CUFPOS402A Information Technology for Production Week Two: File format for video and film production Aspect Ratio and World wide system Progressive Vs. Interlaced Tutorial Creating PDF document CPU - The Central Processing Unit (CPU) or the processor is the portion of a computer system that carries out the instructions of a computer program, and is the primary element carrying out the computer's functions. 1
RAM - Random-access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order (i.e., at random). "Random" refers to the idea that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data. By contrast, storage devices such as magnetic discs and optical discs rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than data transfer, and the retrieval time varies based on the physical location of the next item. Graphic Card / Video Card - A video card, video adapter, graphicsaccelerator card, display adapter or graphics card is an expansion card whose function is to generate and output images to a display. Many video cards offer added functions, such as accelerated rendering of 3D scenes and 2D graphics, video capture, TV-tuner adapter, MPEG-2/MPEG-4 decoding, FireWire, light pen, TV output, or the ability to connect multiple monitors (multi-monitor). Other modern high performance video cards are used for more graphically demanding purposes, such as PC games. 2
Graphics processing unit (GPU) A GPU is a dedicated processor optimized for accelerating graphics. The processor is designed specifically to perform floating-point calculations, which are fundamental to 3D graphics rendering. The main attributes of the GPU are the core clock frequency, which typically ranges from 250 MHz to 4 GHz and the number of pipelines (vertex and fragment shaders), which translate a 3D image characterized by vertices and lines into a 2D image formed by pixels. Video Memory The memory capacity of most modern video cards ranges from 128 MB to 4 GB. Since video memory needs to be accessed by the GPU and the display circuitry, it often uses special high-speed or multi-port memory. The effective memory clock rate in modern cards is generally between 400 MHz and 3.8 GHz. Video memory may be used for storing other data as well as the screen image, such as the Z-buffer, which manages the depth coordinates in 3D graphics, textures, vertex buffers, and compiled shader programs. 3
Hard Drive A hard disk drive (hard disk, hard drive, HDD) is a non-volatile storage device for digital data. It features one or more rotating rigid platters on a motor-driven spindle within a metal case. Data is encoded magnetically by read/write heads that float on a cushion of air above the platters RAID RAID, an acronym for redundant array of inexpensive disks or redundant array of independent disks, is a technology that provides increased storage reliability through redundancy, combining multiple low-cost, lessreliable disk drives components into a logical unit where all drives in the array are interdependent. Defragmentation In the context of administering computer systems, defragmentation is a process that reduces the amount of fragmentation in file systems. It does this by physically organizing the contents of the disk to store the pieces of each file close together and contiguously. Cause of Fragmentation Fragmentation occurs when the operating system cannot or will not allocate enough contiguous space to store a complete file as a unit, but instead puts parts of it in gaps between other files (usually those gaps exist because they formerly held a file that the operating system has subsequently deleted or because the operating system allocated excess space for the file in the first place). Larger files and greater numbers of files also contribute to fragmentation and consequent performance loss. Defragmentation attempts to alleviate these problems. 4
RAID Level 0 - Striped Disk Array without Fault Tolerance: Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost. Level 1 - Mirroring and Duplexing: Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks. Level 5 - Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID. Level 6 - Independent Data Disks with Double Parity: Provides block-level striping with parity data distributed across all disks. I/O (Input / Output) Short for input/output (pronounced "eye-oh"). The term I/O is used to describe any program, operation or device that transfers data to or from a computer and to or from a peripheral device. Every transfer is an output from one device and an input into another. Devices such as keyboards and mouses are inputonly devices while devices such as printers are output-only. A writable CD-ROM is both an input and an output device. Common I/O for video production USB (Universal Serial Bus) Firewire (IEEE 1397 Interface) Ethernet Port (10Mbps /100Mbps /100 Mbps) ExpressCard ( Sony XDCAM express card) SD Card Slot SDI (Serial Digital Interface) 5
USB / Firewire Comparison SDI (Serial Digital Interface) Serial digital interface (SDI) refers to a family of video interfaces standardized by SMPTE. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video. A related standard, known as high-definition serial digital interface (HD-SDI), is standardized in SMPTE 292M; this provides a nominal data rate of 1.485 Gbit/s. SDI Speed Chart 6
Capture Device High-end production environment often uses 3 rd -party capture device to capture video / audio data. Common capture formats are: 4k, 2k, HD, SD 7
Editing Adobe Premiere Sony Vegas Avid Xpress / Media Composer Apple Final Cut Pro Compositing / Effects Adobe After Effects (Layerbased) Apple Shake (Node-based) Autodesk Flint, Flame and Inferno (Node-based) Blender (Node-based) The Foundry Nuke (Nodebased) Grading Apple Color Da Vinci System Autodesk Lustre 3D Autodesk Maya Autodesk 3D Studio Max Autodesk Softmage Apple Final Cut Pro 8
Adobe Premiere Avid Media Composer 9
Adobe After Effects Apple Shake 10
Autodesk Flame Foundry Nuke 11
Apple Color Da Vinci 2k 12
