func main() {
name := flag.String("o", "./merge.flv", "merged flv name")
flag.Parse()
if flag.NArg() == 0 {
flag.PrintDefaults()
return
}
flvs := make([]*flv.FLV, flag.NArg())
for i := 0; i < len(flvs); i++ {
flvs[i] = flv.New()
}
for i, name := range flag.Args() {
r, err := os.Open(name)
if err != nil {
fmt.Println(err)
return
}
err = flvs[i].ReadFrom(r)
if err != nil {
fmt.Println(err)
return
}
r.Close()
}
for i := 1; i < len(flvs); i++ {
err := flvs[0].Append(flvs[i])
if err != nil {
fmt.Println(err)
return
}
}
w, err := os.Create(*name)
if err != nil {
fmt.Println(err)
return
}
err = flvs[0].WriteTo(w)
if err != nil {
fmt.Println(err)
return
}
w.Close()
}
func MergeFlv(files []string, file string) {
flvs := make([]*flv.Flv, len(files))
for i := 0; i < len(flvs); i++ {
flvs[i] = flv.New()
}
for i, name := range files {
r, err := os.Open(name)
if err != nil {
fmt.Println(err)
return
}
err = flvs[i].ReadFrom(r)
if err != nil {
fmt.Println(err)
return
}
r.Close()
}
r := amf.New()
script := flvs[0].Tags[0].Data
_, script, _ = r.DecodeAMF0(script)
info, script, _ := r.DecodeAMF0(script)
meta := info.(amf.ECMA)
var step int
l := len(flvs[0].Tags)
/*
i,n:=0,0
a,b:=0,0
for ;i<l;i++{
if flvs[0].Tags[i].Video() {
break
}
}
a=i
for l--;i<l;i++{
if flvs[0].Tags[i].Video() {
b=i
n++
}
}
step = (flvs[0].Tags[b].Video()-flvs[0].Tags[a].Video())/n
*/
if rate, ok := meta.Get("framerate").(float64); ok {
step = int(1000 / rate)
} else {
var a [2]int
for i, j := 1, 0; j < 2 && i < l; i++ {
if flvs[0].Tags[i].Video() {
a[j] = i
j++
}
}
step = flvs[0].Tags[a[1]].Time() - flvs[0].Tags[a[0]].Time()
}
place := []int{}
times := []int{}
for i := 1; i < len(flvs); i++ {
l += len(flvs[i].Tags) - 1
}
tag := make([]flv.Tag, l)
copy(tag, flvs[0].Tags)
l = len(flvs[0].Tags)
d, v, a, p := 0, 0, 0, 0
for i := 1; i < l; i++ {
if tag[i].Video() {
if flv.Keyframe(tag[i].Data[0]) {
place = append(place, p)
times = append(times, tag[i].Time())
}
v += tag[i].Size()
} else if tag[i].Audio() {
a += tag[i].Size()
} else if tag[i].Script() {
d += tag[i].Size()
}
p += tag[i].Size() + 15
}
for _, one := range flvs[1:] {
x, y := l-1, 0
for !tag[x].Video() {
x--
}
for !one.Tags[y].Video() {
y++
}
move := tag[x].Time() - one.Tags[y].Time() + step
for i := 1; i < len(one.Tags); i, l = i+1, l+1 {
tag[l] = one.Tags[i]
tag[l].SetTime(tag[l].Time() + move)
if tag[l].Video() {
if flv.Keyframe(tag[l].Data[0]) {
place = append(place, p)
times = append(times, tag[l].Time())
}
v += tag[i].Size()
} else if tag[i].Audio() {
a += tag[i].Size()
} else if tag[i].Script() {
d += tag[i].Size()
}
p += tag[l].Size() + 15
}
}
num := len(times)
if tag[l-1].Time()-tag[l-2].Time() > step {
lasttime := tag[l-2].Time() + step
tag[l-1].SetTime(lasttime)
if tag[l-1].Video() {
if flv.Keyframe(tag[l-1].Data[0]) {
times[num-1] = lasttime
}
}
}
r.Reset()
meta.Del("keyframes")
remain, _ := r.CountAMF0(meta)
header := len(flvs[0].Head) + 4
offset := 11 + 13 + (remain + 18*num + 47) + 3 + 4
positions := make([]interface{}, num)
timestamps := make([]interface{}, num)
for i := 0; i < num; i++ {
positions[i] = float64(place[i] + offset)
timestamps[i] = float64(times[i])
}
duration := float64(tag[l-1].Time()) / 1000
meta.Set("duration", duration)
meta.Set("lasttimestamp", duration)
frame := amf.NewECMA()
frame.Set("filepositions", amf.Strict(positions))
frame.Set("times", amf.Strict(timestamps))
meta.Set("keyframes", amf.Object{"", frame})
meta.Set("filesize", float64(p+offset+header))
meta.Set("datasize", float64(d))
meta.Set("audiosize", float64(a))
meta.Set("videosize", float64(v))
meta.Set("lastkeyframelocation", positions[num-1])
meta.Set("lastkeyframetimestamp", timestamps[num-1])
sx, _ := r.EncodeAMF0("onMetaData")
sy, _ := r.EncodeAMF0(meta)
tag[0].Data = bytes.Join([][]byte{sx, sy, []byte{0, 0, 9}}, nil)
tag[0].SetSize(len(tag[0].Data))
flvs[0].Tags = tag
w, err := os.Create(file)
if err != nil {
fmt.Println(err)
return
}
flvs[0].WriteTo(w)
w.Close()
}