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  1. sleepysaint's guide to adam to get into what.cd without invite
  2.  
  3. begging:
  4.  
  5. I got a list of possible interview questions from some forums. My
  6.  
  7. questions were a little different than these both times but I got
  8.  
  9. some of the same ones. I went through and detailed the correct
  10.  
  11. answers to each of these. You'd do well to study on formats but I
  12.  
  13. hope I've done the grunt work for you.
  14. The bottom line is, they want to know that you understand what
  15.  
  16. transcoding is in all circumstances because they're really
  17.  
  18. intolerance of bad transcodes and lossy music. As such, you should
  19.  
  20. first be familiar with lossy and lossless audio formats.
  21. Allowed on what.cd:
  22. Lossless: FLAC, DTS (don't worry about DTS)
  23. Lossy: MP3 at 192kb/s or GREATER. no less. Ogg. AAC. AC3. (don't
  24.  
  25. worry about AC3)
  26. They'll probably ask you about formats not allowed on what too.
  27. Lossless: FLAC, ALAC, APE, WAV(PCM), WMV, CDDA (CD audio)
  28.  
  29. Read about each of these formats on wiki. Some are container formats,
  30.  
  31. meaning they could contain various types of audio data.
  32.  
  33. http://wiki.hydrogenaudio.org/index.php?
  34.  
  35. title=LAME#Detailed_explanation_.28long_answer.29
  36.  
  37. That's your cheat sheet for MP3 bit rates.
  38. The hydrogenaudio wiki has a lot of info on other things as well, so
  39.  
  40. read up.
  41.  
  42. **The sample questions follow. They might ask you a totally different
  43.  
  44. set of questions about different things, like putting formats in
  45.  
  46. order or who knows what. You can cheat and google or use whatever
  47.  
  48. resources you have handy to find the answer but it's a timed test so
  49.  
  50. you gotta be quick. These are here to show you a lot of repetitive
  51.  
  52. answers that should come quickly. The overarching point is Lossless-
  53.  
  54. >lossy = good and lossy->anything = BAD.
  55.  
  56.  
  57. They're gonna ask you some preliminary questions, probably something
  58.  
  59. along the lines of the following:
  60.  
  61. 1. Why are you interested in becoming a What member?
  62. Because you like obscure music and you're interested in knowing the
  63.  
  64. quality of the music you get, right? Mention liking FLAC and lossless
  65.  
  66. music for bonus points
  67.  
  68. 2. How often do you plan on using the site?
  69. Tell the truth, if you're like me you'll use it all the time.
  70.  
  71. 3. What kind of internet connection do you have?
  72. They're gonna ask you before the interview to do a speedtest at
  73.  
  74. speedtest.net and send them a link to the screenshot. if you normally
  75.  
  76. run on wireless you might wanna wire into the wall when you do this,
  77.  
  78. just to improve ping. they'll accept it no matter what. just tell the
  79.  
  80. truth.
  81.  
  82. 4. Are you a member of any other private trackers?
  83. Have a screenshot of your demonoid stats and username uploaded
  84.  
  85. somewhere, link them.
  86.  
  87. 5. How much experience do you have creating & uploading torrents?
  88.  
  89. Which BT client do you use?
  90. Tell them the truth.
  91.  
  92. 7. How big is your music/cd collection? What bitrates/formats? Where
  93.  
  94. did you get your collection (internet-where?/own rips-read ahead)
  95. Tell them the truth.
  96.  
  97. 8. What application do you usually use to rip CDs & how many you have
  98.  
  99. (estimate)?
  100. Tell them you use Exact Audio Copy to rip CDs and if you've never
  101.  
  102. used it before then tell them that's what you plan to use.
  103.  
  104. 9. What is the difference between a lossy & a lossless audio codec?
  105. A lossless audio codec preserves all of the auditory information from
  106.  
  107. the source data. A lossy codec irretrievably loses some of the
  108.  
  109. auditory data due to compression, resulting in a lower quality sound
  110.  
  111. but a smaller file size.
  112.  
