Restructure and rewrite some parts of the README

README.md

@@ -1,9 +1,10 @@
 
-<details><summary>what could it be?</summary>
+Definitely not an unofficial commandline downloader for https://gronkh.tv
 
-<br>
+## Compatibility
 
-Definetly not a commandline downloader for https://gronkh.tv risen from the dead.
+This tool is only compatible with recent Linux-based operating systems.  
+To run it on Windows, make use of WSL.
 
 ## Features
 
@@ -13,26 +14,27 @@ Definetly not a commandline downloader for https://gronkh.tv risen from the dead
 - Continuable Downloads
 - Show infos about that Episode
 
-## Known Issues
+## Known Issues / Limitations
 
-- Downloads are capped to 10 Mbyte/s and buffering is simulated to pre-empt IP blocking due to API ratelimiting
-- Start- and stop-timestamps are not very accurate (± 8 seconds)
-- Some videoplayers may have problems with the resulting file. To fix this, you can use ffmpeg to rewrite the video into a MKV-File: `ffmpeg -i video.ts -acodec copy -vcodec copy video.mkv`
-
-## Supported Platforms
-
-Only compatible with Linux.
+- Downloads are **capped to 10 Mbyte/s by default** and buffering is simulated to pre-empt IP blocking due to API rate-limiting
+- Because of the length of video chunks, **start- and stop-timestamps are inaccurate** (± 8 seconds)
+- **Some videoplayers may have problems with the downloaded video file**. To fix this, you can use ffmpeg to rewrite the video into a MKV-File:  
+  `ffmpeg -i video.ts -acodec copy -vcodec copy video.mkv`
 
 ## Download / Installation
 
-New versions will appear under [Releases](https://github.com/ChaoticByte/lurch-dl/releases). Just download the application and run it via the terminal/cmd/powershell/...
+New versions will appear under [Releases](https://github.com/ChaoticByte/lurch-dl/releases).  
+Just download the application and run it via your favourite terminal emulator.
 
-On Linux, you may have to mark the file as executable before being able to run it.
+> Note: **You may have to mark the file as executable before being able to run it.**
+
+## Usage
 
-## Cli Usage
 
 Run `lurch-dl --help` to see available options.
 
+> Note: This tool runs entirely on the command line.
+
 ### Examples
 
 Download a video in its best available format:
@@ -105,5 +107,3 @@ Specify a filename:
 ```
 ./lurch-dl --url https://gronkh.tv/streams/777 --output Stream777.ts
 ```
-
-</details>

VERSION

@@ -1 +1 @@
-2.1.1
+2.1.2

cli/cli.go

@@ -3,7 +3,6 @@
 package main
 
 import (
-	"errors"
 	"flag"
 	"fmt"
 	"os"
@@ -38,7 +37,7 @@ func XtermSetTitle(title string) {
 
 // Commandline
 
-type Arguments struct {
+var Arguments struct {
 	Url string `json:"url"`
 	FormatName string `json:"format_name"`
 	OutputFile string `json:"output_file"`
@@ -50,12 +49,11 @@ type Arguments struct {
 	Help bool `json:"-"`
 	VideoInfo bool `json:"-"`
 	ListFormats bool `json:"-"`
-	UnparsedChapterNum   int  `json:"chapter_num"`
+	ChapterNum   int  `json:"chapter_num"`
 	// Parsed
 	Video core.GtvVideo `json:"-"`
 	StartDuration time.Duration `json:"-"`
 	StopDuration time.Duration `json:"-"`
-	ChapterIdx int `json:"-"`
 	Ratelimit float64 `json:"-"`
 }
 
@@ -84,96 +82,91 @@ lurch-dl --url string       The url to the video
 Version: ` + core.Version)
 }
 
