Compression comparison

[Dee Mon]

It is said here
http://www.techsmith.com/codecs/ensh...ompression.asp
that "EnSharpen delivers the highest compression in the industry for screen recording and animated content".

But did someone do any testing and comparing with other lossless codecs such as CamStudio, CorePNG and so on?

On the page above there is a file which EnSharpen proudly compressed to 293 kb. I took MSU Screen Capture Lossless Codec (http://www.compression.ru/video/ls-c..._codec_en.html) and compressed this file to 97 kb. Three times better.

But this is only one file. Can anyone compress some files with EnSharpen and upload them somewhere so that we could recompress them with other codecs and compare?

[dro085]

Hmmm... you wouldn't happen to be from MSU would you? [] On the MSU page, it says:<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">We also compared our codec with TechSmith EnSharpen which "delivers the highest compression in the industry for screen recording and animated content" (link).
We took the video sequence (640x480, 214 frames, RGB16) used by TechSmith to demonstrate its superiority and compressed it with our codec 3 times better, even though EnSharpen worked in RGB16 and MSU Screen Capture worked in RGB24.
Resulting file: somewins.avi (97 KB).<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Hmmm... 97 KB sounds pretty good. This peaked my curiosity, so I did some investigation. I noticed a couple things:
1. The 97 KB file (somewins.avi) posted on this site is an AVI, whereas the EnSharpen file is MOV. So, we're not exactly comparing apples to apples here. EnSharpen is a port of the TechSmith Screen Capture Codec (TSCC) to the QuickTime architecture, and so a better comparison would be TSCC and the MSU codec.
2. The somewins.avi file has only a single key frame (the first frame). EnSharpen defaults to a key frame every 80 frames. With only 213 frames, the EnSharpen file had 3 key frames whereas the somewins.avi had only 1. Adjusting the key frame rate for EnSharpen to every 500 so that it would have only a single key frame (the first frame) yielded an 85 KB MOV file.
3. The uncompressed source on the EnSharpen page is 16-bit (to save on bandwidth from others downloading this file). This is why EnSharpen compressed it as a 16-bit MOV. EnSharpen can output 16-bit, 24-bit, or 32-bit, but by default it will not increase or decrease the bit depth in order to preserve colors and get the smallest file size possible. Since the source is 16-bit, if you output to 24-bit, you will not gain any color information, but you will likely have a larger file. In my tests, I could only get the MSU codec to output 24-bit.
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">But this is only one file. Can anyone compress some files with EnSharpen and upload them somewhere so that we could recompress them with other codecs and compare?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">True, this is just one file. I'm sure we could each come up with examples where the content is perfect for the optimizations in the codec. Camtasia Studio does screen recording, and it has a 30 day free trial. So, if you're looking for content, you could download the trial and record a few tests with TSCC and then recompress with a different codec to compare.

Dave O'Rourke
Camtasia Studio
Lead Developer

[Dee Mon]

Thanks a lot for this info!
I'll do some more testing.

Yes, I am from MSU group (Moscow State University, Russia), author of mentioned codec.

[smidog]

I downloaded and installed both Techsmith Screen Capture Codec and MSU Lossless Codec. I can see them were successfully installed under Video Codec.

As a beginner and like to compress some AVI files to reduce storage space, how do I "run" either of the above codec program ? I don't any Icon nor program....... Do I need any other software ? I have Movie Maker.

Joe

[Jimb]

Dave,

Thanks for filling in the additional information. You made things clearer. I'd looked at the MSU codec only yesterday and after your post read up on ensharpen. I've been using Camtasia since version 3 and had never noticed it includes the ensharpen codec. While this is not the right forum I am curious and wonder if you can enlighten me on a related question.

For some time now I have been encoding our screen captures as Quicktime .MOV's (H264/AAC) Are there any advantages to using ensharpen over quicktime?

Regards - Jimb