AVFMedium.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_AVF_MEDIUM_H
#define META_OCEAN_MEDIA_AVF_MEDIUM_H
 
#include "ocean/media/avfoundation/AVFoundation.h"
 
#include "ocean/base/Singleton.h"
 
#include "ocean/media/Medium.h"
 
#include <AVFoundation/AVFoundation.h>
 
namespace Ocean
{
 
namespace Media
{
 
namespace AVFoundation
{
 
/**
 * This is the base class for all AVFoundation mediums.
 * Beware: When using AV foundation objects within a console application on macOS, the main loop needs to be executed regularly.<br>
 * The main loop is handling events neccessary in AVFoundation, however a console application commonly is a blocking application and therefore never invokes the main loop.
 * @see Platform::Apple::System::runMainLoop().
 * @ingroup mediaavf
 */
class AVFMedium : virtual public Medium
{
    protected:
 
        /**
         * This class implements a manager for audio sessions.
         */
        class AudioSessionManager : public Singleton<AudioSessionManager>
        {
            friend class Singleton<AudioSessionManager>;
 
            public:
 
#ifndef OCEAN_PLATFORM_BUILD_APPLE_MACOS
 
                /**
                 * Initializes the audio session.
                 * @param avAudioSessionCategory The preferred category to be used
                 * @param avAudioSessionMode The preferred mode to be used
                 */
                void initialize(const AVAudioSessionCategory avAudioSessionCategory, const AVAudioSessionMode avAudioSessionMode);
 
#endif // OCEAN_PLATFORM_BUILD_APPLE_MACOS
 
                /**
                 * Starts an audio session.
                 * Each successful call of start() needs to be balanced with a call of stop().
                 * @return True, if the session was started successfully; False, if the session could not be started
                 * @see stop().
                 */
                bool start();
 
                /**
                 * Stops an audio session after is has been started.
                 * @see start().
                 */
                void stop();
 
                /**
                 * Requests record permission.
                 * The session must have been started already.
                 */
                void requestRecordPermission();
 
            protected:
 
                /**
                 * Default constructor.
                 */
                AudioSessionManager() = default;
 
            protected:
 
#ifndef OCEAN_PLATFORM_BUILD_APPLE_MACOS
 
                /// The usage counter.
                unsigned int usageCounter_ = 0u;
 
                /// The audio session for iOS platforms.
                AVAudioSession* avAudioSession_ = nullptr;
 
                /// The category which is used.
                AVAudioSessionCategory avAudioSessionCategory_ = AVAudioSessionCategoryAmbient;
 
                /// The mode which is used.
                AVAudioSessionMode avAudioSessionMode_ = AVAudioSessionModeDefault;
 
                /// The manager's lock.
                Lock lock_;
 
#endif // OCEAN_PLATFORM_BUILD_APPLE_MACOS
        };
 
    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 AVFMedium(const std::string& url);
 
        /**
         * Destructs a AVFMedium object.
         */
        ~AVFMedium() 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;
 
    protected:
 
        /// Start timestamp
        Timestamp startTimestamp_;
 
        /// Pause timestamp
        Timestamp pauseTimestamp_;
 
        /// Stop timestamp
        Timestamp stopTimestamp_;
};
 
}
 
}
 
}
 
#endif // META_OCEAN_MEDIA_AVF_MEDIUM_H