mpegts

package module
v0.0.0-...-f6032e5 Latest Latest
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 Go to latest Published: Aug 15, 2024 License: MIT Imports: 7 Imported by: 0

README

go-mpegts

Go Reference

MPEG-TS

Features:

  • TS header parser
  • TS Slicer
  • PSI Assembler/Packetizer
    • PAT
    • PMT
    • SDT
  • PES header parser
  • CRC32 (ITU V.42)
  • Textcode
    • GB 2312-1980
    • ISO/IEC 6937
    • ISO/IEC 8859

Installation

To install the library use the following command in the project directory:

go get github.com/cesbo/go-mpegts

Documentation

Index

Examples

Constants

View Source 
const (
	PatHeaderSize  = 8
	PatMaximumSize = 1024
	PatItemSize    = 4
)
View Source 
const (
	PmtHeaderSize  = 12
	PmtMaximumSize = 1024
	PmtItemSize    = 5
)
View Source 
const (
	// First 3 bytes of the PSI packet. Contains Table ID and Section Length
	PsiHeaderSize = 3

	// The maximum number of bytes in a section of
	// a ITU-T Rec. H.222.0 | ISO/IEC 13818-1 defined PSI table is 1024 bytes.
	// The maximum number of bytes in a private_section is 4096 bytes.
	// Includes PsiHeaderSize
	PsiMaximumSize = 4096
)
View Source 
const (
	SdtHeaderSize  = 11
	SdtMaximumSize = 1024
	SdtItemSize    = 5
)
View Source 
const (
	SyncByte   uint8 = 0x47
	PacketSize int   = 188
)
View Source 
const (
	ProgramClock = 27e6 // 27MHz
)
View Source 
const (
	SystemClock = 90000 // 90kHz
)

Variables

View Source 
var (
	ErrCC          = errors.New("psi: discontinuity received")
	ErrPUSI        = errors.New("psi: pointer field out of range")
	ErrAssemblePSI = errors.New("psi: assemble failed")
	ErrCRC         = errors.New("psi: checksum not match")
	ErrPsiFormat   = errors.New("psi: invalid format")
)
View Source 
var (
	ErrSyncTS      = errors.New("ts slicer: sync error")
	ErrNotComplete = errors.New("ts slicer: not complete")
)
View Source 
var (
	ErrDescriptorFormat = errors.New("descriptor: invalid format")
)
View Source 
var (
	ErrPatFormat = errors.New("pat: invalid format")
)
View Source 
var (
	ErrPmtFormat = errors.New("pmt: invalid format")
)
View Source 
var (
	ErrSdtFormat = errors.New("sdt: invalid format")
)
View Source 
var NullTS = TS{}/* 188 elements not displayed */

Functions

This section is empty.

Types

type AssembleFn 

type AssembleFn func(error)

PSI assembler callback

type Desc_48 

type Desc_48 struct {
	ServiceProviderName string
	ServiceName         string
}

func (*Desc_48) Decode 

func (d *Desc_48) Decode(desc Descriptors) error

func (*Desc_48) Encode 

func (d *Desc_48) Encode() (desc Descriptors)

func (*Desc_48) String 

func (d *Desc_48) String() string

type Desc_7A 

type Desc_7A struct {
	// contains filtered or unexported fields
}

func (*Desc_7A) AsvcFlag 

func (d *Desc_7A) AsvcFlag() bool

func (*Desc_7A) BsidFlag 

func (d *Desc_7A) BsidFlag() bool

func (*Desc_7A) ComponentTypeFlag 

func (d *Desc_7A) ComponentTypeFlag() bool

func (*Desc_7A) Decode 

func (d *Desc_7A) Decode(desc Descriptors) error

func (*Desc_7A) Encode 

func (d *Desc_7A) Encode() (desc Descriptors)

func (*Desc_7A) MainidFlag 

func (d *Desc_7A) MainidFlag() bool

func (*Desc_7A) Mixinfoexists 

func (d *Desc_7A) Mixinfoexists() bool

func (*Desc_7A) String 

func (d *Desc_7A) String() string

func (*Desc_7A) Substream1Flag 

func (d *Desc_7A) Substream1Flag() bool

func (*Desc_7A) Substream2Flag 

func (d *Desc_7A) Substream2Flag() bool

func (*Desc_7A) Substream3Flag 

func (d *Desc_7A) Substream3Flag() bool

type Descriptors 

type Descriptors []byte

func (Descriptors) Check 

func (d Descriptors) Check() error

func (Descriptors) Next 

func (d Descriptors) Next() Descriptors

type PAT 

type PAT struct {
	Items []*PatItem
	// contains filtered or unexported fields
}

PAT is Program Association Table

func NewPat 

func NewPat() *PAT

func (*PAT) Finalize 

func (p *PAT) Finalize()

