Talk:Comparison of video codecs

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[edit] Reliable sources

I have some information on Forbidden Technologies Blackbird video codec, which I helped develop. I am working on this article which mentions it. What level of reliable source do people on this comparison expect for codec information? And what do people here count as reliable sources?

The FORscene article is now live. Stephen B Streater 17:44, 11 June 2006 (UTC)

[edit] More codecs to compare.

Since codecs are COmpression/DECompression libraries, here are a bunch of well-known ones:

  • DivX4/5/6
  • XviD
  • FFmpeg (libavcodec)
  • 3ivx
  • MPEG-1
  • MPEG-2
  • RealVideo
  • Sorenson (used in QuickTime video encoding typically)
  • x264
  • MPEG-4 Part 10 (H.264, MPEG-4 AVC)
  • MPEG-4 ASP
  • Theora
  • WMV1/2/3

—The preceding unsigned comment was added by JVz (talk • contribs) 00:15, 5 July 2006 (UTC).

Given the ambitious title, the tables should at least make an effort to include more than a handful of entires right from the start, even if the fields are left blank for now. AndreasWittenstein 02:01, 29 March 2007 (UTC)
I think the standards should be included in the article as opposed to actual codecs. E.g. H.264 (the standard) instead of x264, MPEG-4 ASP instead of DivX/XviD/3ivx. The differences between the actual codecs are so small that it wouldn't be very useful to include them all separately.
FFmpeg doesn't qualify for inclusion, it's an encoder for all kinds of codecs rather than a codec. MrTroy 06:36, 5 July 2006 (UTC)
I think this whole article is flawed and confused. It suggests it compares codecs, that is software. The table includes details such as price, license etc., which is related to the particular software implementation, not the specifications (for example, Theora licensed under BSD, that is, it's a piece of software). Yet, these things are mixed with specifications (compression standards such as H.264). So I think this article should either be completely reworked from the ground up or simply deleted. — J. M. 02:22, 14 December 2006 (UTC)
In ordinary usage, 'video codec' refers to a product, not a coding specification, so this article should only compare actual codecs. A comparison of Image compression coding specfications should entitled as such, though I personally can't imagine much use for such an article. AndreasWittenstein 02:01, 29 March 2007 (UTC)
Yes, like I said earlier, the whole article doesn't make sense. It says it compares codecs, but then it includes the H.264 compression standard with all those nonsensical details such as "Latest stable version" and "Cost (USD)". So I removed H.264, but now the article seems even more useless than before, comparing only 5 video codecs, missing many other popular ones. —J. M. 04:43, 29 March 2007 (UTC)

[edit] More features in comparison

A lot of codecs are very similar. The article would benefit from new columns to show the differences. I suggest

  • The problem the codec is designed to solve
  • How the codec degrades when datarate is reduced
  • How the codec degrades when available CPU for playback is reduced
It's impossible to include that kind of information in a table-based page like this. You would need to include graphs, screenshots, etc. That's not encyclopedic (or Wikipedic), that's something for a website about digital video. MrTroy 12:27, 5 July 2006 (UTC)
I agree that a detailed analysis of whether one version was better than another in different circumstances should be in your website review. The idea here would be to say whether frame rate or image quality are reduced, for example. This wouldn't need a graph. See MPEG/Blackbird example below. Stephen B Streater 14:12, 5 July 2006 (UTC)
  • Whether the codec can handle varying bandwidth and CPU as often happens with streaming
  • Is a live version available
  • Implementation details
  • Dynamism

To illustrate how this might work, consider the FORscene video codec, Blackbird, and how it differs from MPEG:

  • MPEG is designed for video streaming, Blackbird is designed for Web-based video editing
  • MPEG goes blocky when datarate is reduced, Blackbird gives lower frame rate
  • MPEG can't play back on slower systems, Blackbird gives lower frame rate
  • MPEG datarate is decided at compression time, so can't handle streaming over a connection with an unpredictably varying datarate very well. Blackbird sets image size depending on sampled datarate, and adjusts frame rate to use available datarate during playback
  • MPEG has a few frames latency for live video. Blackbird latency is higher - typically a few seconds
  • MPEG players are often implemented in embedded systems eg set top boxes. Blackbird player is implemented in Java which means upgrades can be distributed without requiring a computer upgrade
  • Each MPEG standard is fixed. Blackbird's Java implementation means it can be upgraded at any time

