Macgasm » Adv. Tips

A Beginner’s Guide to Video: Part One

Grant Brunner — Mon, 24 Nov 2008 19:00:40 +0000

Part I: Intro to Video

Complexity is an unfortunate byproduct of technology. Many substantial innovations we have seen in the last hundred or so years are very hard to understand on the surface. The process of compression is incredibly hard to understand in full unless you feel like studying volumes upon volumes of specifications for codecs (Compressor/Decompressors). Luckily, we don’t have to understand the intricacies of compression to use it handily. Before I continue further about compression, there are some important highlights about video sources that I need to touch on.

In its most simple form: Video is a sequence of still images shown in rapid succession to imply movement. That is the basis on which everything else is built upon. Each individual still image is called a “Frame.” The number of frames displayed in one second is called the “Frame rate.” The frame rate is an important factor. In order for the illusion of movement in video to work, we must show many frames in a single second. Fifteen frames per second is essentially the bare minimum for movement to look smooth. However, there are two standards for video in North America: 24 frames per second for film and 29.97 frames per second for television. To keep optimal visual quality, the frame rate of the video should be maintained. If frames are dropped, the video becomes choppy looking. If we add frames where none existed originally, we have to either double-up on certain frames or try to interpolate in between frames. This adds tremendous amounts of hassle and quirkiness, so it should be avoided when possible.

The width and the height of video are expressed as two numbers with an “x” between them. For example: 640×480 is known as the resolution for standard definition video. That means there are six hundred and forty lines from side to side, and four hundred and eighty lines top to bottom. There are four resolutions in North America that are the most common: 640×480, 720×480, 1280×720, and 1920×1080. As I explained earlier, 640×480 is called “Standard Definition.” Most televisions in North America will accept this resolution. 720×480 is essentially a modification of standard definition used by DVDs to maintain the 16:9 aspect ratio (The long rectangle shape of the image) instead of 640×480’s 4:3 aspect ratio (The more squarish rectangle shape of the image). 1280×720 and 1920×1080 are both known as “High definition” video. Both of these are 16:9 aspect ratio. Here is where video starts to build complexity (And we haven’t even gotten to compression yet!).

In order to use our airwaves more efficiently and to deal with less than stellar television sets, we introduced a method of halving the bandwidth used called “Interlacing.” Introduced in the early years of television, interlacing essentially means that only half of the image changes in each individual frame. In the first frame, all of the odd numbered horizontal lines will change. In the second frame, all of the even numbered horizontal lines will change. That pattern repeats itself over and over to display video that looks smooth to our eyes. The problem with interlacing is that it can cause the video to look odd to us under some circumstances. Because half of the image is always one frame behind the other half, fast moving events can look like they are being torn apart.

It is clearly to our advantage to know if the video we’re using is interlaced or not, so we end up calling different types of video by specific names. For example, 640×480 sources are often interlaced, but we are slowly moving over to “Progressive” video which updates each frame completely. 640×480 video that is interlaced is labeled “480i” while 640×480 video that is progressive is labeled “480p.” Sometimes 480p is called “Enhanced Definition” video. On the Hi-Def side of things, 1280×720 video is always (At least commercially) progressive, so it is known as 720p. 1920×1080 is most often broadcast with interlacing, so it is called 1080i. However, high definition video players like Blu-Ray and the ill-fated HD-DVD can both play 1920×1080 as a progressive signal, so that is called 1080p.

Now that we have the very basics of video, we can move forward into compression, how it works, what it means to us, and how we can use it to our benefit. In the next part of this four-part series I’ll explain the basics of compression and what it means to the average Mac user.

Create a real DIY ipod/iphone dock.

Joshua Schnell — Sat, 25 Oct 2008 19:00:12 +0000

There’s hardcoare, and than there’s really HARDCORE!!!1!!!

We’ve all seen the do-it-yourself dock articles that are being passed around the internet lately, but frankly, they all suck the big one. These guys give you a step-by-step run through of creating a dock with your usb connector and the insert apple gives you with your ipod.

