Init commit

server/core/lib/live-videos/preprocessed-video.ts

@@ -0,0 +1,110 @@
+import { logger, loggerTagsFactory } from '@server/helpers/logger.js'
+import { tryAtomicMove } from '@server/helpers/fs.js'
+import { CONFIG } from '@server/initializers/config.js'
+import { remove } from 'fs-extra/esm'
+import { existsSync } from 'node:fs'
+import { dirname } from 'node:path'
+import { spawn } from 'node:child_process'
+
+const lTags = loggerTagsFactory('live-videos', 'preprocessed-video')
+
+export function getLiveVideoBurnedPath (videoPath: string) {
+  return `${videoPath}.burned.mp4`
+}
+
+export function getLiveVideoSubtitlePath (videoPath: string) {
+  if (existsSync(videoPath + '.vtt')) return videoPath + '.vtt'
+  if (existsSync(videoPath + '.srt')) return videoPath + '.srt'
+
+  return null
+}
+
+export function getLiveVideoPlaybackInputPath (videoPath: string) {
+  const burnedPath = getLiveVideoBurnedPath(videoPath)
+  return existsSync(burnedPath) ? burnedPath : videoPath
+}
+
+export async function syncPreprocessedLiveVideo (videoPath: string) {
+  const subtitlePath = getLiveVideoSubtitlePath(videoPath)
+  const burnedPath = getLiveVideoBurnedPath(videoPath)
+
+  if (!subtitlePath) {
+    await remove(burnedPath).catch(() => undefined)
+    return null
+  }
+
+  const tmpOutputPath = `${burnedPath}.tmp.mp4`
+  await remove(tmpOutputPath).catch(() => undefined)
+
+  const ffmpegPath = CONFIG.LIVE.FFMPEG.PATH?.trim() || 'ffmpeg'
+  const subtitleFilterPath = escapeSubtitleFilterPath(subtitlePath)
+  const ffmpegArgs = [
+    '-y',
+    '-hide_banner',
+    '-loglevel', 'warning',
+    '-i', videoPath,
+    '-map', '0:v:0',
+    '-map', '0:a?',
+    '-vf', `subtitles=${subtitleFilterPath}`,
+    '-c:v', 'libx264',
+    '-preset', 'veryfast',
+    '-c:a', 'aac',
+    '-movflags', '+faststart',
+    tmpOutputPath
+  ]
+
+  await runFFmpeg(ffmpegPath, ffmpegArgs, { videoPath, subtitlePath })
+  await remove(burnedPath).catch(() => undefined)
+  await tryAtomicMove(tmpOutputPath, burnedPath)
+
+  return burnedPath
+}
+
+function escapeSubtitleFilterPath (subtitlePath: string) {
+  return subtitlePath
+    .replace(/\\/g, '\\\\')
+    .replace(/:/g, '\\:')
+    .replace(/ /g, '\\ ')
+    .replace(/\[/g, '\\[')
+    .replace(/\]/g, '\\]')
+    .replace(/,/g, '\\,')
+    .replace(/'/g, "\\'")
+}
+
+function runFFmpeg (ffmpegPath: string, ffmpegArgs: string[], meta: { videoPath: string, subtitlePath: string }) {
+  return new Promise<void>((resolve, reject) => {
+    const ffmpegProcess = spawn(ffmpegPath, ffmpegArgs, {
+      cwd: dirname(meta.videoPath),
+      stdio: [ 'ignore', 'ignore', 'pipe' ]
+    })
+
+    let stderrBuffer = ''
+
+    ffmpegProcess.stderr.on('data', chunk => {
+      const line = chunk?.toString?.() || ''
+      stderrBuffer = (stderrBuffer + line).slice(-4_000)
+    })
+
+    ffmpegProcess.once('error', err => {
+      reject(err)
+    })
+
+    ffmpegProcess.once('exit', code => {
+      if (code === 0) {
+        resolve()
+        return
+      }
+
+      const stderr = stderrBuffer.trim()
+
+      logger.error('Cannot preprocess live video with burned subtitles.', {
+        code,
+        stderr,
+        ...meta,
+        ...lTags()
+      })
+
+      reject(new Error(stderr || `ffmpeg exited with code ${code}`))
+    })
+  })
+}