How do I record my screen using VLC or other software without wasting CPU?

Question

I'm using VLC to record and save an output file of my screen.

The biggest problem is that VLC uses a very high amount of CPU. For a Core 2 Duo that is not a big deal, but in some old PCs (like with a P4) this is very annoying.

Can you help me to choose/set the best option for encapsulation and video codec settings? I'm not interested in audio.

For some reasons I need to have a lighter video file. I tried using MP4, but it really uses a lot of CPU, also on a Core 2 Duo.

Maybe VLC is not as good as some other software. If you have an alternative, the only requirements that it should have are:

• the possibility to start it by command line

• free

• a lighter output file

Answer 1

There will always be tradeoffs.

MP4 is a compressed media format. Compression requires CPU time. Compression of a real-time screen requires a lot of CPU time right as the video is being taken.

Uncompressed media formats generally require less real-time CPU processing, but they also take up a much larger amount of disk space, memory, and other resources and so can be just as hard on a computer as compressed media.

Due to the enourmous size of uncompressed media, there really aren't any uncompressed video formats. Audio is much smaller and so there are uncompressed audio formats. You really need to just choose the one that gives the best trade-off of size and CPU time and use that. Trying different codecs can also be helpful for speeding up the compression/decompression processes.

These trade-offs tend to just about balance each other out. The only reason to use a compressed media type is because uncompressed media formats are just so much larger in size.

And a P4 is really, really old by the standards of today's software, especially media software.

I have not worked with screen recorders, generally, but a google search of lightweight screen recorders showed a result called Jing, which is apparently written by the folks who brought us Camtasia, which is a popular and capable recording suite. Jing is apparently designed to help tech staff see what users are experiencing and send them video instructions on how to resolve their problems. As such, it is supposedly rather lightweight. And because of their target market, the output files are probably rather efficiently compressed as well.

Answer 2

I recommend CamStudio, it's free and open source and "CamStudio also comes with its own Lossless Codec that produces crystal clear results with a much smaller filesize compared with other more popular codecs".

I have used this CamStudio Codec and it is astonishing how compact it compresses the videos. It is strictly built for Windows screen capturing.

In addition, it was originally written by a company called Rendersoft a decade ago, so it has a legacy of tight, efficient code that should perform very well even on a P4 system.

Here is a quote from the original Readme of the CamStudio Codec:

"CamStudio Lossless Codec v1.1 Copyright 2003 RenderSoft Software

• CamStudio Lossless Codec is a very fast codec optimized for screen capture applications.
• It operates in RGB mode and is able to compress 16, 24 or 32 bit RGB bitmaps.
• It supports temporal compression and is able to render the movies with perfect quality. ...
• CamStudio codec is able to compress using two lossless compression algorithms : LZO and GZIP.
• The LZO algorithm is very fast and is best used for screen capturing."