Calculates LastSectionNumber

func (*PAT) Packetizer 

func (p *PAT) Packetizer() *PsiPacketizer

Packetizer returns a new PsiPacketizer to get TS packets from PAT

Example 
pat := NewPat()
pat.SetVersion(1)
pat.SetTSID(1)

item := NewPatItem()
item.SetPNR(1)
item.SetPID(1031)
pat.Items = append(pat.Items, item)

pat.Finalize()

ts := NewTS(0)
for pack := pat.Packetizer(); pack.Next(ts); ts.IncrementCC() {
	// TS Header with Payload start offset
	fmt.Printf("%X...\n", ts[:25])
}

Output:

474000100000B00D0001C300000001E407FF2D3E2FFFFFFFFF...

func (*PAT) ParsePatSection 

func (p *PAT) ParsePatSection(b []byte) error
Example 
data := []byte{
	0x00, 0xB0, 0x0D, 0x70, 0xE9, 0xDD, 0x00, 0x00,
	0x00, 0x01, 0xE0, 0x42, 0xAE, 0xF4, 0xD8, 0x1C,
}

pat := new(PAT)
if err := pat.ParsePatSection(data); err != nil {
	panic(err)
}

fmt.Println("TSID", pat.TSID())
for _, item := range pat.Items {
	fmt.Printf("Program Number %d PID %d\n", item.PNR(), item.PID())
}

Output:

TSID 28905
Program Number 1 PID 66

func (*PAT) SetTSID 

func (p *PAT) SetTSID(tsid uint16)

func (*PAT) SetVersion 

func (p *PAT) SetVersion(version uint8)

func (*PAT) TSID 

func (p *PAT) TSID() uint16

Returns Transport Stream ID

func (*PAT) Version 

func (p *PAT) Version() uint8

type PCR 

type PCR uint64

PCR is Program Clock Reference 

const (
	NonPcr PCR = (1 << 33) * 300
	MaxPcr PCR = NonPcr - 1
)

func (PCR) Add 

func (p PCR) Add(u PCR) PCR

Add returns the timestamp p+u

func (PCR) Bitrate 

func (p PCR) Bitrate(bytes int) int

Bitrate returns bitrate in bits per second for delta PCR.

func (PCR) Delta 

func (p PCR) Delta(previous PCR) PCR

Delta returns the difference p-previous considering value overflow

func (PCR) EstimatedPCR 

func (p PCR) EstimatedPCR(previous PCR, lastBlock, currentBlock uint64) PCR

EstimatedPCR returns estimated PCR value 

| time -->
| X---------X---------X
|  \         \         \
|   \         \         estimated PCR
|    \         current PCR
|     previous PCR

- lastBlock - bytes between PCR(previous) and PCR(current) - currentBlock - bytes between PCR(current) and PCR(estimated)

func (PCR) Jitter 

func (p PCR) Jitter(previous PCR) time.Duration

Jitter returns the difference between two PCR values in nanoseconds

type PES 

type PES []byte

func (PES) CheckPrefix 

func (p PES) CheckPrefix() bool

CheckPrefix checks is PES prefix equal to 0x000001.

func (PES) DTS 

func (p PES) DTS() Timestamp

DTS returns DTS value.

func (PES) HasDTS 

func (p PES) HasDTS() bool

HasDTS checks a Decoding TimeStamp (DTS) is defined in the PES header. DTS field presents only in pair with PTS field. If DTS field is not presented than DTS value equal to PTS.

func (PES) HasPTS 

func (p PES) HasPTS() bool

HasPTS checks is a Presentation Time Stamp (PTS) defined in the PES header. PTS field presents only for elementary streams.

func (PES) IsES 

func (p PES) IsES() bool

Returns true if PES has an Elementary Stream data

func (PES) PTS 

func (p PES) PTS() Timestamp

PTS returns PTS value.

func (PES) SetDTS 

func (p PES) SetDTS(value Timestamp)

