[FFmpeg-user] Can I get some help converting .sec files?

[Paul B Mahol]

On 8/25/18, LH <drivebee at pm.me> wrote:
> Hi, I have a Samsung security system which saves video in the .sec format
> which no other app can play. The Samsung SmartViewer app has developed
> issues and is no longer updated/supported so, as a result, I cannot play
> saved .sec files with it, either. So- I can save video but there is no way
> to watch it. However, I can convert these .sec files to mp4 with ffmpeg,
> using this command:
>
> ffmpeg -i (name of file).sec (name of final file).mp4
>
> It throws errors such as:
>
> [h264 @ 000000000057fb00] Invalid NAL unit 8, skipping.
> [libx264 @ 0000000000516800] frame= 176 QP=25.50 NAL=2 Slice:B Poc:352 I:3
> P:485  SKIP:821  size=1220 bytes
>
> but it still works well enough that I can watch the video with any app that
> plays mp4. However, the video is sped up quite a bit so that it appears to
> be in fast motion. I suppose it's the Samsung app that is doing this but
> since I can't watch it until I convert it, I don't know for sure. I figured
> out that it is about 3.3 times faster. I can convert the video and also slow
> it down to normal speed with the command:
>
> ffmpeg -i (name of file).sec -filter:v "setpts=3.3*PTS"  (name of final
> file).mp4
>
> but the video loses quality and horizontal lines appear in it.
>
> Is there a better command for converting .sec to .mp4 while correcting the
> speed and preserving the quality? I don't have the skills to understand the
> ffmpeg documentation and how to choose the best command for my purposes,
> it's way over my head, but I can copy commands someone gives me and use
> them.
>
> I realize there won't be a perfect way to do this but I'd like to get the
> best results possible.
>
> I am using ffmpeg-20180824-4d87cd2-win64-static with Windows 7.
>
> I hope I am posting this correctly and if not please let me know.
>
> Thank you, LH

Please provide input file.