Talk:MPEG-1 Audio Layer II

message: Musicam is the name used for MP2 in the specifications for DAB and Astra Digital Radio as well as in the BBCs DAB documents - it may not be a common name these days for MPEG 1 Layer 2 audio compression, but it seems to be common enough in older documents, leading me to think its not "incorrectly" called Musicam. --Kiand 02:18, 3 February 2006 (UTC)
replies: text: Support. I deleted the corresponding passage. --Abdull 17:55, 7 March 2006 (UTC)
thread_title:  ""incorrectly" called Musicam" 

message: Sorry if this has previously been mentioned, but why is history on MP2 stored in the MP3 article. (Just look at the top of this article and there is a link saying For details and a short historic introduction to MP2. Surely because it is related to MP2 then it should be in this article and not in the MP3 article. Matthuxtable 16:29, 15 March 2006 (UTC)
replies: text: P.s. There's a section on my talk page if you want me to see your reply as I may forget to check back here. See User talk Matthuxtable Special Reply Section. Many thanks Matthuxtable 16:30, 15 March 2006 (UTC)

text: I heard a rumor that the patents for MP2 are expired.  True?  The "For details and a short historic introduction to MP2, see MP3." is quite bad. — Omegatron 16:29, 20 July 2006 (UTC)
thread_title: Links to MP3

message: The second section is just swirling with stuff that just goes right over my head and I consider myself pretty tech-savvy. I think it  ought to either be removed or heavily rewritten to follow the KISS principle. — User:ACupOfCoffee@ 17:28, 3 October 2006 (UTC)
replies: text: I added links for sampling rate and bitrate to the second section.  Does that help? Daniel.Cardenas 20:10, 3 October 2006 (UTC)
thread_title:  Too technical 

message: This is the fundamental difference between Musicam (the MPEG1 Audio family) and the subsequent audio compression codecs. Musicam based codecs (MP2, MP3) have put first a focus on time domain critical audio sequences which are more typical in classical music and professional applications (studio) whereas subsequent codecs have ignored this demanding requirement to focus on less critical (frequency domain)light music audio materials.
:The above text implies that there is a clear-cut class distinction between "time-domain-critical" music and "light music". It seems to say that codecs after Musicam (MP2, MP3) ignore time-domain fidelity. What is meant by "put a focus on" will I think be unclear to general readers.
:I would prefer a clearer text that makes these points:
* All of these codecs are lossy meaning that in order to compress data rate they introduce distortions in both the time and frequency domains
* Successive codecs in the family achieve compression by increasingly complex methods that exploit the characteristic of human hearing that some distortions go unnoticed.
* Time-domain distortion alone has been found to be almost imperceptible except for very critical listeners to some audio material.  Cuddlyable3 12:41, 11 May 2007 (UTC)
thread_title:  Is this over-simplified? 

message: * AAC and to a lesser extent Ogg Vorbis and AC-3 audio codecs are still affected by the same fundamental problem in the codec model that the triangle, kabuki, glockenspiel and crysaglott revealed -- coding signals with complex impulses and high energy transients are always poorly reproduced. //This is the fundamental difference between Musicam (the MPEG1 Audio family) and the subsequent audio compression codecs. Musicam based codecs (MP2, MP3) have put first a focus on time domain critical audio sequences which are more typical in classical music and professional applications (studio) whereas subsequent codecs have ignored this demanding requirement to focus on less critical (frequency domain)light music audio materials.
To me, the above looks like a FUD (Fear, Uncertainty, and Doubt) statement. Could someone please find a citation or remove it. The term "subsequent codecs" especially is far too general. I don't know much about AC-3 but I do know Ogg Vorbis allows frame sizes to be specified in the header to enable better handling of high energy transients. Additionally, a lot of tuning to handle high energy transients has been done because of previous Vorbis problems with pre-echo.
:Please sign your posts. I think comparative information about rival codecs would be handled better on another page such as audio_compression or list_of_codecs than here. However it is unhelpful to bring amateur psychobabble jargon to this discussion. Cuddlyable3 08:31, 15 June 2007 (UTC)
replies: text: None of that was intended to be 'psychobabble jargon'. MP2 uses frame sizes of 1152 samples to encode sound. Ogg Vorbis allows specification of 2 frame sizes at the start of a file from 64 - 8192 samples. Smaller frame sizes allow high-energy transients to be handled better. I'm not trying to handle a discussion of codecs or make a really confusing argument, I'm just pointing out why I think the statement is FUD and why it would just nice to have a citation for it. -Francis
In response to FUD concerns - the statement "Some important (mostly undocumented) events in the development of MP2 stand out." really started alarm bells ringing. If theses import developments are undocumented then the subsequent content is at best original research, although it seems to me a conspiracy theory about how the codec developers want to ruin music with newer codecs. I've decided to delete some of the most confusing and dubious "undocumented evens", if anyone can find some citations then perhaps they could be reinstated. JohnPW (talk) 18:24, 16 January 2009 (UTC)
thread_title:  FUD? 