SetDTS sets DTS value and turn on DTS flag.

func (PES) SetLength 

func (p PES) SetLength(value int)

SetLength sets PES_packet_length field. Value specifying the number of bytes in the PES packet following the last byte of the field. 0 allowed only for video elementary stream.

func (PES) SetPTS 

func (p PES) SetPTS(value Timestamp)

SetPTS sets PTS value and turn on PTS flag.

func (PES) SetPrefix 

func (p PES) SetPrefix()

SetPrefix sets PES prefix to 0x000001.

func (PES) SetStreamID 

func (p PES) SetStreamID(streamID uint8)

SetStreamID sets Stream ID field.

func (PES) StreamID 

func (p PES) StreamID() uint8

StreamID returns the type and number of the elementary stream. Audio streams (0xC0-0xDF), Video streams (0xE0-0xEF)

type PID 

type PID uint16

PID is Packet Identifier 

const (
	NonPid PID = 8192
	MaxPid PID = NonPid - 1
)

type PMT 

type PMT struct {
	Items []*PmtItem
	// contains filtered or unexported fields
}

PMT is Program Map Table

func NewPmt 

func NewPmt() *PMT

func (*PMT) AppendDescriptors 

func (p *PMT) AppendDescriptors(desc Descriptors)

func (*PMT) Descriptors 

func (p *PMT) Descriptors() Descriptors

func (*PMT) Finalize 

func (p *PMT) Finalize()

Calculates LastSectionNumber

func (*PMT) PCR 

func (p *PMT) PCR() PID

func (*PMT) PNR 

func (p *PMT) PNR() uint16

func (*PMT) Packetizer 

func (p *PMT) Packetizer() *PsiPacketizer

Packetizer returns a new PsiPacketizer to get TS packets from PMT

func (*PMT) ParsePmtSection 

func (p *PMT) ParsePmtSection(b []byte) error

func (*PMT) SetPCR 

func (p *PMT) SetPCR(pcr PID)

func (*PMT) SetPNR 

func (p *PMT) SetPNR(pnr uint16)

func (*PMT) SetVersion 

func (p *PMT) SetVersion(version uint8)

func (*PMT) Version 

func (p *PMT) Version() uint8

type PSI 

type PSI struct {
	TableID           uint8
	Version           uint8
	SectionNumber     uint8
	LastSectionNumber uint8
	CRC               uint32
	// contains filtered or unexported fields
}

Program Specific Information (ISO 13818-1 / 2.4.4)

func (*PSI) Assemble 

func (p *PSI) Assemble(packet TS, fn AssembleFn)

Assembles TS packets into single PSI. Calls fn when PSI is ready or error occurs

func (*PSI) Clear 

func (p *PSI) Clear()

Clears buffer

func (*PSI) Payload 

func (p *PSI) Payload() []byte

Returns PSI payload and assembling error status. Should be used in AssembleFn. Buffer length is equal to PsiHeaderSize + Section Length.

type PatItem 

type PatItem struct {
	// contains filtered or unexported fields
}

func NewPatItem 

func NewPatItem() *PatItem

func (*PatItem) PID 

func (p *PatItem) PID() PID

Returns PID of the Program Map Table

func (*PatItem) PNR 

func (p *PatItem) PNR() uint16

Returns Program Number

func (*PatItem) SetPID 

func (p *PatItem) SetPID(pid PID)

func (*PatItem) SetPNR 

func (p *PatItem) SetPNR(pnr uint16)

type PmtItem 

type PmtItem struct {
	// contains filtered or unexported fields
}

PMT Item contains information about elementary stream

func NewPmtItem 

func NewPmtItem() *PmtItem

func (*PmtItem) AppendDescriptors 

func (p *PmtItem) AppendDescriptors(desc Descriptors)

func (*PmtItem) Clone 

func (p *PmtItem) Clone() *PmtItem

func (*PmtItem) Descriptors 

func (p *PmtItem) Descriptors() Descriptors

func (*PmtItem) PID 

func (p *PmtItem) PID() PID

func (*PmtItem) SetPID 

func (p *PmtItem) SetPID(pid PID)

func (*PmtItem) SetType 

func (p *PmtItem) SetType(ty uint8)

func (*PmtItem) StreamType 

func (p *PmtItem) StreamType() StreamType

StreamType returns stream type by element ID and related descriptors

func (*PmtItem) Type 

func (p *PmtItem) Type() uint8

type PsiPacketizer 

type PsiPacketizer struct {
	// contains filtered or unexported fields
}

PsiPacketizer is a helper to splits PSI section into multiple TS packets. If data more than fits into one section, it will be split into multiple sections.

