使用FFmpeg生成Webp缩略图报错：需手动选择编码器

当尝试从视频导出WebP格式缩略图时，出现以下错误：

Default encoder for format webp (codec webp) is probably disabled. Please choose an encoder manually.

使用的代码（基于fluent-ffmpeg） #

ffmpeg()
    .input(videoInput)
    .screenshot({
      count: 5,
      folder: outDir,
      filename: "thumbnail-%i.webp"
    })
    .on('end', () => {
      console.log('Thumbnail exporting finished!');
      return res()
    })
    .on('start', (stdout) => {
      console.log(stdout);
    })
    .on('error', (err) => {
      console.log('Error in generating thumbnails:', err.message);
      return rej(err)
    })

执行的FFmpeg命令及报错信息 #

ffmpeg -ss 0.8722221666666666 -i /var/folders/tk/4cc2j1r97tn36yc4zytl6xdr0000gn/T/temp-dir-55738-M4xzH9y06CGs/3dbedb5a-8a70-4199-a225-e0c973bd7f56/3dbedb5a-8a70-4199-a225-e0c973bd7f56-baity-intro.mp4 -y -filter_complex split=5[screen0][screen1][screen2][screen3][screen4] -vframes 1 -map [screen0] /var/folders/tk/4cc2j1r97tn36yc4zytl6xdr0000gn/T/temp-dir-55738-M4xzH9y06CGs/3dbedb5a-8a70-4199-a225-e0c973bd7f56/thumbnail-1.webp -vframes 1 -map [screen1] -ss 0.8722221666666666 /var/folders/tk/4cc2j1r97tn36yc4zytl6xdr0000gn/T/temp-dir-55738-M4xzH9y06CGs/3dbedb5a-8a70-4199-a225-e0c973bd7f56/thumbnail-2.webp -vframes 1 -map [screen2] -ss 1.7444443333333335 /var/folders/tk/4cc2j1r97tn36yc4zytl6xdr0000gn/T/temp-dir-55738-M4xzH9y06CGs/3dbedb5a-8a70-4199-a225-e0c973bd7f56/thumbnail-3.webp -vframes 1 -map [screen3] -ss 2.6166665 /var/folders/tk/4cc2j1r97tn36yc4zytl6xdr0000gn/T/temp-dir-55738-M4xzH9y06CGs/3dbedb5a-8a70-4199-a225-e0c973bd7f56/thumbnail-4.webp -vframes 1 -map [screen4] -ss 3.4888886666666674 /var/folders/tk/4cc2j1r97tn36yc4zytl6xdr0000gn/T/temp-dir-55738-M4xzH9y06CGs/3dbedb5a-8a70-4199-a225-e0c973bd7f56/thumbnail-5.webp
Error in generating thumbnails: ffmpeg exited with code 1: Automatic encoder selection failed for output stream #0:0. Default encoder for format webp (codec webp) is probably disabled. Please choose an encoder manually.
Error selecting an encoder for stream 0:0

Error: ffmpeg exited with code 1: Automatic encoder selection failed for output stream #0:0. Default encoder for format webp (codec webp) is probably disabled. Please choose an encoder manually.
Error selecting an encoder for stream 0:0

解决方案 #

1. 手动指定WebP编码器 #

修改代码，在screenshot配置中添加codec: 'libwebp'，强制FFmpeg使用WebP编码器：

ffmpeg()
    .input(videoInput)
    .screenshot({
      count: 5,
      folder: outDir,
      filename: "thumbnail-%i.webp",
      codec: 'libwebp' // 新增指定编码器
    })
    .on('end', () => {
      console.log('Thumbnail exporting finished!');
      return res()
    })
    .on('start', (stdout) => {
      console.log(stdout);
    })
    .on('error', (err) => {
      console.log('Error in generating thumbnails:', err.message);
      return rej(err)
    })

2. 验证FFmpeg是否支持libwebp #

如果修改后仍报错，先检查FFmpeg是否编译了WebP支持：
执行以下命令：

ffmpeg -encoders | grep webp

若输出包含libwebp，说明支持；若无输出，需重新编译FFmpeg并添加--enable-libwebp参数，或通过包管理器安装带WebP支持的预编译版本。

内容的提问来源于stack exchange，提问作者Mohammed Baqer