package ts
import (
"github.com/ziutek/dvb"
"io"
"os"
"syscall"
)
var (
// ErrSync means a lost of MPEG-TS synchronization.
ErrSync = dvb.TemporaryError("MPEG-TS synchronization error")
)
// PktReader is an interface that wraps the ReadPkt method.
type PktReader interface {
// ReadPkt reads one MPEG-TS packet.
// If it returns ErrSync or dvb.ErrOverflow you can try to read next
// packet.
ReadPkt(Pkt) error
}
// PktStreamReader wraps any io.Reader interface and returns PktReader and
// PktReplacer implementation for read MPEG-TS packets from stream of bytes.
// Internally it doesn't allocate any memory so is friendly for real-time
// applications (it doesn't cause GC to run).
//
// Using PktStreamReader you can start read at any point in stream. If the start point
// doesn't match a beginning of a packet, PktReader returns ErrSync and
// tries to synchronize during next read.
type PktStreamReader struct {
func (nit NIT) Current() bool {
return Table(nit).Current()
}
func (nit NIT) NetId() uint16 {
return Table(nit).TableIdExt()
}
func (nit NIT) s() Section {
if len(nit) == 0 {
panic("NIT doesn't contain valid data")
}
return nit[0]
}
var ErrNITSectionLen = dvb.TemporaryError("incorrect NIT section length")
// Update reads next NIT from r
func (nit *NIT) Update(r SectionReader, actualMux bool, current bool) error {
tableId := byte(0x41)
if actualMux {
tableId = 0x40
}
return (*Table)(nit).Update(r, tableId, true, current, ISOSectionMaxLen)
}
// Descriptors returns network descriptors list
func (nit NIT) Descriptors() TableDescriptors {
// BUG: Network descriptros can be in more than one (first) section. They
// should be located in the first sections of table and they should end
// before first not empty transport stream looop.
type SDT Table
func (sdt SDT) Version() int8 {
return Table(sdt).Version()
}
func (sdt SDT) Current() bool {
return Table(sdt).Current()
}
func (sdt SDT) MuxId() uint16 {
return Table(sdt).TableIdExt()
}
var ErrSDTSectionLen = dvb.TemporaryError("incorrect SDT section length")
// Update reads next SDT from r
func (sdt *SDT) Update(r SectionReader, actualMux bool, current bool) error {
tableId := byte(0x46)
if actualMux {
tableId = 0x42
}
t := (*Table)(sdt)
err := t.Update(r, tableId, true, current, ISOSectionMaxLen)
if err != nil {
return err
}
for _, s := range *t {
if len(s.Data()) < 2 {
t.Reset()
package psi
import (
"github.com/ziutek/dvb"
"time"
)
const TDTSectionLen = 3 + 5
var ErrTDTSectionSyntax = dvb.TemporaryError("incorrect TDT section syntax")
func ParseTDT(s Section) (time.Time, error) {
if s.TableId() != 0x70 || s.GenericSyntax() || !s.PrivateSyntax() || s.Len() != TDTSectionLen {
return time.Time{}, ErrTDTSectionSyntax
}
return decodeMJDUTC(s[3:8])
}
type TDT Section
func MakeTDT() TDT {
s := MakeEmptySection(TDTSectionLen, false)
s.SetTableId(0x70)
s.SetPrivateSyntax(true)
s.Alloc(5, 0)
return TDT(s)
}
// SetTime converts UTC time t to MJD and stores it in tdt. TDT has no
// CRC sum so modified TDT is valid.
func (tdt TDT) SetTime(t time.Time) {
package psi
import (
"github.com/ziutek/dvb"
)
var (
ErrTableSectionNumber = dvb.TemporaryError("Table: incorrect section number")
ErrTableSyntax = dvb.TemporaryError("Table: incorrect section syntax")
)
type Table []Section
func (t Table) check() {
if len(t) == 0 {
panic("table doesn't contain valid data")
}
}
func (t *Table) Reset() {
*t = (*t)[:0]
}
func (t Table) TableId() byte {
t.check()
return t[0].TableId()
}
func (t Table) SetTableId(id byte) {
t.check()
for _, s := range t {
}
func (p PMT) progInfoLen() int {
return int(decodeU16(Section(p).Data()[2:4]) & 0x0fff)
}
func (p PMT) ProgramDescriptors() DescriptorList {
return DescriptorList(Section(p).Data()[4 : 4+p.progInfoLen()])
}
func (p PMT) ESInfo() ESInfoList {
return ESInfoList(Section(p).Data()[4+p.progInfoLen():])
}
var (
ErrPMTSectionSyntax = dvb.TemporaryError("incorrect PMT section syntax")
ErrPMTProgInfoLen = dvb.TemporaryError("incorrect PMT program info length")
)
// AsPMT returns s as PMT or error if s isn't PMT section. This works because
// PMT should fit in one section (other tables occupy multiple sections.
func AsPMT(s Section) (PMT, error) {
if s.TableId() != 2 || !s.GenericSyntax() || s.Number() != 0 ||
s.LastNumber() != 0 {
return nil, ErrPMTSectionSyntax
}
p := PMT(s)
if p.progInfoLen()+4 > len(s.Data()) {
return nil, ErrPMTProgInfoLen
}
return p, nil
package psi
import (
"github.com/ziutek/dvb"
"github.com/ziutek/dvb/ts"
)
var (
ErrSectionLength = dvb.TemporaryError("incorrect value of section_length field")
ErrSectionPointer = dvb.TemporaryError("incorrect pointer_field")
ErrSectionSpace = dvb.TemporaryError("no free space for section decoding")
ErrSectionSyntax = dvb.TemporaryError("section syntax indicator not set")
ErrSectionCRC = dvb.TemporaryError("section has incorrect CRC")
ErrSectionReserved = dvb.TemporaryError("section has wrong value of header reserved bits")
ErrSectionData = dvb.TemporaryError("too few data to decode section")
)
// SectionDecoder can decode section from stream of packets
type SectionDecoder struct {
r ts.PktReplacer
pkt *ts.ArrayPkt
buffered bool // Not processed data in pkt
check bool
}
// NewSectionDecoder creates section decoder. You can use r == nil and
// set source of packets lather using SetPktReplacer or SetPktReader method.
// If check is true decoder checks value of reserved header bits and CRC.
func NewSectionDecoder(r ts.PktReplacer, check bool) *SectionDecoder {
return &SectionDecoder{r: r, pkt: new(ts.ArrayPkt), check: check}
}
