Cutting a video with FFMPEG in the same format/quality?

[Unknown01]

I want to cut MKV files with FFMPEG.

I used the following syntax:

ffmpeg -i input.mkv -ss 00:16:42.752 -codec copy -t 71 -s 700x394 out.mkv

But it gave me a file that starts with a black screen and only sound.

According to the info FFMPEG showed the video codec was h264.

So i went and changed it to this:

ffmpeg -i input.mkv -ss 00:16:42.752 -c:v h264 -t 71 -s 700x394 out.mkv

Also tried with:

-c:v libx264.

Now it worked and there was no black screen, but the video quality is not the same.

Is there something else i should add or change in order to make the cut version the EXACT SAME QUALITY as the original file?

Not better quality.
Not worse quality.

The exact same as the original file.

[JVRaines]

Take a look at this page, especially the Notes.

[Unknown01]

Take a look at this page, especially the Notes.

That certainly explains why the black screen.

How weird the section didn't included anything about how to keep the quality.

[Selur]

anything about how to keep the quality.

stick with "-codec copy" and don't reencode (btw. if you are on windows there a other tools more suited for cutting mkv files)