FFmpeg with VirtualDub miss two first frames

[asaleo]

I have used the Tateu plugin together with VirtualDub and Deshaker for stabilizing videos.
Today I am using ffmpeg for opening mp4 files in VirtualDub.
When I try to use old logfiles, created together with the Tateu plugin in VirtualDub, video stabilization is lost.

I have found that for a video with say 1700 frames, "ffmpeg-video" shows only 1698 frames in VirtualDub but uses 1700 frames during Deshaker stabilization.

Thus the "Tateu logfile" shows values for 1700 frames and the "ffmpeg logfile" shows values for only 1698 frames plus value zero for frame 1699 and 1700.

Frame 3 in tateau-logfile corresponds to frame 1 in ffmpeg logfile.

I use latest ffmpeg version, v1848

I will now mark every new logfile to be able to use the right encoder together with VirtualDub when I need to make changes to my stabilized videos.

Do any of you have an explication for the behavior of ffmpeg?
Regards

[asaleo]

Found more facts about my problem.
ffmpeg v1848 do not work with Deshaker.
I have returned to v1836
Earlier I recognized that v1841 didn´t work with Deshaker either.
It seems that ffmpeg is not tested together with Deshaker.

I have also found that GoPro HD4 Silver files work with both tateu and ffmpeg. No difference in frame numbers. 1080p

GoPro HD2 files (960p) still causes problems with frame numbers which gives different logfiles for files imported to VirtualDub using tateu or ffmpeg encoders.
Regards

[shekh]

It is not completely clear what you are using at each step (and where you see the problem).
By "using ffmpeg" you mean "FFMpeg Input Plugin",
Tateu plugin is afaik mp4 demuxer but uses some sort of vfw codec for actual AVC decoding.
It is a known problem that vfw decoder cannot deliver frame X when you request frame X in random order, easy to confirm by jumping through timeline with some frame-numbered video.

[shekh]

If you are interested in FilterMod and it also has problem, upload your sample files and I will check what is possible to do.

[asaleo]

Thanks shekh for answering.
I have now checked mp4 files from 2010 to 2015.
During check I have VirtualDub opened in two windows,
one window for opening mp4 files with Tateu encoder and the other window for opening mp4 files wiht ffmpeg encoder.

I then open same file in those windows. I expect that first frame in VirtualDub should be identical in those two windows.
Thats not the case for files created by GoPro HD2 mp4 files.
First two frames in "fmpeg-opened" video are missing
Stepping two frames forward in "tateu-opened" video shows frame identical to first frame in "ffmpeg-opened" video.
This will of course create problems when you use logfilers from Deshaker. You have to use right encoder to a specific logfile if you want to make changes in old files.

I can live with this problem but is of course curious why an mp4 file can differ that much.

Both GoPro HD1 and GoPro HD4 Silver do not show this error.

Regards