Talk:Codec

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[edit] Apple Lossless Encoding

Shouldn't [Apple Lossless Encoding] be under lossless, or am I missing something? 1189 13:56, Jun 24, 2004 (UTC)

[edit] Coder/Decoder

I added this wording, since it's also commonly used. It came back with 44,000 Google hits [1], one of which was a definition in the CNET glossary [2]. --Blackcats 15:59, 20 May 2005 (UTC)

I just looked through the article history and found out that a few months ago it used the coder meaning and then it was replaced with compressor. If anything, I think the coder meaning should actually come first, as it has more than twice as many Google hits [3]. It would be nice to find a source for the origin of the term, but just going by the sound of it, "codec" sounds a lot more like "coding" than "compressing." I would think that if the original meaning was compressor/decompressor, then it would be called "comdec" or something like that. --Blackcats 16:20, 20 May 2005 (UTC)
(en)coder/decoder is simply a more general concept. A codec doesn't necessarily compress data, it just converts data from one representation to another. For example, a YUV codec would convert data from RGB to YUV and/or vice-versa. That has nothing to with compression, it might just be a more appropriate representation respectively one that a software or hardware can handle. --82.141.48.65 02:44, 7 Jun 2005 (UTC)
Codec is an acronym for compressor/decompressor, *not* coder/decoder. The YUV "codec" is not a real codec, i.e. it should be named a "filter", because that's what it is. Unfortunately the wrong "coder/decoder" interpretation can be found on many web sites, which doesn't make it more correct, though. The copy-paste mentality makes errors spread world wide nowadays...

[edit] Misleading Information

On the first Paragraph, "Compressor-Decompressor" or "Coder-Decoder" is basically not really the same thing, which need to be explained separately.yaaaaaaaa

On second paragraph, It tells about Video/Audio Codec, which will be more appropiate to be on "Video Codec" or "Audio Codec" Article

The Third paragraph, I believe CoDec is not only about Encoding or Decoding.

The 4th is similar as the second.


^^ agreed --Elin

[edit] Question

How do you get the audio to work?... for the videos at http://www.visual-voice.com/BNN/serieslist.asp

An error pop up reads... This file may not play correctly because it was compressed by using a codec that is not supported.

There's no audio for the videos when trying to view them on this iMac flat panel silvery gooseneck white desklamp shape apple G4 computer with OS X 10.3.9


[edit] Conciseness at the cost of clarity

The explanation "This function is carried out by a video file format (or container), such as *.mpg, *.avi, *.mov, *.mp4, *.rm, *.ogg or *.tta. Some of these formats are limited to containing streams conforming to a small fixed set of codecs, while others are intended to be more general purpose." has just been replaced by a simple link to container formats. I don't think that was a good idea.

I don't really understand all this but reducing everything down to the bare minimum makes it far harder for people like me to understand. To understand what a codec is you need to know what a container format is and to understand what a container format is you need to know what a codec is. Trying to use wiki to get my head round this is a bit like reading an account of the battle of Gettysburg which has been split into Confederate actions at the Battle of Gettysburg and Union actions at the Battle of Gettysburg. Repeating stuff that appears on another page is not the worst thing in the world.Dejvid 19:46, 28 September 2005 (UTC)

IMHO this kind of information should go into Audio file format. --Hhielscher 20:15, 28 September 2005 (UTC)

[edit] bulleted comparisons

wondering why Comparisons is double-bulleted. plz post to my talk page or email me Epl18

[edit] Needlessly complicated?

Is it just me or does this article seem needlessly complex?

I don't think the first paragraph very clearly explains what a codec is. It should separate the two and aim to explain the basic function of a codec, maybe something along these lines:

In Telecommunications, a codec is a portmanteau of COder-DECoder, and is a device or program which deals with the transformation of data signals from analogue to digital, and from digital to analogue.

It also stands for COmpressor/DECompressor, and in this case it is a device or program which compresses data for storage. The same codec then takes data in a compressed state and decompresses it so that it can be run.

Or maybe a device or program which deals with the transformation of data files from a compressed to decompressed state and vice versa. I dunno.

