Add FFmpeg utilities configuration UI and automated downloading

Introduce a new UI for configuring FFmpeg, FFprobe, and FFplay paths with file selection and error handling. Add platform-specific logic for downloading and extracting FFmpeg binaries directly within the application, improving user experience.

internal/ffmpeg/download/service/download_linux.go

@@ -0,0 +1,236 @@
+//go:build linux
+// +build linux
+
+package service
+
+import (
+	"archive/tar"
+	"errors"
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/canvas"
+	"fyne.io/fyne/v2/lang"
+	"fyne.io/fyne/v2/widget"
+	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/internal/application"
+	"github.com/ulikunitz/xz"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+)
+
+func startDownload(app application.AppContract, progressBar *widget.ProgressBar, progressMessage *canvas.Text, save func(ffmpegPath string, ffprobePath string, ffplayPath string) error) error {
+	var err error
+
+	dir, err := localSharePath()
+	if err != nil {
+		return err
+	}
+	dir = filepath.Join(dir, "fyne", app.FyneApp().UniqueID())
+	err = os.MkdirAll(dir, 0755)
+	if err != nil {
+		return err
+	}
+
+	fyne.Do(func() {
+		progressMessage.Text = lang.L("downloadRun")
+		progressMessage.Refresh()
+	})
+	err = downloadFile(dir+"/ffmpeg.tar.xz", "https://github.com/BtbN/FFmpeg-Builds/releases/download/latest/ffmpeg-master-latest-linux64-gpl.tar.xz", progressBar)
+	if err != nil {
+		return err
+	}
+
+	fyne.Do(func() {
+		progressMessage.Text = lang.L("unzipRun")
+		progressMessage.Refresh()
+	})
+	err = unTarXz(dir+"/ffmpeg.tar.xz", dir, progressBar)
+	if err != nil {
+		return err
+	}
+	_ = os.Remove(dir + "/ffmpeg.tar.xz")
+
+	fyne.Do(func() {
+		progressMessage.Text = lang.L("testFF")
+		progressMessage.Refresh()
+	})
+
+	err = save(
+		dir+"/ffmpeg-master-latest-linux64-gpl/bin/ffmpeg",
+		dir+"/ffmpeg-master-latest-linux64-gpl/bin/ffprobe",
+		dir+"/ffmpeg-master-latest-linux64-gpl/bin/ffplay",
+	)
+	if err != nil {
+		return err
+	}
+
+	fyne.Do(func() {
+		progressMessage.Text = lang.L("completedQueue")
+		progressMessage.Refresh()
+	})
+
+	return nil
+}
+
+func localSharePath() (string, error) {
+	xdgDataHome := os.Getenv("XDG_DATA_HOME")
+	if xdgDataHome != "" {
+		return xdgDataHome, nil
+	}
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(homeDir, ".local", "share"), nil
+}
+
+func downloadFile(filepath string, url string, progressBar *widget.ProgressBar) (err error) {
+	progressBar.Value = 0
+	progressBar.Max = 100
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return err
+	}
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	f, err := os.OpenFile(filepath, os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	buf := make([]byte, 32*1024)
+	var downloaded int64
+	for {
+		n, err := resp.Body.Read(buf)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+		if n > 0 {
+			f.Write(buf[:n])
+			downloaded += int64(n)
+			progressBar.Value = float64(downloaded) / float64(resp.ContentLength) * 100
+			fyne.Do(func() {
+				progressBar.Refresh()
+			})
+		}
+	}
+	return nil
+}
+
+func unTarXz(fileTar string, directory string, progressBar *widget.ProgressBar) error {
+	progressBar.Value = 0
+	progressBar.Max = 100
+
+	fyne.Do(func() {
+		progressBar.Refresh()
+	})
+
+	f, err := os.Open(fileTar)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	xzReader, err := xz.NewReader(f)
+	if err != nil {
+		return err
+	}
+
+	tarReader := tar.NewReader(xzReader)
+
+	totalFiles := 0
+	for {
+		_, err := tarReader.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		totalFiles++
+	}
+
+	// Rewind back to the beginning of the file to re-process
+	_, err = f.Seek(0, 0)
+	if err != nil {
+		return err
+	}
+
+	xzReader, err = xz.NewReader(f)
+	if err != nil {
+		return err
+	}
+
+	tarReader = tar.NewReader(xzReader)
+
+	// We count the number of files already unpacked
+	unpackedFiles := 0
+
+	for {
+		header, err := tarReader.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		targetPath := filepath.Join(directory, header.Name)
+		switch header.Typeflag {
+		case tar.TypeDir:
+			err := os.MkdirAll(targetPath, 0755)
+			if err != nil {
+				return err
+			}
+		case tar.TypeReg:
+			outFile, err := os.Create(targetPath)
+			if err != nil {
+				return err
+			}
+			defer outFile.Close()
+
+			_, err = io.Copy(outFile, tarReader)
+
+			if err != nil {
+				return err
+			}
+		default:
+			return errors.New("unsupported file type")
+		}
+
+		unpackedFiles++
+		progressBar.Value = float64(unpackedFiles) / float64(totalFiles) * 100
+		fyne.Do(func() {
+			progressBar.Refresh()
+		})
+	}
+
+	ffmpegPath := filepath.Join(directory, "ffmpeg-master-latest-linux64-gpl", "bin", "ffmpeg")
+	err = os.Chmod(ffmpegPath, 0755)
+	if err != nil {
+		return err
+	}
+
+	ffprobePath := filepath.Join(directory, "ffmpeg-master-latest-linux64-gpl", "bin", "ffprobe")
+	err = os.Chmod(ffprobePath, 0755)
+	if err != nil {
+		return err
+	}
+
+	ffplayPath := filepath.Join(directory, "ffmpeg-master-latest-linux64-gpl", "bin", "ffplay")
+	err = os.Chmod(ffplayPath, 0755)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}