joy4/reader.go
2016-04-19 21:33:07 +08:00

685 lines
13 KiB
Go

package ts
import (
"fmt"
"io"
"io/ioutil"
)
var DebugReader = false
func ReadUInt(r io.Reader, n int) (res uint, err error) {
var b [4]byte
if _, err = r.Read(b[0:n]); err != nil {
return
}
for i := 0; i < n; i++ {
res <<= 8
res |= uint(b[i])
}
return
}
func ReadDummy(r io.Reader, n int) (err error) {
_, err = io.CopyN(ioutil.Discard, r, int64(n))
return
}
func ReadUInt64(r io.Reader, n int) (res uint64, err error) {
var res32 uint
if n > 4 {
if res32, err = ReadUInt(r, n-4); err != nil {
return
}
res |= uint64(res32) << 32
n = 4
}
if res32, err = ReadUInt(r, n); err != nil {
return
}
res |= uint64(res32)
return
}
func ReadTSHeader(r io.Reader) (self TSHeader, err error) {
var flags uint
// sync(8)
// transport_error_indicator(1)
// payload_unit_start_indicator(1)
// transport_priority(1)
// pid(13)
// Scrambling control(2)
// Adaptation field flag(1)
// Continuity counter(4)
if flags, err = ReadUInt(r, 4); err != nil {
return
}
if DebugReader {
fmt.Printf("ts: flags %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{8, "sync"},
{1, "transport_error_indicator"},
{1, "payload_unit_start_indicator"},
{1, "transport_priority"},
{13, "pid"},
{2, "scrambling_control"},
{1, "adaptation_field_flag"},
{1, "payload_flag"},
{4, "continuity_counter"},
},
Val: flags,
Length: 32,
})
}
if flags&0x400000 != 0 {
// When set to '1' it indicates that this TS packet contains the first PES packet.
self.PayloadUnitStart = true
}
if (flags&0xff000000)>>24 != 0x47 {
err = fmt.Errorf("invalid sync")
return
}
self.PID = (flags & 0x1fff00) >> 8
self.ContinuityCounter = flags & 0xf
if flags&0x20 != 0 {
var flags, length uint
if length, err = ReadUInt(r, 1); err != nil {
return
}
if length > 0 {
lr := &io.LimitedReader{R: r, N: int64(length)}
if flags, err = ReadUInt(lr, 1); err != nil {
return
}
if DebugReader {
fmt.Printf("ts: ext_flags %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{1, "discontinuity_indicator"},
{1, "random_access_indicator"},
{1, "elementary_stream_priority_indicator"},
{1, "pcr_flag"},
{1, "opcr_flag"},
{1, "splicing_point_flag"},
{1, "transport_private_data_flag"},
{1, "adaptation_field_extension_flag"},
},
Val: flags,
Length: 8,
})
}
// random_access_indicator
if flags&0x40 != 0 {
self.RandomAccessIndicator = true
}
// PCR
if flags&0x10 != 0 {
var v uint64
if v, err = ReadUInt64(lr, 6); err != nil {
return
}
// clock is 27MHz
self.PCR = UIntToPCR(v)
if DebugReader {
fmt.Printf("ts: PCR %d %f\n", self.PCR, float64(self.PCR)/PCR_HZ)
}
}
// OPCR
if flags&0x08 != 0 {
var v uint64
if v, err = ReadUInt64(lr, 6); err != nil {
return
}
self.OPCR = UIntToPCR(v)
}
// Splice countdown
if flags&0x04 != 0 {
if _, err = ReadUInt(lr, 1); err != nil {
return
}
}
// Transport private data
if flags&0x02 != 0 {
var length uint
if length, err = ReadUInt(lr, 1); err != nil {
return
}
b := make([]byte, length)
if _, err = lr.Read(b); err != nil {
return
}
}
// Adaptation extension
if lr.N > 0 {
if DebugReader {
// rubish
fmt.Println("ts: skip", lr.N)
}
if err = ReadDummy(lr, int(lr.N)); err != nil {
return
}
}
}
}
return
}
func ReadTSPacket(r io.Reader, data []byte) (self TSHeader, n int, err error) {
lr := &io.LimitedReader{R: r, N: 188}
if self, err = ReadTSHeader(lr); err != nil {
return
}
if DebugReader {
fmt.Println("ts: data len", lr.N)
}
if n, err = lr.Read(data[:lr.N]); err != nil {
return
}
return
}
func ReadPSI(r io.Reader) (self PSI, lr *io.LimitedReader, cr *Crc32Reader, err error) {
var flags, pointer, length uint
// pointer field
if pointer, err = ReadUInt(r, 1); err != nil {
return
}
if DebugReader {
fmt.Printf("psi: pointer=%d\n", pointer)
}
if pointer != 0 {
if err = ReadDummy(r, int(pointer)); err != nil {
return
}
}
cr = &Crc32Reader{R: r, Crc32: 0xffffffff}
// table_id
