frozen seconds in beginning of subclip using ffmpeg_extract_subclip()

Hi everyone,

not sure if this is a bug, however I have an issue here:

The docs of ffmpeg state, that -ss should be specified before -i, at least when input seeking.

But I think ffmpeg_extract_subclip(), specifies it after -i. That is at least what causes trouble when I call ffmpeg_extract_subclip()

For myself:

~\AppData\Local\imageio\ffmpeg\ffmpeg-win32-v3.2.4.exe -y -i raw\pt01c.avi -ss 33.00 -t 40.00 -vcodec copy -acodec copy corridor\pt01-corridor.avi

leads to a frozen video sequence of 2-6 seconds in the beginning of the video with sound playing.

Whereas

C:\Users\jog54yy\AppData\Local\imageio\ffmpeg\ffmpeg-win32-v3.2.4.exe -y  -ss 33.00 -i raw\pt01c.avi  -t 40.00 -vcodec copy -acodec copy corridor\pt01-corridor.avi

works as expected.

Is there any thing that I am missing? Is that how it is thought to be? Is there a way to specifiy the order of specification of -iand -ss?

Edit: Looks like Issue #508 but this did not help.

Best Jonas

---

Here’s the rest:

Expected Behavior

No frozen seconds before video starts playing.

Actual Behavior

ffmpeg_extract_subclip() produces frozen seconds before video starts playing, sound is good form the beginning. However, couldn’t test for synchrony (That is what other report as well, when specifing it the wrong way).

Steps to Reproduce the Problem

see above

Specifications

• Python Version: 3.7.0
• Moviepy Version: 0.2.3.5
• Platform Name: Windows
• Platform Version: Windwos 10

[DallasHoelscher]

I know this is closed, but is it possible this issue is still happening with concatenate_videoclips. My clips where I use ffmpeg_extract_subclip() are creating the clips correctly, with no pause. When I concatenate the clips together in the end though the very first clip has a 5 second pause with no audio or video playing.

[Zulko]

@gpotter2 I merged #848. Sorry for being slow.