av/flv/FLV.go

160 lines
3.5 KiB
Go

/*
NAME
FLV.go
DESCRIPTION
See Readme.md
AUTHORS
Saxon A. Nelson-Milton <saxon@ausocean.org>
LICENSE
FLV.go is Copyright (C) 2017 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
along with revid in gpl.txt. If not, see [GNU licenses](http://www.gnu.org/licenses).
*/
package flv
import (
"../tools"
"fmt"
)
const (
headerLength = 72
version = 0x01
maxVideoTagSize = 10000
maxAudioTagSize = 10000
)
const (
VideoTagType = 9
AudioTagType = 8
KeyFrameType = 1
InterFrameType = 2
H264 = 7
AVCNALU = 1
SequenceHeader = 0
DataHeaderLength = 5
NoTimestampExtension = 0
AACAudioFormat = 10
PCMAudioFormat = 0
)
var flvHeaderCode = []byte{0x46, 0x4C, 0x56}
type Header struct {
AudioFlag bool
VideoFlag bool
}
func btb(b bool) byte {
return tools.BoolToByte(b)
}
func (h *Header) ToByteSlice() (output []byte) {
output = make([]byte, 0, headerLength)
output = append(output, flvheaderCode...)
output = append(output, []byte {
version,
0x00 | btb(h.AudioFlag)<<2 | btb(h.VideoFlag),
0x00, 0x00, 0x00, byte(9),
}...)
fmt.Println(output)
return
}
type VideoTag struct {
TagType uint8
DataSize uint32
Timestamp uint32
TimestampExtended uint32
FrameType byte
Codec byte
PacketType byte
CompositionTime uint32
Data []byte
PrevTagSize uint32
}
func (t *VideoTag) ToByteSlice() (output []byte) {
output = make([]byte, 0, maxVideoTagSize)
output = append(output, []byte{
byte(t.TagType),
byte(t.DataSize >> 16),
byte(t.DataSize >> 8),
byte(t.DataSize),
byte(t.Timestamp >> 16),
byte(t.Timestamp >> 8),
byte(t.Timestamp),
byte(t.TimestampExtended),
0x00,
0x00,
0x00,
0x00 | byte(t.FrameType<<4) | byte(t.Codec),
t.PacketType,
byte(t.CompositionTime >> 16),
byte(t.CompositionTime >> 8),
byte(t.CompositionTime),
}...)
output = append(output, t.Data...)
output = append(output, []byte{
byte(t.PrevTagSize >> 24),
byte(t.PrevTagSize >> 16),
byte(t.PrevTagSize >> 8),
byte(t.PrevTagSize),
}...)
return
}
type AudioTag struct {
TagType uint8
DataSize uint32
Timestamp uint32
TimestampExtended uint32
SoundFormat uint8
SoundRate uint8
SoundSize bool
SoundType bool
Data []byte
PrevTagSize uint32
}
func (t *AudioTag) ToByteSlice() (output []byte) {
output = make([]byte, 0, maxVideoTagSize)
output = append(output, []byte{
byte(t.TagType),
byte(t.DataSize >> 16),
byte(t.DataSize >> 8),
byte(t.DataSize),
byte(t.Timestamp >> 16),
byte(t.Timestamp >> 8),
byte(t.Timestamp),
byte(t.TimestampExtended),
0x00,
0x00,
0x00,
byte(t.SoundFormat<<4) | byte(t.SoundRate<<2) | btb(t.SoundSize)<<1 | btb(t.SoundType),
}...)
output = append(output, t.Data...)
output = append(output, []byte{
byte(t.PrevTagSize >> 24),
byte(t.PrevTagSize >> 16),
byte(t.PrevTagSize >> 8),
byte(t.PrevTagSize),
}...)
return
}