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Audio CD ripping – optical drive accuracy listing

208 points by sandreas 4y ago

rahimnathwani 4y ago
Wow I had no idea EAC still existed. Back when I used it, hard drive space was scarce and I thought I was being extravagent ripping my collection at 160kb/s mp3 files. Does EAC today offer any advantage over cdparanoia?
- Crontab 4y ago
  Back when I was ripping my collection to FLAC, I used EAC because of AccurateRip, which is something that cdparanoia did not offer - at least at that time.
- thrtythreeforty 4y ago
  Ha, I like the irony of being picky about the bits that came off the CD then immediately mashing it into a medium-bitrate MP3. I'm not judging; I spent more time curating a WMA collection than I care to admit.
  - brewdad 4y ago
    I keep 3 copies of every CD I own (4 if you count the CD itself). A FLAC copy ripped using EAC that lives on my NAS and gets streamed in my home. An MP3 copy at a 192 bitrate for use in our cars. And a 128 bit OPUS file that lives on my phone. It's a pretty easy workflow. EAC to rip. FlacSquisher to convert to MP3 and OPUS. Then copy the files where they need to go and delete them from my laptop. CD then goes into a bin in the garage until I need it again or want to admire the artwork.
- leokennis 4y ago
  My audio quality journey went from: - 192 kbps CBR mp3 - this was supposed to be good enough (it is) and I had an iPod with only 20 GB so I went with it - V0 VBR mp3 - I told myself I could hear the difference on my now slightly fancier headphones, and this would not kill my OiNK and later What.cd ratio as fast as lossless - FLAC, if possible 192 KHz and 24 bit - now I got into really expensive headphones and I only downloaded the most verified of torrents (if possible vinyl rips) or I ripped using all the EAC/Paranoia guides out there. Played music via Foobar2000 with some plugins to minimize “interference” in the audio path. Had a full DAC + Amp setup - Got a job and kids - 256 kbps VBR AAC, via Bluetooth to my AirPods Pro - I don’t have time anymore to fret about audio quality, streaming is so super convenient and let’s be honest, above a certain baseline no one hears the difference anyway…
  - puzzlingcaptcha 4y ago
    Hearing begins to deteriorate in the late 20s / early 30s, so for better of worse audiophilia is a young people's game.
    - kirenida 4y ago
      That's the funny thing - young people can hear better, but most don't have enough money to buy the really fancy stuff until they get older and their hearing deteriorates.
- snarfy 4y ago
  Exact Audio Copy is a marvel of ripping technology. I would 100% use it if I cared about ripping CDs accurately. Ages ago I made custom cdrom drivers that would purposefully randomize data returned from reads (cd copy protection). EAC would rip right through it without skipping a beat and reconstruct the correct audio. The only way to defeat it was to never return all of data, randomized or not.
ploek 4y ago
Not sure what the confidence intervals of these numbers are. For example, the BH14NS40 drive is listed with an accuracy of 99.4937, whereas the WH14NS40 is listed with 98.0869. These are the same model of drive with the black and the white front respectively.
- sandreas 4y ago
  Sometimes it's different firmware revisions, sometimes it's just statistical noise... I wrote this article mainly for myself... I just converted the dbPowerAmp stats into a somewhat searchable JavaScript table and added some useful notes I found out over the last days. I did not expect HN Top 10 for a whole day with this... :-)
javajosh 4y ago
I wish I could use my physical CD collection as a "pass" to download high quality rips so I can skip the part where I have to do the labor of ripping them myself.
- solardev 4y ago
  That would be awesome. I know some indie bands do that (buy our CD, get free downloads) but it would be better to see an industry effort, the same way we have MoviesAnywhere for films on disc
- gaudat 4y ago
  >high quality rips I cannot unhear the Flintstones now...
- pvg 4y ago
  It's popped up before in various forms, an early one was https://en.wikipedia.org/wiki/MP3.com#My.MP3.com https://en.wikipedia.org/wiki/MP3.com#My.MP3.com https://www.youtube.com/watch?v=DNb4VKln1uw https://www.youtube.com/watch?v=DNb4VKln1uw
  - waffle_ss 4y ago
    Another one was Murfie (now defunct): https://en.wikipedia.org/wiki/Murfie https://en.wikipedia.org/wiki/Murfie
  - QuackyTheDuck 4y ago
    I think iTunes Match still offers this, too.