At least that's how I understand it. The article does not make it clear that the two kinds of codec are used for different things, and this is perhaps one of the most complicated definitions of codec I've seen, and I'm not saying that I'm great at explaining things- but I'm sure someone could do this better.

--Elin

I always use codec to refer to something which compresses and decompresses digital data - for transmission or storage. Stephen B Streater 18:54, 29 June 2006 (UTC)

[edit] NPOV

See fourth paragraph. Someoneinmyheadbutit'snotme 02:49, 10 July 2006 (UTC)

I'm removing the POV tag, since there is no real controversy visible, either here on the talk page, or the article page. --Frescard 04:18, 29 August 2006 (UTC)

[edit] Non-sequitur

The Metal Gear Solid reference might belong on a disambiguation page, but not here.

[edit] Codec Hell

I think the article should mention the problem that many users face, of having to download hundreds of codecs to just try to watch a video.. And sometimes, if the codec is obscure or hard to get, it's not only impossible to watch the file, but you also end up with many installed codec packs that might conflict, sometimes messing up your whole setup so that even playback of previously known files is altered. (And the problem may be hard to track down.. Not all codecs or codec packs have a straightforward uninstall process) --164.77.84.202 16:20, 21 October 2006 (UTC)

There needs to be something about the existing tools for identifying what format a particular media file is in, (or rather what format its contained data is in), and therefore which codec or type of codec needed to decode it. --AC 05:57, 20 October 2007 (UTC)

[edit] Fake codecs

The article should also mention fake codecs, which are used to install spyware/adware.

[edit] Definions and consistency

The article today reads "A codec is a device or program capable of performing encoding and decoding on a digital data stream or signal."

Questions:

  1. This uses the word "and", implying a codec must do both. Yet surely most of the 'codecs' that one downloads, or finds in a device, will only decode, there being no need for encoding. Is the definition wrong, or is it incorrect to call these codecs?
  2. Having established that a codec is a device or software, it then says "There are lossless codecs". Surely, there are lossless encoding/decoding methods, but that is not a codec according to the definition in the article. There will also be lossless/lossy encoding implementations, potentially slightly different.
  3. Similarly, "While many people explain that AVI is a codec" (given that it says this is incorrect but not from a definition point of view) seems to imply that a codec can also be a file format rather than a piece of software.
  4. I observe the quick summary says "This article is on the compression/decompression algorithms...". Is it about algorithms, encoding specifications, file formats, or implementations? All of these are quite distinct it seems to me.

Can anyone clarify? Notinasnaid 09:14, 12 April 2007 (UTC)

1) I think you are taking the words on this article too literally. A codec you download may just be the decoder but mpeg4, divx, etc. are codecs. The both encode (compress) and decode (decompress) data. mplayer has all of these and can do both for, as far as I know, all of them (except maybe real). Cburnett 13:07, 12 April 2007 (UTC)
Well, yes, I am taking the words on the article literally. If they are not literally correct, what are they doing there? Maybe we can fix them if they are wrong, but they certainly shouldn't be left alone if they are wrong. It seems to me... (I should clarify: I am not asking these questions out of idle curiosity but because the article seems to contradict itself, something that I think needs fixing). Notinasnaid 13:17, 12 April 2007 (UTC)
I agree. How can you take the article "too-literally"? Either it is correct or it is incorrect. As it is now, a codec that only encodes isn't a codec, and this is incorrect- for one of many examples, check out the one offered here: http://mp3decoders.mp3-tech.org/decoders_acm.html As the articles definition is incorrect, and inconsistant with the usage of the word, it should be changed. That the article encompases most codecs isn't relevant. If the defintion of a shirt claimed it must have a collar and sleeves, would we leave it despite the existance of sleeveless-shirts? When Cburnett cites the overwhelming majority of shirt have sleeves would we be convinced? No, cuz a shirt doesn't need sleeves to be a shirt, and a codec doesn't need to be able to encode to be a codec.65.185.93.86 (talk) 12:41, 19 March 2008 (UTC)


