bar/media.go

package main

import (
	"fmt"
	"log"
	"os/exec"

	// osc
	"github.com/hypebeast/go-osc/osc"
)

// Base structure for audiovisual media.
// Media is simply a file containing audio and video material.
type Media struct {
	active bool
	cmd    *exec.Cmd
	args   []string
}

// Interface for Media type structs
type MediaPlayer interface {
	play()
	stop()
}

// Run executable
func run(name string, args ...string) *exec.Cmd {
	// Find executable
	//path, err := exec.LookPath(name)
	//if err != nil {
	//	log.Printf("can't find '%s'\n", name)
	//	return nil
	//}

	//println("got path")
	//log.Println("got path:", path, args)
	cmd := exec.Command(name, args...)
	if err := cmd.Run(); err != nil {
		log.Print(err)
		return nil
	}
	return cmd
}

// Run executable
func (player *Media) run(name string, args ...string) {
	player.cmd = exec.Command(name, args...)
	if err := player.cmd.Run(); err != nil {
		log.Print(err)
	}
}

// Play media file via mpv, osc message sets the file path
func (player *Media) play(msg *osc.Message) {
	if player.active {
		log.Print("please stop current player before playing another")
		log.Print(player.cmd)
		return
	}

	uri := getOSC[string](msg)

	osc.PrintMessage(msg)
	if uri == "" {
		log.Print("player won't play without uri")
		return
	}
	player.active = true

	// you can route audio directly through alsa/hdmi but beware of clipping
	//run(player, "mpv", "-fs", "--audio-device=alsa/hdmi", "--volume=25", uri)

	args := append(player.args, uri)
	player.run(args[0], args[1:]...)
	player.active = false
}

// Stop the player by shutting down MPV
func (player *Media) stop(msg *osc.Message) {
	player.quit()
}

// Change volume using amixer command
func (player *Media) volume(msg *osc.Message) {
	level := getOSC[float32](msg)
	run("amixer", "-q", "sset", "Master", fmt.Sprintf("%.2f%%", level*100.0))
}

func (player *Media) quit() {
	if !player.active {
		log.Print("can't kill player if it ain't running")
		return
	}
	if err := player.cmd.Process.Kill(); err != nil {
		log.Print("failed to kill process: ", err)
	}
	player.active = false
}

func NewMPV() *Media {
	media := new(Media)
	media.args = []string{"mpv", "-fs"}
	return media
}

func NewXLEmulator() *Media {
	media := new(Media)
	media.args = []string{"atari800", "-stretch", "3"}
	return media
}