func Stripped(src io.ReadSeeker) (*ioutil.SectionReader, error) {
o1, err := getFirstRealFrameOffset(src)
if err != nil {
return nil, err
}
o2, err := getLastFrameEnd(src)
if err != nil {
return nil, err
}
return ioutil.NewSectionReader(src, o1, o2-o1), nil
}
func Slice(src io.ReadSeeker, cutPoints ...time.Duration) ([]io.ReadSeeker, error) {
pieces := make([]io.ReadSeeker, 0, len(cutPoints)+1)
stripped, err := Stripped(src)
if err != nil {
return nil, err
}
start := stripped.Offset()
end := stripped.Offset() + stripped.Length()
frames, err := GetFrames(src)
if err != nil {
return nil, err
}
var elapsed time.Duration
lastOffset := start
for frames.Next() {
if len(cutPoints) == 0 {
break
}
elapsed += frames.Header().Duration
if cutPoints[0] <= elapsed {
piece := ioutil.NewSectionReader(src, lastOffset, frames.Offset()+frames.Header().Size-lastOffset)
pieces = append(pieces, piece)
lastOffset = frames.Offset() + frames.Header().Size
cutPoints = cutPoints[1:]
}
}
pieces = append(pieces, ioutil.NewSectionReader(src, lastOffset, end-lastOffset))
return pieces, frames.Error()
}