        bool isStarted() const override;
 
        /**
         * Returns the start timestamp.
         * @return Start timestamp
         */
        Timestamp startTimestamp() const override;
 
        /**
         * Returns the pause timestamp.
         * @return Pause timestamp
         */
        Timestamp pauseTimestamp() const override;
 
        /**
         * Returns the stop timestamp.
         * @return Stop timestamp
         */
        Timestamp stopTimestamp() const override;
 
    protected:
 
        /**
         * Creates a new medium by a given url.
         * @param url Url of the medium
         */
        explicit FFMMedium(const std::string& url);
 
        /**
         * Destructs a FFMMedium object.
         */
        ~FFMMedium() override;
 
        /**
         * Starts the medium.
         * The internalStart() function will be called inside.
         * @see Medium::start()
         */
        bool start() override;
 
        /**
         * Pauses the medium.
         * The internalPause() function will be called inside.
         * @see Medium::pause()
         */
        bool pause() override;
 
        /**
         * Stops the medium.
         * The internalStop() function will be called inside.
         * @see Medium::stop()
         */
        bool stop() override;
 
        /**
         * Internally starts the medium.
         * @return True, if succeeded or if the medium is already started
         */
        virtual bool internalStart() = 0;
 
        /**
         * Internally pauses the medium.
         * @return True, if succeeded or if the medium is already paused
         */
        virtual bool internalPause() = 0;
 
        /**
         * Internally stops the medium.
         * @return True, if succeeded or if the medium is already stopped
         */
        virtual bool internalStop() = 0;
 
        /**
         * Creates a FFmpeg context and opens a given file.
         * @param filename The name of the file to open, must be valid
         * @return True, if succeeded
         */
        bool createContextAndOpenFile(const std::string& filename);
 
        /**
         * Releases the FFmpeg context.
         */
        void releaseContext();
 
    protected:
 
        /// FFmpeg's format context object.
        AVFormatContext* avFormatContext_ = nullptr;
 
        /// Start timestamp
        Timestamp startTimestamp_ = Timestamp(false);
 
        /// Pause timestamp
        Timestamp pauseTimestamp_ = Timestamp(false);
 
        /// Stop timestamp
        Timestamp stopTimestamp_ = Timestamp(false);
};
 
}
 
}
 
}
 
#endif // META_OCEAN_MEDIA_FFM_MEDIUM_H