By using AWS re:Post, you agree to the AWS re:Post Terms of Use
AWS re:Postre:Post

AWS Media Convert removes silent audio which causes the output video to be severly out-of-sync with audio

1

Hi re:Post community,

We have been using AWS Elemental MediaConvert for about 3 years but we have encountered some very strange behaviour roughly from the 10th of December 22 onwards. MediaConvert started removing all of the silent audio from our audio inputs and it merges all the speech in the input together. This is causing major syncing issues between the video and the audio in the output file.

The rough specification of our MediaConvert jobs is:

  • video input: H.264 or VP8
  • audio input: Matroska with OPUS
  • output: MPEG-4 AVC (H.264)

We started receiving customer reports on the 12th of December saying that their videos are out of sync. I found a job from 9 Dec that was OK and I cloned and reran the job today (19 Dec). The result from today was missing all the silent audio which was matching all the broken files reported by our customers. The two jobs are using exactly the same inputs and the same configuration.

This makes me think something must've changed internally in MediaConvert that is causing these issues. Perhaps a new setting?

Has anyone experienced the same?

Thanks Michal

  • rePost-User-2457284
    a year ago

    I have also noticed some weirdness with MediaConvert recently. I'm not sure if it's related or not. We have been clipping some videos to extract a portion of the video from the middle. When we specify a start time/end time, AWS seems to be choosing values that are a few seconds off instead, and we haven't been able to figure out why yet. I can't yet say for sure this didn't happen previously, but user bug reports have been in the last week or two. ffmpeg seems to reproduce the same behavior when avoid_negative_ts is not set to make zero, which also may affect audio/video syncing.

Topics
Media Services
Tags
AWS Elemental MediaConvert
Language
English
Michal Chudy
asked a year ago415 views
1 Answer
0

So it appears it was an internal issue with AWS MediaConvert. They fixed it really quickly after confirming the issue.

Michal Chudy
answered a year ago

You are not logged in. Log in to post an answer.

A good answer clearly answers the question and provides constructive feedback and encourages professional growth in the question asker.

Guidelines for Answering Questions

Relevant content