    - steve1977 4y ago
      They problem is that you might get remastered editions of tracks. So don’t actually get what you have on CD.
  - deleted 4y ago
    [deleted]
randombits0 4y ago
If you get even an error-corrected rip, why would that not be perfect? I guess I’m failing to understand how any of this could improve accuracy in any way.
- arbitrage 4y ago
  Error-correction in audio CDs can correct errors up to a specific threshold of corruption. Additionally, there is no way to know that you've passed that threshold -- the drive will just return bits, with no way to guarantee that they're correct. A better description for this is "passive" error-correction. To try to get a 100% bit-perfect rip, it's preferable to start off with a drive that you know minimizes errors in the initial read process.
  - randombits0 4y ago
    Ah, so audio CDs were engineered to provide best effort data correction instead of dead-sure data correction to serve the audio market instead of the data market. That just goes to show the lack of design foresight. They were still thinking in terms of grooves carved in plastic or a waveform on tape.
    - at_a_remove 4y ago
      What do you suppose dead-sure data correction would look like? My guess is that you couldn't fit a lot of information on it, what with the redundancy to make it perfect.
      - Tempest1981 4y ago
        3 copies of each CD, stored in different locations, inserted into different players, interconnected via ...
      - gnramires 4y ago
        With coding dead-sure correct isn't usually much different in capacity -- you usually don't need to sacrifice bandwidth completely to get reliability. In fact, a simple checksum with a good number of bits (e.g. CRC32) will pretty much give dead-sure accuracy (non-adversarial, you can hash e.g. SHA256 to get cryptographic certainty). If errors were evenly distributed (independent and identically distributed bit flips), it's generally very easy and well known how to obtain dead sure error correction, and the bandwidth you get is known as the channel capacity (C) of the medium (usually in bits/bit or bits/symbol) -- a "good code" operating at a rate R < C (under or equal to capacity) will give you this property; good codes, depending on the error rates, require moderately large block sizes (usually from 8b to 1-2kb in practice). Real media like CDs usually have 'burst errors' like scratches that give a whole bunch of successive bit errors; however, there's an interleaving process to "spread" the errors across blocks, i.e. spread the information so it will resist a scratch. In an absolute way, indeed it's impossible to guarantee almost no errors (although you can guarantee almost no undetected errors) -- simply because your CD might be ruined in a way (which I guess isn't all too unlikely). By setting your rate R to a reasonable level above your drive error rates, you can get almost no errors (as few as you like) within those bounds (and fail above). Here's a typical error rate curve for a moderately large (255b) code: https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction#/media/File:RS_BER.png https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_cor...
nickelpro 4y ago
I mean this is mostly nonsense right? The data is digitally encoded 16-bit PCM, and already has builtin CIRC error correction, there is no "quality" or "accuracy". Your software/hardware either correctly ripped the data or it didn't and this can be trivially verified with crc32 against CUETools or AccurateRip or whatever.
- gruez 4y ago
  Evidently not, as seen by the linked post: https://forum.dbpoweramp.com/showthread.php?48320-CD-Drive-Accuracy-2022 https://forum.dbpoweramp.com/showthread.php?48320-CD-Drive-A... The data seems to be based on telemetry collected for a CD ripping software, which I'm slightly more inclined to believe is real than some mumbo jumbo about vinyl warmth or whatever.
  - nickelpro 4y ago
    So look at how the data is broken down: > Drive: HL-DT-ST - BD-RE BH14NS48 (116 users): Submissions: 10260 accurate, 23 inaccurate, 99.7763 % accuracy 23 of these submissions come from a broken drive, or the disc is damaged to the point a correct read cannot be made. It's not that the drive is producing 99.7% accurate data, there are 10260 100% accurate submissions and there are 23 wrong submissions. It's a binary state, either the drive is functional and the CD in decent condition, or the drive is broken/CD is damaged. Some drives may have a higher failure rate than other drives, but every drive is either 100% accurate or busted, there is no 95% accurate drive. That's just a broken drive.
    - mvhvv 4y ago
      It's definitely unclear what "inaccurate" means in this sense? Is an entire track inaccurate if a single sample is inaccurate? In that case then yeah, rather than measuring some level of audio purity, this is measuring your likelihood of getting a perfect rip before taking CD condition into account.
