Why is it so hard to trim a simple MP4 video?

[Filingo]

Hello,

 

I'm trying to find a simple way to trim some videos I have on my PC while keeping the quality. So far what I've tried lowers quality very dramatically. I am uploading them to YouTube and it looks bad

 

I've tried Windows built-in trimmer in the Photos app and it's bad, and I've tried DaVinci Resolve and it's even worse (at 720p 60fps), and it also increases the size of the video...

 

*I also tried VLC record option, but of course that's not trimming and it takes long time to record each part of every video

 

Is there a simple way to trim videos, while keeping the original quality?

 

Thanks

[Kilrah]

Avidemux

[minibois]

Technical reason: MP4 uses interframe compression, which means it compresses not every frame by itself, but it compresses video by looking at the previous frame and only saving what has changed, rather than for example compressing each frame. This means it may be difficult to retain the original quality for programs when cutting a piece out of the video.

 

Practical solution: personally I like using Handbrake. 

Like this you can only cut a piece from the video. It does have to re-render it though, which depending on the CPU you have could take very little or a long time.

You have a lot of options in quality options, so you can make it look as good (or bad) as you want.

[Filingo]

 

4 minutes ago, minibois said:

Technical reason: MP4 uses interframe compression, which means it compresses not every frame by itself, but it compresses video by looking at the previous frame and only saving what has changed, rather than for example compressing each frame. This means it may be difficult to retain the original quality for programs when cutting a piece out of the video.

 

Practical solution: personally I like using Handbrake. 

Like this you can only cut a piece from the video. It does have to re-render it though, which depending on the CPU you have could take very little or a long time.

You have a lot of options in quality options, so you can make it look as good (or bad) as you want.

 

Thank you, but I tried for example to make it 1080p, but the original video resolution was taken at 800*600.

And the original video size is like 60mb and it increases it to 200mb or more

Is there a way to trim the mp4 as high and as close to original as possible and also keeping same size? Or it has to increase much because of the way mp4 is done?

 

 

9 minutes ago, Kilrah said:

Avidemux

Thank you, I will try now

[Filingo]

1 hour ago, Kilrah said:

Avidemux

update: I tried it and it really is working quite well for my needs. thank you! 

[theonly500]

Just trimming shouldn't change much. But since MP4 has a changing per frame compressionrate it will be a bit hit and miss.
And different encoders encode with a different preference.  If you were to figure out the exact settings of your file, then you can make sure, that a shorter video will result in a smaller file. But otherwise you're a little bit bound to what presets the encoder gives you.
 

In Resolve you can set a max datarate, that limits your file size to a fixed point.

In Handbrake you can set a average bitrate. That sort of limits your file size.

In most other encodes you can set a similar option which sets your filesize.
If you want to get a similar filesize to what you got before, just divide the filesize through length of the video before editing and then you got you bitrate.

Edited January 19, 2021 by theonly500
Fixed spelling

[shadow_ray]

It's a command line tool but you can use ffmpeg to cut out a segment without re encoding it.

ffmpeg -ss [start] -i in.mp4 -t [duration] -c copy out.mp4

Source: https://superuser.com/questions/377343/cut-part-from-video-file-from-start-position-to-end-position-with-ffmpeg

 

[Biomecanoid]

7 hours ago, Filingo said:

Hello,

 

I'm trying to find a simple way to trim some videos I have on my PC while keeping the quality. So far what I've tried lowers quality very dramatically. I am uploading them to YouTube and it looks bad

 

I've tried Windows built-in trimmer in the Photos app and it's bad, and I've tried DaVinci Resolve and it's even worse (at 720p 60fps), and it also increases the size of the video...

 

*I also tried VLC record option, but of course that's not trimming and it takes long time to record each part of every video

 

Is there a simple way to trim videos, while keeping the original quality?

 

Thanks

Virtualdub

[DannyJ98]

I usually use Handbrake for doing quick trims and re-encodes, it works well enough for my needs, which is mostly just trimming game clips down and compressing them a little.