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 Video

Transcoding means converting one video format into another. For instance, you may want to transcode a full HD video from your camcorder to play on your mobile device. You can also transcode a DVD that you ripped onto your computer and 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 you can play your videos on virtually any device.

Resolution

Resolution describes the amount of detail in an image. Calculate it by multiplying the number of horizontal and vertical pixels (picture cells) in the image. The higher the resolution the more pixels you will find in the image.

High Resolution

Low Resolution

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.

Resolution Aspect Ratio Use case

320x240 4:3 Multimedia MP3 players

480x320 4:3 iPhone 3

720x576 4:3/16:9 PAL TV, DVD

720x476 4:3/16:9 NTSC TV, DVD

1024x768 4:3 iPad

1280x720 16:9 AVC DSCs (AVCHD Lite), iPhone 4, smart phones

1920x1080 16:9 AVC DSCs, AVCHD camcorders, Blu-ray disc, state-of-the-art smart phones

Typical resolutions, aspect ratios and use cases

Frame Rate

Frame rate is the frequency at which an imaging device produces frames, or unique consecutive images. The minimum interval at which the human eye perceives individual images (frames) as consecutive motion is 18 frames per second. Frame rates can vary, depending on the system and codec. For example, 25 full frames per second (50i = interlaced) are used in PAL TV and 30 full frames (60i = interlaced) in NTSC TV. Computer devices and modern home cinema or mobile devices produce video streams in progressive (p) or interlaced (i) frames with typical frame rates at 50i, 60i, 24p, and 25p.

Bit Rate

Bit rate is the number of "bits per second" (bps) at which the data in a video is delivered. The higher the bit rate, 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.

Compression/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.

CODEC

Encoder SettingsEncoder settings specify the type and quality of encoding that are applied during the encoding process - for example when you convert a full HD video you shot with your camcorder so that you can play it back on your mobile device.

Format Use Case Codec Bit rate Compression

DVD Camcorder, PC & external Player MPEG 2 interframe I-B-P Up to 9 MBit/s medium

AVCHD Camcorder, PC Players, BD-Players, AVCHD Lite in DSCs

H.264/MPEG-4 AVC 4 to 24 Mbit/s high

AVC External Players, iPhone, Android phones, Playstation Portable, etc.

MP4 container: H.264/AVC, MPEG-4 ASP

variable high

MKV Internet video streams, storing movies to file Open source container format not limited to any codec or system. Mainly used : H.264/AVC

variable high

WMV Portable Media Players, PC and External Players, Web

Windows Media Video 9 Variable Up to 5 Mbit/s

Medium to high

WMV HD PC Players, BD-Players Windows Media 9 Advanced Profile (VC-1)

Up to 9 Mbit/s high

3GPP Mobile Phones MPEG-4, H.263 or H.264 variable high

Ripping DVD Video

Ripping refers to transferring a DVD Video to a file or folder on a hard drive.

Nero Recode has a number of options for ripping, including rip to video file, rip to folder (which transfers the original DVD structure), rip and shrink, 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 Factors

Aside from the actual shooting conditions, video image quality depends on a number of factors. The most important factors are resolution (the higher, the better), bit rate (the higher, the better) and codec (the right codec means great results).Of course, the higher the resolution and bit rate, the larger the file size, so it’s important to choose the right profiles for the device used. Nero Recode provides a large selection of profiles, as well as easy ways to adjust video settings for the best quality.

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.

Streaming

Streaming refers to the continuous transmission of data that can already be played during the transmission procedure. This means that it is not necessary to wait until a media file has been transmitted completely before it can be played back.

A TV channel can be received and displayed at the same time without it first 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.

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