    - mlyle 4y ago
      > It's a binary state, either the drive is functional and the CD in decent condition No. How good the drive is at reading marginal discs varies a lot between drives. The problem is, these populations are not identical disks, and the error rates are low enough that we're not really sure we're seeing a good metric of this.
shmerl 4y ago
I don't get it. It's not analog data. So how can quality of digital data differ unless you have deteriorated disk and simply data loss? Is this about what hardware recovers data from defective disks better?
- userbinator 4y ago
  The data is digital but the reading is actually somewhat error-prone; even when the disc and drive are perfect, occasional correctable errors will appear. Also, in audio mode, the error correction is weaker than in data mode.
  - shmerl 4y ago
    So it means some percentage of data can end up being incorrect depending on the quality of the drive?
    - giantrobot 4y ago
      Sort of. If you take the same disc between different drives it's possible to get different readings on each of the drives. Red Book audio data is at a fairly high frequency with multiple channels. A few corrupted samples are likely not noticeable. So its error correction is best effort and interpolates between previous and later samples. Two different drives with different read mechanisms and implementation of the Red Book standard might produce different samples when reading an error and depending on the nature of the error.
    - mlyle 4y ago
      If your disc is marginal, some data can end up being incorrect. Depending upon the quality of the drive mechanism itself, and how it reports errors to the ripping software, you can end up with incorrect data more or less often.
- adql 4y ago
  There is no "digital data" in physical reality. There is "analog data that is within a threshold of the bit that we decided". Hard drive or CD doesn't read "1" or "0", it reads say (after normalization) 0.823V. Or 0.654V. Or 0.983V. The way circuit is designed decides that above some value its "1", below that is "0", but physical deterioration and material variance will change that value and it will differ bit by bit too. It's all good when signal is strong and say all the 1's are > 0.8, all the 0's are < 0.2 but when it starts to blur (again, bad media, degradation etc.) you get bits that can be 1 one read, 0 another. And having "tri state" input that can say "ok, it's between 0.4-0.6, we can't tell whetehr that's 0 or 1" is generally rare.
Nav_Panel 4y ago
Sadly this omits the metric I'm most interested in, which is speed. I've noticed that, with the same rip settings, different drives -- some are a lot faster, but both produce bit-perfect rips. Biggest difference was between a slim, new consumer drive, and an old, late 90s IDE drive. The latter was significantly faster, and had far better error correction too! In general, error correction adds a lot of time. My sense is it will re-read the damaged sectors several times and take the "most common" reading. Then, it compares that with the external full-track hashes to establish correctness. So, it has to do a lot of seeking to read and re-read a damaged portion, which can take minutes for "secure" rips in EAC.
- chasil 4y ago
  I usually rely on cdparanoia, which claims accuracy, but not speed. https://xiph.org/paranoia/ https://xiph.org/paranoia/
- steve1977 4y ago
  Some drives (for example those using Pioneer PureRead) will actually vary parameters like laser power and angle between re-reads, so it‘s possible that a damaged sector can get read probably after some retries.
indigodaddy 4y ago
Can anyone comment on why the author suggests to “DISABLE C2 error correction” beyond his assertion that most drives just don’t do it well? Does it impede the process and/or actually produce inferior rips? Or is it just that in the vast majority of ripping outcomes, C2 error correction makes little to no difference ? (and might perhaps even cause issues?)
- aidenn0 4y ago
  According to wikipedia, C2 error correction is lossy on VCD and CDDA, but not on data CDs.
  - account42 4y ago
    > but not on data CDs Except when intentional errors are used for copy protection.
  - TheRealDunkirk 4y ago
    Why bother? If you make a CD drive to go into a computer (and not a stereo cabinet), why bother to have a lossy error correction method, when you must have a lossless one sitting right beside it?
  - kroeckx 4y ago
    C2 is error detection, not correction. C1 is the error correction. I think what wikipedia is trying to say is that the C2 error detection just points out something is wrong, even after the C1 error correction, and so you can't fix it. But a data CD has additional error correction, so it can correct more errors.
- orev 4y ago
  When ripping with EAC, you want EAC to be doing the error detection/correction, not C2. EAC tries to read the data multiple times and takes the best results. C2 will hide issues in the raw data.
