Implement proper subtitle support in Go

2023-10-16 18:02:13 +02:00 · 2023-10-16 18:02:13 +02:00 · 56a5bdc3ac
commit 56a5bdc3ac
parent 1fa1b559ca
8 changed files with 174 additions and 112 deletions
--- a/files/file.go
+++ b/files/file.go
@ -8,6 +8,7 @@ import (
 	"encoding/hex"
 	"hash"
 	"io"
+	"io/fs"
 	"log"
 	"mime"
 	"net/http"
@ -27,6 +28,11 @@ import (
 const PermFile = 0664
 const PermDir = 0755

+var (
+	reSubDirs = regexp.MustCompile("(?i)^sub(s|titles)$")
+	reSubExts = regexp.MustCompile("(?i)(.vtt|.srt|.ass|.ssa)$")
+)
+
 // FileInfo describes a file.
 type FileInfo struct {
 	*Listing
@ -308,28 +314,46 @@ func (i *FileInfo) detectSubtitles() {
 	}

 	base := strings.TrimSuffix(i.Name, ext)
-	subDirsRegex := regexp.MustCompile("(?i)^sub(s|titles)$")
 	for _, f := range dir {
-		// load all .vtt/.srt subtitles from subs directories
-		if f.IsDir() && subDirsRegex.MatchString(f.Name()) {
+		// load all supported subtitles from subs directories
+		// should cover all instances of subtitle distributions
+		// like tv-shows with multiple episodes in single dir
+		if f.IsDir() && reSubDirs.MatchString(f.Name()) {
 			subsDir := path.Join(parentDir, f.Name())
-			var err error
-			dir, err = afero.ReadDir(i.Fs, subsDir)
-			if err == nil {
-				for _, f := range dir {
-					if !f.IsDir() && (strings.HasSuffix(f.Name(), ".vtt") ||
-						strings.HasSuffix(f.Name(), ".srt")) {
-						i.Subtitles = append(i.Subtitles, path.Join(subsDir, f.Name()))
-					}
-				}
-			}
-		} else if !f.IsDir() && strings.HasPrefix(f.Name(), base) &&
-			(strings.HasSuffix(f.Name(), ".vtt") || strings.HasSuffix(f.Name(), ".srt")) {
-			i.Subtitles = append(i.Subtitles, path.Join(parentDir, f.Name()))
+			i.loadSubtitles(subsDir, base, true)
+		} else if isSubtitleMatch(f, base) {
+			i.addSubtitle(path.Join(parentDir, f.Name()))
 		}
 	}
 }

+func (i *FileInfo) loadSubtitles(subsPath string, baseName string, recursive bool) {
+	dir, err := afero.ReadDir(i.Fs, subsPath)
+	if err == nil {
+		for _, f := range dir {
+			if isSubtitleMatch(f, "") {
+				i.addSubtitle(path.Join(subsPath, f.Name()))
+			} else if f.IsDir() && recursive && strings.HasPrefix(f.Name(), baseName) {
+				subsDir := path.Join(subsPath, f.Name())
+				i.loadSubtitles(subsDir, baseName, false)
+			}
+		}
+	}
+}
+
+func IsSupportedSubtitle(fileName string) bool {
+	return reSubExts.MatchString(fileName)
+}
+
+func isSubtitleMatch(f fs.FileInfo, baseName string) bool {
+	return !f.IsDir() && strings.HasPrefix(f.Name(), baseName) &&
+		IsSupportedSubtitle(f.Name())
+}
+
+func (i *FileInfo) addSubtitle(path string) {
+	i.Subtitles = append(i.Subtitles, path)
+}
+
 func (i *FileInfo) readListing(checker rules.Checker, readHeader bool) error {
 	afs := &afero.Afero{Fs: i.Fs}
 	dir, err := afs.ReadDir(i.Path)
--- a/frontend/src/api/files.ts
+++ b/frontend/src/api/files.ts
@ -205,7 +205,7 @@ export function getSubtitlesURL(file: ResourceItem) {
    inline: "true",
  };

