Video Transcoding Terms Explained Not sure what the aspect ratio is for your iPhone? Can’t tell a bit rate from a frame rate? At a loss when it comes to lossy and lossless codecs? With this helpful reference guide to the most common video terms, you’ll have everything you need to know to start transcoding videos like a pro.
Transcoding VideoTranscoding means converting one video format into another. For instance, youmay want to transcode a full HD video from your camcorder to play on yourmobile device. You can also transcode a DVD that you ripped onto your computerand then encode it into a format that can play on your Smart TV.Nero Recode offers many options for high quality ripping and transcoding, so youcan play your videos on virtually any device.
ResolutionHigh Resolution Resolution describes the amount of detail in an image. Calculate it by multiplying the number of horizontal and vertical pixels (picture cells) inLow Resolution the image. The higher the resolution the more pixels you will find in the image.
Aspect RatioA number that shows the width of an image compared to its height(width:height). The most typical aspect ratios for video formats are 4:3 and 16:9.Typical resolutions, aspect ratios and use casesResolution Aspect Ratio Use case320x240 4:3 Multimedia MP3 players480x320 4:3 iPhone 3720x576 4:3/16:9 PAL TV, DVD720x476 4:3/16:9 NTSC TV, DVD1024x768 4:3 iPad1280x720 16:9 AVC DSCs (AVCHD Lite), iPhone 4, smart phones1920x1080 16:9 AVC DSCs, AVCHD camcorders, Blu-ray disc, state-of-the-art smart phones
Frame RateFrame rate is the frequency at which animaging device produces frames, orunique consecutive images.The minimum interval at which thehuman eye perceives individual images(frames) as consecutive motion is 18frames per second.Frame rates can vary, depending on thesystem and codec. For example, 25 fullframes per second (50i = interlaced) areused in PAL TV and 30 full frames (60i =interlaced) in NTSC TV.Computer devices and modern homecinema or mobile devices produce videostreams in progressive (p) or interlaced (i)frames with typical frame rates at 50i, 60i,24p, and 25p.
Bit RateBit rate is the number of "bits persecond" (bps) at which the data in avideo is delivered. The higher the bitrate, the higher video image quality.
Container A container is a meta- file format whose specification describes how different data elements and metadata coexist in a computer file.
CODECCompression/Decompression (Encoding/Decoding) A codec (or "coder-decoder") is a component within Nero Recode capable of encoding or decoding a digital data stream or signal. Using the right video, image, and audio codecs is critical to converting data with the best possible quality, while maintaining a reasonable file size. Codecs can be lossy and lossless. A lossy codec loses quality with every copy generation while a lossless codec maintains quality from copy to copy.
Encoder SettingsEncoder settings specify the type and quality of encoding that are applied during theencoding process - for example when you convert a full HD video you shot with yourcamcorder so that you can play it back on your mobile device.Format Use Case Codec Bit rate CompressionDVD Camcorder, PC & external Player MPEG 2 interframe I-B-P Up to 9 MBit/s mediumAVCHD Camcorder, PC Players, BD-Players, AVCHD H.264/MPEG-4 AVC 4 to 24 Mbit/s high Lite in DSCsAVC External Players, iPhone, Android phones, MP4 container: variable high Playstation Portable, etc. H.264/AVC, MPEG-4 ASPMKV Internet video streams, storing movies to file Open source container variable high format not limited to any codec or system. Mainly used : H.264/AVCWMV Portable Media Players, PC and External Windows Media Video 9 Variable Up to Medium to high Players, Web 5 Mbit/sWMV HD PC Players, BD-Players Windows Media 9 Up to 9 Mbit/s high Advanced Profile (VC-1)3GPP Mobile Phones MPEG-4, H.263 or H.264 variable high
Ripping DVD VideoRipping refers to transferringa DVD Video to a file orfolder on a hard drive.Nero Recode has a numberof options forripping, including rip tovideo file, rip to folder(which transfers the originalDVD structure), rip andshrink, and only rip audio.
Video Profile A video profile is the key digital information needed to create a video file, such as the video codec, container, audio codec, resolution, and frame rate. Nero Recode provides standard video profile settings, depending on the device on which the video will be played. Each profile can be fine-tuned or completely customized and even saved as new custom profile. Custom profiles can be shared with friends and re-imported into Nero Recode.
Video Image Quality FactorsAside from the actual shooting conditions, video image quality depends on anumber of factors. The most important factors are resolution (the higher, thebetter), bit rate (the higher, the better) and codec (the right codec means greatresults).Of course, the higher the resolution and bit rate, the larger the file size, so it’simportant to choose the right profiles for the device used. Nero Recode provides alarge selection of profiles, as well as easy ways to adjust video settings for the bestquality.
Quality Factor The quality factor defines whether a video’s bit rate is low, good, or too high. The quality factor is defined by the number of bits per pixel per frame to be encoded (Bits/(Pixel*Frame)). The quality factor is an indicative value and may differ depending on the source.
StreamingStreaming refers to the continuous transmission of data that can alreadybe played during the transmission procedure. This means that it is notnecessary to wait until a media file has been transmitted completelybefore it can be played back.A TV channel can be received and displayed at the same time without itfirst having to be saved to the hard drive.
Hardware accelerated AVC transcoding (GPGPU) GPGPU stands for ‘general-purpose computing on graphics processing units’. Modern GPUs can perform computation in applications traditionally handled by the CPU. All major vendors have GPGPU based models on the market. Nero Recode supports any graphics card that supports hardware accelerated AVC encoding (Nvidia CUDATM, AMD App Acceleration, Intel® Quick Sync Video) and helps video get transcoded up to 4 times faster.