dndmusicbot/ytdl.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/tidwall/gjson"
	"golang.org/x/time/rate"
)

var prate = rate.Sometimes{Interval: 1 * time.Second}
var yturl = "https://youtu.be/%s"

func NewYTdl(vid string) ([]byte, error) {
	ytdl := config.GetString("youtube.ytdl")
	uri, err := exec.Command(
		ytdl,
		fmt.Sprintf(yturl, vid),
		"--cookies", "./cookies.txt",
		"--no-call-home",
		"--no-cache-dir",
		"--ignore-errors",
		"--newline",
		"--restrict-filenames",
		"-f", "251",
		"--get-url",
	).Output()
	if err != nil {
		return nil, err
	}

	return uri[:len(uri)-1], nil
}

func DownloadAmbiance(uri string, name string) error {
	ytdl := config.GetString("youtube.ytdl")

	tmpfile, err := exec.Command("mktemp", "/tmp/dnd_XXXXXXXXXXXX.aac").Output()
	if err != nil {
		return err
	}

	tmpfile = tmpfile[:len(tmpfile)-1]

	cmd := exec.Command(
		ytdl,
		uri,
		"--no-call-home",
		"--no-cache-dir",
		"-f", "140",
		"--cookies", "../cookies.txt",
		"-o", string(tmpfile),
		"--force-overwrites",
		"-q",
		"--progress",
		"--progress-template", "%(progress)j",
		"--no-colors",
		"--newline",
		"--fixup", "never",
	)

	cmdout, err := cmd.StdoutPipe()
	if err != nil {
		return err
	}

	err = cmd.Start()
	if err != nil {
		return err
	}

	msg := make(map[string]interface{})
	msg["event"] = "ambiance_download_start"
	data := make(map[string]string)
	data["name"] = name
	msg["payload"] = data
	ws_msg <- msg

	msg = make(map[string]interface{})
	msg["event"] = "ambiance_download_progress"
	data = make(map[string]string)
	scanner := bufio.NewScanner(cmdout)
	for scanner.Scan() {
		prate.Do(func() {
			js := gjson.GetManyBytes(scanner.Bytes(), "status", "downloaded_bytes", "total_bytes", "eta", "speed")
			data["name"] = name
			data["status"] = js[0].String()
			data["downloaded_bytes"] = js[1].String()
			data["total_bytes"] = js[2].String()
			data["eta"] = js[3].String()
			data["speed"] = js[4].String()
			msg["payload"] = data
			ws_msg <- msg
		})
	}
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "reading output:", err)
	}

	err = cmd.Wait()
	if err != nil {
		return err
	}

	msg = make(map[string]interface{})
	msg["event"] = "ambiance_download_complete"
	data = make(map[string]string)
	data["name"] = name
	msg["payload"] = data
	ws_msg <- msg

	ff := exec.Command(
		"ffmpeg",
		"-i", string(tmpfile),
		"-v", "error",
		// "-stats",
		"-progress", "pipe:1",
		"-ar", strconv.Itoa(sampleRate),
		"-ac", strconv.Itoa(channels),
		"-af", "loudnorm=I=-16:LRA=11:TP=-1.5",
		filepath.Join("./ambiance/", name+".mp3"),
	)

	ffprogress, err := ff.StdoutPipe()
	if err != nil {
		return err
	}

	err = ff.Start()
	if err != nil {
		return err
	}

	msg = make(map[string]interface{})
	msg["event"] = "ambiance_encode_start"
	data = make(map[string]string)
	data["name"] = name
	msg["payload"] = data
	ws_msg <- msg

	msg = make(map[string]interface{})
	msg["event"] = "ambiance_encode_progress"
	data = make(map[string]string)
	data["name"] = name

	scanner = bufio.NewScanner(ffprogress)

	for scanner.Scan() {
		p := strings.Split(scanner.Text(), "=")
		if len(p) == 2 {
			data[p[0]] = p[1]
		}

		prate.Do(func() {
			msg["payload"] = data
			ws_msg <- msg
		})
	}
	if err := scanner.Err(); err != nil {
		return err
	}

	err = ff.Wait()
	if err != nil {
		return err
	}

	msg = make(map[string]interface{})
	msg["event"] = "ambiance_encode_complete"
	data = make(map[string]string)
	data["name"] = name
	msg["payload"] = data
	ws_msg <- msg

	return nil
}