mirror
/
av
mirror of https://bitbucket.org/ausocean/av.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Merged in mpegts-testing (pull request #195) 

container/mts: testing for mpegts.go and encoder.go

Approved-by: Alan Noble <anoble@gmail.com>
This commit is contained in:
Saxon Milton 2019-05-13 07:09:08 +00:00
parent dc0ecf712d 51f4d123bf
commit 466552cbf9
7 changed files with 332 additions and 81 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
container/mts/discontinuity.go
View File

@ -4,8 +4,8 @@ NAME
DESCRIPTION
discontinuity.go provides functionality for detecting discontinuities in
mpegts and accounting for using the discontinuity indicator in the adaptation
field.
MPEG-TS and accounting for using the discontinuity indicator in the adaptation
field.
AUTHOR
Saxon A. Nelson-Milton <saxon@ausocean.org>
@ -33,7 +33,7 @@ import (
"github.com/Comcast/gots/packet"
)
// discontinuityRepairer provides function to detect discontinuities in mpegts
// discontinuityRepairer provides function to detect discontinuities in MPEG-TS
// and set the discontinuity indicator as appropriate.
type DiscontinuityRepairer struct {
expCC map[int]int
@ -56,7 +56,7 @@ func (dr *DiscontinuityRepairer) Failed() {
dr.decExpectedCC(PatPid)
}
// Repair takes a clip of mpegts and checks that the first packet, which should
// Repair takes a clip of MPEG-TS and checks that the first packet, which should
// be a PAT, contains a cc that is expected, otherwise the discontinuity indicator
// is set to true.
func (dr *DiscontinuityRepairer) Repair(d []byte) error {

10
container/mts/encoder.go
View File

@ -124,7 +124,7 @@ const (
pcrFreq = 90000 // Hz
)
// Encoder encapsulates properties of an mpegts generator.
// Encoder encapsulates properties of an MPEG-TS generator.
type Encoder struct {
dst io.WriteCloser
@ -201,7 +201,7 @@ func (e *Encoder) TimeBasedPsi(b bool, sendCount int) {
e.pktCount = e.psiSendCount
}
// Write implements io.Writer. Write takes raw h264 and encodes into mpegts,
// Write implements io.Writer. Write takes raw h264 and encodes into MPEG-TS,
// then sending it to the encoder's io.Writer destination.
func (e *Encoder) Write(data []byte) (int, error) {
now := time.Now()
@ -256,7 +256,7 @@ func (e *Encoder) Write(data []byte) (int, error) {
return len(data), nil
}
// writePSI creates mpegts with pat and pmt tables - with pmt table having updated
// writePSI creates MPEG-TS with pat and pmt tables - with pmt table having updated
// location and time data.
func (e *Encoder) writePSI() error {
// Write PAT.
@ -264,7 +264,7 @@ func (e *Encoder) writePSI() error {
PUSI: true,
PID: PatPid,
CC: e.ccFor(PatPid),
AFC: HasPayload,
AFC: hasPayload,
Payload: psi.AddPadding(patTable),
}
_, err := e.dst.Write(patPkt.Bytes(e.tsSpace[:PacketSize]))
@ -282,7 +282,7 @@ func (e *Encoder) writePSI() error {
PUSI: true,
PID: PmtPid,
CC: e.ccFor(PmtPid),
AFC: HasPayload,
AFC: hasPayload,
Payload: psi.AddPadding(pmtTable),
}
_, err = e.dst.Write(pmtPkt.Bytes(e.tsSpace[:PacketSize]))

