audio & video are processed out of sync in some input files
Files that were edited to delay the video by 0.5s are incorrectly seen by GES to have delayed both the audio and video. This bug is NOT triggered if
- I use ffmpeg or Totem (instead of GES),
- I use a synthesiser instead of a studio recording, or
- the video is delayed by 5s instead of 0.5s.
Reproducing the bug
You can download the test cases at https://andrewclausen.net/test.zip. This zip file contains a Makefile that runs the test cases. It requires the following software:
It mixes the audio of X.mkv and X-unsync.mkv (and retains the video of X-unsync.mkv) using two different tools:
- X-ff-mixed.mkv, using ffmpeg, and
- X-ges-mixed.ogv, using Gstreamer Editing Services.
Both should sound the same. In fact, they do sound the same when the input files are constructed with a synthesiser (X=synth). But they sound different -- there is an echo -- when I use my studio recording (X=studio).
studio-ff-mixed.mkv and studio-ges-mixed.ogv sound different (GES broken?)
synth-ff-mixed.mkv and synth-ges-mixed.ogv sounds the same (both correct).