-  return file.subtitles?.map((d) => createURL("api/raw" + d, params));
+  return file.subtitles?.map((d) => createURL("api/subtitle" + d, params));
 }

 export async function usage(url: string) {
--- a/frontend/src/components/files/VideoPlayer.vue
+++ b/frontend/src/components/files/VideoPlayer.vue
@ -1,11 +1,14 @@
 <template>
-  <video
-    ref="videoPlayer"
-    class="video-js"
-    controls
-    style="width: 100%; height: 100%"
-  >
+  <video ref="videoPlayer" class="video-max video-js" controls>
    <source :src="source" />
+    <track
+      kind="subtitles"
+      v-for="(sub, index) in subtitles"
+      :key="index"
+      :src="sub"
+      :label="subLabel(sub)"
+      :default="index === 0"
+    />
    <p class="vjs-no-js">
      Sorry, your browser doesn't support embedded videos, but don't worry, you
      can <a :href="source">download it</a>
@ -20,7 +23,6 @@ import videojs from "video.js";
 import type Player from "video.js/dist/types/player";
 import "videojs-mobile-ui";
 import "videojs-hotkeys";
-import { loadSubtitle } from "@/utils/subtitle";

 import "video.js/dist/video-js.min.css";
 import "videojs-mobile-ui/dist/videojs-mobile-ui.css";
@ -45,6 +47,7 @@ onMounted(() => {
    {
      html5: {
        // needed for customizable subtitles
+        // TODO: add to user settings
        nativeTextTracks: false,
      },
      plugins: {
@ -59,7 +62,6 @@ onMounted(() => {
    // onReady callback
    async () => {
      // player.value!.log("onPlayerReady", this);
-      addSubtitles(props.subtitles);
    }
  );
  // TODO: need to test on mobile
@ -74,21 +76,29 @@ onBeforeUnmount(() => {
  }
 });

-const addSubtitles = async (subtitles: string[] | undefined) => {
-  if (!subtitles) return;
-  // add subtitles dynamically (srt is converted on-the-fly)
-  const subs = await Promise.all(
-    subtitles.map(async (s) => await loadSubtitle(s))
-  );
-  // TODO: player.value wouldnt work here, no idea why
-  const _player = videojs.getPlayer(videoPlayer.value!);
-  for (const [idx, sub] of subs.filter((s) => !!s.src).entries()) {
-    _player.addRemoteTextTrack({
-      src: sub.src,
-      label: sub.label,
-      kind: "subtitles",
-      default: idx === 0,
-    });
+const subLabel = (subUrl: string) => {
+  let url: URL;
+  try {
+    url = new URL(subUrl);
+  } catch (_) {
+    // treat it as a relative url
+    // we only need this for filename
+    url = new URL(subUrl, window.location.origin);
  }
+
+  const label = decodeURIComponent(
+    url.pathname
+      .split("/")
+      .pop()!
+      .replace(/\.[^/.]+$/, "")
+  );
+
+  return label;
 };
 </script>
+<style scoped>
+.video-max {
+  width: 100%;
+  height: 100%;
+}
+</style>
--- a/frontend/src/utils/subtitle.ts
+++ b/frontend/src/utils/subtitle.ts
@ -1,72 +0,0 @@
-import { StatusError } from "@/api/utils";
-
-export async function loadSubtitle(subUrl: string) {
-  let url: URL;
-  try {
-    url = new URL(subUrl);
-  } catch (_) {
-    // treat it as a relative url
-    // we only need this for filename
-    url = new URL(subUrl, window.location.origin);
-  }
-
-  const label = decodeURIComponent(
-    url.pathname
-      .split("/")
-      .pop()!
-      .replace(/\.[^/.]+$/, "")
-  );
-  let src;
-  if (url.pathname.toLowerCase().endsWith(".srt")) {
-    try {
-      const resp = await fetch(subUrl);
-      if (!resp.ok) {
-        throw new StatusError(
-          `Failed to fetch subtitle from ${subUrl}!`,
-          resp.status
-        );
-      }
-      const vtt = srtToVttBlob(await resp.text());
-      src = URL.createObjectURL(vtt);
-    } catch (error) {
-      console.error(error);
-    }
-  } else if (url.pathname.toLowerCase().endsWith(".vtt")) {
-    src = subUrl;
-  }
-  return { src, label };
-}
-
-export function srtToVttBlob(srtData: string) {
-  const VTT_HEAD = "WEBVTT\n\n";
-  // Replace line breaks with \n
-  let subtitles = srtData.replace(/\r\n|\r|\n/g, "\n");
-  // commas -> dots in timestamps
-  subtitles = subtitles.replace(/(\d\d:\d\d:\d\d),(\d\d\d)/g, "$1.$2");
-  // map SRT font colors to VTT cue span classes
-  const colorMap: Record<string, string> = {};
-  // font tags -> ::cue span tags
-  subtitles = subtitles.replace(
-    /<font color="([^"]+)">([\s\S]*?)<\/font>/g,
-    function (_match, color, text) {
-      const key =
-        "c_" + color.replace(/^rgb/, "").replace(/\W/g, "").toLowerCase();
-      colorMap[key] = color;
-      return `<c.${key}>${text.replace("\n", "").trim()}</c>`;
-    }
-  );
-  subtitles = subtitles.replace(/<br\s*\/?>/g, "\n");
-  let vttSubtitles = VTT_HEAD;
-  if (Object.keys(colorMap).length) {
-    let vttStyles = "";
-    for (const cssClass in colorMap) {
-      const color = colorMap[cssClass];
-      // add cue style declaration
-      vttStyles += `::cue(.${cssClass}) {color: ${color};}\n`;
-    }
-    vttSubtitles += vttStyles;
-  }
-  vttSubtitles += "\n"; // an empty line MUST separate styles from subs
-  vttSubtitles += subtitles;
-  return new Blob([vttSubtitles], { type: "text/vtt" });
-}
--- a/go.mod
+++ b/go.mod
@ -32,6 +32,9 @@ require (