Autodesks Lustre File Format for Video & Film Production A file format is a particular way that information is encoded for storage in a computer file. Some file formats are designed to store very particular sorts of data: the JPEG format, for example, is designed only to store static photographic images. Other file formats, however, are designed for storage of several different types of data: the GIF format supports storage of both still images and simple animations, and the QuickTime format can act as a container for many different types of multimedia. A text file is simply one that stores any text, in a format such as ASCII or UTF-8, with few if any control characters. Some file formats, such as HTML, or the source code of some particular programming language, are in fact also text files, but adhere to more specific rules which allow them to be used for specific purposes. Filename extension One popular method in use by several operating systems, including Mac OS X, CP/M, DOS, VMS, VM/ CMS, and Windows, is to determine the format of a file based on the section of its name following the final period. This portion of the filename is known as the filename extension. For example, HTML documents are identified by names that end with.html (or.htm), and GIF images by.gif. Internal metadata A second way to identify a file format is to store information regarding the format inside the file itself. Usually, such information is written in one (or more) binary string(s), tagged or raw texts placed in fixed, specific locations within the file. Since the easiest place to locate them is at the beginning of it, such area is usually called a file header when it is greater than a few bytes, or a magic number if it is just a few bytes long. 13
File Format for Video & Film Production Codec - A codec encodes a data stream or signal for transmission, storage or encryption, or decodes it for playback or editing. Codecs are used in videoconferencing, streaming media and video editing applications. Common known video file format & codec AVI (Audio/Video Interleaved) A file format for storing and playing back movie clips with sound on Windows-based PCs. An AVI file is organized into alternating ("interleaved") chunks of audio and video data. AVI is a container format, meaning that it specifies how the data will be organized, but is not itself a form of audio or video compression. MPEG1. This format is often used in digital cameras and camcorders to capture small, easily transferable video clips. It's also the compression format used to create Video CDs, and commonly used for posting clips on the Internet. The well-known MP3 audio format (see definition below) is part of the MPEG1 codec. MPEG2. Commercially produced DVD movies, home-recorded DVD discs, and most digital satellite TV broadcasts employ MPEG2 video compression to deliver their high-quality picture. MPEG2 is a "heavier" form of compression that removes a larger portion of the original video signal than DV, however, it's more difficult to edit with precision. The MPEG2 codec allows for selectable amounts of compression to be applied, which is how home DVD recorders and hard disk video recorders can offer a range of recording speeds. File Format for Video & Film Production.Common known video file format & codec MPEG4. A flexible MPEG container format used for both streaming and downloadable Web content. It's the video format employed by a growing number of camcorders and cameras DV (Digital Video) DV is the format used by many digital camcorders, usually on Mini DV cassettes. Though the DV format employs a form of lossy video compression (applied in real-time as you record with your camera), it's still memory-intensive. When transferred to a computer, a DV clip requires roughly 1 GB of storage per 5 minutes of video. (Clips are usually stored on the computer as QuickTime or.avi files.) QuickTime QuickTime is a file format for storing and playing back movies with sound. Though developed and supported primarily by Apple, Inc., this flexible format isn't limited to Macintosh operating systems it's also commonly used in Windows systems and other types of computing platforms. In Windows, QuickTime files usually appear with the ".MOV" filename extension. WMV.wmv: A Microsoft format..wmv stands for Windows Media Video..wmv files are tiny because they are highly compressed. This is one of the smallest sharing formats, so it is for the end stages of your video project. 14
File Format for Video & Film Production Aspect Ratio The aspect ratio of an image is the ratio of the width of the image to its height, expressed as two numbers separated by a colon. That is, for an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this same length unit, the height will be measured to be y units. The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1.[1] Two common videographic aspect ratios are 4:3 (1.33:1), universal for standard-definition video formats, and 16:9 (1.78:1), universal to high-definition television and European digital television. 15
Letterboxing Letterboxing is used as an alternative to a full-screen, pan-and-scan transfer of a widescreen film image to videotape or videodisc. In pan-and-scan transfers, the original image is cropped to the narrower aspect ratio of the destination format, usually the 1.33:1 (4:3) ratio of the standard television screen, whereas letterboxing preserves the film's original image composition as seen in the cinema. Letterboxing was developed for use in 4:3 television displays before widescreen television screens were available, but it is also necessary to represent on a 16:9 widescreen display the unaltered original composition of a film with a wider aspect ratio, such as Panavision's 2.35:1 ratio. Letterboxing 16
Progressive Vs. Interlaced Interlace is a technique of improving the picture quality of a video signal without consuming extra bandwidth. Interlaced video was designed for display on CRT televisions. Interlaced scan refers to one of two common methods for "painting" a video image on an electronic display screen (the other being progressive scan) by scanning or displaying each line or row of pixels. This technique uses two fields to create a frame. One field contains all the odd lines in the image, the other contains all the even lines of the image. A PAL based television display, for example, scans 50 fields every second (25 odd and 25 even). The two sets of 25 fields work together to create a full frame every 1/25th of a second, resulting in a display of 25 frames per second. Progressive or non-interlaced scanning is a method for displaying, storing or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to the interlacing used in traditional television systems where only the odd lines, then the even lines of each frame (each image now called a field) are drawn alternately. Progressive Vs. Interlaced 17
Progressive Vs. Interlaced Interlaced Progressive Vs. Interlaced Progressive 18
Progressive Vs. Interlaced De-interlaced World Wide Video System NTSC (480i) 720 x 486 29.97 frame per seconds (FPS) PAL (576i) 768 x 576 24.95 frame per seconds (FSP) 19