  - indigodaddy 4y ago
flobosg 4y ago
This reminds me of “Why I Ripped The Same CD 300 Times” – https://john-millikin.com/%F0%9F%A4%94/why-i-ripped-the-same-cd-300-times https://john-millikin.com/%F0%9F%A4%94/why-i-ripped-the-same... (HN discussion: https://news.ycombinator.com/item?id=17649374 https://news.ycombinator.com/item?id=17649374)
- sandreas 4y ago
  Thank you, this is a great ressource for understanding how cd ripping works! I added this to the article along with some other things, I took from this discussion. Thank you HN for providing more details!
- xtracto 4y ago
  This is a great great read thanks, and the follow up HN comment regarding "weak sectors" is amazing.
rodric 4y ago
X Lossless Decoder is a good alternative for the Mac – and perhaps the only app that runs natively on PowerPC, Intel and ARM! https://tmkk.undo.jp/xld/index_e.html https://tmkk.undo.jp/xld/index_e.html
- ace2358 4y ago
  So many reasons to love this app :)
kobaroko 4y ago
I don't get it. CD is digital isn't zero always zero and one is always one? Are there no checksum or some other methods that ensure that the data is read in correct manner?
- ColonelBlimp 4y ago
  I suggest you read adql's response below. Also copied here just in case: "There is no "digital data" in physical reality. There is "analog data that is within a threshold of the bit that we decided". Hard drive or CD doesn't read "1" or "0", it reads say (after normalization) 0.823V. Or 0.654V. Or 0.983V. The way circuit is designed decides that above some value its "1", below that is "0", but physical deterioration and material variance will change that value and it will differ bit by bit too. It's all good when signal is strong and say all the 1's are > 0.8, all the 0's are < 0.2 but when it starts to blur (again, bad media, degradation etc.) you get bits that can be 1 one read, 0 another. And having "tri state" input that can say "ok, it's between 0.4-0.6, we can't tell whetehr that's 0 or 1" is generally rare."
liotier 4y ago
The much vaunted Plextor aren't as good as I thought they were...
- sandreas 4y ago
  That's something that surprised me, too.
- kevin_thibedeau 4y ago
  They're only listing new drives. Plextor hasn't made their own transports for a long time.
  - liotier 4y ago
    The source doesn't mention anything about that - it merely reflects popular submissions by a self-selected pool.
- rasz 4y ago
  Its amazing how bad interpretation of statistical data can make you think.
speedgoose 4y ago
Is bit perfect reading necessary? It’s so many samples per second, 44100 to be precise, than one bit error once in a while cannot be noticed. And it’s not like audio is actually high fidelity. Any DAC will introduce a lot of errors. And the original recordings are not perfect either. Microphones, loud speakers, amplifiers, that’s a lot more errors than one wrong bit too.
- MaPi_ 4y ago
  I imagine that a bit flip in the most significant bit could cause an unpleasant pop.
  - speedgoose 4y ago
    I'm not sure a loud speaker can produce a pop so quickly.
    - martyvis 4y ago
      A bit flip at the most significant bit is a one cycle 22.05kHz pulse - so yes you almost certainly wouldn't hear it even if the speaker could reproduce it.
      - jefftk 4y ago
        You would totally hear it, as a small click. I had a bug in some audio software I was working with that did almost exactly this, and it sounded terrible.
    - danadam 4y ago
      Here are some examples to listen to: https://audiophilestyle.com/forums/topic/61633-intel-cpus-don%E2%80%99t-support-ecc-memory-how-bad-for-av-quality/#comment-1102705 https://audiophilestyle.com/forums/topic/61633-intel-cpus-do...
      - speedgoose 4y ago
rootw0rm 4y ago
shout out to OiNK, where i first learned about proper rips
letters90 4y ago
No mentioning of abcde ? Would like to know how it's seen in the ripping community https://wiki.ubuntuusers.de/abcde/ https://wiki.ubuntuusers.de/abcde/
- sandreas 4y ago
  thanks, I'll add that later.
kroeckx 4y ago
If you care about accurate rips on Linux, the best tool to use is whipper: https://github.com/whipper-team/whipper https://github.com/whipper-team/whipper. It makes use of the AccurateRip database, which is used to calculate the statistics. I don't know about any other native Linux application that makes use of it. Other tools like cdparanoia, and all the other wrappers around it, just attempt to read it multiple times and still get the wrong result, as the post shows.