Huge props to the guys over at Voltage for putting this together for all of us to see! The sure inspired me to try something similar. I once made a USB hub - mouse pad out of some plexiglass, LEDs… and a USB hub. It didn’t turn out nearly as neat and tidy, nor did it really work. The burns weren’t worth a retry. But, the guys at voltage have kind of inspired me to bust out the dremel with this one.

Rar > Zip especially from the commandline.

Joshua Schnell — Fri, 03 Oct 2008 15:10:30 +0000

Rar seems to be taking over the compression space for many people, and since I get some super satisfaction from using the command line to do things like these I thought I’d point out these command line application that lets you rar files

Figure out your $PATH… type echo $PATH into the terminal.app
Download the program here
Navigate to the proper file location
copy the files to your $PATH location. You’ll need to be able to access super user permissions. So make sure you’re in that mode.
Now you can rar files from the command line. Go get your geek on.

Change your login screen wallpaper image

Joshua Schnell — Mon, 29 Sep 2008 18:17:19 +0000

Sometimes default things get old real fast. We look at them long enough and they start becoming eyesores. This also seems to happen with ever single design project I work on — I start out loving it, and by the time I’m finishing up — I hate it. It’s a disease, and I’m working through it.

One thing that really gets me annoyed is the default login wallpaper. I hated it when I was my default background, and I definitely hate it now that it’s in my face every time I log in.

Essentially we want to hit up /System/Library/CoreServices and replace DefaultDesktop.jpg with whatever your little heart desires. Word of caution, Back that thing up!

You’ll likely be asked to “authenticate”, and to put in your administrator password. So you might want to have those handy.

Getting Front Row to Work on OS X Server

Wayne Dixon — Tue, 23 Sep 2008 11:00:45 +0000

In my post ‘Front Row and OS X Server,’ I bitched about Apple not updating Front Row for 10.5 Server. Well I have found a work around. Here’s how to get it working.

Step 1: Download the latest version of Front Row from Apple (2.1.6 as of this writing).

Step 2: Launch the DMG file.

Step 3: Right Mouse Click on ‘FrontRowPackage2.1.6.pkg’. Click on ‘Show Package Contents’.

Step 4: Double-Click on ‘Contents’.

Step 5: Locate ‘Archive.pax.gz’. Right mouse click and ‘Copy Archive.pax.gz’.

Step 6: Paste the copied archive into a folder somewhere.

Step 7: Double-click on ‘Archive.pax.gz’. Archive.pax will be unpackaged, then decompressed resulting in a folder called ‘System’. Contained within this is the key to getting Front Row working.

Step 8: Eject the FrontRow_2.1.6.dmg file.

Step 9: Navigate through the decompressed folder (System) and locate the three folders named: CoreServices, LaunchAgents, PrivateFrameworks.

Step 10: Launch Terminal. When the prompt comes up, type in ’sudo -s’ (without the quotes) and hit enter. You will be prompted for your password. Enter it in and hit enter again.

NOTE: You are now Super User for your system. Anything you do within this will not prompt for a password and might break the system. Ensure you have a backup and are very comfortable navigating as root. Otherwise, any of the resulting steps can be done using ’sudo’ followed by the command, resulting in needing the root admin password, and allowing you to double-check before doing anything.

Step 11: Type ‘cd /’.

Step 12: Type in ‘mkdir temp’.

Step 13: Type in ‘cd temp’.

Step 14: Type in ‘mkdir frontrow’. This is where the backup of the original Front Row files will be stored.

Step 15: Now that the backup folder is set, type in ‘cd /System/Library/CoreServices’.

Step 16: Type in mv ‘Front\ Row.app’ /temp/frontrow. This will move the Front Row Application to the backup folder we’ve created.

Step 17: Type in ‘cd ..’ to go up one folder.

Step 18: Type in ‘cd LaunchAgents’.

