mirror of https://bitbucket.org/ausocean/av.git
102 lines
2.4 KiB
Go
102 lines
2.4 KiB
Go
/*
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NAME
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PES.go -
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DESCRIPTION
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See Readme.md
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AUTHOR
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Saxon Nelson-Milton <saxon.milton@gmail.com>
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LICENSE
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PES.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
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It is free software: you can redistribute it and/or modify them
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under the terms of the GNU General Public License as published by the
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Free Software Foundation, either version 3 of the License, or (at your
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option) any later version.
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It is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with revid in gpl.txt. If not, see [GNU licenses](http://www.gnu.org/licenses).
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*/
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package nal
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type NALUnit interface {
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ToByteSlice() []byte
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GetType() byte
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}
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type NALSpsPps struct {
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Data []byte
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}
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type NALFragment struct {
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ThreeNUBs byte
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FragmentType byte
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Start bool
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End bool
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Reserved bool
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FiveNUBs byte
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Data []byte
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}
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func GetNalType(unit []byte) byte {
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return unit[0] & 0x1F
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}
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/*
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First byte: [ 3 NAL UNIT BITS | 5 FRAGMENT TYPE BITS]
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Second byte: [ START BIT | END BIT | RESERVED BIT | 5 NAL UNIT BITS]
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Other bytes: [... VIDEO FRAGMENT DATA...]
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*/
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func ParseNALFragment(unit []byte) (u *NALFragment) {
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u = new(NALFragment)
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u.ThreeNUBs = (unit[0] & 0xE0) >> 5
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u.FragmentType = unit[0] & 0x1F
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u.Start = (unit[1] & 0x80) != 0
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u.End = (unit[1] & 0x40) != 0
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u.Reserved = (unit[1] & 0x20) != 0
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u.FiveNUBs = unit[1] & 0x1F
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u.Data = make([]byte,len(unit[2:]))
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copy(u.Data[:],unit[2:])
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return
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}
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func ParseNALSpsPps(unit []byte)(u *NALSpsPps){
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u = new(NALSpsPps)
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u.Data = make([]byte,len(unit))
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copy(u.Data[:],unit[:])
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return
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}
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func (u *NALFragment) ToByteSlice() (output []byte) {
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output = make([]byte, 2+len(u.Data))
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output[0] = ( u.ThreeNUBs << 5 ) | u.FragmentType
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output[1] = boolToByte( u.Start ) << 7 |
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boolToByte( u.End ) << 6 |
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boolToByte( u.Reserved ) << 5 |
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u.FiveNUBs
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copy(output[2:],u.Data)
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return
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}
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func (u *NALFragment) GetType() byte {
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return GetNalType(u.ToByteSlice())
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}
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func (u *NALSpsPps) GetType() byte {
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return GetNalType(u.ToByteSlice())
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}
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func (u *NALSpsPps) ToByteSlice() (output []byte){
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output = make([]byte,len(u.Data))
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output = u.Data
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return
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}
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