Wikipedia:Reference desk/Archives/Computing/2013 January 31

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January 31

Sound quality difference of songs ripped from CDs vs. downloaded from the Internet

A few days ago I asked a question about why the continuous burning and ripping of a song from one CD to the next lowers the audio quality. I have another observation and that is that some of the songs of the songs that are up on the Internet or on file sharing software at 320 kbps have a little bit higher quality than if I rip the same from a CD at 320 kbps. Why is that the case? Are some of those high quality songs up on the Internet and file sharing softwares ripped in a certain way or come from the original source? 71.98.163.183 (talk) 00:10, 31 January 2013 (UTC)

The answer to why they sound different both at 320kbs is maybe they use a different encoder or different settings for the ripping? If sound quality is an issue for you, then use software like (exact audio copy) EAC and rip them to .FLAC files rather than mp3. ---- _nonsense ferret 00:50, 31 January 2013 (UTC)

Probably one of: some part of your premise is not true, your imagination, the specific MP3 encoder used, CBR versus VBR, etc., normalization / ReplayGain, etc.. If you’re still comparing to Windows Media Player, know that people involved in the accurate reproduction of CD audio do not use this software. There have also been some studies suggesting that some people prefer quality-reduced versions of music to lossless copies, as depending on the type of music, certain aspects are given a higher contrast, so to speak (that and many people here music the first time with its quality reduced, and their ears tend to consider alternative qualities forever strange). Generally speaking, if you’re going to paradoxically want to discard information and have the best copy you can get, you need only waste your time with 320 CBR. ¦ Reisio (talk) 00:58, 31 January 2013 (UTC)

Exactly what he said too - in the world of hifi audio, the imagination is the biggest differentiator between different equipment. Properly scientific double blind tests would be the only sensible way to verify which is better, and people with a vested interest in the industry seem strangely unwilling to try this /rant over :) ---- _nonsense ferret 01:07, 31 January 2013 (UTC)

See loudness war - different digital versions of a song can be quite different. -- BenRG (talk) 18:32, 31 January 2013 (UTC)

The MP3 standard only defines how an mp3 file is decoded, i.e. played. It does not say how a music file should be encoded. The quality of the music will depend on the encoder used, and there are no simple rules to decide which one is better.

Encoders are based on a psychoacoustic model: such a model basically tells you how noticable changes made to the music would be, like which parts can be removed without people noticing. When mp3 came out it had a standard encoder, but others have been developed since then. Some of those are optimized for speed, others for quality. The quality is subjective, and it may depend on the type of music as well. LAME is one of the popular encoders. I remember that in the early days of mp3 a "good" one meant a fast one. Ssscienccce (talk) 16:03, 1 February 2013 (UTC)

Historically I think there were some MP3 encoders that introduced audible artifacts even at very high bitrates, but I don't think that's true of any encoder in common use today. MP3 at 320kbps should be indistinguishable from the source unless you have extraordinarily good speakers and hearing. -- BenRG (talk) 18:45, 1 February 2013 (UTC)

Remote desktop

Does anyone know of any software (Win XP) that could allow me to run a game on my desktop, but be able to (stream and) control it via a different computer? I have tried a few remote programs but the lag makes it impossible to play the game. Both computers are behind the same router (I have a very good ISP, too!), so I'm wondering where this lag is coming from if it's not the software (I have tried StreamMyGame - not so good). Can anyone suggest any software or anything else that might work? Thank you in advance! 86.11.247.18 (talk) 00:36, 31 January 2013 (UTC)

The more complex the visual output, the more laggy it will be over a network. ¦ Reisio (talk) 01:00, 31 January 2013 (UTC)

The game would really need to be designed to run over a network. For example, instead of sending every pixel for every frame, it should send higher level instructions, like "move car left one unit". This requires much less data transfer. StuRat (talk) 01:40, 31 January 2013 (UTC)

Have you tried Windows Remote Desktop? Ruslik_Zero 18:45, 31 January 2013 (UTC)

I don't think you're going to get much better results than from a software specifically designed to stream games like StreamMyGame.

Make sure that you're not accidentally streaming it over the internet when you intend to be streaming it over the local lan. Ideally they should both be wired, as well. Not Wifi.

You could also try reducing the resolution. Try reducing it a lot.

(And turn down the graphics settings in the game. If your computer is struggling to play the game, it's going to have trouble when it has to also compress the screen to be transmitted over the network.)APL (talk) 19:44, 31 January 2013 (UTC)

Agreed. Some games have the option to reduce the number of frames per second. In addition, they may have specific graphics settings you can turn off, like "Show particles after explosions". StuRat (talk) 17:22, 1 February 2013 (UTC)

Multiple Choice Question building software/website

Hi There,

I am interested in the Open Education Resources. I want to develop the multiple choice questions for student evaluation for Biology module of The Saylor Foundation Biology Textbook. Can you please suggest a software/website to create them?

Thank you very much. Nirajrm Δ | [sign plz] 00:57, 31 January 2013 (UTC)

That depends on number of questions and size of assignment. The simplest, easiest thing might be using Google Docs form. You may find few alternatives here --Tito Dutta (talk) 01:28, 31 January 2013 (UTC)

Also, your signature contains a disruptive link --Tito Dutta (talk) 01:31, 31 January 2013 (UTC)

Are these questions to be answered online, or printed out ? If they are to be printed out, then any word processor will do. For online tests, you might want to take a look at the way edx.org does it. They have options to set number of attempts allowed for each Q (such as multiples on homework, or just one on tests), discussion pages, etc. StuRat (talk) 01:35, 31 January 2013 (UTC)

Thank you very much guys. I want it to be online and not in the print out format. Signature is fixed now.Nirajrm (talk) 02:23, 31 January 2013 (UTC)

It's not specifically for education, but I've used surveymonkey ([1]) for this sort of thing. It is fast and easy to use. SemanticMantis (talk) 15:54, 31 January 2013 (UTC)