118
container/mts/audio_test.go → container/mts/encoder_test.go
View File

@ -1,12 +1,13 @@
/*
NAME
audio_test.go
encoder_test.go
AUTHOR
Trek Hopton <trek@ausocean.org>
Saxon A. Nelson-Milton <saxon@ausocean.org>
LICENSE
audio_test.go is Copyright (C) 2017-2019 the Australian Ocean Lab (AusOcean)
encoder_test.go is Copyright (C) 2017-2019 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
@ -16,7 +17,7 @@ LICENSE
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.
for more details.
You should have received a copy of the GNU General Public License in gpl.txt.
If not, see http://www.gnu.org/licenses.
@ -40,8 +41,115 @@ type nopCloser struct{ io.Writer }
func (nopCloser) Close() error { return nil }
// TestEncodePcm tests the mpegts encoder's ability to encode pcm audio data.
// It reads and encodes input pcm data into mpegts, then decodes the mpegts and compares the result to the input pcm.
type destination struct {
packets [][]byte
}
func (d *destination) Write(p []byte) (int, error) {
tmp := make([]byte, PacketSize)
copy(tmp, p)
d.packets = append(d.packets, tmp)
return len(p), nil
}
// TestEncodeVideo checks that we can correctly encode some dummy data into a
// valid MPEG-TS stream. This checks for correct MPEG-TS headers and also that the
// original data is stored correctly and is retreivable.
func TestEncodeVideo(t *testing.T) {
Meta = meta.New()
const dataLength = 440
const numOfPackets = 3
const stuffingLen = 100
// Generate test data.
data := make([]byte, 0, dataLength)
for i := 0; i < dataLength; i++ {
data = append(data, byte(i))
}
// Expect headers for PID 256 (video)
// NB: timing fields like PCR are neglected.
expectedHeaders := [][]byte{
{
0x47, // Sync byte.
0x41, // TEI=0, PUSI=1, TP=0, PID=00001 (256).
0x00, // PID(Cont)=00000000.
0x30, // TSC=00, AFC=11(adaptation followed by payload), CC=0000(0).
0x07, // AFL= 7.
0x50, // DI=0,RAI=1,ESPI=0,PCRF=1,OPCRF=0,SPF=0,TPDF=0, AFEF=0.
},
{
0x47, // Sync byte.
0x01, // TEI=0, PUSI=0, TP=0, PID=00001 (256).
0x00, // PID(Cont)=00000000.
0x31, // TSC=00, AFC=11(adaptation followed by payload), CC=0001(1).
0x01, // AFL= 1.
0x00, // DI=0,RAI=0,ESPI=0,PCRF=0,OPCRF=0,SPF=0,TPDF=0, AFEF=0.
},
{
0x47, // Sync byte.
0x01, // TEI=0, PUSI=0, TP=0, PID=00001 (256).
0x00, // PID(Cont)=00000000.
0x32, // TSC=00, AFC=11(adaptation followed by payload), CC=0010(2).
0x57, // AFL= 1+stuffingLen.
0x00, // DI=0,RAI=0,ESPI=0,PCRF=1,OPCRF=0,SPF=0,TPDF=0, AFEF=0.
},
}
// Create the dst and write the test data to encoder.
dst := &destination{}
_, err := NewEncoder(nopCloser{dst}, 25, Video).Write(data)
if err != nil {
t.Fatalf("could not write data to encoder, failed with err: %v\n", err)
}
// Check headers.
var expectedIdx int
for _, p := range dst.packets {
// Get PID.
var _p packet.Packet
copy(_p[:], p)
pid := packet.Pid(&_p)
if pid == VideoPid {
// Get mts header, excluding PCR.
gotHeader := p[0:6]
wantHeader := expectedHeaders[expectedIdx]
if !bytes.Equal(gotHeader, wantHeader) {
t.Errorf("did not get expected header for idx: %v.\n Got: %v\n Want: %v\n", expectedIdx, gotHeader, wantHeader)
}
expectedIdx++
}
}
// Gather payload data from packets to form the total PES packet.
var pesData []byte
for _, p := range dst.packets {
var _p packet.Packet
copy(_p[:], p)
pid := packet.Pid(&_p)
if pid == VideoPid {
payload, err := packet.Payload(&_p)
if err != nil {
t.Fatalf("could not get payload from mts packet, failed with err: %v\n", err)
}
pesData = append(pesData, payload...)
}
}
// Get data from the PES packet and compare with the original data.
pes, err := pes.NewPESHeader(pesData)
if err != nil {
t.Fatalf("got error from pes creation: %v\n", err)
}
_data := pes.Data()
if !bytes.Equal(data, _data) {
t.Errorf("did not get expected result.\n Got: %v\n Want: %v\n", data, _data)
}
}
// TestEncodePcm tests the MPEG-TS encoder's ability to encode pcm audio data.
// It reads and encodes input pcm data into MPEG-TS, then decodes the MPEG-TS and compares the result to the input pcm.
func TestEncodePcm(t *testing.T) {
Meta = meta.New()