Any thoughts? Stephen B Streater 09:59, 5 July 2006 (UTC)

I agree only about the first one, it's actually an useful information. The rest though, would sound like weasel words in favor of Blackbird. --ren 06:34, 19 September 2006 (UTC)
I find the choice of features odd. Under what circumstances would someone want to know the 'highest supported bitrate'? Whether a codec contains patented techniques might be useful for an article about algorithms or specifications, but why for codecs? In order for other contributors to have an incentive to add to this article, it needs to be structured to provide an overview information of general interest to readers, rather than just a few random features of a few random codecs. AndreasWittenstein 02:16, 29 March 2007 (UTC)

[edit] Bias in patents

While I am personally against software patents, many people aren't. The use of "but yes" and "but no" here is obviously biased. In respect of WP:NPOV, I propose discontinuing the use of those templates on this page (whatever the outcome of the template deletion). --Karnesky 01:44, 13 March 2007 (UTC)

[edit] This isn't very useful

i'd expect a list like this would compare the size of the same movie(s) compressed by the different codecs (maybe i'll do it myself) --193.136.128.14 13:26, 17 May 2007 (UTC)

[edit] Patented

What does the "Patented" column mean? Does it mean the particular codec (software implemetation) is patented or the encoding method (specification, compression format) it uses? I would naturally expect the latter, as that's what's relevant and important in most cases. But then Xvid, FFmpeg and x264 should be marked as patented, too, because they use the patented MPEG-4 compression formats. Anyway, this whole patent section is as confusing as the rest of the article. —J. M. 00:39, 25 May 2007 (UTC)

No reply, so I changed the descriptions—what matters for users (and also for example for Linux distribution makers) is whether the compression standard the codecs use is patented or not. Xvid, FFmpeg and x264 use patented MPEG-4 (and other, in the case of FFmpeg) compression formats, that's why patents apply to them in the countries where software patents apply. —J. M. 03:40, 26 May 2007 (UTC)


[edit] QUALITY comparison of codecs?

I'm trying to find a nice, simple resource that compares MPEG2 versus VC1 (aka wmv) codecs. I found pages that compare audio codecs, for example, saying that an AAC+ file can be compressed to half the size of a MP3 file, and yet still score the same in listener tests. ----- Doesn't wikipedia have a similar comparison for video? - Theaveng 16:00, 14 September 2007 (UTC)

There are already several useful links in the article. Bear in mind anything too simple is misleading and anyone who tells you AAC+ can be compressed to half the size of an MP3 file yet still score the same in listener tests is probably talking bullshit since tests tend to vary a lot based on sample type. VC1 can usually achieve roughly equivalent quality to MPEG2 at a lower bitrate. But MPEG4 AVC/h.264 is usually better still. [1] for some comparisons include several different codecs in 2006 [2] and quite a few comparisons of AVC codecs (usually throwing in one MPEG4 ASP sample as well I believe). They don't have VC1 unfortunately this isn't their fault. They rely on the support of vendors/codec developers but MS didn't want to participate [3]. In any case I would also recommend the doom9 forums in general, there are a lot of people there who actually know what they're talking about Nil Einne (talk) 17:26, 19 December 2007 (UTC)
If you review the wiki article about Audio Codecs, there are several tests there (not just one), and they do indeed reveal that an AAC+ codec (which includes SBR to preserve high frequencies) can encode at half the bitrate of MP3, and still score equal quality ratings by the listeners. - Theaveng (talk) 18:33, 20 December 2007 (UTC)


[edit] MERGEFROM: "Differences between mp4 & 3gpp file format"

As mentioned on its talk page, there is no reason for "Differences between mp4 & 3gpp file format" to be a stand-alone article -- the information therein should be merged here. --Ean5533 ( View! / Talk!) 04:30, 16 February 2008 (UTC)