diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..54f589e
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,3 @@
+.PHONY: test
+test:
+	go test -v ./... -cover
\ No newline at end of file
diff --git a/ffmpeg.go b/ffmpeg.go
index 893f3ab..9988acd 100644
--- a/ffmpeg.go
+++ b/ffmpeg.go
@@ -2,72 +2,63 @@ package ffmpeg
 
 import (
 	"context"
-	"errors"
-	"fmt"
+	"log"
 	"os/exec"
-	"strings"
+
+	"fxkt.tech/ffmpeg/filter"
+	"fxkt.tech/ffmpeg/input"
+	"fxkt.tech/ffmpeg/output"
 )
 
 type FFmpeg struct {
-	cmd     string
-	infiles []string
-	filters []*Filter
-	outputs []*Output
-
+	cmd      string
+	y        bool // y is yes for cover output file.
+	inputs   input.Inputs
+	filters  filter.Filters
+	outputs  output.Outputs
 	Sentence string
 }
 
-func NewFFmpeg() *FFmpeg {
+func Default() *FFmpeg {
 	return &FFmpeg{
 		cmd: "ffmpeg",
+		y:   true,
 	}
 }
 
-func (ff *FFmpeg) ChangeCmd(cmd string) {
-	ff.cmd = cmd
+func (ff *FFmpeg) Yes(y bool) {
+	ff.y = y
 }
 
-func (ff *FFmpeg) AddInputs(inputs ...string) {
-	ff.infiles = append(ff.infiles, inputs...)
+func (ff *FFmpeg) AddInput(inputs ...*input.Input) {
+	ff.inputs = append(ff.inputs, inputs...)
 }
 
-func (ff *FFmpeg) AddFilter(filters ...*Filter) {
+func (ff *FFmpeg) AddFilter(filters ...*filter.Filter) {
 	ff.filters = append(ff.filters, filters...)
 }
 
-func (ff *FFmpeg) OutputGraph(output ...*Output) {
-	ff.outputs = output
+func (ff *FFmpeg) AddOutput(outputs ...*output.Output) {
+	ff.outputs = append(ff.outputs, outputs...)
 }
 
-func (ff *FFmpeg) combination() []string {
-	var params []string
-	params = append(params, "-y")
-	for _, infile := range ff.infiles {
-		params = append(params, "-i", infile)
+func (ff *FFmpeg) Params() (params []string) {
+	if ff.y {
+		params = append(params, "-y")
 	}
-
-	var filtersStr []string
-	for _, filter := range ff.filters {
-		filtersStr = append(filtersStr, filter.String())
-	}
-	params = append(params, "-filter_complex", strings.Join(filtersStr, ";"))
-	for _, op := range ff.outputs {
-		params = append(params, op.params...)
-	}
-	return params
+	params = append(params, ff.inputs.Params()...)
+	params = append(params, ff.filters.String())
+	params = append(params, ff.outputs.Params()...)
+	return
 }
 
