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Audio- Video- Image File Formats.Pdf Audio File formats: Most common formats are- 1. PCM: stands for Pulse-Code Modulation, a digital representation of raw analog audio signals. Analog sounds exist as waveforms, and in order to convert a waveform into digital bits, the sound must be sampled and recorded at certain intervals (or pulses). 2. WAV: stands for Waveform Audio File Format. It’s a standard that was developed by Microsoft and IBM back in 1991. 3. AIFF: stands for Audio Interchange File Format. Similar to how Microsoft and IBM developed WAV for Windows, AIFF is a format that was developed by Apple for Mac systems back in 1988. 4. MP3: stands for MPEG-1 Audio Layer 3. It was released back in 1993 and quickly exploded in popularity, eventually becoming the most popular audio format in the world for music files. 5. AAC: stands for Advanced Audio Coding. It was developed in 1997 as the successor to MP3, and while it did catch on as a popular format to use, it never really overtook MP3 as the most popular for everyday music and recording. 6. WMA: stands for Windows Media Audio. It was first released in 1999 and has gone through several evolutions since then, all while keeping the same WMA name and extension. As you might expect, it’s a proprietary format created by Microsoft. 7. FLAC: stands for Free Lossless Audio Codec. A bit on the nose maybe, but it has quickly become one of the most popular lossless formats available since its introduction in 2001. 8. ALAC: stands for Apple Lossless Audio Codec. It was developed and launched in 2004 as a proprietary format but eventually became open source and royalty-free in 2011. ALAC is sometimes referred to as Apple Lossless. Video File formats: Most common formats are- 1. AVI – Audio Video Interleave: AVI files are the long running digital video workhorse from the Microsoft stable. The format’s popularity has dipped in recent times but AVI still reigns supreme with the swarms of legacy videos propagating the internet. AVI was replaced by Microsoft’s Windows Media Video (WMV) format and usually offers less compression than comparable video file formats including MOV and MPEG. 2. MPG – MPEG Video File: This prevalent video file format integrates MPEG-1 and MPEG-2 video and audio compression. MPEG-1 is almost exclusively used for VCDs (Video Compact Disks ), which failed to catch on in the US but remain popular in other countries. MPEG-2 (also known as H.262) is used for DVDs and broadcast HDTV. 3. MP4 – MPEG-4 Video File: The MPEG-4 format is used to share files on the web. Video and audio tracks are compressed separately where the video file is compressed with MPEG-4 encoding and audio with AAC compression, which is the same audio compression type used in .AAC files. 4. WMV – Windows Media Video: The WMV codec is a popular choice for streaming video or audio – where a small portion of a video or audio file downloads and begins to play while the full download continues behind the scenes. WMV includes support for high definition 720 and 1080 resolutions. Based on the ASF container, files ending in the .wmv suffix are normally stored in the .asf container. 5. H.264: The H.264 codec is a popular standard for high definition digital video. It’s a versatile little codec and works with very high and very low bitrates. For example, it can send low resolution and highly compressed videos across the web and then can easily encode high definition movies at high bitrates to play on a HD television. The H.264 codec is often used with digital video cameras and camcorders and it uses the AVCHD container. 6. DivX – DivX-encoded Movie: The editable DivX video file format effectively compresses videos with minimal quality loss while supporting resolutions of up to 1080 HD. This high-quality and high-compress codec is recognised by a handful of DVD players but does not support VCD playback. A good option for making video CDs. 7. MOV or QT – QuickTime: The MOV and QT Apple QuickTime Movie file formats both support a wide range of codecs. The .mov format saves video files and the .qt suffix is cross-platform, meaning that it supports both Mac and Windows systems. The two file extensions are commonly saved together. 8. FLV or SWF – Flash Video: Flash Video has been around for some time and comes in numerous versions. Old Flash videos tend to use the Sorenson codec and new Flash uses H.264. It is a popular container format for streaming videos across the internet but a large drawback is that it is not supported on iOS devices such as iPhones and iPads. 9. ASF – Advanced Systems Format: Another offering from Microsoft, the ASF container normally houses files compressed with Microsoft’s WMA (Windows Media Audio) and WMV codec. Just to confuse the matter further, the files are usually given the .wmv or .wma suffix and not the expected .asf. A form of copy protection is offered with this container through Digital Rights Management (DRM). 10. MKV – Matroska Video: The Matroska Multimedia Container is an open standard, free container format, a file format that can hold an unlimited number of video, audio, picture, or subtitle tracks in one file. Image File formats: Most common formats are- 1. JPEG (.jpg, .jpeg): Stands for Joint Photographic Experts Groups is a “lossy” format meaning that the image is compressed to make a smaller file. The compression does create a loss in quality but this loss is generally not noticeable. JPEG files are very common on the Internet and JPEG is a popular format for digital cameras. 2. Bitmap (.bmp): BMP or Bitmap Image File is a format developed by Microsoft for Windows. There is no compression or information loss with BMP files which allow images to have very high quality, but also very large file sizes. Due to BMP being a proprietary format. 3. TIFF (.tif, .tiff): TIFF or Tagged Image File Format are lossless images files meaning that they do not need to compress or lose any image quality or information (although there are options for compression), allowing for very high- quality images but also larger file sizes. 4. GIF (.gif): GIF or Graphics Interchange Format files are widely used for web graphics, because they are limited to only 256 colors, can allow for transparency, and can be animated. GIF files are typically small is size and are very portable. 5. PNG (.png): PNG or Portable Network Graphics files are a lossless image format originally designed to improve upon and replace the gif format. PNG files are able to handle up to 16 million colors, unlike the 256 colors supported by GIF. 6. EPS (.eps): An EPS or Encapsulated PostScript file is a common vector file type. EPS files can be opened in many illustration applications such as Adobe Illustrator or CorelDRAW. 7. RAW Image Files (.raw, .cr2, .nef, .orf, .sr2, and more): RAW images are images that are unprocessed that have been created by a camera or scanner. Many digital SLR cameras can shoot in RAW, whether it be a .raw, .cr2, or .nef. These RAW images are the equivalent of a digital negative, meaning that they hold a lot of image information, but still need to be processed in an editor such as Adobe Photoshop or Lightroom. .
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