- sandreas 4y ago
  Great addition, thank you... I'll add this to the article soon
- SSLy 4y ago
  Or just run EAC in wine.
- AdmiralAsshat 4y ago
  The frustrating thing about AccurateRip is that several open source apps can pull down from it to compare your local rip, but IIRC the only app that is allowed to push rips back up to the AccurateRip DB (and hence make it more "accurate") is the proprietary, Windows-only EAC.
  - 88 4y ago
    That’s a feature. The value of AccurateRip comes from the accuracy of data submitted to it. Tightly controlling how data can be submitted allows that accuracy to be maintained.
- ubercow13 4y ago
  Isn't "just" attempting to read multiple times basically how AccurateRip is itself populated, as that is how EAC works?
- UltraViolence 4y ago
  Looking at the source code Whipper seems to be a Python wrapper around common command line tools in Linux.
Cockbrand 4y ago
Thank you for posting this! I still have hundreds of CDs that I'd like to rip, but I don't have any device to connect my ancient Plextor SCSI CD drive to. I didn't want to buy just any CD drive because I want to rip these CDs as accurately as possible. One of the top contestants (HP GUE1N) is available for cheap on eBay, so I went and bought one. So I guess I'll do a lot of disc changing during the long winter evenings to come, but then I'll finally be able to throw out all these CDs.
- kevin_thibedeau 4y ago
  I set up a system with two SCSI drives and one USB to mass rip a few hundred discs. Modern Linux can't handle media changes over SCSI without interfering with an existing transfer so I had to synchronize disc swaps on those two drives. I wouldn't attempt it with only one drive.
- TacticalCoder 4y ago
  > I didn't want to buy just any CD drive because I want to rip these CDs as accurately as possible. Ripping software like EAC or whipper do verify, using an online DB of rips, that your rip is 100% bitperfect. So ripping "as accurately as possible" ain't a concern: your rip is either 100% correct, bit for bit, or it's not and you should start over. If you're on Windows use EAC while if you're on Linux, use whipper. I use whipper and it's nowadays stock on many Linux distros (Fedora, Debian, etc.). > but then I'll finally be able to throw out all these CDs. Well I think that legally you need to keep the CDs if you want to keep your rips (it may depend on the country but in Europe you're allowed to rip CDs you physically own).
extropy 4y ago
The accuracy figures in TA are kinda low - 99.7 for the top one, averaging out at 98.5%. Anyone has some idea what is this measuring? Bit accuracy (way too low)? A full disk read 100% error free? The actual accuracy really depends on the quality of the disc, is this measured with a reference disc?
- rasz 4y ago
  Its a shit way of expressing data they collect. It means every single drive model had at least one owner try to rip badly scratched disk.
- gcbirzan 4y ago
  How many of the discs ripped were 100% error free, from what I understand it compares against a database of checksums, the one that has the most 'votes' is considered to be correct.
- kroeckx 4y ago
  This is based on submission to AccurateRip. As I understand it, it's how many tracks submitted by users owning that drive match the what AccurateRip considers the correct rip.
  - TacticalCoder 4y ago
    > As I understand it, it's how many tracks submitted by users owning that drive match the what AccurateRip considers the correct rip. Wait: I'm pretty sure that's not how it works at all. No matter the drive, there's only one correct rip. And two people won't, by coincidence, happen to read the same disc with the exact same error(s). So when you rip and compare to the AccurateRip DB, you know you have the correct rip if it matches the one already in the DB. I don't think AccurateRip "considers" rips correct not: to me it knows with 100% guarantee. Which is the entire selling point of the AccurateRip DB. And which is why it's called that way.
daneel_w 4y ago
Could someone give a brief explanation of why this (bitwise accuracy) is such a problem when reading CDDA discs while it's not a problem at all for regular data discs?
