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AMV Video Format
AMV (Actions Media Video) is a proprietary video file format, produced for MP4 players, as well as S1 MP3 players with video playback. There are two different versions of this format: an older one for Actions chips, and a newer one for ALi’s M5661 chip, sometimes called ALIAVI. Format The container is a modified version of AVI. The video format is a variant of Motion JPEG, with fixed rather than variable quantisation tables. The audio format is a variant of IMA ADPCM, where the first 8 bytes of each frame are origin (16 bits), index (16 bits) and number of encoded 16-bit samples (32 bits); all known AMV files run sound at 22050 samples/second. Low decoder overhead is paramount as the S1 MP3 players have very low-end processors (a Z80 variant). Video compression ratio is low – around 4 pixels/byte, compared with over 10 pixels/byte for MPEG-2 – though as the files are of low resolution (96×96 up to 208×176) and frame rate (10, 12, or 16 frame/s), file sizes ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Video Interleave
Audio Video Interleave (also Audio Video Interleaved and known by its initials and filename extension AVI, usually pronounced ), is a proprietary multimedia container format and Windows standard introduced by Microsoft in November 1992 as part of its Video for Windows software. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback. Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used. Many AVI files use the file format extensions developed by the Matrox OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called "AVI 2.0". In 2010 the US government's National Archives and Records Administration defined AVI as the official wrapper for preserving digital video. History Publishers faced a predicament regarding how they should distribute videos on CD-ROMs. Thirty seconds of video displayed in 24-bit color an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interactive Multimedia Association
The Interactive Multimedia Association (IMA) was an industry association which developed a set of audio algorithms. The most important is the ADPCM algorithm which is in use by Apple and Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing .... The Interactive Multimedia Association ceased operations around 1998. An archived copy of the document IMA Recommended Practices for Enhancing Digital Audio Compatibility in Multimedia Systems (version 3.0), which describes the IMA ADPCM algorithm, is available. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FFmpeg
FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing of video and audio files. It is widely used for format transcoding, basic editing (trimming and concatenation), video scaling, video post-production effects and standards compliance (SMPTE, ITU). FFmpeg also includes other tools: ffplay, a simple media player and ffprobe, a command-line tool to display media information. Among included libraries are libavcodec, an audio/video codec library used by many commercial and free software products, libavformat (Lavf), an audio/video container mux and demux library, and libavfilter, a library for enhancing and editing filters through a Gstreamer-like filtergraph. FFmpeg is part of the workflow of many other software projects, and its libraries are a core part of software media players such as VLC, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverse Engineering
Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accomplishes a task with very little (if any) insight into exactly how it does so. It is essentially the process of opening up or dissecting a system to see how it works, in order to duplicate or enhance it. Depending on the system under consideration and the technologies employed, the knowledge gained during reverse engineering can help with repurposing obsolete objects, doing security analysis, or learning how something works. Although the process is specific to the object on which it is being performed, all reverse engineering processes consist of three basic steps: Information extraction, Modeling, and Review. Information extraction refers to the practice of gathering all relevant information for performing the operation. Modeling refers to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frame Rate
Frame rate (expressed in or FPS) is the frequency (rate) at which consecutive images (frames) are captured or displayed. The term applies equally to film and video cameras, computer graphics, and motion capture systems. Frame rate may also be called the , and be expressed in hertz. Frame rate in electronic camera specifications may refer to the maximal possible rate, where, in practice, other settings (such as exposure time) may reduce the frequency to a lower number. Human vision The temporal sensitivity and resolution of human vision varies depending on the type and characteristics of visual stimulus, and it differs between individuals. The human visual system can process 10 to 12 images per second and perceive them individually, while higher rates are perceived as motion. Modulated light (such as a computer display) is perceived as stable by the majority of participants in studies when the rate is higher than 50 Hz. This perception of modulated light as steady is known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-2
MPEG-2 (a.k.a. H.222/H.262 as was defined by the ITU) is a standard for "the generic video coding format, coding of moving pictures and associated audio information". It describes a combination of Lossy compression, lossy video compression and Lossy compression, lossy audio data compression methods, which permit storage and transmission of movies using currently available storage media and transmission bandwidth. While MPEG-2 is not as efficient as newer standards such as H.264/AVC and HEVC, H.265/HEVC, backwards compatibility with existing hardware and software means it is still widely used, for example in over-the-air digital television broadcasting and in the DVD-Video standard. Main characteristics MPEG-2 is widely used as the format of digital television signals that are broadcast by terrestrial television, terrestrial (over-the-air), Cable television, cable, and direct broadcast satellite Television, TV systems. It also specifies the format of movies and other programs th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zilog Z80
