av/filter/filter.go

/*
NAME
  filter.go

AUTHORS
  Ella Pietraroia <ella@ausocean.org>

LICENSE
  filter.go is 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
  in gpl.txt.  If not, see http://www.gnu.org/licenses.
*/

// Package filter provides the interface and implementations of the filters to be used
// on video input that has been lexed.
package filter

import (
	"fmt"
	"io"
	"time"
)

// Interface for all filters.
type Filter interface {
	io.WriteCloser
	//NB: Filter interface may evolve with more methods as required.
}

// The NoOp filter will perform no operation on the data that is being recieved,
// it will pass it on to the encoder with no changes.
type NoOp struct {
	dst io.Writer
}

func NewNoOp(dst io.Writer) *NoOp { return &NoOp{dst: dst} }

func (n *NoOp) Write(p []byte) (int, error) {
	if frames == 0 {
		t1 = time.Now()
	}
	frames++
	if frames >= 24 {
		fmt.Printf("25 frames takes: %dms\n\n", time.Now().Sub(t1).Milliseconds())
		frames = 0
	}
	return n.dst.Write(p)
}

func (n *NoOp) Close() error { return nil }