Step 19: Type in ‘mv com.apple.RemoteUI.plist /temp/frontrow’. This will backup the RemoteUI plist used by front row.

Step 20: Type in ‘cd ..’ go to up one folder again.

Step 21: Type in ‘cd PrivateFrameworks’.

Step 22: Type in ‘mv BackRow.framework /temp/frontrow’. This will backup the Backrow frameworks.

Step 23: Type in ‘mv iPhotoAccess.framework /temp/frontrow’. This will backup the iPhoto frameworks.

Step 24: Close out of terminal

So far we’ve only moved the files that were going to be overwritten to a backup folder (in case anything goes awry).

Step 25: Within the GUI, go to the folder where you stored the front row decompressed files.

Step 26: Open a new Finder Window by hitting command-N.

Step 27: Hit ctrl-shift-g to bring up the Go To dialog box. Type in ‘/System/Library/CoreServices’.

Step 28: Copy the Front Row application from the decompressed CoreServices Directory to your /System/Library/CoreServices directory. You will be prompted for your administrator password. Type it in when prompted.

Step 29: Copy the com.apple.RemoteUI.plist file from the decompressed ‘LaunchAgents’ folder to your ‘/System/Library/LaunchAgents/’ directory. Again you will be prompted for your administrator password - type it in again.

Step 30: Copy the Backrow.framework and iPhotoAccess.framework directories to your ‘/System/Library/PrivateFrameworks/’ folder. Again, you will be prompted for your admistrator passsword - type it in again.

Step 31: Launch Front Row from Spotlight (command space) and type in Front Row. Hit enter.

Step 32: Enjoy the fact that you can now browse your iTunes library from Front Row on your OS X Server machine.

If anything doesn’t work, remember you have your backups, so you can always put them back to their originals if you need to.

Remember this will need to be done with every subsequent update of Front Row. You can do all of this from the GUI if you want. I just prefer to do the backups via terminal. I realize that not everybody who runs OS X Server will even need to do this update, but there are those few out there who will want to do this. So I thought I’d provide a way for them to so.

If you run into any snags or have other ideas, drop them in the comments.

Get that Bootcamp partition back

Joshua Schnell — Sun, 21 Sep 2008 20:25:15 +0000

Some of the recent switchers that I know decided that it would be in their best interest to have a windows partition set up on their machines with Bootcamp, just in case they needed to get something done with an application that they could not find a replacement. I cringed, I laughed, I obliged them. Usually out of annoyance I would help them set it up. But, a few special cases aside, most have completely migrated to OS X and never use that partition. Their next complaint is all that wasted space that was setup for the Windows install that they never use anymore, and I get asked frequently to get it back and set them free. Here’s Apple’s official procedure for removing Windows.

Open Date & Time preferences and deselect “Set date & time automatically” if it’s checked.
Manually set the clock to a date before September 30, 2007.
Click Save.
Open Boot Camp Assistant Beta (in Applications/Utilities).
Click “Restore the startup disk to a single volume” and click Continue.
Click Restore.
Type in your password and click OK.
Boot Camp Assistant Beta will remove your Windows partition. When finished, click Restart.
Open Date & Time preferences and check “Set date & time automatically” again if you wish to set the clock automatically via the Internet, or manually correct your date settings.

Tunnels are for more than smuggling people across borders.

Joshua Schnell — Fri, 22 Aug 2008 13:00:40 +0000

It seems everytime I read the word tunnel, it’s in reference to people being smuggled across texan/californian borders into the US. While I’m sure they aren’t exactly the greatest means of travel, they aren’t likely very “secure” either. You wouldn’t catch me in one of those, that is for certain. SSH tunnels on the other hand are probably a little more secure at moving “commodities” across borders. In this case, the commodity is data and the border is the “internet.” See where I’m heading with this?

A couple weeks ago someone asked me about a gui for SSH tunnels and I drew an absolute blank. My answer to them was that nothing existed so far as I was aware. Well that all changed today. cocoa-sshtunnel creates ssh tunnels in os x. So there you have it. I stand corrected.

