feat(ffmpeg): add ffmpeg manager, bundle/download ffmpeg in CI and (#11)

* feat(ffmpeg): add ffmpeg manager, bundle/download ffmpeg in CI and

* fix(download-engine): let yt-dlp merge format to avoid codec conflicts and use actual format for filenames

* chore(ci): replace monolithic job with platform-specific reusable jobs

* chore(ci): run build matrix for windows, macos, linux in one to

* feat(ci): remove platform matrix and platform gating to simplify build

* chore(ci): pin github-translate-action to specific commit to ensure

src/main/lib/ffmpeg-manager.ts

@@ -0,0 +1,101 @@
+import { execSync } from 'node:child_process'
+import fs from 'node:fs'
+import os from 'node:os'
+import path from 'node:path'
+
+class FfmpegManager {
+  private ffmpegPath: string | null = null
+
+  async initialize(): Promise<void> {
+    this.ffmpegPath = await this.findFfmpegBinary()
+    console.log('ffmpeg initialized at:', this.ffmpegPath)
+  }
+
+  getPath(): string {
+    if (!this.ffmpegPath) {
+      throw new Error('ffmpeg not initialized. Call initialize() first.')
+    }
+    return this.ffmpegPath
+  }
+
+  private getResourcesPath(): string {
+    if (process.env.NODE_ENV === 'development') {
+      return path.join(process.cwd(), 'resources')
+    }
+    return path.join(process.resourcesPath, 'app.asar.unpacked', 'resources')
+  }
+
+  private async findFfmpegBinary(): Promise<string> {
+    const platform = os.platform()
+    const resourceCandidates: string[] = []
+
+    if (process.env.FFMPEG_PATH && fs.existsSync(process.env.FFMPEG_PATH)) {
+      console.log('Using ffmpeg from FFMPEG_PATH:', process.env.FFMPEG_PATH)
+      return process.env.FFMPEG_PATH
+    }
+
+    if (platform === 'win32') {
+      resourceCandidates.push('ffmpeg.exe')
+    } else if (platform === 'darwin') {
+      resourceCandidates.push('ffmpeg_macos', 'ffmpeg')
+    } else {
+      resourceCandidates.push('ffmpeg_linux', 'ffmpeg')
+    }
+
+    const resourcesPath = this.getResourcesPath()
+    for (const candidate of resourceCandidates) {
+      const fullPath = path.join(resourcesPath, candidate)
+      if (fs.existsSync(fullPath)) {
+        if (platform !== 'win32') {
+          try {
+            fs.chmodSync(fullPath, 0o755)
+          } catch (error) {
+            console.warn('Failed to set executable permission on ffmpeg binary:', error)
+          }
+        }
+        console.log('Using bundled ffmpeg:', fullPath)
+        return fullPath
+      }
+    }
+
+    if (platform === 'darwin') {
+      const commonPaths = ['/opt/homebrew/bin/ffmpeg', '/usr/local/bin/ffmpeg']
+      for (const candidate of commonPaths) {
+        if (fs.existsSync(candidate)) {
+          console.log('Using system ffmpeg:', candidate)
+          return candidate
+        }
+      }
+    }
+
+    if (platform === 'linux' || platform === 'freebsd') {
+      try {
+        const systemPath = execSync('which ffmpeg').toString().trim()
+        if (systemPath && fs.existsSync(systemPath)) {
+          console.log('Using system ffmpeg:', systemPath)
+          return systemPath
+        }
+      } catch (_error) {
+        // Ignore error and continue
+      }
+    }
+
+    if (platform === 'win32') {
+      try {
+        const output = execSync('where ffmpeg').toString().split(/\r?\n/)[0]
+        if (output && fs.existsSync(output)) {
+          console.log('Using system ffmpeg:', output)
+          return output
+        }
+      } catch (_error) {
+        // Ignore error and continue
+      }
+    }
+
+    throw new Error(
+      'ffmpeg not found. Bundle it under resources/ (asarUnpack) or set the FFMPEG_PATH environment variable.'
+    )
+  }
+}
+
+export const ffmpegManager = new FfmpegManager()