if self.TableId, err = ReadUInt(cr, 1); err != nil {
return
}
// reserved(4)=0xb
// section_length(10)
if flags, err = ReadUInt(cr, 2); err != nil {
return
}
length = flags & 0x3FF
if DebugReader {
fmt.Printf("psi: tableid=%d len=%d\n", self.TableId, length)
}
lr = &io.LimitedReader{R: cr, N: int64(length)}
// Table ID extension(16)
if self.TableIdExtension, err = ReadUInt(lr, 2); err != nil {
return
}
// resverd(2)=3
// version(5)
// Current_next_indicator(1)
if flags, err = ReadUInt(lr, 1); err != nil {
return
}
if DebugReader {
fmt.Printf("psi: %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{2, "resverd"},
{5, "version"},
{1, "current_next_indicator"},
},
Val: flags,
Length: 8,
})
}
// section_number(8)
if self.SecNum, err = ReadUInt(lr, 1); err != nil {
return
}
// last_section_number(8)
if self.LastSecNum, err = ReadUInt(lr, 1); err != nil {
return
}
if DebugReader {
fmt.Printf("psi: table_id=%x table_extension=%x secnum=%x lastsecnum=%x\n",
self.TableId,
self.TableIdExtension,
self.SecNum,
self.LastSecNum,
)
}
lr.N -= 4
return
}
func ReadPMT(r io.Reader) (self PMT, err error) {
readDescs := func(lr *io.LimitedReader) (res []Descriptor, err error) {
var desc Descriptor
for lr.N > 0 {
if desc.Tag, err = ReadUInt(lr, 1); err != nil {
return
}
var length uint
if length, err = ReadUInt(lr, 1); err != nil {
return
}
desc.Data = make([]byte, length)
if _, err = lr.Read(desc.Data); err != nil {
return
}
res = append(res, desc)
}
return
}
var lr *io.LimitedReader
var cr *Crc32Reader
//var psi PSI
if _, lr, cr, err = ReadPSI(r); err != nil {
return
}
var flags, length uint
// 111(3)
// PCRPID(13)
if flags, err = ReadUInt(lr, 2); err != nil {
return
}
self.PCRPID = flags & 0x1fff
if DebugReader {
fmt.Printf("pmt: %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{3, "reserved"},
{13, "pcrpid"},
},
Val: flags,
Length: 16,
})
}
// Reserved(4)=0xf
// Reserved(2)=0x0
// Program info length(10)
if flags, err = ReadUInt(lr, 2); err != nil {
return
}
length = flags & 0x3ff
if DebugReader {
fmt.Printf("pmt: ProgramDescriptorsLen=%d\n", length)
}
if length > 0 {
lr := &io.LimitedReader{R: lr, N: int64(length)}
if self.ProgramDescriptors, err = readDescs(lr); err != nil {
return
}
}
for lr.N > 0 {
var info ElementaryStreamInfo
if info.StreamType, err = ReadUInt(lr, 1); err != nil {
return
}
// Reserved(3)
// Elementary PID(13)
if flags, err = ReadUInt(lr, 2); err != nil {
return
}
info.ElementaryPID = flags & 0x1fff
if DebugReader {
fmt.Printf("pmt: info1 %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{3, "reserved"},
{13, "elementary_pid"},
},
Val: flags,
Length: 16,
})
}
// Reserved(6)
// ES Info length(10)
if flags, err = ReadUInt(lr, 2); err != nil {
return
}
length = flags & 0x3ff
if DebugReader {
fmt.Printf("pmt: info2 %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{6, "reserved"},
{10, "es_info_length"},
},
Val: flags,
Length: 16,
})
}
if length > 0 {
lr := &io.LimitedReader{R: lr, N: int64(length)}
if info.Descriptors, err = readDescs(lr); err != nil {
return
}
}
self.ElementaryStreamInfos = append(self.ElementaryStreamInfos, info)
}
if DebugReader {
fmt.Printf("pmt: ProgramDescriptors %v\n", self.ProgramDescriptors)
fmt.Printf("pmt: ElementaryStreamInfos %v\n", self.ElementaryStreamInfos)
}
if err = cr.ReadCrc32UIntAndCheck(); err != nil {
if DebugReader {
fmt.Printf("pmt: %s\n", err)
}
return
}
return
}
func ReadPAT(r io.Reader) (self PAT, err error) {
var lr *io.LimitedReader
var cr *Crc32Reader
//var psi PSI
if _, lr, cr, err = ReadPSI(r); err != nil {
return
}
for lr.N > 0 {
entry := PATEntry{}
if entry.ProgramNumber, err = ReadUInt(lr, 2); err != nil {
return
}
if entry.ProgramNumber == 0 {
if entry.NetworkPID, err = ReadUInt(lr, 2); err != nil {
return
}
entry.NetworkPID &= 0x1fff
} else {
if entry.ProgramMapPID, err = ReadUInt(lr, 2); err != nil {
return