What is SSH Tunneling?

“SSH is frequently used to tunnel insecure traffic over the Internet in a secure way. For example, OS X machines can share files using the SMB protocol, which is not encrypted. If you were to mount a OS X filesystem remotely through the Internet, someone snooping on the connection could see your files. To mount an SMB file system securely, one can establish an SSH tunnel that routes all SMB traffic to the fileserver inside an SSH-encrypted connection. Even though the SMB traffic itself is insecure, because it travels within an encrypted connection it becomes secure” (Wikipedia - I changed windows to OS X– lol).

Thanks google code. You guys rock!

Upgrading your Macbook Hard Drive.

Wayne Dixon — Fri, 15 Aug 2008 13:00:53 +0000

Since I bought my Black Macbook in July of 2007 it has been rock solid with very few problems. Now, I installed Vista on it about six months ago, since I seem to have to support users with Vista (I can do XP Support in my head).

Amongst all of the fun with my server, I haven’t had a chance to do a full backup of everything on the internal drive. (GASP, I know). Not having backups is crazy in my book, so I went out last week and bought a 250GB 2.5” Seagate hard drive to backup my old OS X 10.5 Leopard client info that’s on the drive I want to use for my backup. Why would I do this, you never know if you’re going to need something, and I would rather archive it than destroy that data.

My initial thought was to just use the 250GB hard drive as backup, but then I got to thinking, wait, my macbook only has a 160GB hard drive. My OS X Client data is only 120GB, so why not upgrade the Macbook’s hard drive. If I only had OS X Leopard installed this wouldn’t have been a big problem, just use Super Duper or Carbon Copy Cloner to do the copy, pull out the battery, unscrew the three screws and all would work. But, I installed Vista so the problem became more complicated.

So I did my googling, and ran across WinClone. This was the easy way to save the Bootcamp partition without having to re-install everything. There is one HUGE downside though, but I’ll come to that in just a bit.

So, here was my procedure for upgrading my hard drive:

Pull out my current Macbook’s hard drive.
Partition the new hard drive into two partitions.
Then use WinClone to make an image of the Windows Partition.
Clone my current Macbook’s Mac OS X Partition to the new Partition on the new drive
Restore the Windows Vista Partition using WinClone.
Install new Hard Drive and remove old hard drive
Boot up new hard drive to verify that it all works, both OS X and Vista.
Relax now that it is done?.

Now Let’s dive into each of these individual sections.

Step 1. Pull out my current Macbook’s hard drive.

This was easy enough. Removing the battery and the three screws, and then the hard drive was quite simple and easy. No mess, no fuss.

Step 2. Partition the new hard drive into two partitions.

I bought a 2.5” USB enclosure for the 2.5” hard drive from my Macbook, since I do want to be able to use it later on. I put the new hard drive in this enclosure and then ran Disk Utility to partition the drive into 170GB for Mac OS X, using HFS+ Journaled and 80GB for Vista using MS-DOS. Who knows, I may want to play some Steam on Vista. This went smoothly and as expected from OS X.

Step 3. Use WinClone to make an image of the Windows Partition.

This worked beautifully, yet it took several hours to complete. (This is the downside that I mentioned earlier). So I started making an image of the Windows Partition. I hooked up the drive and enclosure to my iMac and did the WinClone procedure and saved the image to my iMac’s hard drive.

Remember, I have 2 macs, so it might be possible to do this with only one Mac, but it might be a bit slower. And you could have used the Mac Partition of the new hard drive to store the image to be restored. Then delete the file and do the Clone of the OS X Partition.

Step 4. Clone the Macbook’s Mac OS X Partition.

After the WinClone procedure finished I unhooked my old drive and put it back into my Macbook. After replacing the screws and battery I booted up the Macbook into OS X. I hooked up the newly partitioned hard drive to my Macbook and proceeded to use Super Duper to do an exact clone of my OS X Partition. This did take a while, but as expected went flawlessly.’

