Audio.hh

#pragma once

#ifndef __cplusplus
#error "This is a C++ header"
#endif

extern "C" {
#include <libavutil/opt.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswresample/swresample.h>
#include <libavcodec/avfft.h>
#include <memory.h>
}

#include "Utils.hh"
#include <QtGlobal>
#include <QMap>
#include <QVector>
#include <QString>

namespace Vivy
{
class AudioContext;

// The memory representation of an audio file. It is created inplace and should
// not be moved around. It should be used to get the properties of an audio
// file and its streams. The user can use a stream from the file and get data
// from it.
class AudioContext final {
    VIVY_UNMOVABLE_OBJECT(AudioContext)

public:
    // Hold all the data for a stream in an audio file. Should only be owned by
    // the AudioContext class.
    class Stream final {
        VIVY_UNMOVABLE_OBJECT(Stream)

        static inline Utils::DeleterFunctionType<double> dataDeleter =
            std::bind_front(Utils::freePtrIfNotNull<double>, av_free);

        static inline Utils::DeleterFunctionType<AVCodecContext> codecContexteleter =
            std::bind_front(Utils::freePPtrIfNotNull<AVCodecContext>, avcodec_free_context);

        static inline Utils::DeleterFunctionType<AVFrame> avFrameDeleter =
            std::bind_front(Utils::freePPtrIfNotNull<AVFrame>, av_frame_free);

        static inline Utils::DeleterFunctionType<SwrContext> swrContenxtDeleter =
            std::bind_front(Utils::freePPtrIfNotNull<SwrContext>, swr_free);

        // All the used types
        using AVCodecContextPtr = std::unique_ptr<AVCodecContext, decltype(codecContexteleter)>;
        using DataPtr           = std::shared_ptr<double[]>;
        using AVFramePtr        = std::unique_ptr<AVFrame, decltype(avFrameDeleter)>;
        using SwrContextPtr     = std::unique_ptr<SwrContext, decltype(swrContenxtDeleter)>;

    public:
        Stream(AVCodec *, AVFormatContext *, AVStream *, int index);
        ~Stream() noexcept;

        // The non-owning view of the stream's data
        using DataWeakPtr = std::weak_ptr<double[]>;

        // Decode the stream
        void decodeData();
        void cleanUpData() noexcept;
        bool isDecoded() const noexcept;
        int getDataSampleRate() const noexcept;
        size_t getDecodedDataSize() const noexcept;
        size_t getDecodedChunkSize() const noexcept;