  113. 10. What are VBR & CBR? Out of following pick the highest standard
  114.  
  115. LAME mp3 bitrate: 192, V0, V2, 320, V4, 512?
  116. In Constant Bit Rate encoding, the bitrate is kept constant across
  117.  
  118. each sample of audio in the file. In Variable Bit Rate encoding, the
  119.  
  120. encoder (for instance, LAME encoder for MP3s) chooses the number of
  121.  
  122. bits per sample based on the auditory complexity. VBR typically
  123.  
  124. results in more efficient filesizes if comparing equal sound quality
  125.  
  126. between VBR and CBR. (if that last sentence is confusing ignore it)
  127.  
  128. Out of that list, 320CBR is the highest *standard* lame preset for
  129.  
  130. quality, because 512 isn't a LAME standard.
  131.  
  132. 11. What is transcoding, in terms of audio? Transcoding is simply
  133.  
  134. converting a digital audio file from one format to another via a
  135.  
  136. codec. There are four types of transcodes that can happen between
  137.  
  138. digital files:
  139. Lossless to lossless
  140. Lossless to lossy
  141. Lossy to Lossless
  142. Lossy to Lossy
  143.  
  144. Of those, only the first two are allowed on what.cd, as the others
  145.  
  146. are considered "lossy transcodes".
  147.  
  148. 12. Will these transcodes give the same result as if they were done
  149.  
  150. straight from an original cd? "YES" or "NO" for each one please.
  151. a. 320 -> 192 no
  152. b. V2 -> 192 no
  153. c. 256 -> 256 no
  154. d. 256 -> 320 no
  155. e. wma -> mp3 yes
  156. f. FLAC -> mp3 yes
  157. g. mp3 -> Audio CD -> mp3 no
  158. h. mp3 -> Audio CD -> FLAC no
  159.  
  160. The only time it will give the same result as if it came directly
  161.  
  162. from a CD is if it's a lossless format transcoded to something else.
  163.  
  164. ANY TIME you convert from one kind of mp3 to another, it's a bad
  165.  
  166. transcode. ANY TIME you burn a CD from mp3s and rerip it, it's a bad
  167.  
  168. transcode.
  169.  
  170. If no more than one lossless to lossy encoding is permitted which of
  171.  
  172. these transcodes are/is generally acceptable? Give only a YES or NO
  173.  
  174. for each specified example.
  175. a. CDDA->WAV->CBR yes (WAV is lossless)
  176. b. 320->WAV(PCM)->FLAC no (source 320 is lossy)
  177. c. MP3->WMA->AAC no (source MP3 is lossy)
  178. d. AAC->MP3->ALAC no (middle MP3->ALAC is lossy->lossless)
  179. e. FLAC->APE->WAV(PCM) yes (all three are lossless)
  180. f. APE->FLAC->APE yes (same as above)
  181. g. FLAC->WAV(PCM)->CDDA yes (all three are lossless)
  182. h. WAV(PCM)->ALAC->AAC yes (Lossless->lossless->lossy)
  183. i. MP3->APE->FLAC no (source mp3 is lossy)
  184. j. V0->CBR->WAV(PCM) no (two no-nos here)
  185. k. CDDA->WAV(PCM)->MP3 yes
  186. l. V2->V1->V3 no
  187. m. V0->WAV(PCM)->CDDA no
  188.  
  189. I hope you get the idea? Remember these questions will be different.
  190.  
  191. 2. Which conversions are acceptable without having *obvious* quality
  192.  
  193. loss? No more than one (1) lossless to lossy transcode is allowed to
  194.  
  195. take place. Answer Y (YES) or N (NO) to the following:
  196.  
  197. a. 192 MP3 -> 320 MP3 N
  198. b. CDDA (CD) -> FLAC Y
  199. c. 320 MP3 -> 192 MP3 -> q6 Vorbis (Ogg) N
  200. d. FLAC -> CDDA (CD) -> 320 MP3 Y
  201. e. APE -> FLAC -> q7 Vorbis (Ogg) Y
  202. f. WAV (PCM) -> 256 MP3 -> APE -> FLAC N
  203. g. V0 MP3 -> CDDA (CD) -> 320 AAC (MPA/MP4) -> WAV Absolutely NOT
  204. h. ALAC (MPA/MP4) -> CDDA (CD) -> APE -> V2 MP3 -> FLAC no (the last
  205.  