Step 5. Restore Windows Partition using WinClone .

Again, I hooked up the new hard drive to my iMac and went ahead and restored the saved image of Vista from WinClone onto the new hard drive. This, like the initial imaging process took hours to complete. But, I sat and waited and it did finished successfully.

Step 6. Install new hard drive and remove old hard drive.

I followed the same procedure as pulling out the old hard drive earlier. I pulled out the battery, removed the three screws and pulled out the hard drive. The hard drive is in a flimsy aluminum carriage that has a tab to easily pull the hard drive out. This is secured with 4 star screws which, luckily, I had a set of screw drivers that could remove these. I put the carriage on the new hard drive and reinstalled the hard drive, screws and battery.

Step 7. Boot up new hard drive to verify that it all works, both OS X and Vista.

This was the moment of truth. Did I screw something up? Did Winclone fail? Would everything boot up as expected? Well… all copied and booted the first time without any problems. So it was a rousing success. I did test out both Operating Systems just to be sure that everything did work and that it would not crash on me in the middle of something. So far it hasn’t.

Step 8. Relax now that it is done?.

Obviously yes, I could relax knowing that everything booted and all of my data was secure.

Final Thoughts.

So Far everything is working as expected. The only little hitch I have run across is that it does seem to take longer than usual when accounts want to log off. While this isn’t a big problem it is a noticeable difference. I might try running some of the usual things, like Verify Disk and Onyx to clear up any caches and the like, just to see if that will correct the problem. I’d think it would. But if not, it’s not the end of the world.

Networking Devices and Mac OS X

Wayne Dixon — Wed, 13 Aug 2008 01:27:51 +0000

I took a Juniper Firewall + VPN Bootcamp class last week for work (it was free - usually very expensive), and I was thinking about ways to connect from my Macbook to the console port on the Juniper SSG-5 we were configuring. Well, obviously you need a USB to Serial connection, but how do you do actually connect via software.

Well, there is a way to use Terminal as a “Hyper terminal” equivalent for Mac. To do this go into Terminal. Type in “cd /dev” to get to the devices directory. Next type in “ls” to list all of the items in the directory. There will be a bunch. What you’re looking for is what beings with “cu.XXXX”. This is the USB to Serial Adapter. The name of mine is “cu.usbserial”. This name is important.

Next, even from within the same directory, type in “screen /dev/cu.XXXX” where the cu.XXXX is the name of your adapter. This will create a hyper terminal-like session that will allow you to send commands directly to the USB to serial adapter, thus allowing you to configure any device that requires a serial connection.

If you don’t want to deal with the terminal, and if you’re programming network devices where you are comfortable with the command line, there is a GUI version of a program called Quickterm. It’s available from gelhaus.net. Additionally, there is a program called Zterm. I happen to prefer ZTerm since it does allow me to use the backspace key. And since I’m not perfect, it’s very helpful.

Just thought I’d let those guys out there attempting to use a USB to serial adapter know how to connect to their gear. Let me know if there are any problems.

Ripping a DVD from the Terminal isn’t all that “complex”

Joshua Schnell — Sun, 10 Aug 2008 20:12:23 +0000

In an effort to prove just how simple it is to rip a dvd using free alternatives, as well as needing an excuse to demonstrate the simplicity of using the terminal, I’ve decided that installing the HandBrake command line tool was an excellent starting point. The first thing we need to do is to download the commandline tool from the HandBrake website. Open up the package by double clicking it. (Now, there is a graphical interface version for those of you wanting to avoid the terminal, and a quick screencast from our archive about using it here).

Let’s move on with the command line goodness.

