AMovieRecorder.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_A_MOVIE_RECORDER_H
#define META_OCEAN_MEDIA_A_MOVIE_RECORDER_H
 
#include "ocean/media/android/Android.h"
#include "ocean/media/android/NativeMediaLibrary.h"
 
#include "ocean/base/ScopedObject.h"
 
#include "ocean/media/MovieRecorder.h"
 
#include <cstdio>
 
namespace Ocean
{
 
namespace Media
{
 
namespace Android
{
 
#if defined(__ANDROID_API__) && __ANDROID_API__ >= 21
 
/**
 * This class implements a movie recorder class for Android.
 * NOTE: The supported pixel formats for recording may vary from device to device.
 * @ingroup mediaandroid
 */
class OCEAN_MEDIA_A_EXPORT AMovieRecorder : virtual public MovieRecorder
{
    friend class ALibrary;
 
    protected:
 
        /// The default bitrate of the recorder, in bits per second.
        static constexpr int defaultBitrate_ = 2000000; // 2 Mbps
 
        /// Frequency at which I-frames are saved to the output.
        static constexpr int DEFAULT_IFRAME_INTERVAL_SECONDS = 1;
 
        /**
         * Definition of a scoped object for FILE pointers.
         */
        using ScopedFILE = ScopedObjectCompileTimeT<FILE*, FILE*, int, fclose>;
 
    public:
 
        /**
         * Sets the filename of this recorder.
         * The filename must be set before recordings starts.
         * @see MovieRecorder::setFilename().
         */
        bool setFilename(const std::string& filename) override;
 
        /**
         * Sets the preferred frame type of this recorder.
         * @see FrameRecorder::setPreferredFrameType().
         */
        bool setPreferredFrameType(const FrameType& type) override;
 
        /**
         * Sets the preferred bit rate when recording the data.
         * @see Recorder::setPreferredBitrate().
         */
        bool setPreferredBitrate(const unsigned int preferredBitrate) override;
 
        /**
         * Sets the recorder.
         * @see ExplicitRecorder::start().
         */
        bool start() override;
 
        /**
         * Stops the recorder.
         * @see ExplicitRecorder::stop().
         */
        bool stop() override;
 
        /**
         * Returns whether this recorder is currently recording.
         * @return True, if so
         */
        bool isRecording() const override;
 
        /**
         * Returns a list of possible frame encoders for this recorder.
         * @return Encoder names
         */
        Encoders frameEncoders() const override;
 
        /**
         * Returns a pointer to the most recent buffer to be filled immediately and locks it.
         * Beware: Call unlockBufferToFill() once the image data is written to the frame.
         * @param recorderFrame The resulting frame in which the image data can be copied, the frame type of this frame must not be changed
         * @param respectFrameFrequency Flag determining that a buffer will be returned if it is time for a new frame only
         * @return True if the buffer was successfully locked, otherwise false
         */
        bool lockBufferToFill(Frame& recorderFrame, const bool respectFrameFrequency = true) override;
 
        /**
         * Unlocks the filled buffer.
         * Beware: The buffer has to be locked by lockBufferToFill() before.
         */
        void unlockBufferToFill() override;
 
    protected:
 
        /**
         * Creates a new movie recorder object.
         */
        AMovieRecorder();
 
        /**
         * Destroys a movie recorder object.
         */
        ~AMovieRecorder() override;
 
        /**
         * Creates a new media muxer and all associated resources.
         * @return True, if succeeded
         */
        bool createNewMediaCodec();
 
        /**
         * Releases all resources.
         */
        void release();
 
    protected:
 
        /**
         * Reads output from the codec and writes the resulting buffer to the muxer. This function should only be called if input data was previously submitted to the codec.
         * @param loopUntilEndOfStream If true, continuously read from the buffer until an end-of-stream flag is presented; this should only be used when the recording is complete and a buffer with the EOS flag set has been submitted as input to the codec
         * @return True if the read and write succeeded, false otherwise.
         */
        bool readCodecOutputBufferAndWriteToMuxer(const bool loopUntilEndOfStream = false);
 
    protected:
 
        /// The underlying media format
        AMediaFormat* mediaFormat_ = nullptr;
 
        /// The underlying media codec that takes frame data as input and outputs encoded video frames.
        AMediaCodec* mediaCodec_ = nullptr;
 
        /// The underlying media muxer that will save the result to a file containing the codec output.
        AMediaMuxer* mediaMuxer_ = nullptr;
 
        /// The underlying file being written to.
        ScopedFILE file_;
 
        /// Current input buffer index of the codec, valid (>= 0) when the buffer is locked.
        ssize_t bufferIndex_ = -1;
 
        /// Current size of the input buffer for the codec, valid (> 0) when the buffer is locked.
        size_t bufferSize_ = 0;
 
        /// Output track for the muxer.
        ssize_t trackIndex_ = -1;
 
        /// The timestamp of the next frame.
        double nextFrameTimestamp_ = 0.0;
 
        /// True, if the recorder is actively recording frames; false, otherwise.
        bool isRecording_ = false;
 
        /// True, if this recorder is stopped.
        bool isStopped_ = false;
 
        /// The preferred bitrate of the recorder, in bits per second.
        unsigned int preferredBitrate_ = defaultBitrate_;
};
 
#endif // defined(__ANDROID_API__) && __ANDROID_API__ >= 21
 
}
 
}
 
}
 
#endif // META_OCEAN_MEDIA_A_MOVIE_RECORDER_H