Talk:Bit Rate Reduction

FYI, BRR is another term for compression. It uses transformations to modify the Cosine wave, which is secondary to the Sine wave, and creates a smaller file by removing irrelevant wavelengths, but keeping an accurate representation of the original waves intact. It is NOT solely used on the SNES.—The preceding unsigned comment was added by 72.142.7.250 (talk • contribs) 00:34, 7 June 2006 (UTC)

---

Re the above comment, I think it's better to separate the description of the compression format used by the SPC-700 from a discussion of data compression in general. Wikipedia does already have articles on data compression, audio data compression, image compression and video compression which discuss some of the material you've introduced. I have put a disambiguation link at the top of the article to aid the reader's navigation if he arrives at the article and wishes to read about other forms of data compression. Spacepotato 05:02, 7 June 2006 (UTC)

---

So why not just edit the already existing SPC-700 page? Is than not more appropriate? BRR is a very broad subject to discuss, and I think sticking solely to explaining the SPC format (Limited to the obsolete SNES) is very unpractical. To be accurate, this topic should discuss BRR in general and it's entirety, and why you removed my text is beyond me. Yes, Wikipedia has many data compression pages, but it also has a SPC-700 page, so perhaps you should stick your little tidbit there rather than here. Likewise, I'll keep any format-specific information out of it as well. —The preceding unsigned comment was added by 72.142.7.250 (talk • contribs) 23:57, 7 June 2006 (UTC)

---

Merging this article into the SPC700 article would add clutter to it, so I'm not sure that that's a good idea. In any case, I do not think there should be another article on bit-rate reduction in general, because bit-rate reduction means the same thing as data compression. Having two different articles, one on bit-rate reduction and one on data compression, would be like having two different articles, one on frankfurters and one on hot dogs. Spacepotato 05:52, 8 June 2006 (UTC)

---

Somehow I don't think it will, and that analogy is crap. Yes, they MEAN the same thing, but the thing is, BRR applies to a wave signal, and data compression applies to DATA. So tell me once more that a Waveform is the same thing as a Pixel.—Preceding unsigned comment added by 72.142.7.250 (talk • contribs) 00:19, 28 July 2006

---

Whoa there me-bucko, you're just arguing semantics now! BRR as designed, is commonly applied to audio signals, but could just as easily be applied to any signal that was transformed into the frequency domain - even pixels - granted there are many, many better algorithms for compressing other data types. Also saying that BRR yields compression by removing irrelevant wavelengths is utterly incorrect - what part of the algorithm breaks the signal down into sub-bands to determine what "wavelengths" it can lose? BRR is a more elegant differential signal tracking algorithm - utilising four specialised filters to help correct the predictive error during sample interpolation. It is to all intents and purposes ADPCM with better error control. BRR as described in the article is used exclusively by Sony (as they own the two patents), however VAG and XA Audio (used on Sony's playstation) is a variant with better tuned and/or more filter coefficients. Paulie (talk) 18:55, 8 March 2008 (UTC)

---

The BRR encoding makes sense for itself, as it is an exotic algorithm: mixes ADPCM (filter #0) with linear prediction (filters #1, #2 and #3), it is similar to GSM 6.10 codec, but less efficient, although less computationally complex. The relation with the SPC-700 chip is circumstantial, as example, would be trivial replace BRR encoding with ADPCM-only circuitry at sound quality reduction expense. Please, don't remove this article; I think that there is opportunity to add extra insight and value to it. faragon 16:50, 24 March 2008 (UTC)

July 2023: Proposed deletion contested

@CascadeUrbanite proposed this article for deletion today; I contested the deletion and removed the PROD tag. I believe there's sufficient possibility of notability that the article should at least be discussed:

• Google Books search: [1]
• Google Scholar search: [2]

That said, I have concerns. There's the generic concept of "bit rate reduction" -- see our Data compression article. This article is about a specific approach that is (was?) used in the Super Nintendo Entertainment System, the Sony PlayStation and other products.

Should this article have another, less generic name? Is this specific form of compression notable?

I'd rather this article not go to Articles for Deletion before some discussion here. Some of these issues seem a bit nebulous for an efficient AfD -- this page is more open-ended. I think there's good content here that might get junked in a cookie-cutter AfD where discussion might get bogged down by the number of magazine mentions.

