User talk:PolBr

Welcome to Wikimedia Commons, PolBr!

First steps tutorial Our first steps tour and our frequently asked questions will help you a lot after registration. They explain how to customize the interface (for example the language), how to upload files and our basic licensing policy (Wikimedia Commons only accepts free content). You don't need technical skills in order to contribute here. Be bold when contributing and assume good faith when interacting with others. This is a wiki. Getting help More information is available at the community portal. You may ask questions at the help desk, village pump or on IRC channel #wikimedia-commons (webchat). You can also contact an administrator on their talk page. If you have a specific copyright question, ask at the copyright village pump.

Goodies, tips, and tricks Put Babel boxes on your user page so others know what languages you can speak and indicate your graphic abilities. You can find the files you have uploaded in your Uploads. Please sign your name on Talk pages by typing ~~~~. To link to an image page without embedding the image, type: [[:File:Foo.jpg]], which produces: File:Foo.jpg. You may enable gadgets (custom features) for your account. There are several tools to upload files. Have you edited Wikipedia before? This guide might be useful. Made a mistake? Do you want to have a file renamed or moved? Use the move link and wait for an authorized user to rename it. Do you want to have your recently uploaded picture removed? Tag it as {{speedy|reason here}}. For more information read the deletion guidelines.

-- 14:27, 28 January 2012 (UTC)

File:Quadripôle.svg

File:Quadripôle.svg has been listed at Commons:Deletion requests so that the community can discuss whether it should be kept or not. We would appreciate it if you could go to voice your opinion about this at its entry. If you created this file, please note that the fact that it has been proposed for deletion does not necessarily mean that we do not value your kind contribution. It simply means that one person believes that there is some specific problem with it, such as a copyright issue. Please see Commons:But it's my own work! for a guide on how to address these issues. Please remember to respond to and – if appropriate – contradict the arguments supporting deletion. Arguments which focus on the nominator will not affect the result of the nomination. Thank you!

McZusatz (talk) 14:02, 22 April 2012 (UTC)

Thank you very much for your previous uploads. They should be very helpful. I think you uploaded the mentioned file twice, so I requested a deletion. --McZusatz (talk) 14:04, 22 April 2012 (UTC)

File:Quanterr fr.png

---

There seems to be a problem regarding the description and/or licensing of this particular file. It has been found that you've added in the image's description only a Template that's not a license and although it provides useful information about the image, it's not a valid license. Could you please resolve this problem, adding the license in the image linked above? You can edit the description page and change the text. Uploading a new version of the file does not change the description of the file. This page may give you more hints on which license to choose. Thank you.

This message was added automatically by Nikbot, if you need some help about it please read the text above again and follow the links in it, if you still need help ask at the → Commons:Help desk in any language you like to use. --Nikbot 20:40, 26 April 2012 (UTC)

VU meter graph

Hi. The VU graph was created with Synthedit, a virtual modular synthesiser/audio processor. I assumed the VU implementation in the program was correct but it might not be. The scale of the graph must accommodate both the instantaneous signal and the VU signal. I did not think about using the common VU scale. I don't have the original files I used to create the diagram anymore.

I hope this helps.

Your graphs

A credit for the original idea would be nice.

I am confused by the two different scales used on your graphs. Shouldn't the VU response and the original signal use the same scale so we can compare the two responses?

You should also think about how the image will look on when printed to black and white, so avoid using too much colour to create visual differences, but rely more on different tones.

I don't think different program contents would be useful, although if you did want to show another example, something with a smooth envelope, like gentle classical music would be good.. What I would like to see (not sure if others would), is a graph comparing different metering methods like VU, PPM, and the new European loudness standard.

Not simple issues

I credited the original idea to User:Iainf.

The question of the scales is not simple at all to me.

• If the signal graph follows the SVI scale, all levels above -15 dB FS and below minus forty-some go out of the graph, and the steps do not linearly reflect the signal level
• If the VU graph is linear, the great design hack (or bricolage if you want) that the SVI was is lost. The idea was to compensate a necessarily slow response (several were tested) with a diminutive scale and a tweaked alignment level 8 dB below nominal level.

In the present state, the background shows something much like the indication of a PPM in its upwards moves (to represent it accurately you'd need at least 200 px per second) over full scale (-72 ~ 0 dB FS) linear in dB, which represents the signal for reference. To represent the actual meter response, You have to use full scale if you are going to shows the dips in the program. Now the SVI's 0 VU is at -18 dB FS in Europe (-20 dB FS in North America), and its scale is about exponential from -10 to +3 VU (its designers claimed that this was a good enough approximation of RMS around 0 VU). The SVI scale covers at best half of the PPM scale. The question of the scale and the question of the response are mixed by design. I didn't find any ways of making it any simpler, apart from publishing the slope graph (which hopefully demonstrates the scale) and the step graph (which hopefully demonstrates the response time of the needle). The former was originally my test of the level conversion function of my program, and the latter my test of the ballistics filter function of the same.

I thought the graph was already complicated, and I thought about taking information out of it, rather than stacking more. Yet, with colour, adding a notion of the PPM is straightforward. As I wrote above, the rise time of the signal representation is a good approximation of that of a PPM for this timeline scale. The fallback rate is 1.5 s per 20 dB, that is a 4 horizontal to 1 vertical slope on the graph. I could easily add another pale blue area, topped by a little brighter line to represent that. It would have to be in the background so as to avoid obscuring the signal area.

As for the Loudness measurements, that is not possible in this graph. Loudness as by EBU 128 is computed on four different timespans : true-peak, 400ms, 4s, program length. TC electronics have spent much on the production of relevant graphs. The point is : SVI and PPM supposed good will on the user's part to maintain program quality. The loudness competition showed that goodwill was contrary to the competition spirit (and possibly to market, there is discussion on whether listeners actually prefer loud programs on an expanded timespan). The way out is an industry (ITU, EBU, SMPTE) agreement on what is loudness, of the same kind that made SVI standard in the 1930's.

I'll think about your advice on colour. From my experience with low-cost inkjet printer, I think a large colored area is more troublesome than coloured lines. In a standard HTML page, I would have a CSS @-ruleset for printing and possibly a javascript user prompt to get a black and white rendering. The print version would have no fill or a texture fill for the signal, and for black on white rendering, only the -9, -18, -30 and -60 dB FS lines. In wikimedia, I do not think that this is possible.

PolBr (talk) 08:18, 24 May 2012 (UTC)