func permitSkip(frame flv.Frame) (isSkip bool) {
if frame.GetType() == flv.TAG_TYPE_META {
metaBody := frame.GetBody()
buf := bytes.NewReader(*metaBody)
dec := amf0.NewDecoder(buf)
evName, err := dec.Decode()
if err == nil {
switch evName {
case amf0.StringType("onMetaData"):
md, err := dec.Decode()
if err == nil {
var ea map[amf0.StringType]interface{}
switch md := md.(type) {
case *amf0.EcmaArrayType:
ea = *md
case *amf0.ObjectType:
ea = *md
}
for skipK, skipV := range skipMeta {
if s, ok := ea[amf0.StringType(skipK)]; ok {
for _, t := range skipV {
if amf0.StringType(t) == s {
return true
}
}
}
}
}
}
}
}
return false
}
func writeFrames(frReader *flv.FlvReader, frW map[flv.TagType]*flv.FlvWriter, offset int) (outOffset int) {
lastTs := make(map[flv.TagType]map[uint32]uint32)
lastTsDiff := make(map[flv.TagType]map[uint32]uint32)
shiftTs := make(map[flv.TagType]map[uint32]uint32)
for _, c := range []flv.TagType{flv.TAG_TYPE_VIDEO, flv.TAG_TYPE_AUDIO, flv.TAG_TYPE_META} {
lastTs[c] = make(map[uint32]uint32)
lastTsDiff[c] = make(map[uint32]uint32)
shiftTs[c] = make(map[uint32]uint32)
}
updateDts := func(cframe flv.Frame) (newDts uint32) {
c := cframe.GetType()
s := cframe.GetStream()
d := cframe.GetDts()
if lastTs[c][s] > d {
warnTs(lastTs[c][s], s, d)
if fixDts {
newDts := lastTs[c][s] + lastTsDiff[c][s]
shiftTs[c][s] = newDts - d
d += shiftTs[c][s]
}
}
d = uint32(int(float64(d)*scaleDts) + offset)
lastTsDiff[c][s] = d - lastTs[c][s]
lastTs[c][s] = d
return d
}
var lastInTs uint32 = 0
var compensateTs uint32 = 0
for {
var rframe flv.Frame
var err error
var skipBytes int
if readRecover {
rframe, err, skipBytes = frReader.ReadFrameRecover(maxFrameSize)
} else {
rframe, err = frReader.ReadFrame()
}
if err != nil {
log.Fatal(err)
}
if rframe != nil {
if readRecover {
if skipBytes > 0 {
log.Printf("Recover: skip %d bytes, recovered frame length: %d", skipBytes, len(*rframe.GetBody()))
}
if rframe.GetType() == flv.TAG_TYPE_META {
metaBody := rframe.GetBody()
buf := bytes.NewReader(*metaBody)
dec := amf0.NewDecoder(buf)
_, err := dec.Decode()
if err != nil {
log.Printf("Bad metadata at DTS %d", rframe.GetDts())
continue
}
}
}
isCrop := permitCrop(rframe)
isSkip := permitSkip(rframe)
isSplitStream := splitStreams && rframe.GetStream() != 0 && rframe.GetType() != flv.TAG_TYPE_META
if (streams[rframe.GetType()] != -1 && rframe.GetStream() != uint32(streams[rframe.GetType()])) || isCrop || isSkip || isSplitStream {
if compensateDts || isCrop {
compensateTs += (rframe.GetDts() - lastInTs)
}
lastInTs = rframe.GetDts()
if splitStreams {
err = writeStreamFrame(rframe, outOffset)
if err != nil {
log.Fatal(err)
}
}
continue
}
checkSplitWriters(outOffset)
lastInTs = rframe.GetDts()
newDts := updateDts(rframe) - compensateTs
if rframe.GetStream() == 0 {
outOffset = int(newDts)
}
rframe.SetDts(newDts)
err = frW[rframe.GetType()].WriteFrame(rframe)
if err != nil {
log.Fatal(err)
}
} else {
break
}
}
return
}