Why does the video quality suffer after editing?

[henry4956]

I'm doing a tutorial of a app on my laptop. When I save the video without any editing and play it back it's clean and crisp. However every time i edit the video and save again - the video quality is poor. I've been saving as WMV then after editing MP4. Can anyone help me figure this out? Summary video when unedited is crisp, after editing it's blurry

[sum_guy]

wmv is a type of video that is compressed, and then you are compressing it again in mp4 container which could be one of several different compression formats. Your best bet would be to capture with no compression if you have that option and then edit then export to an mp4 container. As it is, you're compressing to wmv and then compressing it in mp4 again.

[henry4956]

the file types I have are avi, wmv, mp4, mp3, flv, mov, webm and mkv
which of these is uncompressed?

[LMotlow]

All of them are. Understand, files like avi, mp4, mkv, many others, are containers -- not formats. They can accept video lossy encoded (lossy compression) using many different codecs.

Lossy encoding means that what you get is less than what you put into it. Each time you modify, recompress, re-encode, etc., you lose even more from the lossy first version. http://www.lockergnome.com/media/2011/08/22/lossy-vs-lossless-video-compression/

In addition, except for losslessly compressed avi (which you apparently are not using), the containers/formats you mention are inter-frame formats that are not designed for edits or mods, much less for more lossy recompression. Editing and not-for-editing formats.

One way to avoid the worst recompression damage is to re-encode at a higher bitrate than the original. The best way is to decode the lossy file to a lossless format (such as huffyuv or Lagarith compressed AVI), clean up the previous compression artifacts and other defects, and re-encode with good codecs and encoders. Better codecs and better encoding do not include wmv.

[henry4956]

You are way above my pay grade when it comes to this. I will read your reply a few times. then I'll try and do what you say. FYI the ultimate destination of the video will be on youtube, in case that changes any of this. I really appreciate your help. Try and be patient with me.

[LMotlow]

If it looks bad in your edit, it'll look worse on UTube.

The idea of video compression is about as entry-level as one can get, short of knowing how to copy a file from one place to another on a PC. But, then, some people don't even know how to do that.

[henry4956]

I didn't say it looks bad on my edit, I said it doesn't look as good as the non-edited vrsn. As far as your comment - I've had this software for 2 days, cut me some slack. I'm a computer programmer of 30 years (I'm no dummy). I'll figure it out, one way or another, with or without condescending comments.

[LMotlow]

Oh. Well, if you're satisfied, there's no problem.

I finally ended my own programming career after 37 years when it got down to working 70 hour weeks.

You didn't mention whose software you've been using for these 2 days. The software can make a difference, too, but no need to get in a hurry about that. Meanwhile, as a programmer you probably know, there really are people who can't copy a file from one place to another on a PC. I'm pretty sure you aren't one of those poor devils, LOL!.

[ezcapper]

Depending on how you want to edit the video (if it is simple cutting and joining parts), I think you can do it without losing any quality loss using the program avidemux. If you want to add things like graphics, there will be quality loss because you are "re-encoding" the video, which means you are losing some information from the original file. You might have to use an avidemux video editing tutorial off of youtube, maybe something like this?

https://www.youtube.com/watch?v=uh_iX4QiKuQ

Make sure you select "copy" in the video and audio options on the left side bar, there will be no quality loss.

if editing to add graphics, or anything not in the original file, you want to use a program where you can save the reencoded file using the h264 codec at a bitrate of 20 mbps. That will give you the least quality loss, but biggest file. It might be an mp4 container, or mkv, or something else, but that is less important than the codec and the bitrate, which determines the quality. Your current program probably uses preset bitrate settings depending on the container you select. Usually mkv, mp4, etc are the ones they set to the highest quality.

An alternative to entering a bitrate value would be to use a program that allows you to enter an alternative h264 quality value instead. This might be referred to as a qp or crf value. A crf value of 17 will have very little quality loss, but again a very big resulting file.

If you don't need to add anything not in the original file, the avidemux option is good, because the final file will be the same proportional size as the original

I don't know how to add graphics, texts, etc to video using a program that will let you choose your output codec and bitrate, but I would imagine someone on here certainly will and can recommend one.

[henry4956]

Oh. Well, if you're satisfied, there's no problem.

I finally ended my own programming career after 37 years when it got down to working 70 hour weeks.

You didn't mention whose software you've been using for these 2 days. The software can make a difference, too, but no need to get in a hurry about that. Meanwhile, as a programmer you probably know, there really are people who can't copy a file from one place to another on a PC. I'm pretty sure you aren't one of those poor devils, LOL!.

I am using Movavi. I tried Quick something or other and it didn't seem suited for Windows. I find Movavi quite easy to use, l have a handle on all of the editing features and was amazed at how easy it is to create a really nice video. I actually noticed that the quality of the video was not as crisp as the actual thing but I was quite satisfied. Then I created one small video that required no editing and that's when I noticed that (without the editing) it's as crisp as the real thing. Maybe I'm just being too fussy. Like I said until I saw the short clip with no editing I was quite content. But I am a perfectionist and (if it's possible with Movavi) to get the edited version to look as clean as the unedited I certainly would like to do that. I don't want to switch to another software, l tried 2 others and found Movavi so much easier to use. This is a one time thing, when I'm done doing my tutorial video for my own app - I won't be needing to use Movavi or anything like it anymore. So since I find Movavi easy to use - I want to solve this with Movavi. IF IT CAN BE SOLVED. Perhaps I should start a new thread and call it 'Movavi video quality after editing'. what do you think