add view.go and docs

README

@@ -1,5 +0,0 @@
-# ffmpeg-go
-
-ffmpeg-go is golang port of https://github.com/kkroening/ffmpeg-python
-
-check ffmpeg_test.go for examples.

README.md

@@ -0,0 +1,41 @@
+# ffmpeg-go
+
+ffmpeg-go is golang port of https://github.com/kkroening/ffmpeg-python
+
+check ffmpeg_test.go for examples.
+
+
+# example 
+
+```go
+split := Input(TestInputFile1).VFlip().Split()
+	split0, split1 := split.Get("0"), split.Get("1")
+	overlayFile := Input(TestOverlayFile).Crop(10, 10, 158, 112)
+err := Concat([]*Stream{
+    split0.Trim(KwArgs{"start_frame": 10, "end_frame": 20}),
+    split1.Trim(KwArgs{"start_frame": 30, "end_frame": 40})}).
+    Overlay(overlayFile.HFlip(), "").
+    DrawBox(50, 50, 120, 120, "red", 5).
+    Output(TestOutputFile1).
+    OverWriteOutput().
+    Run()
+```
+
+# view
+
+function view generate [mermaid](https://mermaid-js.github.io/mermaid/#/) chart, which can be use in markdown or view [online](mermaid-js.github.io/mermaid-live-editor/)
+
+```go
+split := Input(TestInputFile1).VFlip().Split()
+	split0, split1 := split.Get("0"), split.Get("1")
+	overlayFile := Input(TestOverlayFile).Crop(10, 10, 158, 112)
+b, err := Concat([]*Stream{
+    split0.Trim(KwArgs{"start_frame": 10, "end_frame": 20}),
+    split1.Trim(KwArgs{"start_frame": 30, "end_frame": 40})}).
+    Overlay(overlayFile.HFlip(), "").
+    DrawBox(50, 50, 120, 120, "red", 5).
+    Output(TestOutputFile1).
+    OverWriteOutput().View(ViewTypeFlowChart)
+fmt.Println(b)
+```
+![image](./docs/flowchart2.png)

ffmpeg_test.go

@@ -278,3 +278,14 @@ func TestPipe(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, outBuf.Len(), frameSize*(frameCount-startFrame))
 }
+
+func TestView(t *testing.T) {
+	a, err := ComplexFilterExample().View(ViewTypeFlowChart)
+	assert.Nil(t, err)
+
+	b, err := ComplexFilterAsplitExample().View(ViewTypeStateDiagram)
+	assert.Nil(t, err)
+
+	t.Log(a)
+	t.Log(b)
+}

view.go

@@ -0,0 +1,97 @@
+package ffmpeg_go
+
+import (
+	"bytes"
+	"fmt"
+)
+
+type ViewType string
+
+const (
+	// FlowChart the diagram type for output in flowchart style (https://mermaid-js.github.io/mermaid/#/flowchart) (including current state
+	ViewTypeFlowChart ViewType = "flowChart"
+	// StateDiagram the diagram type for output in stateDiagram style (https://mermaid-js.github.io/mermaid/#/stateDiagram)
+	ViewTypeStateDiagram ViewType = "stateDiagram"
+)
+
+func (s *Stream) View(viewType ViewType) (string, error) {
+	switch viewType {
+	case ViewTypeFlowChart:
+		return visualizeForMermaidAsFlowChart(s)
+	case ViewTypeStateDiagram:
+		return visualizeForMermaidAsStateDiagram(s)
+	default:
+		return "", fmt.Errorf("unknown ViewType: %s", viewType)
+	}
+}
+
+func visualizeForMermaidAsStateDiagram(s *Stream) (string, error) {
+	var buf bytes.Buffer
+
+	nodes := getStreamSpecNodes([]*Stream{s})
+	var dagNodes []DagNode
+	for i := range nodes {
+		dagNodes = append(dagNodes, nodes[i])
+	}
+	sorted, outGoingMap, err := TopSort(dagNodes)
+	if err != nil {
+		return "", err
+	}
+
+	buf.WriteString("stateDiagram\n")
+
+	for _, node := range sorted {
+		next := outGoingMap[node.Hash()]
+		for k, v := range next {
+			for _, nextNode := range v {
+				label := string(k)
+				if label == "" {
+					label = "<>"
+				}
+				buf.WriteString(fmt.Sprintf(`    %s --> %s: %s`, node.ShortRepr(), nextNode.Node.ShortRepr(), label))
+				buf.WriteString("\n")
+			}
+		}
+	}
+	return buf.String(), nil
+}
+
+// visualizeForMermaidAsFlowChart outputs a visualization of a FSM in Mermaid format (including highlighting of current state).
+func visualizeForMermaidAsFlowChart(s *Stream) (string, error) {
+	var buf bytes.Buffer
+
+	nodes := getStreamSpecNodes([]*Stream{s})
+	var dagNodes []DagNode
+	for i := range nodes {
+		dagNodes = append(dagNodes, nodes[i])
+	}
+	sorted, outGoingMap, err := TopSort(dagNodes)
+	if err != nil {
+		return "", err
+	}
+	buf.WriteString("graph LR\n")
+
+	for _, node := range sorted {
+		buf.WriteString(fmt.Sprintf(`    %d[%s]`, node.Hash(), node.ShortRepr()))
+		buf.WriteString("\n")
+	}
+	buf.WriteString("\n")
+
+	for _, node := range sorted {
+		next := outGoingMap[node.Hash()]
+		for k, v := range next {
+			for _, nextNode := range v {
+				label := string(k)
+				if label == "" {
+					label = "<>"
+				}
+				buf.WriteString(fmt.Sprintf(`    %d --> |%s| %d`, node.Hash(), label, nextNode.Node.Hash()))
+				buf.WriteString("\n")
+			}
+		}
+	}
+
+	buf.WriteString("\n")
+
+	return buf.String(), nil
+}