 require (
 	github.com/andybalholm/brotli v1.0.4 // indirect
+	github.com/asticode/go-astikit v0.20.0 // indirect
+	github.com/asticode/go-astisub v0.25.0 // indirect
+	github.com/asticode/go-astits v1.8.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dsnet/compress v0.0.2-0.20210315054119-f66993602bf5 // indirect
 	github.com/dsoprea/go-logging v0.0.0-20200517223158-a10564966e9d // indirect
--- a/go.sum
+++ b/go.sum
@ -47,6 +47,14 @@ github.com/andybalholm/brotli v1.0.4 h1:V7DdXeJtZscaqfNuAdSRuRFzuiKlHSC/Zh3zl9qY
 github.com/andybalholm/brotli v1.0.4/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
 github.com/asdine/storm/v3 v3.2.1 h1:I5AqhkPK6nBZ/qJXySdI7ot5BlXSZ7qvDY1zAn5ZJac=
 github.com/asdine/storm/v3 v3.2.1/go.mod h1:LEpXwGt4pIqrE/XcTvCnZHT5MgZCV6Ub9q7yQzOFWr0=
+github.com/asticode/go-astikit v0.20.0 h1:+7N+J4E4lWx2QOkRdOf6DafWJMv6O4RRfgClwQokrH8=
+github.com/asticode/go-astikit v0.20.0/go.mod h1:h4ly7idim1tNhaVkdVBeXQZEE3L0xblP7fCWbgwipF0=
+github.com/asticode/go-astisub v0.25.0 h1:wEHp7QSwcZytKA6LhA4I0XpyCidqGR0qB2r3p4vkEHc=
+github.com/asticode/go-astisub v0.25.0/go.mod h1:WTkuSzFB+Bp7wezuSf2Oxulj5A8zu2zLRVFf6bIFQK8=
+github.com/asticode/go-astisub v0.26.0 h1:Ka1oUyWzo/lIx7RX97GI1QdbClqYVxI0ExKuZRN/cDk=
+github.com/asticode/go-astisub v0.26.0/go.mod h1:WTkuSzFB+Bp7wezuSf2Oxulj5A8zu2zLRVFf6bIFQK8=
+github.com/asticode/go-astits v1.8.0 h1:rf6aiiGn/QhlFjNON1n5plqF3Fs025XLUwiQ0NB6oZg=
+github.com/asticode/go-astits v1.8.0/go.mod h1:DkOWmBNQpnr9mv24KfZjq4JawCFX1FCqjLVGvO0DygQ=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
@ -219,6 +227,7 @@ github.com/pierrec/lz4/v4 v4.1.15 h1:MO0/ucJhngq7299dKLwIMtgTfbkoSPF6AoMYDd8Q4q0
 github.com/pierrec/lz4/v4 v4.1.15/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/pkg/profile v1.4.0/go.mod h1:NWz/XGvpEW1FyYQ7fCx4dqYBLlfTcE+A9FLAkNKqjFE=
 github.com/pkg/sftp v1.13.1/go.mod h1:3HaPG6Dq1ILlpPZRO0HVMrsydcdLt6HRDccSgb87qRg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
@ -359,6 +368,7 @@ golang.org/x/net v0.0.0-20200520182314-0ba52f642ac2/go.mod h1:qpuaurCH72eLCgpAm/
 golang.org/x/net v0.0.0-20200625001655-4c5254603344/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200707034311-ab3426394381/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
+golang.org/x/net v0.0.0-20200904194848-62affa334b73/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20201031054903-ff519b6c9102/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20201209123823-ac852fbbde11/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
--- a/http/http.go
+++ b/http/http.go
@ -84,6 +84,7 @@ func NewHandler(
 		Handler(monkey(previewHandler(imgSvc, fileCache, server.EnableThumbnails, server.ResizePreview), "/api/preview")).Methods("GET")
 	api.PathPrefix("/command").Handler(monkey(commandsHandler, "/api/command")).Methods("GET")
 	api.PathPrefix("/search").Handler(monkey(searchHandler, "/api/search")).Methods("GET")
+	api.PathPrefix("/subtitle").Handler(monkey(subtitleHandler, "/api/subtitle")).Methods("GET")