I'm also pinging major editors: @Lord Nightmare and @Spacepotato

I know just enough about this topic to be dangerous.

Thanks, --A. B. ^{(talk • contribs • global count)} 03:07, 26 July 2023 (UTC)

@A. B. I was contesting the notability of the specific compression outlined in this article, not the overall concept. More specifically, I am concerned about the notability and relevance of this compression method in the context of the platforms the article mentions; searches in Google Books for it with regard to some of the platforms (SNES, PlayStation, Mac Quadra) either return short lists and/or include irrelevant sources. With the results for the CD-i, I could see a small portion of the article be suitable enough to merge into the CD-i article with proper citations since it describes a media format, but I think the rest of the content would be unsuitable for any merge on the grounds of WP:TMI, especially when its reliance on WP:PATENTS for notability and sourcing appears to constitute WP:OR. CascadeUrbanite (talk) 00:35, 27 July 2023 (UTC)

It's been a long time since I last edited the article, but there's a few interesting bits which have come to light since: This compression format is also part of the CD-XA standard from the "Green Book" rainbow book. (The CD-XA ADPCM format corresponds to the later version from the wikipedia article, as seen on the Quadra and Playstation as well as CD-I is, I mean; the 'older' version on the SNES can be thought more of as a prototype); another system which uses a nearly identical compression scheme is certain firmwares of the audio DSP on the gamecube, which use an even more advanced version with 16 sets of IIR coefficients, and the 'audio blob' header contains all 16 sets of coefficients, so they are definable by the user/audio-compresssor.

The compression system can be thought of as a form of 'block-adpcm' with the ADPCM information stored as a side-channel (the audio block headers within the audio stream) as opposed to more typical ADPCM formats like IMA-ADPCM or OKI/Dialogic ADPCM where the block evolution information is stored as part of each 4-bit compressed sample and dependent on previous state. Lord Nightmare (talk) 10:27, 2 August 2023 (UTC)

I'm happy with what you experts decide. I just didn't want to see this information disappear quietly into the night without smart people talking it over, which y'all seem to be doing.

--A. B. ^{(talk • contribs • global count)} 10:33, 2 August 2023 (UTC)

@Lord Nightmare and A. B.: I'm sorry, but it doesn't matter how interesting the subject is; all of the content in this article, whether it remains separate or merged into another article like CD-i, needs to abide by WP:RS, WP:V, and WP:OR like every other article on Wikipedia. At the very least, I highly doubt the patents can be used to substantiate the claim of its presence in the SNES and PlayStation here since I can't find any mention of them in the mentioned relevant patents themselves (US5111530 and US5978492) or in a reliable secondary source such as the IEEE; even if WP:OR was less restrictive, the patent list sticker at the bottom of every PlayStation wouldn't be useful as a reference either since the list varied with each revision. With the CD-i and CD-XA stuff, I could potentially see enough notable content in the context of the format to warrant its inclusion in the CD-i article, but I am certain that at least the decompression algorithm section wholly fails WP:GNG and would be unsuitable even for the CD-i article; remember, as editors of an encyclopedia, we need to provide summaries of knowledge, not manuals and other forms of verbose information that only caters to a specific group of people. CascadeUrbanite (talk) 04:43, 8 August 2023 (UTC)

At the very least, the information on this page should be merged into the Adaptive_differential_pulse-code_modulation article, as BRR/CD-XA is a form of "block ADPCM", where the data is broken into blocks with side-channel data (in this case, the filter selection and the shift/gain for said block) stored in the block header. Lord Nightmare (talk) 18:48, 13 September 2023 (UTC)

@Lord Nightmare Like I suggested earlier, I think it would be more appropriate to merge the most suitably cited information into the CD-i article since it would be relevant within the context of the format; after all, CDs were originally intended to store audio only, without any video accompanying it. "Block ADPCM", as you described, seems to describe the ADPCM used in the WAV format as well; I would suggest a brief summary of the concept within the article to cover both formats, but I can't find much in the way of reliable sources describing the WAV ADPCM to recommend it. CascadeUrbanite (talk) 05:06, 26 September 2023 (UTC)