-func CliParseArguments() (Arguments, error) {
+func CliParseArguments() error {
 	var err error
 	var ratelimitMbs float64
-	a := Arguments{}
-	flag.BoolVar(&a.Help, "h", false, "")
-	flag.BoolVar(&a.Help, "help", false, "")
-	flag.BoolVar(&a.VideoInfo, "info", false, "")
-	flag.StringVar(&a.Url, "url", "", "")
-	flag.IntVar(&a.UnparsedChapterNum, "chapter", 0, "") // 0 -> chapter idx -1 -> complete stream
-	flag.StringVar(&a.FormatName, "format", "auto", "")
-	flag.StringVar(&a.OutputFile, "output", "", "")
-	flag.StringVar(&a.TimestampStart, "start", "", "")
-	flag.StringVar(&a.TimestampStop, "stop", "", "")
-	flag.BoolVar(&a.Overwrite, "overwrite", false, "")
-	flag.BoolVar(&a.ContinueDl, "continue", false, "")
+	flag.BoolVar(&Arguments.Help, "h", false, "")
+	flag.BoolVar(&Arguments.Help, "help", false, "")
+	flag.BoolVar(&Arguments.VideoInfo, "info", false, "")
+	flag.StringVar(&Arguments.Url, "url", "", "")
+	flag.IntVar(&Arguments.ChapterNum, "chapter", 0, "") // 0 -> chapter idx -1 -> complete stream
+	flag.StringVar(&Arguments.FormatName, "format", "auto", "")
+	flag.StringVar(&Arguments.OutputFile, "output", "", "")
+	flag.StringVar(&Arguments.TimestampStart, "start", "", "")
+	flag.StringVar(&Arguments.TimestampStop, "stop", "", "")
+	flag.BoolVar(&Arguments.Overwrite, "overwrite", false, "")
+	flag.BoolVar(&Arguments.ContinueDl, "continue", false, "")
 	flag.Float64Var(&ratelimitMbs, "max-rate", 10.0, "")
 	flag.Parse()
-	a.Video, err = core.ParseGtvVideoUrl(a.Url)
+	Arguments.Video, err = core.ParseGtvVideoUrl(Arguments.Url)
 	if err != nil {
-		return a, err
+		return err
 	}
-	if a.Video.Category != "streams" {
-		return a, errors.New("video category '" + a.Video.Category + "' not supported")
-	}
-	if a.TimestampStart == "" {
-		a.StartDuration = -1
+	if Arguments.TimestampStart == "" {
+		Arguments.StartDuration = -1
 	} else {
-		a.StartDuration, err = time.ParseDuration(a.TimestampStart)
+		Arguments.StartDuration, err = time.ParseDuration(Arguments.TimestampStart)
 		if err != nil {
-			return a, err
+			return err
 		}
 	}
-	if a.TimestampStop == "" {
-		a.StopDuration = -1
+	if Arguments.TimestampStop == "" {
+		Arguments.StopDuration = -1
 	} else {
-		a.StopDuration, err = time.ParseDuration(a.TimestampStop)
+		Arguments.StopDuration, err = time.ParseDuration(Arguments.TimestampStop)
 		if err != nil {
-			return a, err
+			return err
 		}
 	}
-	a.ChapterIdx = a.UnparsedChapterNum - 1
-	a.Ratelimit = ratelimitMbs * 1_000_000.0 // MB/s -> B/s
-	if a.Ratelimit <= 0 {
-		return a, errors.New("the value of --max-rate must be greater than 0")
+	Arguments.Ratelimit = ratelimitMbs * 1_000_000.0 // MB/s -> B/s
+	if Arguments.Ratelimit <= 0 {
+		return &GenericCliAgumentError{Msg: "the value of --max-rate must be greater than 0"}
 	}
-	return a, err
+	return err
 }
 
