mediamtx/internal/formatprocessor/mpeg2audio.go

115 lines
2.4 KiB
Go

package formatprocessor
import (
"fmt"
"time"
"github.com/bluenviron/gortsplib/v3/pkg/formats"
"github.com/bluenviron/gortsplib/v3/pkg/formats/rtpmpeg2audio"
"github.com/pion/rtp"
"github.com/bluenviron/mediamtx/internal/logger"
)
// UnitMPEG2Audio is a MPEG-1/2 Audio data unit.
type UnitMPEG2Audio struct {
BaseUnit
PTS time.Duration
Frames [][]byte
}
type formatProcessorMPEG2Audio struct {
udpMaxPayloadSize int
format *formats.MPEG2Audio
encoder *rtpmpeg2audio.Encoder
decoder *rtpmpeg2audio.Decoder
}
func newMPEG2Audio(
udpMaxPayloadSize int,
forma *formats.MPEG2Audio,
generateRTPPackets bool,
_ logger.Writer,
) (*formatProcessorMPEG2Audio, error) {
t := &formatProcessorMPEG2Audio{
udpMaxPayloadSize: udpMaxPayloadSize,
format: forma,
}
if generateRTPPackets {
err := t.createEncoder()
if err != nil {
return nil, err
}
}
return t, nil
}
func (t *formatProcessorMPEG2Audio) createEncoder() error {
t.encoder = &rtpmpeg2audio.Encoder{
PayloadMaxSize: t.udpMaxPayloadSize - 12,
}
return t.encoder.Init()
}
func (t *formatProcessorMPEG2Audio) Process(unit Unit, hasNonRTSPReaders bool) error { //nolint:dupl
tunit := unit.(*UnitMPEG2Audio)
if tunit.RTPPackets != nil {
pkt := tunit.RTPPackets[0]
// remove padding
pkt.Header.Padding = false
pkt.PaddingSize = 0
if pkt.MarshalSize() > t.udpMaxPayloadSize {
return 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.CreateDecoder2()
if err != nil {
return err
}
}
frames, pts, err := t.decoder.Decode(pkt)
if err != nil {
if err == rtpmpeg2audio.ErrNonStartingPacketAndNoPrevious || err == rtpmpeg2audio.ErrMorePacketsNeeded {
return nil
}
return err
}
tunit.Frames = frames
tunit.PTS = pts
}
// route packet as is
return nil
}
// encode into RTP
pkts, err := t.encoder.Encode(tunit.Frames, tunit.PTS)
if err != nil {
return err
}
tunit.RTPPackets = pkts
return nil
}
func (t *formatProcessorMPEG2Audio) UnitForRTPPacket(pkt *rtp.Packet, ntp time.Time) Unit {
return &UnitMPEG2Audio{
BaseUnit: BaseUnit{
RTPPackets: []*rtp.Packet{pkt},
NTP: ntp,
},
}
}