gstreamer-graphix/gstreamer/input.go

package gstreamer

import (
	"fmt"
	"github.com/rs/zerolog"
	"github.com/tinyzimmer/go-gst/gst"
)

func (i *InputElement) create(pipeline *gst.Pipeline, log zerolog.Logger) error {
	elements := map[string]element{}
	e, err := gst.NewElementWithName(i.Type, i.Name)
	if err != nil {
		log.Error().Msgf("could not create element %s: %v\n", i.Name, err)
		return fmt.Errorf("could not create element %s", i.Name)
	}
	for prop, value := range i.Properties {
		setPropertyWrapper(e, prop, value)
	}
	err = pipeline.Add(e)
	if err != nil {
		log.Error().Msgf("could not add element %s to pipeline: %v\n", i.Name, err)
		return fmt.Errorf("could not add element %s to pipeline", i.Name)
	}
	input := element{element: e, name: i.Name, next: fmt.Sprintf("%s-decodebin", i.Name)}
	elements[i.Name] = input
	// ====================

	//====================
	// DECODEBIN
	e, err = gst.NewElementWithName("decodebin", fmt.Sprintf("%s-decodebin", i.Name))
	if err != nil {
		log.Error().Msgf("could not create decodebin for %s: %v\n", i.Name, err)
		return fmt.Errorf("could not create decodebin for %s", i.Name)
	}
	err = pipeline.Add(e)
	if err != nil {
		log.Error().Msgf("could not add decodebin for %s to pipeline: %v\n", i.Name, err)
		return fmt.Errorf("could not add decodebin for %s to pipeline", i.Name)
	}
	decodebin := element{element: e, name: fmt.Sprintf("%s-decodebin", i.Name), prev: i.Name, next: fmt.Sprintf("%s-videoconvert", i.Name)}
	elements[fmt.Sprintf("%s-decodebin", i.Name)] = decodebin
	err = input.linkElementWrapper(&decodebin, log)
	if err != nil {
		log.Error().Msgf("could not link %s to %s: %v\n", i.Name, fmt.Sprintf("%s-decodebin", i.Name), err)
		return fmt.Errorf("could not link %s to %s", i.Name, fmt.Sprintf("%s-decodebin", i.Name))
	}
	//====================

	// ====================
	// VIDEOCONVERT
	e, err = gst.NewElementWithName("videoconvert", fmt.Sprintf("%s-videoconvert", i.Name))
	if err != nil {
		log.Error().Msgf("could not create videoconvert for %s: %v\n", i.Name, err)
		return fmt.Errorf("could not create videoconvert for %s", i.Name)
	}
	err = pipeline.Add(e)
	if err != nil {
		log.Error().Msgf("could not add videoconvert for %s to pipeline: %v\n", i.Name, err)
		return fmt.Errorf("could not add videoconvert for %s to pipeline", i.Name)
	}
	videoconvert := element{element: e, name: fmt.Sprintf("%s-videoconvert", i.Name), prev: fmt.Sprintf("%s-decodebin", i.Name), next: fmt.Sprintf("%s-videoscale", i.Name)}
	elements[fmt.Sprintf("%s-videoconvert", i.Name)] = videoconvert
	err = input.linkElementWrapper(&videoconvert, log)
	if err != nil {
		log.Error().Msgf("could not link %s to %s: %v\n", i.Name, fmt.Sprintf("%s-videoconvert", i.Name), err)
		return fmt.Errorf("could not link %s to %s", i.Name, fmt.Sprintf("%s-videoconvert", i.Name))
	}
	//=====================

	//=====================
	// VIDEOSCALE
	e, err = gst.NewElementWithName("videoscale", fmt.Sprintf("%s-videoscale", i.Name))
	if err != nil {
		log.Error().Msgf("could not create videoscale for %s: %v\n", i.Name, err)
		return fmt.Errorf("could not create videoscale for %s", i.Name)
	}
	err = pipeline.Add(e)
	if err != nil {
		log.Error().Msgf("could not add videoscale for %s to pipeline: %v\n", i.Name, err)
		return fmt.Errorf("could not add videoscale for %s to pipeline", i.Name)
	}
	videoscale := element{element: e, name: fmt.Sprintf("%s-videoscale", i.Name), prev: fmt.Sprintf("%s-videoconvert", i.Name), next: fmt.Sprintf("%s-videorate", i.Name)}
	elements[fmt.Sprintf("%s-videoscale", i.Name)] = videoscale
	err = videoconvert.linkElementWrapper(&videoscale, log)
	if err != nil {
		log.Error().Msgf("could not link %s to %s: %v\n", fmt.Sprintf("%s-videoconvert", i.Name), fmt.Sprintf("%s-videoscale", i.Name), err)
		return fmt.Errorf("could not link %s to %s", fmt.Sprintf("%s-videoconvert", i.Name), fmt.Sprintf("%s-videoscale", i.Name))
	}
	//=====================

	//=====================
	// VIDEORATE
	e, err = gst.NewElementWithName("videorate", fmt.Sprintf("%s-videorate", i.Name))
	if err != nil {
		log.Error().Msgf("could not create videorate for %s: %v\n", i.Name, err)
		return fmt.Errorf("could not create videorate for %s", i.Name)
	}
	err = pipeline.Add(e)
	if err != nil {
		log.Error().Msgf("could not add videorate for %s to pipeline: %v\n", i.Name, err)
		return fmt.Errorf("could not add videorate for %s to pipeline", i.Name)
	}
	videorate := element{element: e, name: fmt.Sprintf("%s-videorate", i.Name), prev: fmt.Sprintf("%s-videoscale", i.Name), outputCaps: i.Caps}
	elements[fmt.Sprintf("%s-videorate", i.Name)] = videorate
	err = videoscale.linkElementWrapper(&videorate, log)
	if err != nil {
		log.Error().Msgf("could not link %s to %s: %v\n", fmt.Sprintf("%s-videoscale", i.Name), fmt.Sprintf("%s-videorate", i.Name), err)
		return fmt.Errorf("could not link %s to %s", fmt.Sprintf("%s-videoscale", i.Name), fmt.Sprintf("%s-videorate", i.Name))
	}

	i.elements = elements

	return nil
}

func (i *InputElement) getLastElement() *element {
	e := i.elements[fmt.Sprintf("%s-videorate", i.Name)]
	return &e
}