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HD HDMI video recorder of 2 different models gave mp4 files of different size & compressing mp4 without loss

sunhux used Ask the Experts™

I have the above HDMI HD video recorder which just broke (the power is intermittent):
a typical 1 hr 50 mins movie from my Set-Top box will record into about 7.5-8GB of
mp4 videos.

As the above broke & the cost has increased, I got the cheaper recorder below instead:
For exactly the same movie of same duration, the recorded videos take 15-16GB of

Thought both of them are HD (1080p), so what's the difference?  In terms of
fps (frames per sec) or just simply the latter's video compression is poor?

Is there any way or free tool to compress the mp4 without loss of the video
quality including the fps??  

I've come across a tool (can't recall) that could convert/compress jpg images
but not for mp4 or webm or mkv videos
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If anyone can recommend a good HDMI (not the RGB type) video recorder that gives high quality
recording with small video files, that'll be most welcome
Video compression can be called poor, but it's all SUBJECTIVE.

The bigger file may very well be of VERY high quality. How can you call a picture perfect file that's a bit bigger POOR?
On the other hand, the smaller files, may very well be LOW QUALITY in the eye of an expert (low fps, lots of artifacts, color change etc etc). You may call it perfect, other may call it POOR.

Your question about compression WITHOUT loss of quality, is basically NOT possible. The point of compression is to make the file smaller with minimum loss possible. Some do it better than others.

You can either keep your current hardware, and use another software pass to make it smaller, or try another piece of hardware (but maybe read reviews or ask questions to the manufacturer to be sure what the resulting files will be like).
To do another compression pass, use this software:


You can tweak a bit, and the longer you process the file, the higher quaility the resulting file will be.
Most Valuable Expert 2013

Your recorder might still do this, it's likely it's picked a high bitrate to save the file, look through the manual for options on recording quality.
Newer machines are able to process recordings faster than their predecessors and as a result can save more data and so you get a bigger file, frames are less compressed and are sampled more frequently.

The options you'll have to reduce quality should let you reduce this until you're at the best your older machine was capable of!


Kimputer, I cant tell with my bare eyes which of the 2 recorder give better recorded video but just for my personal consumption, I'm happy with the smaller sized recorded video, taking much less space on my HDD.  Will try out the tool.

MASQ, those China-made recorders dont come with manuals so I guess I'll write to manufacturer but as I've bought, guess I'll find ways to shrink the videos or hv to get bigger HDD
Most Valuable Expert 2013
Will let you compare the settings used to record the two files.