func (*PsiPacketizer) Next 

func (p *PsiPacketizer) Next(ts TS) bool

type SDT 

type SDT struct {
	Items []*SdtItem
	// contains filtered or unexported fields
}

SDT is Service Description Table

func NewSdt 

func NewSdt() *SDT

func (*SDT) Actual 

func (s *SDT) Actual() bool

func (*SDT) Finalize 

func (s *SDT) Finalize()

Calculates LastSectionNumber

func (*SDT) ONID 

func (s *SDT) ONID() uint16

func (*SDT) Packetizer 

func (s *SDT) Packetizer() *PsiPacketizer

Packetizer returns a new PsiPacketizer to get TS packets from SDT

func (*SDT) ParseSdtSection 

func (s *SDT) ParseSdtSection(b []byte) error

func (*SDT) SetONID 

func (s *SDT) SetONID(onid uint16)

func (*SDT) SetTSID 

func (s *SDT) SetTSID(tsid uint16)

func (*SDT) SetVersion 

func (s *SDT) SetVersion(version uint8)

func (*SDT) TSID 

func (s *SDT) TSID() uint16

func (*SDT) Version 

func (s *SDT) Version() uint8

type ScramblingControl 

type ScramblingControl byte
const (
	NotScrambled     ScramblingControl = 0
	ScrambledEvenKey ScramblingControl = 2 // 10
	ScrambledOddKey  ScramblingControl = 3 // 11
)

type SdtItem 

type SdtItem struct {
	// contains filtered or unexported fields
}

func NewSdtItem 

func NewSdtItem() *SdtItem

func (*SdtItem) AppendDescriptors 

func (s *SdtItem) AppendDescriptors(desc Descriptors)

Appends descriptors to the last added item

func (*SdtItem) Descriptors 

func (s *SdtItem) Descriptors() Descriptors

func (*SdtItem) IsPresentFollowing 

func (s *SdtItem) IsPresentFollowing() bool

Returns true if present-following information is present in the stream EIT_present_following_flag

func (*SdtItem) IsSchedule 

func (s *SdtItem) IsSchedule() bool

Returns true if schedule information is present in the stream EIT_schedule_flag

func (*SdtItem) IsScrambled 

func (s *SdtItem) IsScrambled() bool

Returns false if stream is not scrambled Returns true if one or more streams may be controlled by a CA system free_CA_mode

func (*SdtItem) RunningStatus 

func (s *SdtItem) RunningStatus() uint8

func (*SdtItem) ServiceID 

func (s *SdtItem) ServiceID() uint16

func (*SdtItem) SetPresentFollowing 

func (s *SdtItem) SetPresentFollowing(flag bool)

func (*SdtItem) SetRunningStatus 

func (s *SdtItem) SetRunningStatus(status uint8)

func (*SdtItem) SetSchedule 

func (s *SdtItem) SetSchedule(flag bool)

func (*SdtItem) SetScrambled 

func (s *SdtItem) SetScrambled(flag bool)

func (*SdtItem) SetServiceID 

func (s *SdtItem) SetServiceID(id uint16)

type Slicer 

type Slicer struct {
	// contains filtered or unexported fields
}

Slicer is a tool for split TS buffer to TS packets. If buffer length is not multiple to TS packet size it store remain data in the internal buffer and will be used on the next iteration.

Example 
slicer := Slicer{}
buffer := NullTS

for packet := slicer.Begin(buffer); packet != nil; packet = slicer.Next() {
	fmt.Println("PID", packet.PID())
}

Output:

PID 8191

func (*Slicer) Begin 

func (s *Slicer) Begin(buffer []byte) TS

Prepares buffer and get first packet

func (*Slicer) Err 

func (s *Slicer) Err() error

Returns number of bytes processed and error if happens

func (*Slicer) Next 

func (s *Slicer) Next() TS

Get next packet

type StreamType 

type StreamType int

StreamType is an elementary stream type 

const (
	StreamData StreamType = iota
	StreamVideoH261
	StreamVideoH262
	StreamVideoH263
	StreamVideoH264
	StreamVideoH265
	StreamAudioMP2
	StreamAudioMP3
	StreamAudioAAC
	StreamAudioLATM
	StreamAudioAC3
	StreamAudioEAC3
	StreamDataSCTE35
	StreamDataSubtitles
	StreamDataTeletext
	StreamDataAIT
)

func (StreamType) String 

func (t StreamType) String() string

type TS 

type TS []byte

ISO/IEC 13818-1 : 2.4.3 Specification of the Transport Stream syntax and semantics

