Jump to content

Video Quality?


root012
 Share

Recommended Posts

Video quality depends on FFmpeg options that you use in Settings -> Video Formats. Specifically there is an option named -crf <number> which controls rate factor (it is called Constant Rate Factor):

 

video_quality_crf.thumb.png.38a2d27ca1bec6b849f2bc8c273118fe.png

 

Here is what KVS documentation says:

 

The -crf 25 parameter sets the video quality factor (the less this value, the higher the quality). When you use this parameter, the videos will be encoded with permanent quality and dynamic bitrate. It means that video fragments where quality loss is not critical (motion pieces etc) will be encoded with lower quality. At the same time, fragments where quality loss would be noticeable will have higher quality and higher bitrate. A possible disadvantage here is that you can't predict file size and requires a few test iterations before you establish values that work best for you. We recommend setting this parameter to a value between 20 and 35.

 

You can read more about CRF here:

https://slhck.info/video/2017/02/24/crf-guide.html

  • Like 1
Link to comment
Share on other sites

  • 2 years later...

It depends on what you do in your video editor and how you then save this video. Every time you need to re-convert a video you are losing some small portion of its original quality. This is like re-saving JPG image many times:

https://improvephotography.com/2484/does-saving-a-jpeg-multiple-times-reduce-image-quality/

However in practice if you don't re-save with poor compression ratio the visual quality loss will be unnoticeable.

  • Like 1
Link to comment
Share on other sites

On 8/28/2021 at 5:14 AM, Lococent said:

do I lose the quality of the video after I edit it in some application (for example, in inshot) and then upload it in KVS?

In fact, if you edit in inshot and then upload the video to kvs, then you are unlikely to lose much in the quality of the file, just as if you were editing in this video editor (I'm just giving it as an example because I use it). But if you edit a video in some online editor, it can spoil the quality of the video more than any other editor.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...