message: Does anyone know when the last patents expire for MPEG-1 Audio Layer II?   which expires on  July 21, 2008 seems to apply to MP2.  Are there any other MP3 patents that apply to MP2? Jrincayc (talk) 15:15, 1 June 2008 (UTC)
replies: text: User:Rcooley suggested I take a look at the article: "Low bit-rate coding of high-quality audio signals. An introduction to the MASCAM system" by G. Thiele, G. Stoll and M. Link, published in EBU Technical Review, no. 230, pp. 158-181, August 1988.  This article includes features like scale factors, subband coding, and allocating different numbers of bits to different subbands for each sample that are later used in MPEG-1 Audio Layer II (MP2).  I am trying to track down more information on the Pseudo-Quadrature Mirror Filters that is used for encoding and decoding the audio in MP2 since that is the remaining piece of MP2 that might be original enough to have a strong patent. Anybody have any information about the filters used in MP2?  Jrincayc (talk) 00:48, 26 December 2008 (UTC)
thread_title:  Patent Expiration? 

message: Howto was added to the "How the MP2 codec works".  After reading over the section, I disagree that the section was providing instructions on how to do something. Can you be more specific? Jrincayc (talk) 12:21, 14 July 2008 (UTC)
thread_title:  Howto? 

message: why is this article called "MPEG-1 Audio Layer II" but the mp3 one called "mp3" shouldn't they both by either "MPEG-1 Audio Layer 2" and "MPEG-1 Audio Layer 3" respectivly or simply "mp2" and "mp3"? -- Sonarpulse | Talk 05:27, 25 August 2008 (UTC)
replies: text: mp2 is not as popular as mp3 so mp3 gets the popular name and mp2 gets the more technical name. Daniel.Cardenas (talk) 17:14, 25 August 2008 (UTC)
thread_title:  Title 

message: I have deleted the unsourced paragraphs from the History of Development from MP2 to MP3 section, based on what seemed from the page history to be consensus by several wikipedia users and only opposed by one, who has now left the project. The statements were unsourced, and is so at variance with reality (if newer codecs are inferior, why are they being used, even replacing older ones?) that I doubt they could be true. Wingedsubmariner (talk) 15:11, 20 March 2009 (UTC)
thread_title:  History of Development 

message: As far as I know the ISO/IEC 13818-3 (MPEG-2) extended all MPEG-1 Audio Layers, not only Layer II. See article MP3. The MP3 (MPEG-1 Layer III) was extended also in ISO/IEC 13818-3. Source: http://www.mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm
I suggest to remove redirection from ISO/IEC 13818-3 to MPEG-1 Layer II. There could be a separate article about ISO/IEC 13818-3 with informations about defined changes to MPEG-1 audio.
--89.173.68.106 (talk) 11:13, 21 June 2009 (UTC)
replies: text: As I see, there is also a wrong redirection from ISO/IEC 11172-3 to MPEG-1 Layer II. This ISO standard defined MPEG-1 audio with layers I, II and III. I suggest removal of this redirection. ISO/IEC 11172-3 could be a separate article for example with name MPEG-1 Audio containig short informations about Layers I, II and III. --89.173.68.106 (talk) 11:26, 21 June 2009 (UTC)
thread_title:  Incorrect redirection from ISO/IEC 13818-3 to MPEG-1 Layer II 

message: Maybe something about software and hardware encoders? I think some are available e.g. for television broadcasters. 83.26.110.196 (talk) 18:38, 29 November 2011 (UTC)
thread_title:  Encoders 

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thread_title:  External links modified 

message: A good improvement to this article would be including information about the patent status (if all expired or not). I could not easily find these data, though... By the way, kuro5hin is dead, so the link "Patent Status of MPEG-1, H.261 and MPEG-2" is broken!--200.223.199.146 (talk) 11:46, 9 December 2016 (UTC)
thread_title:  Patent 

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message: This article should be renamed to MP2 (audio coding format) to avoid confusion between the name that includes all versions (MP2) and names for specific versions (MPEG-1 Audio Layer II, MPEG-2 Audio Layer II). --Fernando Trebien (talk) 21:28, 11 March 2020 (UTC)
thread_title:  Rename to avoid confusion with specific versions