  206. two are lossy to lossless)
  207.  
  208. got those from <@clockoutx> only got 5 right for this havn't changed
  209.  
  210. them so again up to you to find out them
  211.  
  212. 1. How often will you use the site?
  213. Be honest, I use it multiple times daily unlike any other music site
  214.  
  215. I've ever been on including demonoid.
  216.  
  217. 2. How long will you seed for daily, and how long in total?
  218. As long as you can, never stop seeding.
  219.  
  220. 3. What is the concept of maintaing a ratio?
  221. You know this.
  222.  
  223. 4. Will you be able to maintain an acceptable ratio on What.cd? Can
  224.  
  225. you prove to me that you have been able to do this on other private
  226.  
  227. bittorrent sites?
  228. You'll try your best by limiting your downloads until you've uploaded
  229.  
  230. your fair share.
  231.  
  232. 1. Explain how lossy and lossless audio codecs are different Give
  233.  
  234. three examples of each.
  235. This is a repeat question. I'll repeat what I said above: A lossless
  236.  
  237. audio codec preserves all of the auditory information from the source
  238.  
  239. data. A lossy codec irretrievably loses some of the auditory data due
  240.  
  241. to compression, resulting in a lower quality sound but a smaller file
  242.  
  243. size.
  244.  
  245. Lossy codec examples: AAC, Ogg vorbis, MP3
  246. Lossless codec examples: FLAC, ALAC, APE
  247.  
  248. 2. What is CBR & VBR? How are they different? Explain.
  249. Repeat answer: In Constant Bit Rate encoding, the bitrate is kept
  250.  
  251. constant across each sample of audio in the file. In Variable Bit
  252.  
  253. Rate encoding, the encoder (for instance, LAME encoder for MP3s)
  254.  
  255. chooses the number of bits per sample based on the auditory
  256.  
  257. complexity. VBR typically results in more efficient filesizes if
  258.  
  259. comparing equal sound quality between VBR and CBR. (if that last
  260.  
  261. sentence is confusing ignore it)
  262.  
  263. 3. What is v0?
  264. V0 ("Preset Fast Extreme") is a VBR preset in the LAME mp3 encoder.
  265.  
  266. The target bit rate for V0 MP3 is 245kbit/s but obviously can vary.
  267.  
  268. 4. What is the highest possible mp3 bitrate?
  269. 320kbit/s CBR is the highest possible using LAME encoder.
  270.  
  271. 5. Give examples of methods that could be used to prove an audio file
  272.  
  273. is actually the type of format/bitrate advertised.
  274. Using a program such as Audio Identifier will help, but one way that
  275.  
  276. works well is looking at the frequency spectrogram of the audio file.
  277.  
  278. If it has been transcoded from a lossy source, there should be
  279.  
  280. telltale signs (a distinct pattern or line at a lower frequency than
  281.  
  282. the claimed bitrate should cut off at).
  283.  
  284. 6. - Define transcoding - In terms of audio.
  285. Is it good or bad and why?
  286. Are there good AND bad transcodes? Explain.
  287. Transcoding is just converting digital audio data from one form to
  288.  
  289. another. Transcoding is good because it allows people to convert a
  290.  
  291. very large lossless format into something compressed/more manageable.
  292.  
  293. Without transcoding there would be no way to put your CD collection
  294.  
  295. on your iPod. But there are bad ways of transcoding - that is, taking
  296.  
  297. a lossy file such as an MP3 and transcoding it again. Since it has
  298.  
  299. already been compressed in a lossy format, any more transcoding done
  300.  
  301. to the file will result it a great loss of information and much
  302.  
  303. poorer sound quality. A good transcode is one that comes from a
  304.  
  305. lossless source, such as an original CD or a FLAC file.
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