130
container/mts/mpegts.go
View File

@ -1,7 +1,7 @@
/*
NAME
mpegts.go - provides a data structure intended to encapsulate the properties
of an MpegTs packet and also functions to allow manipulation of these packets.
of an MPEG-TS packet and also functions to allow manipulation of these packets.
DESCRIPTION
See Readme.md
@ -35,11 +35,7 @@ import (
"github.com/Comcast/gots/packet"
)
// General mpegts packet properties.
const (
PacketSize = 188
PayloadSize = 176
)
const PacketSize = 188
// Program ID for various types of ts packets.
const (
@ -52,7 +48,7 @@ const (
// StreamID is the id of the first stream.
const StreamID = 0xe0
// HeadSize is the size of an mpegts packet header.
// HeadSize is the size of an MPEG-TS packet header.
const HeadSize = 4
// Consts relating to adaptation field.
@ -163,28 +159,28 @@ type Packet struct {
Payload []byte // Mpeg ts Payload
}
// FindPmt will take a clip of mpegts and try to find a PMT table - if one
// FindPmt will take a clip of MPEG-TS and try to find a PMT table - if one
// is found, then it is returned along with its index, otherwise nil, -1 and an error is returned.
func FindPmt(d []byte) ([]byte, int, error) {
return FindPid(d, PmtPid)
}
// FindPat will take a clip of mpegts and try to find a PAT table - if one
// FindPat will take a clip of MPEG-TS and try to find a PAT table - if one
// is found, then it is returned along with its index, otherwise nil, -1 and an error is returned.
func FindPat(d []byte) ([]byte, int, error) {
return FindPid(d, PatPid)
}
// FindPid will take a clip of mpegts and try to find a packet with given PID - if one
// FindPid will take a clip of MPEG-TS and try to find a packet with given PID - if one
// is found, then it is returned along with its index, otherwise nil, -1 and an error is returned.
func FindPid(d []byte, pid uint16) (pkt []byte, i int, err error) {
if len(d) < PacketSize {
return nil, -1, errors.New("Mmpegts data not of valid length")
return nil, -1, errors.New("MPEG-TS data not of valid length")
}
for i = 0; i < len(d); i += PacketSize {
p := (uint16(d[i+1]&0x1f) << 8) | uint16(d[i+2])
if p == pid {
pkt = d[i+4 : i+PacketSize]
pkt = d[i : i+PacketSize]
return
}
}
@ -194,16 +190,69 @@ func FindPid(d []byte, pid uint16) (pkt []byte, i int, err error) {
// FillPayload takes a channel and fills the packets Payload field until the
// channel is empty or we've the packet reaches capacity
func (p *Packet) FillPayload(data []byte) int {
currentPktLen := 6 + asInt(p.PCRF)*6 + asInt(p.OPCRF)*6 +
asInt(p.SPF)*1 + asInt(p.TPDF)*1 + len(p.TPD)
if len(data) > PayloadSize-currentPktLen {
p.Payload = make([]byte, PayloadSize-currentPktLen)
currentPktLen := 6 + asInt(p.PCRF)*6
if len(data) > PacketSize-currentPktLen {
p.Payload = make([]byte, PacketSize-currentPktLen)
} else {
p.Payload = make([]byte, len(data))
}
return copy(p.Payload, data)
}