 // Main
 
 func CliRun() int {
-	cli := Cli{}
 	defer fmt.Print("\n")
 	// cli arguments & help text
 	flag.Usage = CliShowHelp
-	args, err := CliParseArguments()
-	if args.Help {
+	err := CliParseArguments()
+	if Arguments.Help {
 		CliShowHelp()
 		return 0
-	} else if args.Url == "" || err != nil {
+	} else if Arguments.Url == "" || err != nil {
 		CliShowHelp()
 		if err != nil {
-			cli.ErrorMessage(err)
+			CliErrorMessage(err)
 		}
 		return 1
 	}
 	// detect terminal features
 	XtermDetectFeatures()
-	//
-	api := core.GtvApi{};
 	// Get video metadata
 	if CliXtermTitle {
 		XtermSetTitle("lurch-dl - Fetching video metadata ...")
 	}
-	streamEp, err := api.GetStreamEpisode(args.Video.Id)
+	streamEp, err := core.GetStreamEpisode(Arguments.Video.Id)
 	if err != nil {
-		cli.ErrorMessage(err)
+		CliErrorMessage(err)
 		return 1
 	}
 	fmt.Print("\n")
 	fmt.Printf("Title:     %s\n", streamEp.Title)
 	// Check and list chapters/formats and exit
-	if args.ChapterIdx >= 0 {
-		if args.ChapterIdx >= len(streamEp.Chapters) {
-			cli.ErrorMessage(&core.ChapterNotFoundError{ChapterNum: args.UnparsedChapterNum})
-			CliAvailableChapters(streamEp.Chapters)
-			return 1
-		}
+	targetChapter, err := streamEp.GetChapterByNumber(Arguments.ChapterNum)
+	if err != nil {
+		CliErrorMessage(err)
+		CliAvailableChapters(streamEp.Chapters)
+		return 1
 	}
-	if args.VideoInfo {
+	if Arguments.ChapterNum > 0 && len(streamEp.Chapters) > 0 {
+		fmt.Printf("Chapter:   %v. %v\n", Arguments.ChapterNum, targetChapter.Title)
+	}
+	// Video Info
+	if Arguments.VideoInfo {
 		fmt.Printf("Episode:   %s\n", streamEp.Episode)
 		fmt.Printf("Length:    %s\n", streamEp.Length)
 		fmt.Printf("Views:     %d\n", streamEp.Views)
@@ -195,42 +188,36 @@ func CliRun() int {
 		CliAvailableChapters(streamEp.Chapters)
 		return 0
 	}
-	format, err := streamEp.GetFormatByName(args.FormatName)
+	format, err := streamEp.GetFormatByName(Arguments.FormatName)
 	if err != nil {
-		cli.ErrorMessage(err)
+		CliErrorMessage(err)
 		CliAvailableFormats(streamEp.Formats)
 		return 1
 	}
 	fmt.Printf("Format:    %v\n", format.Name)
-	// chapter
-	targetChapter := core.Chapter{Index: -1} // set Index to -1 for noop
-	if len(streamEp.Chapters) > 0 && args.ChapterIdx >= 0 {
-		targetChapter = streamEp.Chapters[args.ChapterIdx]
-		fmt.Printf("Chapter:   %v. %v\n", args.UnparsedChapterNum, targetChapter.Title)
-	}
 	// We already set the output file correctly so we can output it
-	if args.OutputFile == "" {
-		args.OutputFile = streamEp.GetProposedFilename(args.ChapterIdx)
+	if Arguments.OutputFile == "" {
+		Arguments.OutputFile = streamEp.GetProposedFilename(targetChapter)
 	}
 	// Start Download
-	fmt.Printf("Output:    %v\n", args.OutputFile)
+	fmt.Printf("Output:    %v\n", Arguments.OutputFile)
 	fmt.Print("\n")
 	successful := false
 	aborted := false
-	for p := range api.DownloadEpisode(
+	for p := range core.DownloadStreamEpisode(
 		streamEp,
 		targetChapter,
-		args.FormatName,
-		args.OutputFile,
-		args.Overwrite,
-		args.ContinueDl,
-		args.StartDuration,
-		args.StopDuration,
-		args.Ratelimit,
+		Arguments.FormatName,
+		Arguments.OutputFile,
+		Arguments.Overwrite,
+		Arguments.ContinueDl,
+		Arguments.StartDuration,
+		Arguments.StopDuration,
+		Arguments.Ratelimit,
 		make(chan os.Signal, 1),
 	) { // Iterate over download progress
 		if p.Error != nil {
-			cli.ErrorMessage(p.Error)
+			CliErrorMessage(p.Error)
 			return 1
 		}
 		if p.Success {
@@ -238,7 +225,7 @@ func CliRun() int {
 		} else if p.Aborted {
 			aborted = true
 		} else {
-			cli.DownloadProgress(p.Progress, p.Rate, p.Delaying, p.Waiting, p.Retries, p.Title)
+			CliDownloadProgress(p.Progress, p.Rate, p.Delaying, p.Waiting, p.Retries, p.Title)
 		}
 	}
 	fmt.Print("\n")
@@ -246,7 +233,7 @@ func CliRun() int {
 		fmt.Print("\nAborted.                                                ")
 		return 130
 	} else if !successful {
-		cli.ErrorMessage(errors.New("download failed"))
+		CliErrorMessage(&GenericDownloadError{})
 		return 1
 	} else { return 0 }
 }
@@ -270,9 +257,7 @@ func CliAvailableFormats(formats []core.VideoFormat) {
 	fmt.Print("\n")
 }
 
