Cracking the Code uses slow-motion video to conduct detailed analysis of extreme guitar technique, and ShredCam is what makes it all possible. ShredCam is a Mac application which can capture video from digital sources and replay that video at reduced speed, without affecting the pitch of the recorded audio. Video and audio can be permanently exported in slow-motion without recompressing or otherwise affecting the quality of the source material. This lets you create high-quality slow-motion footage that can be easily imported into video editing applications like Apple's iMovie and Final Cut Pro.

If you own a Mac running Tiger (Mac OS X 10.4 or higher), you can actually download a copy of ShredCam and use it to analyze your own playing. At the moment, ShredCam is free. It's also not supported in any way, and you use it your own risk. Suggestions for improvement are of course welcome.

ShredCam.zip (296KB)

As we discover in Cracking the Code, virtuoso shredders employ a range of subtle techniques they may be only partially aware of. The speeds at which these techniques occur means they are generally invisible to observers as well. It is only under the microscope of slow-motion video that they become apparent. How, you ask, can an accomplished player be unaware of the picking and fretting motions they're using? Very easily. A typical example from my own playing appears in the video clip to the left. This is an arpeggio lick in which consecutive downstrokes are used to connect high-speed sweeps. It's an unorthodox approach, and one I was not aware I was using until I viewed the video. This is not a fluke; in retrospect it's something I do quite consistently when faced with repeating arpeggio figures that both start and end on the same pickstroke. In fact, in Al DiMeola's self-titled 1991 REH instructional video, he devotes an entire chapter to his use of consecutive pickstrokes in arpeggio playing. It's a good bet I copped this technique from Al at some level.

RECORDING: ShredCam is built on Quicktime, so it will work with any Mac-compatible video source, like an iSight, or a DV camcorder. Plug in your video device, launch ShredCam, and open the recorder window. ShredCam will detect the device and begin displaying live video on the screen. A click of the record button begins capturing the video to the location of your choosing, and another click of the record button stops capturing.

RAM DISK: ShredCam works fine with normal-speed cameras and movies, but it is especially adapted for high-speed scientific cameras. Such cameras, like the Basler a602fc which is used in Cracking the Code, typically record uncompressed video at 60 frames per second or higher. Data rates can easily run in excess of 20 or 30 megabytes per second, which is beyond the reach of many consumer hard drives, particularly those found in laptops. To accommodate these kinds of cameras, ShredCam offers built-in RAM disk recording. Simply click the RAM box on the recorder window, and ShredCam will set aside a portion of your machine's memory for movie recording. Movies are recorded to the RAM disk, and automatically transferred to the designated recording folder upon completion. The RAM disk is destroyed by unchecking the RAM box, or destroyed automatically when you quit ShredCam.

PLAYBACK: When you're done capturing, ShredCam automatically opens your movie in the player window. ShredCam can also open Quicktime movies you may have created in other programs or downloaded from the 'net. Simply open the player window and locate your movie. The player window displays relevant statistics such as size, data rate, and frame rate. Basic transport controls are provided, and a speed slider adjusts playback rate from normal-speed (100%) to quarter-speed (25%).

EXPORT: When you've arrived at a playback rate you're happy with, a click of the export button saves a copy of the movie with the new settings. This is a lossless process that preserves the quality of the original video footage (i.e. without recompression) by simply inserting more time between the video frames. Audio tracks are processed with a time-stretching algorithm which preserves the pitch of the original audio track.

If you're interested in recreating the ShredCam setup used in Cracking the Code, here's what you'll need. Most importantly, you'll need a high-grade scientific video camera. These are usually Firewire, and conform the IIDC, or "Instrumentation & Industrial Digital Camera" standard. I use the Basler a602fc. This camera is capable of 100 frames per second at its native 656 x 490 resolution. At reduced sizes, the camera will capture well into the multiple-hundreds of frames per second. For example, at a resolution of 512 x 384, the camera pumps out over 130 frames per second in full color. Sweet.

Next, you'll need software. The Apple iSight is actually an IIDC-compliant camera, but for whatever reason, Apple's built-in IIDC drivers frequently do not work with other cameras. For this project I used the most excellent IOXPerts Industrial Camera Driver for Mac OS X. IOXPerts is a software developer that specializes in Mac video drivers, and they've been doing it for years. Their Industrial Camera Driver integrates seamlessly with Quicktime, making it simple to access advanced features of the cameras they support. In addition, Steve Sisak, master hacker and the fearless leader of IOXPerts, was an indispensable technical resource during the development of the ShredCam software. Many thanks to him and his team.