Example 
packet := TS([]byte{0x47, 0x40, 0x11, 0x15})
fmt.Println("PID", packet.PID(), "CC", packet.CC())

Output:

PID 17 CC 5

func NewTS 

func NewTS(pid PID) TS

NewTS allocates new TS packet. Sets sync byte and PID

func (TS) CC 

func (p TS) CC() uint8

CC returns continuity counter value. Continuity Counter is a 4-bit field incrementing by 1 for each packet with payload on the same PID.

func (TS) CheckCC 

func (p TS) CheckCC(previous uint8) (uint8, bool)

CheckCC checks continuity counter Returns current CC and true if CC is equal to expected value

func (TS) ClearAF 

func (p TS) ClearAF()

ClearAF clears the Adaptation Field bit

func (TS) ClearPUSI 

func (p TS) ClearPUSI()

ClearPUSI clears Payload Unit Start Indicator bit

func (TS) Fill 

func (p TS) Fill(size int)

Fill fills incomplete TS packet with adaptation field stuffing bytes

func (TS) HasAF 

func (p TS) HasAF() bool

HasAF checks the Adaptation Field bit

func (TS) HasPCR 

func (p TS) HasPCR() bool

HasPCR returns true if PCR flag is set in the Adaptation Field. Make sure that Adaptation Field is not empty: packet HeaderSize() more or equal than 6 bytes.

func (TS) HasPUSI 

func (p TS) HasPUSI() bool

HasPUSI checks is payload starts in the packet (Payload Unit Start Indicator)

func (TS) HasPayload 

func (p TS) HasPayload() bool

HasPayload checks is packet has payload

func (TS) HasTEI 

func (p TS) HasTEI() bool

HasTEI checks the Transport Error Indicator bit

func (TS) HeaderSize 

func (p TS) HeaderSize() int

HeaderSize returns size of packet header

func (TS) IncrementCC 

func (p TS) IncrementCC()

IncrementCC increments continuity counter in packet

func (TS) PCR 

func (p TS) PCR() PCR

PCR returns PCR value from the Adaptation Field. Packet should be with Adaptation Field

func (TS) PID 

func (p TS) PID() PID

PID returns packet identifier value. PID is a 13-bit field that identifies the payload carried in the packet.

func (TS) Payload 

func (p TS) Payload() []byte

Payload returns payload if available

func (TS) SetAF 

func (p TS) SetAF()

SetAF sets Adaptation Field bit

func (TS) SetCC 

func (p TS) SetCC(cc uint8)

SetCC sets continuity counter in packet

func (TS) SetPCR 

func (p TS) SetPCR(value PCR)

SetPCR sets PCR flag and PCR value in the Adaptation Field.

func (TS) SetPID 

func (p TS) SetPID(pid PID)

SetPID sets PID in packet

func (TS) SetPUSI 

func (p TS) SetPUSI()

SetPUSI sets Payload Unit Start Indicator bit

func (TS) SetPayload 

func (p TS) SetPayload()

SetPayload sets Payload bit

func (TS) TSC 

func (p TS) TSC() ScramblingControl

TSC returns 2-bit Transport Scrambling Control field

type Timestamp 

type Timestamp uint64

Timestamp is a 33-bit MPEG-2 timestamp for PTS/DTS 

const (
	NonTimestamp Timestamp = 1 << 33
	MaxTimestamp Timestamp = NonTimestamp - 1
)

func Scale 

func Scale(duration, timescale int) Timestamp

Scale returns the timestamp from the duration and timescale. For example, need to get number of 90kHz ticks in 250 milliseconds. Duration is 250 and the timescale is 1000 - number of milliseconds in second. `Scale(250, 1000)` return 22500 ticks

func (Timestamp) Add 

func (t Timestamp) Add(u Timestamp) Timestamp

Add returns the timestamp t+u

func (Timestamp) Delta 

func (t Timestamp) Delta(previous Timestamp) Timestamp

Delta returns the difference t-u considering value overflow

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