我正在使用ffmpeg在AWS Lambda上创建视频缩略图。我将文件下载到/ tmp目录中，但是ffmpeg无法访问它并给出错误
[错误：元数据不包含持续时间，中止屏幕截图创建]
当我使用ffmpeg检查媒体信息时，它正在提供输出
{ ffmpegversion: 0, title: '', artist: '', album: '', track: '', date: '', durationraw: '', durationsec: 0, synched: false, major_brand: undefined, video: { container: '', bitrate: 0, codec: '', resolution: { w: 0, h: 0 }, resolutionSquare: { w: 0, h: NaN }, rotate: 0, fps: 0, stream: 0, aspect: 0, pixel: 0 }, audio: { codec: '', bitrate: 0, sample_rate: 0, stream: 0 } }
我使用fs模块检查该位置的文件存在，并提供输出
{ dev: 1793, mode: 33204, nlink: 1, uid: 496, gid: 495, rdev: 0, blksize: 4096, ino: 11, size: 21152, blocks: 48, atime: Thu Sep 01 2016 13:30:46 GMT+0000 (UTC), mtime: Thu Sep 01 2016 13:30:46 GMT+0000 (UTC), ctime: Thu Sep 01 2016 13:30:46 GMT+0000 (UTC), birthtime: Thu Sep 01 2016 13:30:46 GMT+0000 (UTC) }