-func (ff *FFmpeg) Run() error {
-	params := ff.combination()
-	cmd := exec.CommandContext(context.Background(), ff.cmd, params...)
-	ff.Sentence = cmd.String()
-	fmt.Println(ff.Sentence)
-	outBytes, err := cmd.CombinedOutput()
-	fmt.Println(string(outBytes))
-
-	if err != nil || cmd.ProcessState.ExitCode() != 0 {
-		sls := strings.Split(string(outBytes), "\n")
-		err = errors.New(strings.ReplaceAll(strings.Join(sls[len(sls)-4:len(sls)-1], "|"), "\n", "|"))
+func (ff *FFmpeg) Run(ctx context.Context) (err error) {
+	cc := exec.CommandContext(ctx, ff.cmd, ff.Params()...)
+	ff.Sentence = cc.String()
+	retbytes, err := cc.CombinedOutput()
+	if err != nil {
+		return
 	}
-	return err
+	log.Println(string(retbytes))
+	return
 }
diff --git a/ffmpeg_test.go b/ffmpeg_test.go
new file mode 100644
index 0000000..05ff503
--- /dev/null
+++ b/ffmpeg_test.go
@@ -0,0 +1,41 @@
+package ffmpeg
+
+import (
+	"context"
+	"testing"
+
+	"fxkt.tech/ffmpeg/filter"
+	"fxkt.tech/ffmpeg/input"
+	"fxkt.tech/ffmpeg/output"
+)
+
+func TestFFmpeg(t *testing.T) {
+	ff := Default()
+	ff.AddInput(
+		input.New(
+			input.SetI("vieo.mp4"),
+		),
+	)
+	ff.AddFilter(
+		filter.New(
+			filter.SetInStream("0"),
+			filter.SetContent("scale=trunc(oh*a/2)*2:720"),
+			filter.SetOutStream("x720"),
+		),
+		filter.New(
+			filter.SetInStream("x720"),
+			filter.SetContent("delogo=0:0:100:100"),
+			filter.SetOutStream("xx720"),
+		),
+	)
+	ff.AddOutput(
+		output.New(
+			output.SetMap("xx720"),
+			output.SetMap("0:a"),
+			output.SetMetadata("comment=yilan888"),
+			output.SetFile("out720.mp4"),
+		),
+	)
+	ff.Run(context.Background())
+	t.Log(ff.Sentence)
+}
diff --git a/filter.go b/filter.go
deleted file mode 100644
index 9220254..0000000
--- a/filter.go
+++ /dev/null
@@ -1,30 +0,0 @@
-package ffmpeg
-
-import "fmt"
-
-type Filter struct {
-	alias   string
-	content string
-	others  []string
-}
-
-func NewFilter(alias string, content string, others ...string) *Filter {
-	return &Filter{
-		alias:   alias,
-		content: content,
-		others:  others,
-	}
-}
-
-//
-func (f *Filter) String() string {
-	var steamsAlias string
-	for _, other := range f.others {
-		steamsAlias = fmt.Sprintf("%s[%s]", steamsAlias, other)
-	}
-	var alias string
-	if f.alias != "" {
-		alias = fmt.Sprintf("[%s]", f.alias)
-	}
-	return fmt.Sprintf("%s%s%s", steamsAlias, f.content, alias)
-}
diff --git a/filter/filter.go b/filter/filter.go
new file mode 100644
index 0000000..8e7b45f
--- /dev/null
+++ b/filter/filter.go
@@ -0,0 +1,44 @@
+package filter
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Filter struct {
+	// instreams  []string
+	// content    string
+	// outstreams []string
+	opt *option
+}
+
+func New(opts ...OptionFunc) *Filter {
+	o := &option{}
+	for _, opt := range opts {
+		opt(o)
+	}
+	return &Filter{
+		opt: o,
+	}
+}
+
+func (f *Filter) Params() (params []string) {
+	if len(f.opt.instreams) != 0 {
+		for _, stream := range f.opt.instreams {
+			params = append(params, fmt.Sprintf("[%s]", stream))
+		}
+	}
+	if f.opt.content != "" {
+		params = append(params, f.opt.content)
+	}
+	if len(f.opt.outstreams) != 0 {
+		for _, stream := range f.opt.outstreams {
+			params = append(params, fmt.Sprintf("[%s]", stream))
+		}
+	}
+	return
+}
+
+func (f *Filter) String() string {
+	return strings.Join(f.Params(), "")
+}
diff --git a/filter/filter_option.go b/filter/filter_option.go
new file mode 100644
index 0000000..3d3153c
--- /dev/null
+++ b/filter/filter_option.go
@@ -0,0 +1,27 @@
+package filter
+
+type OptionFunc func(*option)
+
+type option struct {
+	instreams  []string
+	content    string
+	outstreams []string
+}
+
+func SetInStream(s string) OptionFunc {
+	return func(o *option) {
+		o.instreams = append(o.instreams, s)
+	}
+}
+
+func SetContent(c string) OptionFunc {
+	return func(o *option) {
+		o.content = c
+	}
+}
+
+func SetOutStream(s string) OptionFunc {
+	return func(o *option) {
+		o.outstreams = append(o.outstreams, s)
+	}
+}
diff --git a/filter/filters.go b/filter/filters.go
new file mode 100644
index 0000000..9f013ca
--- /dev/null
+++ b/filter/filters.go
@@ -0,0 +1,16 @@
+package filter
+
+import "strings"
+
+type Filters []*Filter
+
+func (filters Filters) Params() (params []string) {
+	for _, filter := range filters {
+		params = append(params, filter.String())
+	}
+	return
+}
+
+func (filters Filters) String() string {
+	return strings.Join(filters.Params(), ";")
+}
diff --git a/input/input.go b/input/input.go
index d262f5f..747a4c9 100644
--- a/input/input.go
+++ b/input/input.go
@@ -5,22 +5,33 @@ import (
 	"strings"
 )
 
