vdk/format/fmp4/hlsfrag.go

101 lines
2.4 KiB
Go
Raw Permalink Normal View History

2021-04-20 01:59:55 +08:00
package fmp4
import (
"errors"
"fmt"
"sync"
"time"
"github.com/deepch/vdk/av"
"github.com/deepch/vdk/format/fmp4/fmp4io"
"github.com/deepch/vdk/format/fmp4/fragment"
)
var (
shdrOnce sync.Once
shdr []byte
)
// MovieFragmenter breaks a stream into segments each containing both tracks from the original stream
type MovieFragmenter struct {
tracks []*TrackFragmenter
fhdr []byte
vidx int
seqNum uint32
shdrw bool
}
// NewMovie creates a movie fragmenter from a stream
func NewMovie(streams []av.CodecData) (*MovieFragmenter, error) {
f := &MovieFragmenter{
tracks: make([]*TrackFragmenter, len(streams)),
vidx: -1,
}
atoms := make([]*fmp4io.Track, len(streams))
var err error
for i, cd := range streams {
f.tracks[i], err = NewTrack(cd)
if err != nil {
return nil, fmt.Errorf("track %d: %w", i, err)
}
atoms[i] = f.tracks[i].atom
if cd.Type().IsVideo() {
f.vidx = i
}
}
if f.vidx < 0 {
return nil, errors.New("no video track found")
}
f.fhdr, err = MovieHeader(atoms)
if err != nil {
return nil, err
}
return f, err
}
// Fragment produces a fragment out of the currently-queued packets.
func (f *MovieFragmenter) Fragment() (fragment.Fragment, error) {
dur := f.tracks[f.vidx].Duration()
var tracks []fragmentWithData
for _, track := range f.tracks {
tf := track.makeFragment()
if tf.trackFrag != nil {
tracks = append(tracks, tf)
}
}
if len(tracks) == 0 {
return fragment.Fragment{}, nil
}
f.seqNum++
initial := !f.shdrw
f.shdrw = true
frag := marshalFragment(tracks, f.seqNum, initial)
frag.Duration = dur
return frag, nil
}
// WritePacket formats and queues a packet for the next fragment to be written
func (f *MovieFragmenter) WritePacket(pkt av.Packet) error {
return f.tracks[pkt.Idx].WritePacket(pkt)
}
// Duration calculates the elapsed duration between the first and last pending video frame
func (f *MovieFragmenter) Duration() time.Duration {
return f.tracks[f.vidx].Duration()
}
// MovieHeader marshals an init.mp4 for the fragmenter's tracks
func (f *MovieFragmenter) MovieHeader() (filename, contentType string, blob []byte) {
return "init.mp4", "video/mp4", f.fhdr
}
// NewSegment indicates that a new segment has begun and the next call to
// Fragment() should include a leading FTYP header
func (f *MovieFragmenter) NewSegment() {
f.shdrw = false
}
func (f *MovieFragmenter) TimeScale() uint32 {
return 90000
}