add custom transform example and remove calls to deprecated methods

examples/plugins/basetransform/internal/customtransform/element.go

@@ -0,0 +1,68 @@
+package customtransform
+
+import (
+	"github.com/go-gst/go-glib/glib"
+	"github.com/go-gst/go-gst/gst"
+	"github.com/go-gst/go-gst/gst/base"
+)
+
+type customBaseTransform struct{}
+
+// ClassInit is the place where you define pads and properties
+func (*customBaseTransform) ClassInit(klass *glib.ObjectClass) {
+	class := gst.ToElementClass(klass)
+	class.SetMetadata(
+		"custom base transform",
+		"Transform/demo",
+		"custom base transform",
+		"Wilhelm Bartel <bartel.wilhelm@gmail.com>",
+	)
+	class.AddPadTemplate(gst.NewPadTemplate(
+		"src",
+		gst.PadDirectionSource,
+		gst.PadPresenceAlways,
+		gst.NewCapsFromString("audio/x-raw,channels=2,rate=48000"),
+	))
+	class.AddPadTemplate(gst.NewPadTemplate(
+		"sink",
+		gst.PadDirectionSink,
+		gst.PadPresenceAlways,
+		gst.NewCapsFromString("audio/x-raw,channels=2,rate=48000"),
+	))
+}
+
+// SetProperty gets called for every property. The id is the index in the slice defined above.
+func (s *customBaseTransform) SetProperty(self *glib.Object, id uint, value *glib.Value) {}
+
+// GetProperty is called to retrieve the value of the property at index `id` in the properties
+// slice provided at ClassInit.
+func (o *customBaseTransform) GetProperty(self *glib.Object, id uint) *glib.Value {
+	return nil
+}
+
+// New is called by the bindings to create a new instance of your go element. Use this to initialize channels, maps, etc.
+//
+// Think of New like the constructor of your struct
+func (*customBaseTransform) New() glib.GoObjectSubclass {
+	return &customBaseTransform{}
+}
+
+// InstanceInit should initialize the element. Keep in mind that the properties are not yet present. When this is called.
+func (s *customBaseTransform) InstanceInit(instance *glib.Object) {}
+
+func (s *customBaseTransform) Constructed(o *glib.Object) {}
+
+func (s *customBaseTransform) Finalize(o *glib.Object) {}
+
+// see base.GstBaseTransformImpl interface for the method signatures of the virtual methods
+//
+// it is not required to implement all methods
+var _ base.GstBaseTransformImpl = nil
+
+func (s *customBaseTransform) SinkEvent(self *base.GstBaseTransform, event *gst.Event) bool {
+	return self.ParentSinkEvent(event)
+}
+
+func (s *customBaseTransform) SrcEvent(self *base.GstBaseTransform, event *gst.Event) bool {
+	return self.ParentSrcEvent(event)
+}

examples/plugins/basetransform/internal/customtransform/register.go

@@ -0,0 +1,23 @@
+package customtransform
+
+import (
+	"github.com/go-gst/go-gst/gst"
+	"github.com/go-gst/go-gst/gst/base"
+)
+
+// Register needs to be called after gst.Init() to make the gocustombin available in the standard
+// gst element registry. After this call the element can be used like any other gstreamer element
+func Register() bool {
+	return gst.RegisterElement(
+		// no plugin:
+		nil,
+		// The name of the element
+		"gocustomtransform",
+		// The rank of the element
+		gst.RankNone,
+		// The GoElement implementation for the element
+		&customBaseTransform{},
+		// The base subclass this element extends
+		base.ExtendsBaseTransform,
+	)
+}

examples/plugins/basetransform/main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/signal"
+
+	"github.com/go-gst/go-gst/examples/plugins/basetransform/internal/customtransform"
+	"github.com/go-gst/go-gst/gst"
+)
+
+func run(ctx context.Context) error {
+	ctx, cancel := signal.NotifyContext(ctx, os.Interrupt)
+	defer cancel()
+
+	gst.Init(nil)
+
+	customtransform.Register()
+
+	pipeline, err := gst.NewPipelineFromString("audiotestsrc ! gocustomtransform ! fakesink")
+
+	if err != nil {
+		return err
+	}
+
+	pipeline.SetState(gst.StatePlaying)
+
+	<-ctx.Done()
+
+	pipeline.BlockSetState(gst.StateNull)
+
+	gst.Deinit()
+
+	return ctx.Err()
+}
+
+func main() {
+	ctx := context.Background()
+
+	err := run(ctx)
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+	}
+}