-// Input is 输入.
+// Input is common input info.
 type Input struct {
-	i   string   // 输入的媒体文件
-	ss  int64    // 媒体文件选择的起始时间点
-	t   int64    //从起始时间开始的持续时间
-	ext []string // 额外字段
+	// i   string   // i is input file.
+	// ss  int64    // ss is starttime.
+	// t   int64    // t is duration.
+	// ext []string // extra params.
+	opt *option
+}
+
+func New(opts ...OptionFunc) *Input {
+	o := &option{}
+	for _, opt := range opts {
+		opt(o)
+	}
+	return &Input{
+		opt: o,
+	}
 }
 
 func (i *Input) Params() (params []string) {
-	if i.ss != 0 {
-		params = append(params, "-ss", strconv.FormatInt(i.ss, 10))
+	if i.opt.ss != 0 {
+		params = append(params, "-ss", strconv.FormatInt(i.opt.ss, 10))
 	}
-	if i.t != 0 {
-		params = append(params, "-t", strconv.FormatInt(i.t, 10))
+	if i.opt.t != 0 {
+		params = append(params, "-t", strconv.FormatInt(i.opt.t, 10))
 	}
-	params = append(params, "-i", i.i)
+	params = append(params, "-i", i.opt.i)
 	return
 }
 
diff --git a/input/input_option.go b/input/input_option.go
new file mode 100644
index 0000000..4c6b930
--- /dev/null
+++ b/input/input_option.go
@@ -0,0 +1,16 @@
+package input
+
+type OptionFunc func(*option)
+
+type option struct {
+	i   string   // i is input file.
+	ss  int64    // ss is starttime.
+	t   int64    // t is duration.
+	ext []string // extra params.
+}
+
+func SetI(i string) OptionFunc {
+	return func(o *option) {
+		o.i = i
+	}
+}
diff --git a/input/inputs.go b/input/inputs.go
new file mode 100644
index 0000000..e558d17
--- /dev/null
+++ b/input/inputs.go
@@ -0,0 +1,10 @@
+package input
+
+type Inputs []*Input
+
+func (inputs Inputs) Params() (params []string) {
+	for _, input := range inputs {
+		params = append(params, input.Params()...)
+	}
+	return
+}
diff --git a/internal/pkg/strconv/strconv.go b/internal/pkg/strconv/strconv.go
new file mode 100644
index 0000000..402b013
--- /dev/null
+++ b/internal/pkg/strconv/strconv.go
@@ -0,0 +1,31 @@
+package strconv
+
+import "strconv"
+
+func ToInt32(s string) (int32, error) {
+	i, err := strconv.ParseInt(s, 10, 32)
+	if err != nil {
+		return 0, err
+	}
+	return int32(i), nil
+}
+
+func ToInt64(s string) (int64, error) {
+	return strconv.ParseInt(s, 10, 64)
+}
+
+func ToInt32ByFloatString(s string) (int32, error) {
+	f, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0, err
+	}
+	return int32(f), nil
+}
+
+func ToInt64ByFloatString(s string) (int64, error) {
+	f, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0, err
+	}
+	return int64(f), nil
+}
diff --git a/output/outout.go b/output/outout.go
index 01d28b9..6a12877 100644
--- a/output/outout.go
+++ b/output/outout.go
@@ -1,6 +1,70 @@
 package output
 