// Bytes interprets the fields of the ts packet instance and outputs a
// corresponding byte slice
func (p *Packet) Bytes(buf []byte) []byte {
if buf == nil || cap(buf) < PacketSize {
buf = make([]byte, PacketSize)
}
if p.OPCRF {
panic("original program clock reference field unsupported")
}
if p.SPF {
panic("splicing countdown unsupported")
}
if p.TPDF {
panic("transport private data unsupported")
}
if p.AFEF {
panic("adaptation field extension unsupported")
}
buf = buf[:6]
buf[0] = 0x47
buf[1] = (asByte(p.TEI)<<7 | asByte(p.PUSI)<<6 | asByte(p.Priority)<<5 | byte((p.PID&0xFF00)>>8))
buf[2] = byte(p.PID & 0x00FF)
buf[3] = (p.TSC<<6 | p.AFC<<4 | p.CC)
var maxPayloadSize int
if p.AFC&0x2 != 0 {
maxPayloadSize = PacketSize - 6 - asInt(p.PCRF)*6
} else {
maxPayloadSize = PacketSize - 4
}
stuffingLen := maxPayloadSize - len(p.Payload)
if p.AFC&0x2 != 0 {
buf[4] = byte(1 + stuffingLen + asInt(p.PCRF)*6)
buf[5] = (asByte(p.DI)<<7 | asByte(p.RAI)<<6 | asByte(p.ESPI)<<5 | asByte(p.PCRF)<<4 | asByte(p.OPCRF)<<3 | asByte(p.SPF)<<2 | asByte(p.TPDF)<<1 | asByte(p.AFEF))
} else {
buf = buf[:4]
}
for i := 40; p.PCRF && i >= 0; i -= 8 {
buf = append(buf, byte((p.PCR<<15)>>uint(i)))
}
for i := 0; i < stuffingLen; i++ {
buf = append(buf, 0xff)
}
curLen := len(buf)
buf = buf[:PacketSize]
copy(buf[curLen:], p.Payload)
return buf
}
func asInt(b bool) int {
if b {
return 1
@ -218,55 +267,6 @@ func asByte(b bool) byte {
return 0
}
// Bytes interprets the fields of the ts packet instance and outputs a
// corresponding byte slice
func (p *Packet) Bytes(buf []byte) []byte {
if buf == nil || cap(buf) != PacketSize {
buf = make([]byte, 0, PacketSize)
}
buf = buf[:0]
stuffingLength := 182 - len(p.Payload) - len(p.TPD) - asInt(p.PCRF)*6 -
asInt(p.OPCRF)*6 - asInt(p.SPF)
var stuffing []byte
if stuffingLength > 0 {
stuffing = make([]byte, stuffingLength)
}
for i := range stuffing {
stuffing[i] = 0xFF
}
afl := 1 + asInt(p.PCRF)*6 + asInt(p.OPCRF)*6 + asInt(p.SPF) + asInt(p.TPDF) + len(p.TPD) + len(stuffing)
buf = append(buf, []byte{
0x47,
(asByte(p.TEI)<<7 | asByte(p.PUSI)<<6 | asByte(p.Priority)<<5 | byte((p.PID&0xFF00)>>8)),
byte(p.PID & 0x00FF),
(p.TSC<<6 | p.AFC<<4 | p.CC),
}...)
if p.AFC == 3 || p.AFC == 2 {
buf = append(buf, []byte{
byte(afl), (asByte(p.DI)<<7 | asByte(p.RAI)<<6 | asByte(p.ESPI)<<5 |
asByte(p.PCRF)<<4 | asByte(p.OPCRF)<<3 | asByte(p.SPF)<<2 |
asByte(p.TPDF)<<1 | asByte(p.AFEF)),
}...)
for i := 40; p.PCRF && i >= 0; i -= 8 {
buf = append(buf, byte((p.PCR<<15)>>uint(i)))
}
for i := 40; p.OPCRF && i >= 0; i -= 8 {
buf = append(buf, byte(p.OPCR>>uint(i)))
}
if p.SPF {
buf = append(buf, p.SC)
}
if p.TPDF {
buf = append(buf, append([]byte{p.TPDL}, p.TPD...)...)
}
buf = append(buf, p.Ext...)
buf = append(buf, stuffing...)
}
buf = append(buf, p.Payload...)
return buf
}
type Option func(p *packet.Packet)
// addAdaptationField adds an adaptation field to p, and applys the passed options to this field.

