/* DESCRIPTION file.go provides an implementation of the AVDevice interface for media files. AUTHORS Saxon A. 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 in gpl.txt. If not, see http://www.gnu.org/licenses. */ package file import ( "errors" "fmt" "io" "os" "bitbucket.org/ausocean/av/revid/config" ) // AVFile is an implementation of the AVDevice interface for a file containg // audio or video data. type AVFile struct { f io.ReadCloser cfg config.Config } // NewAVFile returns a new AVFile. func New() *AVFile { return &AVFile{} } // Name returns the name of the device. func (m *AVFile) Name() string { return "File" } // Set simply sets the AVFile's config to the passed config. func (m *AVFile) Set(c config.Config) error { m.cfg = c return nil } // Start will open the file at the location of the InputPath field of the // config struct. func (m *AVFile) Start() error { var err error m.f, err = os.Open(m.cfg.InputPath) if err != nil { return fmt.Errorf("could not open media file: %w", err) } return nil } // Stop will close the file such that any further reads will fail. func (m *AVFile) Stop() error { return m.f.Close() } // Read implements io.Reader. If start has not been called, or Start has been // called and Stop has since been called, an error is returned. func (m *AVFile) Read(p []byte) (int, error) { if m.f != nil { return m.f.Read(p) } return 0, errors.New("AV file is closed") }