Node.js Ffmpeg无法访问aws labmda上的文件

我正在使用ffmpeg在AWS Lambda上创建视频缩略图。我在/tmp目录下下载了该文件，但ffmpeg无法访问它，并给出了错误消息

[错误：元数据不包含持续时间，正在中止屏幕快照创建]

当我使用ffmpeg检查媒体信息时，它会给出输出

{ 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 } }

{ 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) }

我使用了

fs

模块来检查该位置上的文件是否存在，它给出了输出

{ 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 } }

{ 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) }