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// Output is common output info.
 type Output struct {
-	maps []string
-	f    string
+	// maps                  []string // mean is -map.
+	// cv, ca                string   // cv is c:v, ca is c:a.
+	// metadatas             []string // mean is -metadata.
+	// threads               int32    // thread counts, default 4.
+	// max_muxing_queue_size int32    // queue size when muxing, default 4086.
+	// movflags              string   // location of mp4 moov.
+	// f                     string   // f is -f format.
+	// file                  string
+	opt *option
+}
+
+func New(opts ...OptionFunc) *Output {
+	o := &option{
+		threads:               4,
+		max_muxing_queue_size: 4086,
+		movflags:              "faststart",
+	}
+	for _, opt := range opts {
+		opt(o)
+	}
+	return &Output{
+		opt: o,
+	}
+}
+
+func (o *Output) Params() (params []string) {
+	if len(o.opt.maps) != 0 {
+		for _, m := range o.opt.maps {
+			params = append(params, "-map", fmt.Sprintf("[%s]", m))
+		}
+	}
+	if o.opt.cv != "" {
+		params = append(params, "c:v", o.opt.cv)
+	}
+	if o.opt.ca != "" {
+		params = append(params, "c:a", o.opt.ca)
+	}
+	if len(o.opt.metadatas) != 0 {
+		for _, m := range o.opt.metadatas {
+			params = append(params, "-metadata", m)
+		}
+	}
+	if o.opt.max_muxing_queue_size != 0 {
+		params = append(params, "-max_muxing_queue_size", strconv.FormatInt(int64(o.opt.max_muxing_queue_size), 10))
+	}
+	if o.opt.movflags != "" {
+		params = append(params, "-movflags", o.opt.movflags)
+	}
+	if o.opt.f != "" {
+		params = append(params, "-f", o.opt.f)
+	}
+	if o.opt.file != "" {
+		params = append(params, o.opt.file)
+	}
+	return
+}
+
+func (o *Output) String() string {
+	return strings.Join(o.Params(), " ")
 }
diff --git a/output/output_option.go b/output/output_option.go
new file mode 100644
index 0000000..3695a15
--- /dev/null
+++ b/output/output_option.go
@@ -0,0 +1,32 @@
+package output
+
+type OptionFunc func(*option)
+
+type option struct {
+	maps                  []string // mean is -map.
+	cv, ca                string   // cv is c:v, ca is c:a.
+	metadatas             []string // mean is -metadata.
+	threads               int32    // thread counts, default 4.
+	max_muxing_queue_size int32    // queue size when muxing, default 4086.
+	movflags              string   // location of mp4 moov.
+	f                     string   // f is -f format.
+	file                  string
+}
+
+func SetMap(m string) OptionFunc {
+	return func(o *option) {
+		o.maps = append(o.maps, m)
+	}
+}
+
+func SetMetadata(md string) OptionFunc {
+	return func(o *option) {
+		o.metadatas = append(o.metadatas, md)
+	}
+}
+
+func SetFile(f string) OptionFunc {
+	return func(o *option) {
+		o.file = f
+	}
+}
diff --git a/output/outputs.go b/output/outputs.go
new file mode 100644
index 0000000..092ddab
--- /dev/null
+++ b/output/outputs.go
@@ -0,0 +1,10 @@
+package output
+
+type Outputs []*Output
+
+func (Outputs Outputs) Params() (params []string) {
+	for _, output := range Outputs {
+		params = append(params, output.Params()...)
+	}
+	return
+}
diff --git a/question.md b/question.md
index f4fbfa1..5a10b3c 100644
--- a/question.md
+++ b/question.md
@@ -27,7 +27,7 @@ ffmpeg
 -y
 -t 5
 -i in.mp4 -i logo.png
--filter_complex '[0]delogo=1490:40:400:100[p1];[p1]split=2[p1_hd][p1_sd];[p1_hd]scale=-1:720[p2_hd];[p2_hd][1]overlay=W-w-10:10[p_hd];[p1_sd]scale=-1:540[p2_sd];[p2_sd][1]overlay=W-w-10:10[p_sd]'
+-filter_complex '[0]delogo=1490:40:400:100[p1];[p1]split=2[p1_hd][p1_sd];[p1_hd]scale=trunc(oh*a/2)*2:720[p2_hd];[p2_hd][1]overlay=W-w-10:10[p_hd];[p1_sd]scale=-1:540[p2_sd];[p2_sd][1]overlay=W-w-10:10[p_sd]'
 
 -map '[p_hd]'
 -map 0:a
@@ -40,4 +40,8 @@ ffmpeg
 out_hd.mp4
 
 -map '[p_sd]' -map 0:a -metadata comment=fu789sg -c:v libwz264 -c:a copy -threads 4 -max_muxing_queue_size 4086 -movflags faststart out_sd.mp4
-```
\ No newline at end of file
+
+trunc(oh*a/2)*2:720
+720:trunc(ow/a/2)*2
+```
+
diff --git a/test/example_test.go b/test/example_test.go
deleted file mode 100644
index 449b273..0000000
--- a/test/example_test.go
+++ /dev/null
@@ -1,47 +0,0 @@
-package test
-
-import (
-	"testing"
-
-	"fxkt.tech/ffmpeg"
-)
-
-func TestExample(t *testing.T) {
-	ff := ffmpeg.NewFFmpeg()
-	ff.AddInputs(
-		"video.mp4",
-		"logo.png",
-	)
-	ff.AddFilter(
-		ffmpeg.NewFilter("dl", `delogo=0:0:400:200`, "0"),
-		ffmpeg.NewFilter("d_480][d_360", `split=2`, "dl"),
-		ffmpeg.NewFilter("rlt_480", `scale=trunc(oh*a/2)*2:480`, "d_480"),
-		ffmpeg.NewFilter("rlt_360", `scale=trunc(oh*a/2)*2:360`, "d_360"),
-	)
-	ff.OutputGraph(
-		ffmpeg.NewOutput(
-			"-map", "[rlt_480]",
-			"-map", "0:a",
-			"-metadata", "comment=fu789sg",
-			"-c:v", "libx264", "-c:a", "copy",
-			"-threads", "4",
-			"-max_muxing_queue_size", "4086",
-			"-movflags", "faststart",
-			"out_480.mp4",
-		),
-		ffmpeg.NewOutput(
-			"-map", "[rlt_360]",
-			"-map", "0:a",
-			"-metadata", "comment=fu789sg",
-			"-c:v", "libx264", "-c:a", "copy",
-			"-threads", "4",
-			"-max_muxing_queue_size", "4086",
-			"-movflags", "faststart",
-			"out_480.mp4",
-		),
-	)
-	err := ff.Run()
-	if err != nil {
-		t.Fatal(err)
-	}
-}