Now we open the terminal using spotlight.
Enter the following command to change the location and directory we are in ‘cd /Volumes/HandBrake‘.
Now if we type ‘ls‘ we should see a listing of files and folders available in our current location.
The Handbrake team has pre-compiled the application for us, so we just have to move the file to our terminal applications folder.
This is pretty simple, but can get a little complicated. Essentially your terminal applications folder is whatever is in your $Path location. If you’re not sure what that means you might want to read this post. Basically you’ll be able to access that application from any folder or location in the terminal instead of having to navigate to the folder where the application is residing.
Now we will copy the file to our path location. Type ‘sudo cp HandBrakeCLI /usr/bin‘. **Note: there is a space between the I in HandBrakeCLI and the first /.** You should be prompted to input your password, and then the file will be copied to the aformentioned location of ‘/usr/bin’.
We are almost there. Don’t give up now. Movie bliss is just around the corner…for free.
So, since we’re going to be copying dvd’s to our machines, we’re going to want to go to the movie folder, so we can store our movies in the appopriate folder. Type ‘cd ~/Movies‘. We’re now in the movies folder. Let’s rip a dvd.
We should probably note that there is a list of presets available for ripping your movies into various formats, such as iPods, Apple TV, Normal, PS3, PSP…and a whole slew of other options. To see these options type ‘HandBrakeCLI –preset-list’ and you will get a listing of your available options. For instance ‘+ Animation :’ is one option, and ‘+ Quicktime :’ is another. For simplicity’s sake we’re just going to use the Normal preset here.
So, one line of code that is really simple to explain will rip dvd: sudo HandBrakeCLI -i /Volumes/EMPIRE_RECORDS -o EMPIRE_RECORDS.mp4 –preset=”Normal”

I’m going to break it down chunk by chunk here so that you can get a complete grasp of what’s going on.

sudo

The ’sudo’ means you want to run an application as an administrator. So, we’re essentially telling the computer run the application with the privileges it needs to do so. In this case, it’s running the HandBrakeCLI application. If you’re getting a weird error when you type in sudo, it probably means that you haven’t set the password yet. You can do this by typing ‘sudo passwd root‘ into the terminal. You will be prompted for passwords. Once you get that out of the way, the rest of the tutorial should fall into place for you.

HandBrakeCLI

HandBrakeCLI is the name of the application we’ve installed at the beginning of this post, and it is the application we will be using to rip the dvds we want both now and in the future.

-i

The ‘-i’ in this line means that we will be telling the computer where the input is, which, in this case, is the location of the dvd.

/Volumes/EMPIRE_RECORDS

The ‘/Volumes/EMPIRE_RECORDS’ is the location of the dvd. Every dvd from now until god knows when will be in the /Volumes/ location. It will then be followed up with the name of the dvd. If you really want to cheat here, just look on your desktop at the name of the dvd. It is case sensitive, so pay attention to this detail or the whole process won’t work. That also goes for anything in the terminal.

-o EMPIRE_RECORDS.mp4

That’s the letter ‘o’ and not the number zero. I’m sure you’ve been able to deduce that this stands for output. We’re telling the machine where the application will be placing the file when it’s done making a copy of it. If you’ve followed the tutorial step by step until this point, you’ll know that we’re in the “Movies” folder already. So in this string we’re saying… put EMPIRE_RECORDS.mp4 into our current folder.

–preset=”Normal”

We’ve already talked about this, but let’s have a nice little reminder. HandBrakeCLI comes with a series of presets for copying your films. We’ve decided on “Normal,” but you can change it any time by using the steps listed above.

More Info

Just in case you really, really, really want to geek out you can get more options by visiting the wiki here.

Macgasm » Adv. Tips

A Beginner’s Guide to Video: Part One

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Create a real DIY ipod/iphone dock.

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Rar > Zip especially from the commandline.

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Change your login screen wallpaper image

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Getting Front Row to Work on OS X Server

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Get that Bootcamp partition back

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Tunnels are for more than smuggling people across borders.

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Upgrading your Macbook Hard Drive.

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Networking Devices and Mac OS X

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Ripping a DVD from the Terminal isn’t all that “complex”

Let’s move on with the command line goodness.

sudo

HandBrakeCLI

-i

/Volumes/EMPIRE_RECORDS

-o EMPIRE_RECORDS.mp4

–preset=”Normal”

More Info

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