143
container/mts/mpegts_test.go Normal file
View File

@ -0,0 +1,143 @@
/*
NAME
mpegts_test.go
DESCRIPTION
mpegts_test.go contains testing for functionality found in mpegts.go.
AUTHORS
Saxon A. Nelson-Milton <saxon@ausocean.org>
LICENSE
Copyright (C) 2019 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
in gpl.txt. If not, see http://www.gnu.org/licenses.
*/
package mts
import (
"bytes"
"testing"
"github.com/Comcast/gots/packet"
)
// TestBytes checks that Packet.Bytes() correctly produces a []byte
// representation of a Packet.
func TestBytes(t *testing.T) {
const payloadLen, payloadChar, stuffingChar = 120, 0x11, 0xff
const stuffingLen = PacketSize - payloadLen - 12
tests := []struct {
packet Packet
expectedHeader []byte
}{
{
packet: Packet{
PUSI: true,
PID: 1,
RAI: true,
CC: 4,
AFC: HasPayload | HasAdaptationField,
PCRF: true,
PCR: 1,
},
expectedHeader: []byte{
0x47, // Sync byte.
0x40, // TEI=0, PUSI=1, TP=0, PID=00000.
0x01, // PID(Cont)=00000001.
0x34, // TSC=00, AFC=11(adaptation followed by payload), CC=0100(4).
byte(7 + stuffingLen), // AFL=.
0x50, // DI=0,RAI=1,ESPI=0,PCRF=1,OPCRF=0,SPF=0,TPDF=0, AFEF=0.
0x00, 0x00, 0x00, 0x00, 0x80, 0x00, // PCR.
},
},
}
for testNum, test := range tests {
// Construct payload.
payload := make([]byte, 0, payloadLen)
for i := 0; i < payloadLen; i++ {
payload = append(payload, payloadChar)
}
// Fill the packet payload.
test.packet.FillPayload(payload)
// Create expected packet data and copy in expected header.
expected := make([]byte, len(test.expectedHeader), PacketSize)
copy(expected, test.expectedHeader)
// Append stuffing.
for i := 0; i < stuffingLen; i++ {
expected = append(expected, stuffingChar)
}
// Append payload to expected bytes.
expected = append(expected, payload...)
// Compare got with expected.
got := test.packet.Bytes(nil)
if !bytes.Equal(got, expected) {
t.Errorf("did not get expected result for test: %v.\n Got: %v\n Want: %v\n", testNum, got, expected)
}
}
}
// TestFindPid checks that FindPid can correctly extract the first instance
// of a PID from an MPEG-TS stream.
func TestFindPid(t *testing.T) {
const targetPacketNum, numOfPackets, targetPid, stdPid = 6, 15, 1, 0
// Prepare the stream of packets.
var stream []byte
for i := 0; i < numOfPackets; i++ {
pid := uint16(stdPid)
if i == targetPacketNum {
pid = targetPid
}
p := Packet{
PID: pid,
AFC: hasPayload | hasAdaptationField,
}
p.FillPayload([]byte{byte(i)})
stream = append(stream, p.Bytes(nil)...)
}
// Try to find the targetPid in the stream.
p, i, err := FindPid(stream, targetPid)
if err != nil {
t.Fatalf("unexpected error finding PID: %v\n", err)
}
// Check the payload.
var _p packet.Packet
copy(_p[:], p)
payload, err := packet.Payload(&_p)
if err != nil {
t.Fatalf("unexpected error getting packet payload: %v\n", err)
}
got := payload[0]
if got != targetPacketNum {
t.Errorf("payload of found packet is not correct.\nGot: %v, Want: %v\n", got, targetPacketNum)
}
// Check the index.
_got := i / PacketSize
if _got != targetPacketNum {
t.Errorf("index of found packet is not correct.\nGot: %v, want: %v\n", _got, targetPacketNum)
}
}

2
container/mts/psi/helpers.go
View File

@ -125,7 +125,7 @@ func trimTo(d []byte, t byte) []byte {
}
// addPadding adds an appropriate amount of padding to a pat or pmt table for
// addition to an mpegts packet
// addition to an MPEG-TS packet
func AddPadding(d []byte) []byte {
t := make([]byte, PacketSize)
copy(t, d)

2
container/mts/psi/psi.go
View File

@ -32,7 +32,7 @@ import (
"github.com/Comcast/gots/psi"
)
// PacketSize of psi (without mpegts header)
// PacketSize of psi (without MPEG-TS header)
const PacketSize = 184
// Lengths of section definitions.