 Okay, today we're going to be solving the hidden message I posted a couple days ago on July 2nd and again, I'm trying to make these progressively harder and Luckily there are a handful of people who made it through this secret message at the time of recording this So let's go ahead and look at the original video and it's a video of me talking Maybe hear that in the background there are some modem tones And I am talking about dial-up modems and I make a hint towards modem speeds of 56k Which I even said in the video it was a hint so at this point you're going to want to you know Download the video and figure out how to decode the modem tones So if you don't know how to do that you can always use Google and I'll type in Linux Decode modem tones and the first thing that comes up is a program called mini modem Which should be in your repository? so use your package manager to install that and it allows you to generate and And decode Modem tones there's lots of protocols if that's the right word out there for different types of tones one I've used in the past called psk 31 The reason I went with mini modem over or something like psk 31 or the other ones is just because this is a nice Shell option all the applications I know I know three or maybe four that can do other tones like the psk 31 But they're all gooey's and that's just overkill for what I'm trying to do I want to just pipe my message in to generate it and then hand it a file and have it decode it so mini modem is what I went with and That's how you figure that out another way you might have figured it out Although I don't anybody knows this is if you look at the source code for that YouTube video There's a section called keywords, which is what's I have the tags I put for that video and the tag I put for that video was mini modem I don't know where else you can see the tags for a video But right there and I'll tell you that might come in handy in the future knowing that Because I might put other information there again little tips and stuff for some videos But mini modems the program we're going to use Let's go to our shell here and the first thing we need to do again is download the YouTube video So I'm going to use YouTube DL and pass it the URL for that video It's only a 20 second video should so it should download pretty fast now at this point We know we want an audio file because that's what Mini modem is going to take and I'm just going to take the video and create a wave file out the audio of it So I'm going to say ffmpeg. I'm going to give it the name of our video file And I'll just call the output m.wave now we have a wave file now I can say mini modem and We're going to do dash dash rx for receive when I'm generating it. I used dash dash tx dash dash which is transmit and our T our x is received and The part in the video I talked about 56k modems that through some people off some people were putting 56,000 I want you to put there was 56 We're going to do dash f for file and give it our file input, but this will not work when I hit enter It tells us that your stream must be one channel not to our video file is a Stereo and this program only takes mono not a problem at all. We run the same ffm Ffmpeg command, but I'm going to add dash ac for audio channel and do one and that will give us a mono file It will ask me if I want to override the last one I'm just going to say yes, and now we have a new wave file and we can run that same command again it takes that audio file and These lines of the pounds you can ignore the standard output is just this year Which is a song by me and it just tells you to go there and comment So that is how you decode that now 56k is or 56 is just one of the rates Which is rather slow. I actually again time this out So it'd be a 20 second video approximately for this message, but the same message could have been transmitted in Probably about a second by upping that number letting you know that because that may happen in the future Well, I'm trying to think of anything else. I wanted to say about this, but that's pretty much it I'll post another hidden message video in a couple of days. Oh, I do want to give credit to the people who made it again I'm posting this I'm recording this video a little earlier than I'm posting it, but at the time of recording it Well, let's go to the video where they were supposed to go We'll pause that and So these are the people that made it there and they have explained they all pretty much the same thing Oh another thing I wanted to say is you might have been confused in the video. I'm talking and you have the modem sounds Some people thought that maybe one was in one channel and one was in the other But no, you can talk over these audible type channels And as long as you're not making too much noise or a staticky noise You it should decode of course I test these before I make them public. So I knew that it worked So no, you didn't have to remove the my voice at all. This is true with a lot of these tones So what's great about these things is a little more information here Dial up modems for those of you remember the noise and it's actually the tones It's like your modem was basically like an audio card listening to that and decoding them similar things again I said like PSK 31 There's a lot of other formats out there that are used in ham radio for sending messages So you can chat with people that way But another example is if you pick up any of your credit cards or any type of swipe card with a magnet strip I've mentioned in previous videos those magnet strips in the back are the Basically the same exact thing as a cassette tape and actually if you pull the cassette tape head the reader out of a cassette tape player You can actually read the magnet stripe on cards like that and you'll hear tones And then you just need software to decode them you can actually find software out there That will decode cards like that. So that's a little more information on there. I hope you enjoyed this video I hope you learned something. I hope you look forward to the next in video again I'm having fun making these. I hope you guys are having fun trying to solve them and You know it takes a little bit, you know of figuring out But once you know what you need to do, it's usually only a couple of steps I don't do anything. We're it's gonna take you hours to decode something You just need to figure it out But look for those hidden messages in the videos and as always I thank you for watching and I hope that you have a great day