H264Decoder.h

#pragma once
 
#include "Module.h"
#include <vector>
 
class H264DecoderProps : public ModuleProps
{
public:
    H264DecoderProps(uint _lowerWaterMark = 300, uint _upperWaterMark = 350)
    {
        lowerWaterMark = _lowerWaterMark;
        upperWaterMark = _upperWaterMark;
    }
    uint lowerWaterMark;
    uint upperWaterMark;
};
 
class H264Decoder : public Module
{
public:
    H264Decoder(H264DecoderProps _props);
    virtual ~H264Decoder();
    bool init();
    bool term();
    bool processEOS(string& pinId);
 
protected:
    bool process(frame_container& frames);
    bool processSOS(frame_sp& frame);
    void addInputPin(framemetadata_sp& metadata, string& pinId);
    bool validateInputPins();
    bool validateOutputPins();
    bool shouldTriggerSOS();
    void flushQue();
    bool handleCommand(Command::CommandType type, frame_sp& frame);
 
private:
    void bufferDecodedFrames(frame_sp& frame);
    void bufferBackwardEncodedFrames(frame_sp& frame, short naluType);
    void bufferAndDecodeForwardEncodedFrames(frame_sp& frame, short naluType);
 
    class Detail;
    boost::shared_ptr<Detail> mDetail;
    bool mShouldTriggerSOS;
    framemetadata_sp mOutputMetadata;
    std::string mOutputPinId;
    H264DecoderProps mProps;
 
 
    /* Used to buffer multiple complete GOPs 
    note that we decode frames from this queue in reverse play*/
    std::deque<std::deque<frame_sp>> backwardGopBuffer;
    /* buffers the incomplete GOP */
    std::deque<frame_sp> latestBackwardGop;
    /* It buffers only one latest GOP 
    used in cases where partial GOP maybe in cache and rest of the GOP needs to be decoded
    note that since there is no buffering in forward play, we directly decode frames from module queue*/
    std::deque<frame_sp> latestForwardGop;
    std::map<uint64, frame_sp> decodedFramesCache;
    void sendDecodedFrame();
    bool mDirection;
    bool dirChangedToFwd = false;
    bool dirChangedToBwd = false;
    bool foundIFrameOfReverseGop = false;
    bool decodePreviousFramesOfTheForwardGop = false;
    bool prevFrameInCache = false;
    void decodeFrameFromBwdGOP();
    std::deque<uint64_t> incomingFramesTSQ;
    void clearIncompleteBwdGopTsFromIncomingTSQ(std::deque<frame_sp>& latestGop);
    void saveSpsPps(frame_sp frame);
    void* prependSpsPps(frame_sp& iFrame, size_t& spsPpsFrameSize);
    void dropFarthestFromCurrentTs(uint64_t ts);
    frame_sp mHeaderFrame;
    boost::asio::const_buffer spsBuffer;
    boost::asio::const_buffer ppsBuffer;
    std::mutex m;
    int framesToSkip = 0;
    int iFramesToSkip = 0;
    int currentFps = 24;
    int previousFps = 24;
    float playbackSpeed = 1;
    int gop;
    uint64_t lastFrameSent;
    bool resumeFwdPlayback = true;
    bool resumeBwdPlayback = true;
    bool resumePlayback = true;
    int incomingFramesTSQSize = 0;
};