Saturday 26 November 2016

CODECs for videos

  • A codec is a device or software that is used to compress or decompress a digital media file, such as a video.
  • The “codec” can be dividing into two parts: encode and decode.
  • The encoder performs the compression (encoding) function and the decoder performs the decompression (decoding) function.
  • Some codecs include both of these components and some codecs only include one of them.
  • Some of the more important ones are H.264, DivX, WMV, Theora, and the VP9.

1. H.264

  • H.264 is also known as MEPG-4 AVC. H.264 uses the latest innovations in video compression technology to provide consistently crisp and clear video for the best possible viewing.
Advantages
  • H.264 delivers incredible video quality at data rates one-fourth to one-half the size of previous video formats.
  • H.264 offers dramatically lower bit rates and better picture quality.
  • It is 2X times more efficient than MPEG-4. and file size is 3X times smaller than comparable MPEG-2 Codecs.
Disadvantages
  • H.264 requires longer encoding time.
  • It is certainly not constricted and low-bandwidth friendly.
  • Licensing agreements are complicated.

2. DivX

  • DivX is a brand name of products created by DivX, Inc. The DivX codec uses lossy MPEG-4 Part 2 compression and it isfully MPEG-4-Advanced Simple Profile compliant; MPEG-4 ASP.
Advantages
  • The Divx codec is quite simple to set up and use.
  • It is popular due to its ability to compress lengthy video segments into small sizes while maintaining relatively high visual quality.
Disadvantages
  • It’s a commercial codec, so in order to get all the options you have to pay money for it.

3. WMV

  • WMV is a Windows codec. We specifically support WMV 8, which is confusingly the same as WMV2.
Advantages
  • Smaller in file size. Compatible well with any Windows PC.
Disadvantages
  • compatable issues other os.
  • Needs plug-ins like Flip4Mac when playing WMV files on Mac; Video transmission has a delay.

4. Theora

  • Theora is a free lossy video compression format. It is developed by the Xiph.Org Foundation and distributed without licensing fees alongside their other free and open media projects, including the Vorbis audio format and the Ogg container.
Advantages
  • The video codec is fix in WME, you don't need to install any external codecs with your game.
  • Theora codec is license free.
  • Unlike AVI files, Theora videos can be stored inside WME packages. No need to store the video files separately.
Disadvantages
  • The Theora codec is is not yet fully finished and optimized.
  • Being still in development means it's not yet widely supported by many video editing programs. This is likely to change in the future, though, as it did with the Vorbis audio format.

5. VP9

  • VP9 is an open and royalty free video coding format developed by Google.
  • VP9 is a successor to VP8 and competes with MPEGs High Efficiency Video Coding (HEVC/H.265). At first, VP9 was mainly used on Google's popular video platform YouTube.
Advantages
  • It is open source.
  • Faster loading videos and cheaper internet bills.
Disadvantages
  • Mobile phone support for recording VP9 is a tougher sell because the codec must work harder to encode the video than to decode it.

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