はじまりの大地

packages/ffmpeg/src/ffmpeg-images.ts

@@ -0,0 +1,141 @@
+import { MutexInterface } from 'async-mutex'
+import { FfprobeData } from 'fluent-ffmpeg'
+import { FFmpegCommandWrapper, FFmpegCommandWrapperOptions } from './ffmpeg-command-wrapper.js'
+import { getVideoStreamDuration } from './ffprobe.js'
+
+export class FFmpegImage {
+  private readonly commandWrapper: FFmpegCommandWrapper
+
+  constructor (options: FFmpegCommandWrapperOptions) {
+    this.commandWrapper = new FFmpegCommandWrapper(options)
+  }
+
+  convertWebPToJPG (options: {
+    path: string
+    destination: string
+  }): Promise<void> {
+    const { path, destination } = options
+
+    this.commandWrapper.buildCommand(path)
+      .output(destination)
+
+    return this.commandWrapper.runCommand({ silent: true })
+  }
+
+  processGIF (options: {
+    path: string
+    destination: string
+    newSize: { width: number, height: number }
+  }): Promise<void> {
+    const { path, destination, newSize } = options
+
+    this.commandWrapper.buildCommand(path)
+      .fps(20)
+      .size(`${newSize.width}x${newSize.height}`)
+      .output(destination)
+
+    return this.commandWrapper.runCommand()
+  }
+
+  // ---------------------------------------------------------------------------
+
+  async generateThumbnailFromVideo (options: {
+    fromPath: string
+    output: string
+    framesToAnalyze: number
+    scale?: {
+      width: number
+      height: number
+    }
+    ffprobe?: FfprobeData
+  }) {
+    const { fromPath, ffprobe } = options
+
+    let duration = await getVideoStreamDuration(fromPath, ffprobe)
+    if (isNaN(duration)) duration = 0
+
+    this.buildGenerateThumbnailFromVideo(options)
+      .seekInput(duration / 2)
+
+    try {
+      return await this.commandWrapper.runCommand()
+    } catch (err) {
+      this.commandWrapper.debugLog('Cannot generate thumbnail from video using seek input, fallback to no seek', { err })
+
+      this.commandWrapper.resetCommand()
+
+      this.buildGenerateThumbnailFromVideo(options)
+
+      return this.commandWrapper.runCommand()
+    }
+  }
+
+  private buildGenerateThumbnailFromVideo (options: {
+    fromPath: string
+    output: string
+    framesToAnalyze: number
+    scale?: {
+      width: number
+      height: number
+    }
+  }) {
+    const { fromPath, output, framesToAnalyze, scale } = options
+
+    const command = this.commandWrapper.buildCommand(fromPath)
+      .videoFilter('thumbnail=' + framesToAnalyze)
+      .outputOption('-frames:v 1')
+      .outputOption('-q:v 5')
+      .outputOption('-abort_on empty_output')
+      .output(output)
+
+    if (scale) {
+      command.videoFilter(`scale=${scale.width}x${scale.height}:force_original_aspect_ratio=decrease`)
+    }
+
+    return command
+  }
+
+  // ---------------------------------------------------------------------------
+
+  async generateStoryboardFromVideo (options: {
+    path: string
+    destination: string
+
+    // Will be released after the ffmpeg started
+    inputFileMutexReleaser: MutexInterface.Releaser
+
+    sprites: {
+      size: {
+        width: number
+        height: number
+      }
+
+      count: {
+        width: number
+        height: number
+      }
+
+      duration: number
+    }
+  }) {
+    const { path, destination, sprites } = options
+
+    const command = this.commandWrapper.buildCommand(path)
+
+    const filter = [
+      // Fix "t" variable with some videos
+      `setpts='N/FRAME_RATE/TB'`,
+      // First frame or the time difference between the last and the current frame is enough for our sprite interval
+      `select='isnan(prev_selected_t)+gte(t-prev_selected_t,${options.sprites.duration})'`,
+      `scale=${sprites.size.width}:${sprites.size.height}`,
+      `tile=layout=${sprites.count.width}x${sprites.count.height}`
+    ].join(',')
+
+    command.outputOption('-filter_complex', filter)
+    command.outputOption('-frames:v', '1')
+    command.outputOption('-q:v', '2')
+    command.output(destination)
+
+    return this.commandWrapper.runCommand()
+  }
+}