I fail to cut videos with Free software

[arnoldpredator]

Hi folks,

This is so frustrating, I downloaded a video from youtube and when I try to cut it with VidCutter (which is the software that I like the most) the initial frame is always wrong, for example if I tell the programme to start the cut at 1:03:500 and and at 1:05:500 I expect the video to be just 2 seconds long, but it is actually longer! and the first frame starts at something like 1:00:300.

I don't know what is going on, I used MediaInfo and found it is a video constant frame rate, but an audio variable bitrate.

I also found this review:

https://www.videohelp.com/software/VidCutter/comments#13202

"Hey there guys,

Just letting you know that v4.5.0 is currently in the works and its main feature will be smart cutting, which translates to frame-accurate cutting. This is the technique by which a small portion at the beginning and end of your clip is reencoded and the majority in the middle is direct-copied as it already does. The result is frame accurate cuts just as you set them in the user interface and encoding only applies to small 2 or so second long clips so while it may be a little slower by a few seconds the trade off is guaranteed what you see is what you get functionality.

For the tech savvy, we're referring to GOP cuts on IDR keyframes and similar smart cut techniques as used by the more expensive commercial apps. Very few, if any tools, exist out there that are open-source and free that offer this feature as far as we were able to find anyways.

Should be ready for release by end of August.

Cya!
"

Apparently they are aware of the problem but the new version that should solve the problem has not been released.

FInally after installing like 10 programmes I found 1 that does the job, which is SolveygMM video splitter home edition... but it costs 40$ and that is a lot of money for me.

[Bernix]

The video as you pointed is Group Of Picture based. If you are interesting in only short part, so easiest way is to re encode it all. Try Avidemux set point a for start set point b for end, choose video x264, x265, xvid or what you want. Audio to copy, and Output format for what you want. (mkv, mp4, ts) they are most used.
Configure video (to your desired settings(size and quality))
Save as insert name. O.K. and how much work is done you can see in progress bar, or switch to detailed view with encoding speed etc.
When I recorded some TV show, that first frame isnt I frame, I select the first frame of the show and set mark A there. then Iam looking for sharp cut as near as possible, so next frame is I frame (keyframe) then I set B mark one frame before this I frame. Re encoding it. Whole part. Then I go to B mark move one frame after this. Set mark A there (I frame) and B mark at the end of the show. Copy video, copy audio (output format at both is mkv) Then I save the rest of the show.
Now I open mkvtoolnix. Open Start part (that I whole re encoded) right click on this and select append (then i choose part that I copy video copy audio) and start muxing. So I do manually what is vidcutter supposed to do automatically but never did.

Bernix

[arnoldpredator]

The video as you pointed is Group Of Picture based. If you are interesting in only short part, so easiest way is to re encode it all. Try Avidemux set point a for start set point b for end, choose video x264, x265, xvid or what you want. Audio to copy, and Output format for what you want. (mkv, mp4, ts) they are most used.
Configure video (to your desired settings(size and quality))
Save as insert name. O.K. and how much work is done you can see in progress bar, or switch to detailed view with encoding speed etc.
When I recorded some TV show, that first frame isnt I frame, I select the first frame of the show and set mark A there. then Iam looking for sharp cut as near as possible, so next frame is I frame (keyframe) then I set B mark one frame before this I frame. Re encoding it. Whole part. Then I go to B mark move one frame after this. Set mark A there (I frame) and B mark at the end of the show. Copy video, copy audio (output format at both is mkv) Then I save the rest of the show.
Now I open mkvtoolnix. Open Start part (that I whole re encoded) right click on this and select append (then i choose part that I copy video copy audio) and start muxing. So I do manually what is vidcutter supposed to do automatically but never did.

Bernix

Thanks for your answer, let's see if I understand this:

-Apparently I have to "preprocess" the video so it can be read by the cutters frame by frame instead of jumping just into key frames, Is this correct? I have installed Avidemux but can't find some of the options you mention. I have a question, point A is the first frame and point B is the last one? So the output will work as I want? I tried but didn't work, maybe I did something wrong.

[Bernix]

Hi,
no, you dont need pre processing video. Actually Avidemux indexed video when not mp4 and maybe ts. Load of mkv or mpg last some time.
Here I made image, but sorry I must laugh to myself...

[Attachment 43411 - Click to enlarge]
There under the timeline is A and B in somewhat blueish weird color Pressing A mark start point on timeline. Move where you want end and press B (is next to A icon also in weird color)
When your starting point of selection A mark is on I frame like in video (but there is exception i will not explained it now) B Mark frame position isn't important. So you can use copy video, copy audio and save as and result will be perfect.
But when A isnt on I (for short i suppose it is keyframe) frame then you have to re-encoded video. So you have to choose where is copy under video to x264 or x265 or what you want. Then when you click save as, then it will last longer. Because whole selected part must be re-encoded. Then in mkvtoolnix you can merge different parts of video with same resolution, and audio. Best is when the video parts are encoded in same encoder and fps and resolution.
So I do first part of video this way, re-encoding and then paste rest of video which i get copy video copy audio, because I know I started the second part started on Keyframe.
I am not good in explaining, so if you have any question, ask and I will try to explain.

Bernix

[arnoldpredator]

Hi,
no, you dont need pre processing video. Actually Avidemux indexed video when not mp4 and maybe ts. Load of mkv or mpg last some time.
Here I made image, but sorry I must laugh to myself...

[Attachment 43411 - Click to enlarge]
There under the timeline is A and B in somewhat blueish weird color Pressing A mark start point on timeline. Move where you want end and press B (is next to A icon also in weird color)
When your starting point of selection A mark is on I frame like in video (but there is exception i will not explained it now) B Mark frame position isn't important. So you can use copy video, copy audio and save as and result will be perfect.
But when A isnt on I (for short i suppose it is keyframe) frame then you have to re-encoded video. So you have to choose where is copy under video to x264 or x265 or what you want. Then when you click save as, then it will last longer. Because whole selected part must be re-encoded. Then in mkvtoolnix you can merge different parts of video with same resolution, and audio. Best is when the video parts are encoded in same encoder and fps and resolution.
So I do first part of video this way, re-encoding and then paste rest of video which i get copy video copy audio, because I know I started the second part started on Keyframe.
I am not good in explaining, so if you have any question, ask and I will try to explain.

Bernix

I succeeded in cuting a file, so thank you so much!

[Bernix]

Good to hear that you manage it even my step by step tutorial was very chaotic.
This way, you can also delete unwanted commercials. Set A mark to start of commercial, set B mark to first frame of TV show after commercial and delete it. Because there are usually more of them You have to do it several times. Then You mark A on Start of TV show, B at the end and re-encode it all. It takes long time, but you save lot of space cutting off commercials and re compressing the video. But to properly setup encoding for your "personal quality" want to test different settings in configure tabs.
Nice to hear that You have done it!!!

Bernix