2) Why does the lossless attribute of a codec make it not a codec? I don't think you understand either lossless or codec very well (no offense intended yet you seem to insist you do know what it means). Lossless means that there is no information lost during the encoding. FLAC is lossless. JPEG can be lossless with a particular quantization matrix. Both FLAC and JPEG are definitely codecs. Cburnett 13:07, 12 April 2007 (UTC)
I may have phrased my question badly. I am quite happy that there are lossless and lossy methods and software. If JPEG is a codec, then presumably the definition in the article is wrong, since JPEG is an encoding technique, not a piece of software or device. Notinasnaid 13:17, 12 April 2007 (UTC)
If JPEG is an encoding technique only then how do you expect to view the JPEG? That's write: you decode it. You decode it by doing things in the opposite order of encoding yielding an image approximately/exactly the same as the original depending on if you use a lossy/lossless quantization matrix. Cburnett 13:40, 12 April 2007 (UTC)
Sorry, I'm still not explaining myself. Yes, JPEG has a specification which defines or implies encoding and decoding methods. But clearly JPEG does not fit the definition "A codec is a device or program capable of performing encoding and decoding on a digital data stream or signal." How about if the sentence was A codec is a device or program capable of performing encoding and/or decoding on a digital data stream or signal, or the specification or algorithm that describes how that that encoding or decoding is to be done? Notinasnaid 13:48, 12 April 2007 (UTC)
3) A file format is not a codec. Cburnett 13:07, 12 April 2007 (UTC)
Good. So should the paragraph starting "While many people explain that AVI is a codec, they are incorrect" be removed, since it does seem to suggest that some file formats (which are not containers) - yes? Notinasnaid 13:17, 12 April 2007 (UTC)
Not removed, changed. Many people assume that AVI is a codec (I can hear it now: "it's a file suffix like .jpg so isn't a codec?") and there's nothing wrong with exaplining that AVI, RIFF, ogg, etc. are containers not codecs. Though, if you really really wanted to, you can argue that a container format is a codec because it does encode data into a specific form an decode it back into its original form. More of a trivial codec in comparison with "real" codecs. This is more of an academic argument though. Cburnett 13:40, 12 April 2007 (UTC)
4) They are all different perspectives on the same thing. A specification outlines how a codec should perform. An algorithm is a specific way to perform a codec. An implementation is a specific written way of doing an algorithm. You have to store the encoded data somehow and thus a file format is needed. Cburnett 13:07, 12 April 2007 (UTC)
So, how should the definition be rewritten so that it is correct, since it suggests it only applies to implementations? Notinasnaid 13:17, 12 April 2007 (UTC)
Personally, I'm fine with it. However, I think it could be partially rewritten and broken up into sections. (Most articles could use this anyway.) Cburnett 13:40, 12 April 2007 (UTC)
Sorry, I think pedantry has its place and an encylopedia is one of those places. The definition should be accurate, so I can indeed take the words in the article literally. I don't think we should aim any lower than that. I have no view (yet) on whether the article should be broken up, though a proper lead section which summarised/repeated what followed would be good. Notinasnaid 13:48, 12 April 2007 (UTC)
At the end of the day, JPEG is a codec and JFIF is a file format commonly used to contain JPEG encoded data. Cburnett 13:07, 12 April 2007 (UTC)

[edit] Lower bit rate codecs

I agree that Lower bit rate codecs should be merged with Codec. Biscuittin 17:15, 13 October 2007 (UTC)


[edit] External Links

I've removed the spammy external links section. --Mdwyer (talk) 18:03, 23 November 2007 (UTC)

[edit] Capitalization

Since when did the the abbreviation CODEC become an all lowercase word? —Preceding unsigned comment added by Andreas Toth (talk • contribs) 02:04, 22 February 2008 (UTC)

[edit] How is a Codec chosen?

In Windows Media Player, how is a codec chosen for playing a selected video file? David (talk) 16:27, 16 March 2008 (UTC)

[edit] merge endec into codec

I suggest that the "endec" article should be merged with the "codec" article, since the current version of the endec leaves me confused about the distinction (if any) between an "endec" and a "codec". Even if there is some subtle distinction, perhaps they are similar enough that a single article describing both of them (and also the subtle distinction between them) would be better than 2 separate articles -- similar to the way one article covers both Myanmar and Burma. --68.0.124.33 (talk) 14:50, 29 May 2008 (UTC)