api/vk: add transcript-only downloads

api/README.md

@@ -36,7 +36,7 @@ if the desired service isn't supported yet, feel free to create an appropriate i
 | twitch clips      | ✅            | ✅         | ✅         | ❌              | ✅         | ✅              |
 | twitter/x         | ✅            | ✅         | ✅         | ❌              | ➖         | ➖              |
 | vimeo             | ✅            | ✅         | ✅         | ❌              | ✅         | ✅              |
-| vk videos & clips | ✅            | ❌         | ✅         | ❌              | ✅         | ✅              |
+| vk videos & clips | ✅            | ❌         | ✅         | ✅              | ✅         | ✅              |
 | youtube           | ✅            | ✅         | ✅         | ✅              | ✅         | ✅              |
 
 | emoji   | meaning                 |

api/src/processing/match.js

@@ -103,6 +103,9 @@ export default async function({ host, patternMatch, params, authType }) {
                     accessKey: patternMatch.accessKey,
                     quality: params.videoQuality,
                     subtitleLang,
+                    isCaptionOnly,
+                    captionLanguage: params.captionLanguage || subtitleLang,
+                    captionFormat: params.captionFormat,
                 });
                 break;
 

api/src/processing/service-config.js

@@ -1,7 +1,7 @@
 import UrlPattern from "url-pattern";
 
 export const audioIgnore = new Set(["vk", "ok", "loom"]);
-export const captionOnlyServices = new Set(["loom", "rutube", "youtube"]);
+export const captionOnlyServices = new Set(["loom", "rutube", "vk", "youtube"]);
 export const hlsExceptions = new Set(["dailymotion", "vimeo", "rutube", "bsky", "youtube"]);
 
 export const services = {

api/src/processing/services/vk.js

@@ -1,4 +1,8 @@
 import { env } from "../../config.js";
+import {
+    createCaptionResponse,
+    matchesCaptionLanguage,
+} from "../helpers/captions.js";
 
 const resolutions = ["2160", "1440", "1080", "720", "480", "360", "240", "144"];
 
@@ -80,7 +84,16 @@ const getVideo = async (ownerId, videoId, accessKey) => {
     return video;
 }
 
-export default async function ({ ownerId, videoId, accessKey, quality, subtitleLang }) {
+export default async function ({
+    ownerId,
+    videoId,
+    accessKey,
+    quality,
+    subtitleLang,
+    isCaptionOnly,
+    captionLanguage,
+    captionFormat,
+}) {
     const token = await getToken();
     if (!token) return { error: "fetch.fail" };
 
@@ -103,6 +116,26 @@ export default async function ({ ownerId, videoId, accessKey, quality, subtitleL
         return { error: "content.video.unavailable" };
     }
 
+    if (isCaptionOnly) {
+        const subtitle = video.subtitles?.find(subtitle =>
+            subtitle.title?.endsWith(".vtt")
+            && matchesCaptionLanguage(subtitle.lang, captionLanguage)
+        );
+        if (!subtitle) return { error: "fetch.empty" };
+
+        const id = `${ownerId}_${videoId}${accessKey ? `_${accessKey}` : ''}`;
+        return createCaptionResponse({
+            url: subtitle.url,
+            format: captionFormat,
+            language: subtitle.lang,
+            service: "vk",
+            id,
+            title: video.title?.trim(),
+            source: `https://vk.com/video${id}`,
+            headers: { "user-agent": vkClientAgent },
+        });
+    }
+
     if (!video.files || !video.duration) {
         return { error: "fetch.fail" };
     }

api/src/util/tests/vk.json

@@ -61,6 +61,19 @@
             "status": "tunnel"
         }
     },
+    {
+        "name": "standalone transcript",
+        "url": "https://vkvideo.ru/video-26006257_456245538",
+        "params": {
+            "downloadMode": "captions",
+            "captionFormat": "txt",
+            "captionLanguage": "ru"
+        },
+        "expected": {
+            "code": 200,
+            "status": "tunnel"
+        }
+    },
     {
         "name": "ancient video (fallback to 240p)",
         "url": "https://vk.com/video-1959_28496479",