-type Cli struct{}
-
-func (cli *Cli) DownloadProgress(progress float32, rate float64, delaying bool, waiting bool, retries int, title string) {
+func CliDownloadProgress(progress float32, rate float64, delaying bool, waiting bool, retries int, title string) {
 	if retries > 0 {
 		if retries == 1 {
 			fmt.Print("\n")
@@ -291,7 +276,7 @@ func (cli *Cli) DownloadProgress(progress float32, rate float64, delaying bool,
 	}
 }
 
-func (cli *Cli) ErrorMessage(err error) {
+func CliErrorMessage(err error) {
 	fmt.Print("\n")
 	fmt.Println("An error occured:", err)
 }

cli/errors.go

@@ -0,0 +1,15 @@
+package main
+
+type GenericCliAgumentError struct {
+	Msg string
+}
+
+func (err *GenericCliAgumentError) Error() string {
+	return err.Msg
+}
+
+type GenericDownloadError struct {}
+
+func (err *GenericDownloadError) Error() string {
+	return "download failed"
+}

core/errors.go

@@ -35,7 +35,7 @@ type FileExistsError struct {
 }
 
 func (err *FileExistsError) Error() string {
-	return "File '" + err.Filename + "' already exists. See the available options on how to proceed."
+	return "file '" + err.Filename + "' already exists - see the available options on how to proceed"
 }
 
 type FormatNotFoundError struct {
@@ -43,7 +43,7 @@ type FormatNotFoundError struct {
 }
 
 func (err *FormatNotFoundError) Error() string {
-	return "Format " + err.FormatName + " is not available."
+	return "format " + err.FormatName + " is not available"
 }
 
 type ChapterNotFoundError struct {
@@ -51,5 +51,27 @@ type ChapterNotFoundError struct {
 }
 
 func (err *ChapterNotFoundError) Error() string {
-	return fmt.Sprintf("Chapter %v not found.", err.ChapterNum)
+	return fmt.Sprintf("chapter %v not found", err.ChapterNum)
+}
+
+type VideoCategoryUnsupportedError struct {
+	Category string
+}
+
+func (err *VideoCategoryUnsupportedError) Error() string {
+	return fmt.Sprintf("video category '%v' not supported", err.Category)
+}
+
+type GtvVideoUrlParseError struct {
+	Url string
+}
+
+func (err *GtvVideoUrlParseError) Error() string {
+	return fmt.Sprintf("Could not parse URL %v", err.Url)
+}
+
+type DownloadInfoFileReadError struct {}
+
+func (err *DownloadInfoFileReadError) Error() string {
+	return "could not read download info file, can't continue download"
 }

core/gtv_api.go

@@ -4,7 +4,6 @@ package core
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"iter"
@@ -25,6 +24,18 @@ const RatelimitDelayAfter = 5.0 // in Seconds; Delay the next chunk download aft
 const ApiBaseurlStreamEpisodeInfo = "https://api.gronkh.tv/v1/video/info?episode=%s"
 const ApiBaseurlStreamEpisodePlInfo = "https://api.gronkh.tv/v1/video/playlist?episode=%s"
 
+type DownloadProgress struct {
+	Aborted bool
+	Error error
+	Success bool
+	Delaying bool
+	Progress float32
+	Rate float64
+	Retries int
+	Title string
+	Waiting bool
+}
+
 var ApiHeadersBase = http.Header{
 	"User-Agent":      {"Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/119.0"},
 	"Accept-Language": {"de,en-US;q=0.7,en;q=0.3"},
@@ -48,9 +59,7 @@ var ApiHeadersVideoAdditional = http.Header{
 	"Accept": {"*/*"},
 }
 
-type GtvApi struct{}
-
-func (api *GtvApi) GetStreamEpisode(episode string) (StreamEpisode, error) {
+func GetStreamEpisode(episode string) (StreamEpisode, error) {
 	ep := StreamEpisode{}
 	ep.Episode = episode
 	info_data, err := httpGet(
@@ -93,7 +102,7 @@ func (api *GtvApi) GetStreamEpisode(episode string) (StreamEpisode, error) {
 	return ep, err
 }
 
