mediamtx/internal/formatprocessor/mpeg4_video.go

173 lines
3.8 KiB
Go

package formatprocessor //nolint:dupl
import (
"bytes"
"errors"
"fmt"
"time"
"github.com/bluenviron/gortsplib/v4/pkg/format"
"github.com/bluenviron/gortsplib/v4/pkg/format/rtpmpeg4video"
"github.com/bluenviron/mediacommon/pkg/codecs/mpeg4video"
"github.com/pion/rtp"
"github.com/bluenviron/mediamtx/internal/unit"
)
// MPEG-4 video related parameters
var (
MPEG4VideoDefaultConfig = []byte{
0x00, 0x00, 0x01, 0xb0, 0x01, 0x00, 0x00, 0x01,
0xb5, 0x89, 0x13, 0x00, 0x00, 0x01, 0x00, 0x00,
0x00, 0x01, 0x20, 0x00, 0xc4, 0x8d, 0x88, 0x00,
0xf5, 0x3c, 0x04, 0x87, 0x14, 0x63, 0x00, 0x00,
0x01, 0xb2, 0x4c, 0x61, 0x76, 0x63, 0x35, 0x38,
0x2e, 0x31, 0x33, 0x34, 0x2e, 0x31, 0x30, 0x30,
}
)
type formatProcessorMPEG4Video struct {
udpMaxPayloadSize int
format *format.MPEG4Video
encoder *rtpmpeg4video.Encoder
decoder *rtpmpeg4video.Decoder
randomStart uint32
}
func newMPEG4Video(
udpMaxPayloadSize int,
forma *format.MPEG4Video,
generateRTPPackets bool,
) (*formatProcessorMPEG4Video, error) {
t := &formatProcessorMPEG4Video{
udpMaxPayloadSize: udpMaxPayloadSize,
format: forma,
}
if generateRTPPackets {
err := t.createEncoder()
if err != nil {
return nil, err
}
t.randomStart, err = randUint32()
if err != nil {
return nil, err
}
}
return t, nil
}
func (t *formatProcessorMPEG4Video) createEncoder() error {
t.encoder = &rtpmpeg4video.Encoder{
PayloadMaxSize: t.udpMaxPayloadSize - 12,
PayloadType: t.format.PayloadTyp,
}
return t.encoder.Init()
}
func (t *formatProcessorMPEG4Video) updateTrackParameters(frame []byte) {
if bytes.HasPrefix(frame, []byte{0, 0, 1, byte(mpeg4video.VisualObjectSequenceStartCode)}) {
end := bytes.Index(frame[4:], []byte{0, 0, 1, byte(mpeg4video.GroupOfVOPStartCode)})
if end < 0 {
return
}
conf := frame[:end+4]
if !bytes.Equal(conf, t.format.Config) {
t.format.SafeSetParams(conf)
}
}
}
func (t *formatProcessorMPEG4Video) remuxFrame(frame []byte) []byte {
if bytes.HasPrefix(frame, []byte{0, 0, 1, byte(mpeg4video.VisualObjectSequenceStartCode)}) {
end := bytes.Index(frame[4:], []byte{0, 0, 1, byte(mpeg4video.GroupOfVOPStartCode)})
if end >= 0 {
frame = frame[end+4:]
}
}
if bytes.Contains(frame, []byte{0, 0, 1, byte(mpeg4video.GroupOfVOPStartCode)}) {
f := make([]byte, len(t.format.Config)+len(frame))
n := copy(f, t.format.Config)
copy(f[n:], frame)
frame = f
}
return frame
}
func (t *formatProcessorMPEG4Video) ProcessUnit(uu unit.Unit) error { //nolint:dupl
u := uu.(*unit.MPEG4Video)
t.updateTrackParameters(u.Frame)
u.Frame = t.remuxFrame(u.Frame)
if len(u.Frame) != 0 {
pkts, err := t.encoder.Encode(u.Frame)
if err != nil {
return err
}
for _, pkt := range u.RTPPackets {
pkt.Timestamp += t.randomStart + uint32(u.PTS)
}
u.RTPPackets = pkts
}
return nil
}
func (t *formatProcessorMPEG4Video) ProcessRTPPacket( //nolint:dupl
pkt *rtp.Packet,
ntp time.Time,
pts int64,
hasNonRTSPReaders bool,
) (unit.Unit, error) {
u := &unit.MPEG4Video{
Base: unit.Base{
RTPPackets: []*rtp.Packet{pkt},
NTP: ntp,
PTS: pts,
},
}
t.updateTrackParameters(pkt.Payload)
// remove padding
pkt.Header.Padding = false
pkt.PaddingSize = 0
if pkt.MarshalSize() > t.udpMaxPayloadSize {
return nil, fmt.Errorf("payload size (%d) is greater than maximum allowed (%d)",
pkt.MarshalSize(), t.udpMaxPayloadSize)
}
// decode from RTP
if hasNonRTSPReaders || t.decoder != nil {
if t.decoder == nil {
var err error
t.decoder, err = t.format.CreateDecoder()
if err != nil {
return nil, err
}
}
frame, err := t.decoder.Decode(pkt)
if err != nil {
if errors.Is(err, rtpmpeg4video.ErrMorePacketsNeeded) {
return u, nil
}
return nil, err
}
u.Frame = t.remuxFrame(frame)
}
// route packet as is
return u, nil
}