av/protocol/rtp/client.go

125 lines
2.3 KiB
Go

/*
NAME
client.go
DESCRIPTION
client.go provides an RTP client that will receive RTP on a UDP connection
AUTHOR
Saxon A. Nelson-Milton <saxon@ausocean.org>
LICENSE
rtp.go is Copyright (C) 2018 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 rtp
import (
"io"
"net"
"sync"
"bitbucket.org/ausocean/utils/ring"
)
const (
chanSize = 10
)
type Client struct {
conn *net.UDPConn
wg sync.WaitGroup
done chan struct{}
ring *ring.Buffer
op func([]byte) ([]byte, error)
ErrChan chan error
}
func NewClient(addr string, op func([]byte) ([]byte, error)) (*Client, error) {
c := &Client{
done: make(chan struct{}, 10),
ring: ring.NewBuffer(10, 4096, 0),
}
a, err := net.ResolveUDPAddr("udp", addr)
if err != nil {
return nil, err
}
c.conn, err = net.ListenUDP("udp", a)
if err != nil {
return nil, err
}
return c, nil
}
func (c *Client) Start() {
c.wg.Add(1)
go c.recv()
}
func (c *Client) recv() {
defer c.wg.Done()
buf := make([]byte, 4096)
for {
select {
case <-c.done:
return
default:
n, _, err := c.conn.ReadFromUDP(buf)
if err != nil {
c.ErrChan <- err
continue
}
var _buf []byte
switch c.op {
case nil:
_buf = buf[:n]
default:
_buf, err = c.op(buf[:n])
if err != nil {
c.ErrChan <- err
continue
}
}
_, err = c.ring.Write(_buf)
c.ring.Flush()
if err != nil {
c.ErrChan <- err
continue
}
}
}
}
func (c *Client) Stop() {
close(c.done)
c.conn.Close()
c.wg.Wait()
}
func (c *Client) Read(p []byte) (int, error) {
chunk, err := c.ring.Next(0)
if err != nil {
return 0, io.EOF
}
n := copy(p, chunk.Bytes())
chunk.Close()
chunk = nil
return n, nil
}