av/codec/mjpeg/utils.go

75 lines
1.6 KiB
Go

/*
DESCRIPTION
utils.go provides buffer utilities used by jpeg.go.
TODO: make this exported in codecutil.
AUTHOR
Saxon Nelson-Milton <saxon@ausocean.org>
LICENSE
Copyright (C) 2019 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 http://www.gnu.org/licenses.
*/
package mjpeg
import (
"encoding/binary"
"io"
)
type putBuffer struct {
len int
bytes []byte
}
func newPutBuffer(b []byte) *putBuffer { return &putBuffer{bytes: b} }
func (p *putBuffer) Write(b []byte) (int, error) {
copy(p.bytes[p.len:], b)
p.len += len(b)
return len(b), nil
}
func (p *putBuffer) writeTo(d io.Writer) (int, error) {
n, err := d.Write(p.bytes[0:p.len])
p.len -= n
return n, err
}
func (p *putBuffer) put16(v uint16) {
binary.BigEndian.PutUint16(p.bytes[p.len:], v)
p.len += 2
}
func (p *putBuffer) put8(v uint8) {
p.bytes[p.len] = byte(v)
p.len++
}
func (p *putBuffer) putBytes(src []byte) {
copy(p.bytes[p.len:], src)
p.len += len(src)
}
func (p *putBuffer) put16At(v uint16, i int) {
binary.BigEndian.PutUint16(p.bytes[i:], v)
}
func (p *putBuffer) reset() {
p.len = 0
}