Talk:Dolby Digital

message: The AC-3 codec is at least 18 years old and patents were for 17 years following the date of issuance back then. Does this mean all the foundational patents have expired and it is legal to use a free encoder/decoder now? Is there a list of patent numbers somewhere? This is not clear cut because Dolby still licenses AC-3, but that may simply be for the use of their logo for all I know; also, submarine patents were still legal so they could have been granted additional patents on AC-3 much later than 1992. 96.57.9.142 (talk) 13:58, 28 October 2010 (UTC)
thread_title:  Patents? 

message: *I'd like to see a bit more technical detail here. It should *at a very minimum* at least be mentioned that it uses a logarithmic scale for quantization rather than the more standard linear scale. As far as I know it is significantly different from standard PCM-based encoders that some in-depth discussion would be useful.
*Dolby TrueHD's sample rate is listed as being 96 khz; however this is only the case when encoded over 8 channels or more (as listed here with 14), but can actually sample at rates up to 192 khz when encoded over 6 channels. --Photoactivist (talk) 01:37, 3 September 2008 (UTC)
thread_title:  technical details? 

message: What does the "mandatory" vs. "optional" in the status column in the "Dolby Technologies in Packaged Media Formats" table refer to? Does this refer to whether players of the particular media format (e.g. DVD) require a Dolby decoder?--GregRM 01:19, 14 August 2006 (UTC)
thread_title:  "Dolby Technologies in Packaged Media Formats" question 

message: *The bit rates are unclear.  It would be nice to see both the compressed data rate encoded onto the media, and the per channel PCM rate (such as 96hkz/24 bits or whatever.)
*Dolby Digital's bit depth is not mentioned, in comparison to Dolby TrueHD which is listed as having 24 bit depth.
: The bit rate on Laserdisc is 384 kbps for all the extra channels combined (i.e. surround L/R, center and subwoofer). That is 96 kbps per channel, theoretically. 44.1 kHz and 16 bits. Same on DVD but 448 kbps total there, so 112 kbps per channel. -- Alexey Topol (talk) 23:14, 10 February 2019 (UTC)
thread_title:  Bitrates 

message: I have been involved in a spirited discussion about some external SourceForge links with Dolby Interactive Marketing on my  user talk page.  The whole conversation really belongs here, so I thought a link should be mentioned such that it doesn't get lost beneath the wikipedia noise floor. (Requestion 17:10, 21 December 2006 (UTC)
thread_title:  External Links 

message: I am not an expert but is the opening sentence correct in stating that Dolby is as series of "lossy audio compression" given Dolby TrueHD?  —Preceding unsigned comment added by 92.5.2.87 (talk) 16:55, 3 August 2008 (UTC)
thread_title:  Opening sentence correct? 

message: The comparison chart is too big to fit on 1024px and narrower displays without scrolling. Maybe we can shorten the word "Mandatory" or get rid of one of the categories(HDDVD)?  —Preceding unsigned comment added by Drizek (talk • contribs) 22:18, 27 March 2009 (UTC)
thread_title:  Comparison Chart Width 

message: This section needs a rewrite regarding hardware DDL support by some sound cards. X-FI's DDL support is software based, and I believe this is also the case for C-Media cards. It may be true for some other cards mentioned there, too. I will try and edit this section, at least as far as X-Fi sounds cards are concerned. Any comments? --Piotr Wwa (talk) 22:10, 31 August 2010 (UTC)
thread_title:  Dolby Digital Live: not always in hardware 

message: This article mentions that "Dolby is part of a group of organizations involved in the development of AAC (Advanced Audio Coding), part of MPEG specifications, and considered the successor to MP3. AAC outperforms MP3 at any bitrate, but is more complex.[19]". But what has this to do with AC3? The section doesn't explain the relationship of AC-3 to MP3, or say whether AAC outperforms AC-3. FurrySings (talk) 22:51, 20 February 2011 (UTC)
thread_title:  What is relationship with MP3? 

message: I think the article should include all the official logos used by Dolby Labs. for Dolby Digital. They can include a short description, like "Original logo, used from 1995-1999" ... here's a reminder of how the original logo looked like, just a low-quality pic of it: http://imageshack.com/scaled/large/32/k7tj.gif It would be great if somebody could create a high-res vector graphics version of that and put it into the article.  -- Alexey Topol (talk) 23:17, 21 October 2013 (UTC)
thread_title:  Original logo missing 

message: What is AC-3 in this context? The acronym(?) is used without any reference or explenation.
Theking2 (talk) 15:05, 25 April 2015 (UTC)
thread_title:  Dolby digital 

message: "ac3freedomday" --Hong620 (talk) 15:56, 21 March 2017 (UTC)
thread_title:  At midnight on March 20, 2017, Dolby's last relevant patent on Dolby Digital expired. 

message: The original logo should be added to the article.  -- Alexey Topol (talk) 20:40, 10 February 2019 (UTC)
thread_title:  Original logo "DOLBY SURROUND AC-3 DIGITAL" is missing