CD Player出現在光頭的拾訊部份及光碟的反射層; 電腦出現在軟件層面及電腦內的EMI干擾. 點解用$100 CD-ROM rip都可以做到0% loss, 而CDT就要$100000都未必做到呢? 因為rip碟要讀幾次, 唔係real-time, 可以從中修正CD-ROM hardware的缺憾. 但用CDT讀碟就必需real-time. 要real-time做到0% loss, 就需要在CDT的設計上落大量功夫, 隻CD的反射層亦要夠平, 反射率要夠高, 先會好聲.
@其實CDP係一路轉一路讀, 同埋只讀一次, 吾知前面師兄有無提過, 不過帖太長, 無心機睇了; 電腦用DVD/BLURAY/CD-ROM係不斷重覆讀取, 同一段DATA會讀取3, 4次...
tomtomsuccess 發表於 2013-10-4 10:21 static/image/common/back.gif
music CD did not record the master file's check sum data, so what's the point to compare the check ...
It is only absolute correctness vs relative correctness.If majority get the same result, likely you can deduce the result is correct.
On the other hand, if someone opens another topic "How much data is lost in CDP playback ?", based on your statement "no master value to compare" , you also have no way to justify an expensive CDP / CDT can pickup signal correctly.
ok102006 發表於 2013-10-4 11:03 static/image/common/back.gif
Audio CDs do not use WAV as their sound format, CD using Red Book audio instead.
CD 轉成 file 會 lo ...
師兄有無玩埋 MPD kit 之類？
tomtomsuccess 發表於 2013-10-4 10:17 static/image/common/back.gif
係你先咁好心機寫出來, 其實, google下都有, D人又唔做功課......
抵加你分....
未係見到Ching你欲言又止,咪可讓小弟放工途中,比我回憶年少時既認知{:6_240:} .成讓成讓{:6_195:}
本帖最後由 agic 於 2013-10-4 17:24 編輯
itoy2008 發表於 2013-10-4 16:58 static/image/common/back.gif
未係見到Ching你欲言又止,咪可讓小弟放工途中,比我回憶年少時既認知 .成讓成讓...
{:1_338:}
agic 發表於 2013-10-4 17:22 static/image/common/back.gif
SCSI ..... {:8_399:} caddy tray既plextor....
kc2wong 發表於 2013-10-4 13:43 static/image/common/back.gif
It is only absolute correctness vs relative correctness.If majority get the same result, likely...
Haha, your question simply is getting back to the first CD appeared in the world. We are actually listening digital music which is already LOSSY (so, in principal, what we are comparing, we have been listening LOSSY file since we have CD-DA, haha, it is just 16/44.1 for representing analogue signal) due to sampling{:6_126:} . But from pyscoacoustic model, and the bandwidth and storage issues in 90's, compression is needed and thus huge compression gain can be done in frequency domain or the spectrum or exactly on the cepstrum, which is the basis of mp1, mp2 and finally the popular mp3 audio coding used the ISO/IEC standard in 90's.{:6_142:}
So, if our discussion prolong, haha, one day, there should no Blu-ray as we will watch raw picture of frame size 1920x1080 which correspond to proximate the lines of 1080 film's scan lines (~HDTV). It use MPEG-4/H.26x family codec design with audio bitstream or lossless PCM for multiple channels! We can see no more compression technique is required in such huge storage and big bandwidth Era to audio source. {:6_193:}
That's how VCD or MPEG-1 claiming to store moving picture of 320x240 or 352x288 (PAL or NTSC) in 90's. Thus, for a second of video at that time it requires 320x240 pixels x 3 Bytes (RGB or YCrCb:4:44:4) x 30 frames (NTSC) = 6912000Bytes ~or> 1 CD-ROM data storage!!!{:6_154:}That's why VCD can store 1 hour of video we can say the compression ratio is of up to 60x60 times!
