Codec Basics
Posted: Sun Jun 12, 2011 12:56 am
Hey-- since we're still in a wait/see on the Wiki for the new site; and, being this is the Codecs/Encoding subforum, can we get a sticky going on codec basics?
So, stuff like--
Codecs: A codec is a computer program capable of encoding and/or decoding a digital data stream or signal. (Wikipedia Definition)
Examples: DIVX, XVID, H264, VC1, MPEG2 are all Video Codecs. AC3, AAC, MP3, DTS are all Audio Codecs.
Containers: A file wrapper that "contains" various codec streams into a single file.
Examples: .WMV, .AVI, .MP4, .TS, .M2TS, .MKV, .WTV, .DVR-MS are all Video File containers that can contain certain combinations of Video AND Audio streams within a single file.
Transcoding: The process of taking a media file and converting it from one set of container/codecs to another.
Example: Taking a .VOB file that has MPEG2 audio & video and converting it into a .AVI file that use h264 video & AC3 audio.
Muxing: The process of taking individual audio and video stream files and putting them succinctly into a single container file.
DeMuxing: The Reverse. Taking a single media file and pulling the individual streams out into their own separate raw stream files.
Example: Movie.AVI made up of h264/ac3 will be demuxed into two files-- a Movie.h264 video-only file, and a Move.ac3 audio-only file.
So, stuff like--
Codecs: A codec is a computer program capable of encoding and/or decoding a digital data stream or signal. (Wikipedia Definition)
Examples: DIVX, XVID, H264, VC1, MPEG2 are all Video Codecs. AC3, AAC, MP3, DTS are all Audio Codecs.
Containers: A file wrapper that "contains" various codec streams into a single file.
Examples: .WMV, .AVI, .MP4, .TS, .M2TS, .MKV, .WTV, .DVR-MS are all Video File containers that can contain certain combinations of Video AND Audio streams within a single file.
Transcoding: The process of taking a media file and converting it from one set of container/codecs to another.
Example: Taking a .VOB file that has MPEG2 audio & video and converting it into a .AVI file that use h264 video & AC3 audio.
Muxing: The process of taking individual audio and video stream files and putting them succinctly into a single container file.
DeMuxing: The Reverse. Taking a single media file and pulling the individual streams out into their own separate raw stream files.
Example: Movie.AVI made up of h264/ac3 will be demuxed into two files-- a Movie.h264 video-only file, and a Move.ac3 audio-only file.