av/packets/RtpToTsConverter.go

230 lines
7.0 KiB
Go

/*
NAME
RtpToTsConverter.go - provides utilities for the conversion of Rtp packets
to equivalent MpegTs packets.
DESCRIPTION
See Readme.md
AUTHOR
Saxon Nelson-Milton <saxon.milton@gmail.com>
LICENSE
RtpToTsConverter.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with revid in gpl.txt. If not, see [GNU licenses](http://www.gnu.org/licenses).
*/
package packets
import (
_ "fmt"
"os"
)
type RtpToTsConverter interface {
Convert()
}
type rtpToTsConverter struct {
TsChan <-chan *MpegTsPacket
tsChan chan<- *MpegTsPacket
InputChan chan<- RtpPacket
inputChan <-chan RtpPacket
NalInputChan chan<- []byte
nalInputChan <-chan []byte
currentTsPacket *MpegTsPacket
payloadByteChan chan byte
currentCC byte
}
func NewRtpToTsConverter() (c *rtpToTsConverter) {
c = new(rtpToTsConverter)
tsChan := make(chan *MpegTsPacket, 100)
c.TsChan = tsChan
c.tsChan = tsChan
inputChan := make(chan RtpPacket, 100)
c.InputChan = inputChan
c.inputChan = inputChan
nalInputChan := make(chan []byte, 10000)
c.NalInputChan = nalInputChan
c.nalInputChan = nalInputChan
c.currentCC = 0
return
}
func (c *rtpToTsConverter) Convert() {
file, _ := os.Create("video")
pesPktChan := make(chan []byte, 1000)
pesDataChan := make(chan byte, 50000)
payloadByteChan := make(chan byte, 100000)
var rtpBuffer [](*RtpPacket)
for {
select {
default:
case rtpPacket := <-c.inputChan:
rtpBuffer = append(rtpBuffer, &rtpPacket)
if len(rtpBuffer) > 2 {
// if there's something weird going on with sequence numbers then
// insertion sort
if rtpPacket.SequenceNumber < rtpBuffer[len(rtpBuffer)-2].SequenceNumber {
for i := 1; i < len(rtpBuffer); i++ {
for j := i; j > 0 && rtpBuffer[j].SequenceNumber < rtpBuffer[j-1].SequenceNumber; j-- {
temp := rtpBuffer[j]
rtpBuffer[j] = rtpBuffer[j-1]
rtpBuffer[j-1] = temp
}
}
}
}
if len(rtpBuffer) > 200 {
// Discard everything before a type 7
for GetOctectType(rtpBuffer[0]) != 7 {
rtpBuffer = rtpBuffer[1:]
}
// get sps
sps := make([]byte, len(rtpBuffer[0].Payload))
copy(sps[:], rtpBuffer[0].Payload[:])
rtpBuffer = rtpBuffer[1:]
// get pps
pps := make([]byte, len(rtpBuffer[0].Payload))
copy(pps[:], rtpBuffer[0].Payload[:])
rtpBuffer = rtpBuffer[1:]
// get sei
sei := make([]byte, len(rtpBuffer[0].Payload))
copy(sei[:], rtpBuffer[0].Payload[:])
rtpBuffer = rtpBuffer[1:]
// while we haven't reached the next sps in the buffer
for GetOctectType(rtpBuffer[0]) != 7 {
switch GetOctectType(rtpBuffer[0]) {
case 28:
if GetStartBit(rtpBuffer[0]) == 1 {
var buffer []byte
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, []byte{0x09, 0x10}...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, sps...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, pps...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, sei...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, rtpBuffer[0].Payload[0]&0xE0|rtpBuffer[0].Payload[1]&0x1F)
buffer = append(buffer, rtpBuffer[0].Payload[2:]...)
rtpBuffer = rtpBuffer[1:]
for {
buffer = append(buffer, rtpBuffer[0].Payload[2:]...)
if getEndBit(rtpBuffer[0]) == 1 {
rtpBuffer = rtpBuffer[1:]
c.NalInputChan <- buffer
file.Write(buffer)
break
}
rtpBuffer = rtpBuffer[1:]
}
}
case 1:
var buffer []byte
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, []byte{0x09, 0x10}...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, sps...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, pps...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, sei...)
buffer = append(buffer, []byte{0x00, 0x00, 0x01}...)
buffer = append(buffer, rtpBuffer[0].Payload[0]&0xE0|rtpBuffer[0].Payload[1]&0x1F)
buffer = append(buffer, rtpBuffer[0].Payload[2:]...)
rtpBuffer = rtpBuffer[1:]
c.NalInputChan <- buffer
file.Write(buffer)
default:
}
}
}
case nalUnit := <-c.nalInputChan:
for ii := range nalUnit {
pesDataChan <- nalUnit[ii]
}
pesDataChanLen := len(nalUnit)
pesPkt := new(PESPacket)
pesPkt.StreamID = 0xE0
pesPkt.Length = uint16(3 + pesDataChanLen)
pesPkt.ScramblingControl = 0
pesPkt.Priority = true
pesPkt.DAI = false
pesPkt.Copyright = false
pesPkt.Original = true
pesPkt.PDI = 0
pesPkt.ESCR = false
pesPkt.ESRate = false
pesPkt.DSMTrickMode = false
pesPkt.ACI = false
pesPkt.CRC = false
pesPkt.Ext = false
pesPkt.HeaderLength = 0
pesPkt.Data = make([]byte, pesDataChanLen)
for ii := 0; ii < pesDataChanLen; ii++ {
pesPkt.Data[ii] = <-pesDataChan
}
pesPktChan <- pesPkt.ToByteSlice()
case pesPkt := <-pesPktChan:
for ii := range pesPkt {
payloadByteChan <- pesPkt[ii]
}
firstPacket := true
for len(payloadByteChan) > 0 {
lengthOfByteChan := len(payloadByteChan)
c.currentTsPacket = new(MpegTsPacket)
c.currentTsPacket.SyncByte = 0x47
c.currentTsPacket.TEI = false
c.currentTsPacket.PUSI = false
if firstPacket { // if it's the start of the payload
c.currentTsPacket.PUSI = true
firstPacket = false
}
c.currentTsPacket.Priority = false
c.currentTsPacket.PID = 256
c.currentTsPacket.TSC = 0
c.currentTsPacket.CC = c.currentCC
if c.currentCC++; c.currentCC > 15 {
c.currentCC = 0
}
payloadLength := 182
if lengthOfByteChan < 182 {
payloadLength = lengthOfByteChan
}
c.currentTsPacket.AFC = 3
stuffingLength := 182 - payloadLength
c.currentTsPacket.AF = make([]byte, 2+stuffingLength) // adaptationfield flag length = 16
c.currentTsPacket.AF[0] = byte(1 + stuffingLength)
c.currentTsPacket.AF[1] = 0
if c.currentTsPacket.PUSI {
c.currentTsPacket.AF[1] = 0x00
}
for ii := 0; ii < stuffingLength; ii++ {
c.currentTsPacket.AF[2+ii] = 0xFF
}
c.currentTsPacket.Payload = make([]byte, payloadLength)
for ii := 0; ii < payloadLength; ii++ {
c.currentTsPacket.Payload[ii] = <-payloadByteChan
}
c.tsChan <- c.currentTsPacket
}
}
}
}