IMediaSamples.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "Containers/Array.h"
#include "Math/Range.h"
#include "Misc/Timespan.h"
#include "Misc/Optional.h"
#include "Templates/SharedPointer.h"
#include "IMediaTimeSource.h"
 
class IMediaAudioSample;
class IMediaBinarySample;
class IMediaOverlaySample;
class IMediaTextureSample;
 
 
class IMediaSamples
{
public:
 
    //~ The following methods are optional
 
    virtual bool FetchAudio(TRange<FTimespan> TimeRange, TSharedPtr<IMediaAudioSample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
    virtual bool FetchAudio(TRange<FMediaTimeStamp> TimeRange, TSharedPtr<IMediaAudioSample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
 
    virtual bool FetchCaption(TRange<FTimespan> TimeRange, TSharedPtr<IMediaOverlaySample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
    virtual bool FetchCaption(TRange<FMediaTimeStamp> TimeRange, TSharedPtr<IMediaOverlaySample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
 
    virtual bool FetchMetadata(TRange<FTimespan> TimeRange, TSharedPtr<IMediaBinarySample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
    virtual bool FetchMetadata(TRange<FMediaTimeStamp> TimeRange, TSharedPtr<IMediaBinarySample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
 
    virtual bool FetchSubtitle(TRange<FTimespan> TimeRange, TSharedPtr<IMediaOverlaySample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
    virtual bool FetchSubtitle(TRange<FMediaTimeStamp> TimeRange, TSharedPtr<IMediaOverlaySample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
 
    virtual bool FetchVideo(TRange<FTimespan> TimeRange, TSharedPtr<IMediaTextureSample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
    virtual bool FetchVideo(TRange<FMediaTimeStamp> TimeRange, TSharedPtr<IMediaTextureSample, ESPMode::ThreadSafe>& OutSample)
    {
        return false; // override in child classes, if supported
    }
 
    virtual void FlushSamples()
    {
        // override in child classes, if supported
    }
 
    virtual void SetSampleBufferSize(int32 BufferSize) {};
 
    enum class EFetchBestSampleResult
    {
        Ok = 0,
        NoSample,
        PurgedToEmpty,
        NotSupported,
    };
    virtual EFetchBestSampleResult FetchBestVideoSampleForTimeRange(const TRange<FMediaTimeStamp>& TimeRange, TSharedPtr<IMediaTextureSample, ESPMode::ThreadSafe>& OutSample, bool bReverse, bool bConsistentResult)
    {
        return EFetchBestSampleResult::NotSupported;
    }
    virtual void SetMinExpectedNextSequenceIndex(TOptional<int32> InNextSequenceIndex) { }
 
    virtual bool PeekVideoSampleTime(FMediaTimeStamp& TimeStamp) = 0;
 
    virtual bool PeekVideoSampleTimeRanges(TArray<TRange<FMediaTimeStamp>>& TimeRange) { return false; }
    virtual bool PeekAudioSampleTimeRanges(TArray<TRange<FMediaTimeStamp>>& TimeRange) { return false; }
 
    virtual bool DiscardVideoSamples(const TRange<FMediaTimeStamp>& TimeRange, bool bReverse) { return false; }
    virtual bool DiscardAudioSamples(const TRange<FMediaTimeStamp>& TimeRange, bool bReverse) { return false; }
    virtual bool DiscardCaptionSamples(const TRange<FMediaTimeStamp>& TimeRange, bool bReverse) { return false; }
    virtual bool DiscardSubtitleSamples(const TRange<FMediaTimeStamp>& TimeRange, bool bReverse) { return false; }
    virtual bool DiscardMetadataSamples(const TRange<FMediaTimeStamp>& TimeRange, bool bReverse) { return false; }
 
    virtual uint32 PurgeOutdatedVideoSamples(const FMediaTimeStamp& ReferenceTime, bool bReversed, FTimespan MaxAge) { return 0; };
    virtual uint32 PurgeOutdatedCaptionSamples(const FMediaTimeStamp& ReferenceTime, bool bReversed, FTimespan MaxAge) { return 0; };
    virtual uint32 PurgeOutdatedSubtitleSamples(const FMediaTimeStamp& ReferenceTime, bool bReversed, FTimespan MaxAge) { return 0; };
    virtual uint32 PurgeOutdatedMetadataSamples(const FMediaTimeStamp& ReferenceTime, bool bReversed, FTimespan MaxAge) { return 0; };
 
    virtual bool CanReceiveVideoSamples(uint32 Num) const { return true; }
    virtual bool CanReceiveAudioSamples(uint32 Num) const { return true; }
    virtual bool CanReceiveSubtitleSamples(uint32 Num) const { return true; }
    virtual bool CanReceiveCaptionSamples(uint32 Num) const { return true; }
    virtual bool CanReceiveMetadataSamples(uint32 Num) const { return true; }
 
    virtual int32 NumAudioSamples() const { return -1; }
    virtual int32 NumCaptionSamples() const { return -1; }
    virtual int32 NumMetadataSamples() const { return -1; }
    virtual int32 NumSubtitleSamples() const { return -1; }
    virtual int32 NumVideoSamples() const { return -1; }
 
    virtual uint32 GetNumDroppedVideoSamples(bool bInClearToZero) { return 0U; }
    virtual uint32 GetNumDroppedAudioSamples(bool bInClearToZero) { return 0U; }
    virtual uint32 GetNumDroppedSubtitleSamples(bool bInClearToZero) { return 0U; }
    virtual uint32 GetNumDroppedCaptionSamples(bool bInClearToZero) { return 0U; }
    virtual uint32 GetNumDroppedMetadataSamples(bool bInClearToZero) { return 0U; }
 
public:
 
    virtual ~IMediaSamples() { }
};