I bet there is a list somewhere but here are some places I would recommend you use:
domaintools.com - that told me what was registered by who and when, etc and also let me know how many times the name was dropped and who else owned it in the whois history. This is really great to see because you can see if it was owned by investors and look at nameserver history etc to see if it was say parked at a domain parking company. If I see that a name was parked somewhere by an investor and dropped, especially many times, that is a giant red flag to me. I may still buy it for other reasons but all signs point to this name not making any money on parking or sales.
I dont know if your budget allows for it, I use a paid membership there to unlock some of these data points. To me domaintools is invaluable. There are other sites that offer free services that maybe some people here can share with you. I mainly use domaintools so I wouldn't feel comfortable telling you to use something I am not very familiar with.
I also looked quickly at google.com, that is it just googled the term. There's many things I don't know and I always check to see if there is an industry term, abbreviation, or something in another language etc that would make it valuable. Just today I saw a domain sell for a large amount and thought why would anyone buy that? Then I checked google to find it was a very good keyword in another language. So when I checked your domain a couple different ways such as Mp4lab.com, Mp4lab, Mp4 lab, etc I saw very few search results and also no ads at all on the top or right hand side of the page. Meaning, not many people have content about this term, and no one wants to pay to show up in the search results for it.
I also know the market well since I live in it 10 hours or so a day for many years. I don't see a market for this name so using those two tools quickly told me all I needed to confirm my suspicions. If they had shown otherwise I would have kept digging with a few more things.
Right now when people are talking about liquid names they tend to be talking about LL, LLL, NN, NNN, and even LLLL and some LN combinations like LNL, but liquidity in the market changes so while right now LLLL and NNNN names are pretty easy to resell a couple years ago they were not. A good place to check the trends on what is selling now is dnjournal.com, Ron Jackson does an excellent job of keeping tabs on big public sales each week. You would probably also benefit from various bloggers who report end user sales such as domainnamewire.com.