-func (api *GtvApi) GetStreamChunkList(video VideoFormat) (ChunkList, error) {
+func GetStreamChunkList(video VideoFormat) (ChunkList, error) {
 	baseUrl := video.Url[:strings.LastIndex(video.Url, "/")]
 	data, err := httpGet(video.Url, []http.Header{ApiHeadersBase, ApiHeadersMetaAdditional}, time.Second*10)
 	if err != nil {
@@ -103,7 +112,7 @@ func (api *GtvApi) GetStreamChunkList(video VideoFormat) (ChunkList, error) {
 	return chunklist, err
 }
 
-func (api *GtvApi) DownloadEpisode(
+func DownloadStreamEpisode(
 	ep StreamEpisode,
 	chapter Chapter,
 	formatName string,
@@ -118,7 +127,7 @@ func (api *GtvApi) DownloadEpisode(
 	return func (yield func(DownloadProgress) bool) {
 		// Set automatic values
 		if outputFile == "" {
-			outputFile = ep.GetProposedFilename(chapter.Index)
+			outputFile = ep.GetProposedFilename(chapter)
 		}
 		if chapter.Index >= 0 {
 			if startDuration < 0 {
@@ -157,7 +166,7 @@ func (api *GtvApi) DownloadEpisode(
 		if continueDl {
 			infoFileData, err := os.ReadFile(infoFilename)
 			if err != nil {
-				yield(DownloadProgress{Error: errors.New("could not access download info file, can't continue download")})
+				yield(DownloadProgress{Error: &DownloadInfoFileReadError{}})
 				return
 			}
 			i, err := strconv.ParseInt(string(infoFileData), 10, 32)
@@ -181,7 +190,7 @@ func (api *GtvApi) DownloadEpisode(
 		}
 		// download
 		format, _ := ep.GetFormatByName(formatName) // we don't have to check the error, as it was already checked by CliRun()
-		chunklist, err := api.GetStreamChunkList(format)
+		chunklist, err := GetStreamChunkList(format)
 		chunklist = chunklist.Cut(startDuration, stopDuration)
 		if err != nil {
 			yield(DownloadProgress{Error: err})

core/gtv_common.go

@@ -3,7 +3,6 @@
 package core
 
 import (
-	"errors"
 	"fmt"
 	"regexp"
 	"time"
@@ -40,10 +39,13 @@ func ParseGtvVideoUrl(url string) (GtvVideo, error) {
 	video := GtvVideo{}
 	match := videoUrlRegex.FindStringSubmatch(url)
 	if len(match) < 2 {
-		return video, errors.New("Could not parse URL " + url)
+		return video, &GtvVideoUrlParseError{Url: url}
 	}
 	video.Category = match[1]
 	video.Id = match[2]
+	if video.Category != "streams" {
+		return video, &VideoCategoryUnsupportedError{Category: video.Category}
+	}
 	return video, nil
 }
 
@@ -109,9 +111,21 @@ func (ep *StreamEpisode) GetFormatByName(formatName string) (VideoFormat, error)
 	}
 }
 
-func (ep *StreamEpisode) GetProposedFilename(chapterIdx int) string {
-	if chapterIdx >= 0 && chapterIdx < len(ep.Chapters) {
-		return fmt.Sprintf("GTV%04s - %v. %s.ts", ep.Episode, chapterIdx+1, sanitizeUnicodeFilename(ep.Chapters[chapterIdx].Title))
+func (ep *StreamEpisode) GetChapterByNumber(number int) (Chapter, error) {
+	chapter := Chapter{Index: -1} // set Index to -1 for noop
+	idx := number-1
+	if idx >= 0 && idx >= len(ep.Chapters) {
+		return chapter, &ChapterNotFoundError{ChapterNum: number}
+	}
+	if len(ep.Chapters) > 0 && idx >= 0 {
+		chapter = ep.Chapters[idx]
+	}
+	return chapter, nil
+}
+
+func (ep *StreamEpisode) GetProposedFilename(chapter Chapter) string {
+	if chapter.Index >= 0 && chapter.Index < len(ep.Chapters) {
+		return fmt.Sprintf("GTV%04s - %v. %s.ts", ep.Episode, chapter.Index, sanitizeUnicodeFilename(ep.Chapters[chapter.Index].Title))
 	} else {
 		return sanitizeUnicodeFilename(ep.Title) + ".ts"
 	}

core/interface.go

@@ -1,13 +0,0 @@
-package core
-
-type DownloadProgress struct {
-	Aborted bool
-	Error error
-	Success bool
-	Delaying bool
-	Progress float32
-	Rate float64
-	Retries int
-	Title string
-	Waiting bool
-}