 	public := api.PathPrefix("/public").Subrouter()
 	public.PathPrefix("/dl").Handler(monkey(publicDlHandler, "/api/public/dl/")).Methods("GET")
--- a/http/subtitle.go
+++ b/http/subtitle.go
@ -0,0 +1,86 @@
+package http
+
+import (
+	"bytes"
+	"net/http"
+	"strings"
+
+	"github.com/asticode/go-astisub"
+	"github.com/filebrowser/filebrowser/v2/files"
+)
+
+var subtitleHandler = withUser(func(w http.ResponseWriter, r *http.Request, d *data) (int, error) {
+	if !d.user.Perm.Download {
+		return http.StatusAccepted, nil
+	}
+
+	file, err := files.NewFileInfo(files.FileOptions{
+		Fs:         d.user.Fs,
+		Path:       r.URL.Path,
+		Modify:     d.user.Perm.Modify,
+		Expand:     false,
+		ReadHeader: d.server.TypeDetectionByHeader,
+		Checker:    d,
+	})
+	if err != nil {
+		return errToStatus(err), err
+	}
+
+	// TODO: no idea what this does
+	// if files.IsNamedPipe(file.Mode) {
+	// 	setContentDisposition(w, r, file)
+	// 	return 0, nil
+	// }
+
+	if file.IsDir {
+		return http.StatusBadRequest, nil
+	}
+
+	return subtitleFileHandler(w, r, file)
+})
+
+func subtitleFileHandler(w http.ResponseWriter, r *http.Request, file *files.FileInfo) (int, error) {
+	// if its not a subtitle file, reject
+	if !files.IsSupportedSubtitle(file.Name) {
+		return http.StatusBadRequest, nil
+	}
+
+	fd, err := file.Fs.Open(file.Path)
+	if err != nil {
+		return http.StatusInternalServerError, err
+	}
+	defer fd.Close()
+
+	// load subtitle for conversion to vtt
+	var sub *astisub.Subtitles
+	if strings.HasSuffix(file.Name, ".srt") {
+		sub, err = astisub.ReadFromSRT(fd)
+	} else if strings.HasSuffix(file.Name, ".ass") || strings.HasSuffix(file.Name, ".ssa") {
+		sub, err = astisub.ReadFromSSA(fd)
+	}
+	if err != nil {
+		return http.StatusInternalServerError, err
+	}
+
+	// TODO: not sure if this is needed here
+	setContentDisposition(w, r, file)
+	w.Header().Add("Content-Security-Policy", `script-src 'none';`)
+	w.Header().Set("Cache-Control", "private")
+	// force type to text/vtt
+	w.Header().Set("Content-Type", "text/vtt")
+
+	// serve vtt file directly
+	if sub == nil {
+		http.ServeContent(w, r, file.Name, file.ModTime, fd)
+		return 0, nil
+	}
+
+	// convert others to vtt and serve from buffer
+	var buf = &bytes.Buffer{}
+	err = sub.WriteToWebVTT(buf)
+	if err != nil {
+		return http.StatusInternalServerError, err
+	}
+	http.ServeContent(w, r, file.Name, file.ModTime, bytes.NewReader(buf.Bytes()))
+	return 0, nil
+}