diff --git a/filter_context.go b/filter_context.go
index 8232046..c911a40 100644
--- a/filter_context.go
+++ b/filter_context.go
@@ -39,15 +39,3 @@ func (fc *FilterContext) Free() {
 func (fc *FilterContext) Class() *Class {
 	return newClassFromC(unsafe.Pointer(fc.c))
 }
-
-// https://ffmpeg.org/doxygen/7.0/structAVFilterContext.html#addd946fbe5af506a2b19f9ad7cb97c35
-func (fc *FilterContext) SetHardwareDeviceContext(hdc *HardwareDeviceContext) {
-	if fc.c.hw_device_ctx != nil {
-		C.av_buffer_unref(&fc.c.hw_device_ctx)
-	}
-	if hdc != nil {
-		fc.c.hw_device_ctx = C.av_buffer_ref(hdc.c)
-	} else {
-		fc.c.hw_device_ctx = nil
-	}
-}
diff --git a/filter_graph.go b/filter_graph.go
index bd26739..46ec6a2 100644
--- a/filter_graph.go
+++ b/filter_graph.go
@@ -4,7 +4,6 @@ package astiav
 import "C"
 import (
 	"errors"
-	"math"
 	"unsafe"
 )
 
@@ -155,17 +154,3 @@ func (g *FilterGraph) SendCommand(target, cmd, args string, f FilterCommandFlags
 	})
 	return
 }
-
-// https://ffmpeg.org/doxygen/7.0/structAVFilterGraph.html#a0ba5c820c760788ea5f8e40c476f9704
-func (g *FilterGraph) NbFilters() int {
-	return int(g.c.nb_filters)
-}
-
-// https://ffmpeg.org/doxygen/7.0/structAVFilterGraph.html#a1dafd3d239f7c2f5e3ac109578ef926d
-func (g *FilterGraph) Filters() (fs []*FilterContext) {
-	fcs := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.AVFilterContext)(nil))](*C.AVFilterContext))(unsafe.Pointer(g.c.filters))
-	for i := 0; i < g.NbFilters(); i++ {
-		fs = append(fs, newFilterContext(fcs[i]))
-	}
-	return
-}
diff --git a/filter_graph_test.go b/filter_graph_test.go
index 0f1b533..9e5d11d 100644
--- a/filter_graph_test.go
+++ b/filter_graph_test.go
@@ -247,43 +247,6 @@ func TestFilterGraph(t *testing.T) {
 	require.Equal(t, 1, len(os))
 	require.Equal(t, MediaTypeAudio, os[0].MediaType())
 
-	fg3 := AllocFilterGraph()
-	require.NotNil(t, fg3)
-	defer fg3.Free()
-	outputs := AllocFilterInOut()
-	br := FindFilterByName("buffer")
-	brCtx, err := fg3.NewBuffersrcFilterContext(br, "in")
-	require.NoError(t, err)
-	brCtxParameters := AllocBuffersrcFilterContextParameters()
-	brCtxParameters.SetPixelFormat(PixelFormatYuv420P)
-	brCtxParameters.SetSampleAspectRatio(NewRational(1, 1))
-	brCtxParameters.SetWidth(1080)
-	brCtxParameters.SetHeight(720)
-	brCtxParameters.SetTimeBase(NewRational(1, 30))
-	err = brCtx.SetParameters(brCtxParameters)
-	require.NoError(t, err)
-	err = brCtx.Initialize(nil)
-	require.NoError(t, err)
-	outputs.SetName("in")
-	outputs.SetFilterContext(brCtx.FilterContext())
-	outputs.SetPadIdx(0)
-	outputs.SetNext(nil)
-	inputs := AllocFilterInOut()
-	bs := FindFilterByName("buffersink")
-	bsCtx, err := fg3.NewBuffersinkFilterContext(bs, "out")
-	require.NoError(t, err)
-	inputs.SetName("out")
-	inputs.SetFilterContext(bsCtx.FilterContext())
-	inputs.SetPadIdx(0)
-	inputs.SetNext(nil)
-	err = fg3.Parse("movie=filename=testdata/video.mp4[mv];[in][mv]overlay=x=100:y=100[ol];[ol]scale=w=1080:h=720[out]", outputs, inputs)
-	require.NoError(t, err)
-	var filterNames string
-	for _, filterContext := range fg3.Filters() {
-		filterNames += fmt.Sprintf("[%s]", filterContext.Class().ItemName())
-	}
-	require.Equal(t, "[in][out][Parsed_movie_0][Parsed_overlay_1][Parsed_scale_2]", filterNames)
-
 	// TODO Test BuffersrcAddFrame
 	// TODO Test BuffersinkGetFrame
 }