}
entry.ProgramMapPID &= 0x1fff
}
self.Entries = append(self.Entries, entry)
}
if err = cr.ReadCrc32UIntAndCheck(); err != nil {
if DebugReader {
fmt.Printf("pat: %s\n", err)
}
return
}
if DebugReader {
fmt.Printf("pat: %v\n", self)
}
return
}
func ReadPESHeader(r io.Reader) (res *PESHeader, err error) {
var flags, length uint
self := &PESHeader{}
// http://dvd.sourceforge.net/dvdinfo/pes-hdr.html
// start code 000001
if flags, err = ReadUInt(r, 3); err != nil {
return
}
if flags != 0x000001 {
err = fmt.Errorf("invalid PES header")
return
}
if self.StreamId, err = ReadUInt(r, 1); err != nil {
return
}
if length, err = ReadUInt(r, 2); err != nil {
return
}
if DebugReader {
fmt.Printf("pes: StreamId=%x length=%d\n", self.StreamId, length)
}
if length == 0 {
length = 1 << 31
}
lrAll := &io.LimitedReader{R: r, N: int64(length)}
lr := lrAll
// 10(2)
// PES scrambling control(2)
// PES priority(1)
// data alignment indicator(1)
// copyright(1)
// original or copy(1)
if _, err = ReadUInt(lr, 1); err != nil {
return
}
if DebugReader {
fmt.Printf("pes: %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{2, "scrambling_control"},
{1, "priority"},
{1, "data_alignment_indicator"},
{1, "copyright"},
{1, "original_or_copy"},
},
Val: flags,
Length: 6,
})
}
// PTS DTS flags(2)
// ESCR flag(1)
// ES rate flag(1)
// DSM trick mode flag(1)
// additional copy info flag(1)
// PES CRC flag(1)
// PES extension flag(1)
if flags, err = ReadUInt(lr, 1); err != nil {
return
}
if DebugReader {
fmt.Printf("pes: %s\n", FieldsDumper{
Fields: []struct {
Length int
Desc string
}{
{2, "pts_dts_flags"},
{1, "escr_flag"},
{1, "es_rate_flag"},
{1, "dsm_trick_mode_flag"},
{1, "additional_copy_info_flag"},
{1, "pes_crc_flag"},
{1, "pes_extension_flag"},
},
Val: flags,
Length: 8,
})
}
// PES header data length(8)
if length, err = ReadUInt(lr, 1); err != nil {
return
}
lr = &io.LimitedReader{R: lr, N: int64(length)}
if flags&0x80 != 0 {
var v uint64
if v, err = ReadUInt64(lr, 5); err != nil {
return
}
self.PTS = PESUIntToTs(v)
if DebugReader {
fmt.Printf("pes: pts %d %f\n", self.PTS, float64(self.PTS)/float64(PTS_HZ))
}
}
if flags&0x40 != 0 && flags&0x80 != 0 {
var v uint64
if v, err = ReadUInt64(lr, 5); err != nil {
return
}
self.DTS = PESUIntToTs(v)
if DebugReader {
fmt.Printf("pes: dts %d %f\n", self.DTS, float64(self.DTS)/float64(PTS_HZ))
}
}
// ESCR flag
if flags&0x20 != 0 {
if _, err = ReadUInt64(lr, 6); err != nil {
return
}
}
// ES rate flag
if flags&0x10 != 0 {
if _, err = ReadUInt64(lr, 3); err != nil {
return
}
}
// additional copy info flag
if flags&0x04 != 0 {
if _, err = ReadUInt(lr, 1); err != nil {
return
}
}
// PES CRC flag
if flags&0x02 != 0 {
if _, err = ReadUInt(lr, 2); err != nil {
return
}
}
// PES extension flag
if flags&0x01 != 0 {
var flags uint
// PES private data flag(1)
// pack header field flag(1)
// program packet sequence counter flag(1)
// P-STD buffer flag(1)
// 111(3)
// PES extension flag 2(1)
if flags, err = ReadUInt(lr, 1); err != nil {
return
}
// PES private data flag(1)
if flags&0x80 != 0 {
// if set to 1 16 bytes of user defined data is appended to the header data field
if err = ReadDummy(lr, 16); err != nil {
return
}
}
// pack header field flag(1)
if flags&0x40 != 0 {
// if set to 1 the 8-bit pack field length value is appended to the header data field
if err = ReadDummy(lr, 1); err != nil {
return
}
}
// program packet sequence counter flag(1)
if flags&0x20 != 0 {
if err = ReadDummy(lr, 2); err != nil {
return
}
}
// P-STD buffer flag(1)
if flags&0x10 != 0 {
if err = ReadDummy(lr, 2); err != nil {
return
}
}
// PES extension flag 2(1)
if flags&0x01 != 0 {
if err = ReadDummy(lr, 2); err != nil {
return
}
}
}
if lr.N > 0 {
if err = ReadDummy(lr, int(lr.N)); err != nil {
return
}
}
if lrAll.N < 65536 {
self.DataLength = uint(lrAll.N)
}
res = self
return
}