Relatively, mp2 is the associated coding format for VCD at that time. Storing MP2 or even MP3 is comparatively low demand, but we need quality! Cuz human sensation system can easily sense auditory noise easier than visual noise or defects. Where no one can imagine we can listen to such poor quality of MP3 in 90's and bought lots of different portable MP3 players. Until today, 10GB network, listing lossless music of even up to 32/384k, whereas 32 means 32bits or 2 to the power 32, which is a huge step size for representing the ampitude (-2,147,483,647 to +2,147,483,648) . From our human ears, we sometimes can still feel the dynamic range of 16bits and claiming the human voice is too small volume comparatively to the background music, esp in Movie, or "not very smooth" enough... especially for scratched CDs or the resultant glitch, pop sound, but how about 24bits or 32bits, what is the sound of glitch or defacted surface of a scratched damaged CD? a smooth pop sound, haha.{:8_390:}[利申,金耳仔我唔係.不過可能有人既聽覺可以勁到上"矛盾對決". 金耳仔vs HD audio {:8_403:} ]
In short, as we have been already listening CD-DA, we are actually listening lossy reconstructed PCM to fake our ears that is the "original" from mastering in a high quality recording system/room. So, if the production is higher bit, higher sampling frequency, and you like the song, simply 科水 immediately. Otherwise if it again and again use various different CD media to tape down with CD-DA format (but not DSD, another story), why we need to buy it in expensive price, e.g. K2HD, AMCD, xxyyCD, answer is very simple, better quality of the disc, plastics, chemical, durable, ...etc.科水 again if we like {:8_377:}
So if play CAS, probably chings like me is trying out DSD. It's time to play CAS 2.0, let me coin this name out haha! Take on your Jean 501 or recently LKS to pk the PCM 16/44.1 which should still tell different on PCM 16/44.1... 點都好,手上既rip檔咪大部份都係from CD-DA... Can a CAS2.0's DAC easily KO the previous DAC? I am now awaiting for my new 501... {:6_235:}
Anyhow just my two cent{:6_122:} 因office環境, 好難打中文快...岩睇加下分,小弟想升下level,哈哈.
P.S. the quality of burn an ISO cloned backup from a music disc (for backup purpose ar...{:8_390:} ) is not the same as if you copy all the trackXX.cda to trackXX.wav and burn it again using CD-DA format. You can try, i tried long time ago, however, i don't know if today's CD-ROM or DVD-ROM or BD-ROM reading technique is better than the past, but still optical-2-digital issue happens. Thanks for reading{:8_389:}有錯物打我.
beerboy 發表於 2013-10-4 17:34 static/image/common/back.gif
SCSI .....caddy tray既plextor....
Same gen woo. Need Caddy tray to play CD-R!!!! At that time, i remember one of my experiment is to over burn the disc! However, the Plextor laser ben got over heat power and melt{:8_369:}the surface of my CD-R!!! At that time, each CD-R i bought is either Sony or TDK, and costs $120 per one!!! Shit!{:8_370:}
itoy2008 發表於 2013-10-4 17:47 static/image/common/back.gif
Same gen woo. Need Caddy tray to play CD-R!!!! At that time, i remember one of my experiment is to ...
大cart $1200，一代Yamaha Pro CD-writer十二个，二代scis II刀成皮
玩Hifi又好玩乜L春刀系要交学费，甘岩线八·九零年代学费令舍贵，但贵得泥<值>
本帖最後由 jaffeinism 於 2013-10-4 18:41 編輯
Raphael 發表於 2013-10-3 22:44 static/image/common/back.gif
師兄，音樂 CD 嘅數據同一般 data CD 嘅數據唔同
Data CD 每個 file 都有詳細既 metadata，甚至傳送時每 ...
CDP每次PLAY都會有吾同JITTER ... {:1_352:}
吾同價錢既CDP播放都會吾同聲, 越貴既CDP聽得越多野, 你攞部8K既同30K既比, 8K既米又係有 LOSE ...
所以呢的野無絕對... {:1_352:}
