Pipeline.h

#pragma once
#define GST_USE_UNSTABLE_API 1

#include <chrono>
#include <cstdint>
#include <gst/gst.h>
#include <map>
#include <memory>
#include <string>

struct Config;

namespace http
{
class WhipClient;
}

class Pipeline
{
public:
    Pipeline(http::WhipClient& whipClient, const Config& config);
    ~Pipeline();

    void run();
    void stop();

    void onDemuxPadAdded(GstPad* newPad);
    void onDemuxNoMorePads();
    void onOfferCreated(GstPromise* promise);
    void onNegotiationNeeded();
    void onIceCandidate(guint mLineIndex, gchar* candidate);

    static gboolean pipelineBusWatch(GstBus* /*bus*/, GstMessage* message, gpointer userData);
    static void demuxPadAddedCallback(GstElement* /*src*/, GstPad* newPad, gpointer userData);
    static void demuxNoMorePadsCallback(GstElement* /*src*/, gpointer userData);
    static void onOfferCreatedCallback(GstPromise* promise, gpointer userData);
    static void onNegotiationNeededCallback(GstElement* /*webRtcBin*/, gpointer userData);
    static void onIceCandidateCallback(GstElement* /*webrtc*/, guint mLineIndex, gchar* candidate, gpointer userData);

private:
private:
    enum class ElementLabel
    {
        UDP_SOURCE,
        UDP_QUEUE,
        TS_DEMUX,

        SRT_SOURCE,

        TEE,
        RESTREAM_QUEUE,
        UDP_DEST,
        SRT_DEST,

        H264_PARSE,
        H264_DECODE,

        H265_PARSE,
        H265_DECODE,

        VIDEO_CONVERT,

        CLOCK_OVERLAY,

        MPEG2_PARSE,
        MPEG2_DECODE,

        RTP_VIDEO_ENCODE,
        RTP_VIDEO_PAYLOAD,
        RTP_VIDEO_PAYLOAD_QUEUE,
        RTP_VIDEO_FILTER,

        AAC_PARSE,
        AAC_DECODE,

        PCM_PARSE,

        OPUS_PARSE,
        OPUS_DECODE,

        AUDIO_CONVERT,
        AUDIO_RESAMPLE,

        RTP_AUDIO_ENCODE,
        RTP_AUDIO_PAYLOAD,
        RTP_AUDIO_PAYLOAD_QUEUE,
        RTP_AUDIO_FILTER,

        WEBRTC_BIN
    };

    http::WhipClient& whipClient_;
    const Config& config_;

    GstBus* pipelineMessageBus_;
    GstElement* pipeline_;
    std::map<ElementLabel, GstElement*> elements_;

    std::string whipResource_;
    std::string etag_;

    void makeElement(const ElementLabel elementLabel, const char* element);
    void onH264SinkPadAdded(GstPad* newPad);
    void onH265SinkPadAdded(GstPad* newPad);
    void onMpeg2SinkPadAdded(GstPad* newPad);
    void onAacSinkPadAdded(GstPad* newPad);
    void onPcmSinkPadAdded(GstPad* newPad);
    void onOpusSinkPadAdded(GstPad* newPad);

    GstElement* addClockOverlay(GstElement* lastElement);
};