The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples were delivered in March 1976, and it was officially introduced on the market in July 1976. With the revenue from the Z80, the company built its own chip factories and grew to over a thousand employees over the following two years. The Zilog Z80 is a software-compatible extension and enhancement of the Intel 8080 and, like it, was mainly aimed at embedded systems. Although used in that role, the Z80 also became one of the most widely used CPUs in desktop computers and home computers from the 1970s to the mid-1980s. It was also common in military applications, musical equipment such as synthesizers (like the Roland Jupiter-8), and coin-operated arcade games of the late 1970s and early 1980s, including '' Pac-Man''. Zilog licensed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADPCM
Adaptive differential pulse-code modulation (ADPCM) is a variant of differential pulse-code modulation (DPCM) that varies the size of the quantization step, to allow further reduction of the required data bandwidth for a given signal-to-noise ratio. Typically, the adaptation to signal statistics in ADPCM consists simply of an adaptive scale factor before quantizing the difference in the DPCM encoder. ADPCM was developed for speech coding by P. Cummiskey, Nikil S. Jayant and James L. Flanagan at Bell Labs in 1973. In telephony In telephony, a standard audio signal for a single phone call is encoded as 8000 analog samples per second, of 8 bits each, giving a 64 kbit/s digital signal known as DS0. The default signal compression encoding on a DS0 is either μ-law (mu-law) PCM (North America and Japan) or A-law PCM (Europe and most of the rest of the world). These are logarithmic compression systems where a 13- or 14-bit linear PCM sample number is mapped into an 8-bit value. This sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantization (image Processing)
Quantization, involved in image processing, is a lossy compression technique achieved by compressing a range of values to a single quantum (discrete) value. When the number of discrete symbols in a given stream is reduced, the stream becomes more compressible. For example, reducing the number of colors required to represent a digital image makes it possible to reduce its file size. Specific applications include DCT data quantization in JPEG and DWT data quantization in JPEG 2000. Color quantization Color quantization reduces the number of colors used in an image; this is important for displaying images on devices that support a limited number of colors and for efficiently compressing certain kinds of images. Most bitmap editors and many operating systems have built-in support for color quantization. Popular modern color quantization algorithms include the nearest color algorithm (for fixed palettes), the median cut algorithm, and an algorithm based on octrees. It is common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion JPEG
Motion JPEG (M-JPEG or MJPEG) is a video compression format in which each video frame or interlaced field of a digital video sequence is compressed separately as a JPEG image. Originally developed for multimedia PC applications, Motion JPEG enjoys broad client support: most major web browsers and players provide native support, and plug-ins are available for the rest. Software and devices using the M-JPEG standard include web browsers, media players, game consoles, digital cameras, IP cameras, webcams, streaming servers, video cameras, and non-linear video editors. History Motion JPEG was originally developed for multimedia PC applications. Early implementations of MJPEG were generally implemented in Hardware. C-Cube was an early proponent with their CL550 JPEG codec been used in several hardware implementations. It was announced that the NeXTdimension from NeXT would ship with an onboard CL550 to implement MJPEG. This was however later shelved and wasn't included in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acer Laboratories Incorporated
ALi Corporation (also known as Acer Laboratories Incorporated or Acer Labs Inc., and commonly known as ALi) is a major designer and manufacturer of embedded systems integrated circuits, and a former manufacturer of personal computer integrated circuits. It is based in Taiwan, and is a subsidiary of the Acer group. The company was founded in 1987, its president is Teddy Lu. Part of ALi including the personal computer integrated circuits business was spun off as ULi Electronics Inc. in June 2003. ULi was acquired by Nvidia in 2006 for $52 million. Products Chipsets 80X86 Chipsets Pentium and Socket 7 Chipsets Slot 1 and Socket 370 Chipsets Slot A and Socket A Chipsets Socket 478 Chipsets Socket 754/ 939/940 Chipsets Southbridge Chips Image:Gigabyte GA-5AX rev. 3.0 20081118.jpg, ALi M1541-based motherboard with AMD K6-2 300MHz processor. Image:Ali M1535.jpg, ALi M1535 southbridge chip from a Fujitsu Lifebook P series laptop VGA * M3141 * M3143 * M3145A A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actions Semiconductor
Actions Semiconductor Co. Ltd. () is a Chinese fabless semiconductor company founded in 2000 and headquartered in Zhuhai, Guangdong province. The company has about 600 employees and designs SoCs for tablets, digital audio players, photo viewers and related products. Products The following is a list of system-on-chips developed and marketed by Actions Semiconductor, mainly targeting tablets. Adoption S1 MP3 players use chipsets designed by Actions. In 2012, Actions Semiconductor produced the ATM7029 which is a quad-core ARM Cortex-A5-based SoC using Vivante Corporations GC1000 GPU. This SoC has been used in the Ainol NOVO10 Hero II tablet and other low end tablets. For Q2 2014, Actions was reported to be fourth largest supplier of tablet processors to the Chinese market. Legal cases At one point, Actions was sued by SigmaTel with SigmaTel prevailing. The findings were that Actions infringed upon SigmaTel by directly copying the ASICs designed by SigmaTel, once a wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
