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galene/rtpconn/rtpreader.go

118 lines
2.4 KiB
Go

package rtpconn
import (
"io"
"log"
"strings"
"github.com/pion/rtp"
"github.com/pion/rtp/codecs"
"github.com/pion/webrtc/v3"
"galene/packetcache"
"galene/rtptime"
)
func isVP8Keyframe(packet *rtp.Packet) bool {
var vp8 codecs.VP8Packet
_, err := vp8.Unmarshal(packet.Payload)
if err != nil {
return false
}
return vp8.S != 0 && vp8.PID == 0 &&
len(vp8.Payload) > 0 && (vp8.Payload[0]&0x1) == 0
}
func readLoop(conn *rtpUpConnection, track *rtpUpTrack) {
writers := rtpWriterPool{conn: conn, track: track}
defer func() {
writers.close()
close(track.readerDone)
}()
isvideo := track.track.Kind() == webrtc.RTPCodecTypeVideo
codec := track.track.Codec()
sendNACK := track.hasRtcpFb("nack", "")
buf := make([]byte, packetcache.BufSize)
var packet rtp.Packet
for {
bytes, err := track.track.Read(buf)
if err != nil {
if err != io.EOF {
log.Printf("%v", err)
}
break
}
track.rate.Accumulate(uint32(bytes))
err = packet.Unmarshal(buf[:bytes])
if err != nil {
log.Printf("%v", err)
continue
}
track.jitter.Accumulate(packet.Timestamp)
kf := false
if isvideo && strings.ToLower(codec.MimeType) == "video/vp8" {
kf = isVP8Keyframe(&packet)
}
first, index := track.cache.Store(
packet.SequenceNumber, packet.Timestamp,
kf, packet.Marker, buf[:bytes],
)
_, rate := track.rate.Estimate()
delta := packet.SequenceNumber - first
if (delta & 0x8000) != 0 {
delta = 0
}
// send a NACK if a packet is late by 65ms or 2 packets,
// whichever is more
packets := rate / 16
if packets > 24 {
packets = 24
}
if packets < 2 {
packets = 2
}
// send NACKs for more recent packets, this makes better
// use of the NACK bitmap
unnacked := uint16(4)
if unnacked > uint16(packets) {
unnacked = uint16(packets)
}
if uint32(delta) > packets {
found, first, bitmap := track.cache.BitmapGet(
packet.SequenceNumber - unnacked,
)
if found && sendNACK {
err := conn.sendNACK(track, first, bitmap)
if err != nil {
log.Printf("%v", err)
}
}
}
delay := uint32(rtptime.JiffiesPerSec / 1024)
if rate > 512 {
delay = rtptime.JiffiesPerSec / rate / 2
}
writers.write(packet.SequenceNumber, index, delay,
isvideo, packet.Marker)
select {
case action := <-track.localCh:
err := writers.add(action.track, action.add)
if err != nil {
log.Printf("add/remove track: %v", err)
}
default:
}
}
}