- TazeTSchnitzel 4y ago
  The problem is that there's several layers of encoding and encapsulation, each with their own type of error correction and bits of extra information, and the system was designed to hide all the layers from the end user; in its normal mode of operation, the final output of the CD drive is audio (digital or analogue), not the contents of an “audio file” or anything like that. There's also the fact that audio CD drives aren't designed for truly random access (jumping to different tracks is approximate IIRC). So it's a problem to dump because there's many options for which layer to dump, and it depends on the drive which layer you can get to, and whether you can get it without error correction already applied. For data discs (or more accurately, the data portion of a disc, because some discs have other types of content on them too), the drive essentially functions as a standard random-access block device, just like a hard drive or floppy disk. The error correction etc is still hidden from you, but as long as your entire disc is just data, there's an easy, obvious thing to dump: the bytes of that block device.
- tremon 4y ago
  In addition to what the sibling says, CDDA discs have less error correction than CDROM discs. Each audio sector (frame) carries 2352 bytes of audio data, while a data sector carries just 2048 bytes of data; a different coding is used to reduce bit errors, at the expense of storage capacity. On top of that, the audio extraction mode (in the drive) is usually optimized for constant-time delivery rather than accuracy; if an audio sector is damaged, most players will opt to deliver inaccurate data rather than stop the audio stream altogether.
  - kroeckx 4y ago
    An audio CD has 2352 audio bytes per sector. The sector also contains C1 error correction and C2 error detection. On a data CD, those 2352 bytes are split in 2048 data bytes, plus an additional 4 error detection, 276 error correction, plus some other bytes including an address. So there is an extra layer of error correction.
PaulHoule 4y ago
It is possible to make a CD that has a DTS data stream on it instead of a PCM stream and most home theatre receivers will process it as a 5.1 multichannel signal if you connect the SPIDF output of a CD player to the receiver. https://en.wikipedia.org/wiki/5.1_Music_Disc https://en.wikipedia.org/wiki/5.1_Music_Disc I have a 300 disc Sony changer that I am filling up with DTS discs. The normal interpolation algorithm in CD players is not going to work right for a DTA stream so the quality of the stream is excellent. This guy dumped the digital output of two identical CDs into a digital recorder and found the output was bit-by-bit identical https://www.youtube.com/watch?v=f-QxLAxwxkM https://www.youtube.com/watch?v=f-QxLAxwxkM For the life of me I can’t figure out why Techmoan hasn’t demoed a DTS cd on his show.
- sandreas 4y ago
  Cool.
_def 4y ago
> NEVER normalize (!!) Why not? Shouldn't it be non-destructive?
- UltraViolence 4y ago
  No, it recomputes the samples and there's always some loss during this process.
  - brewdad 4y ago
    I realized that I had normalization set to 98%. I think that's the only setting I changed after going through all of the menus. I'm not re-ripping hundreds of CDs at this point, so I guess I'll have to live with almost accurate. :)
- nayuki 4y ago
  Suppose you have an unsigned 16-bit integer signal of [0, 1, 3, 2000]. You want to multiply every value by some scaling constant so that the maximum value is 65535. So the multiplier is 65535/2000, and the intermediate result is [0, 32.7675, 98.3025, 65535]. But because the output must be integers, so decimals will get rounded off. It is possible to restore the original numbers exactly if you know the scaling factor, but it's an extra complication that is not worth the hassle. It's better not to burn the normalization into the CD rip; it's better to do normalization on the fly at playback time.
UltraViolence 4y ago
I just want to add that you don't need special ripping software. Just clean your CD's carefully and meticulously before ripping. If possible also clean the CD-ROM player lens using a cotton swab wrapped in non-abrasive lens tissue (available at photographic stores) and dipped in lens cleaning fluid. Check that your ripping software doesn't do any other processing. For example the 'freac' ripping software has an "Enable Signal Processing" menu item which should be turned off.
amelius 4y ago
The problem: some music isn't even released on CD anymore.
- deleted 4y ago
  [deleted]
indigodaddy 4y ago
I’ve been using CyanRip and it’s been working nicely. Has excellent defaults Eg just run cyanrip from cli with a CD in and it rips to flac in the current dir with the most sensible/reasonable defaults (at least it’s opinions have worked for me). https://github.com/cyanreg/cyanrip https://github.com/cyanreg/cyanrip
- sandreas 4y ago
  thanks, will add this later

208 points by sandreas 4y ago

Wow I had no idea EAC still existed. Back when I used it, hard drive space was scarce and I thought I was being extravagent ripping my collection at 160kb/s mp3 files. Does EAC today offer any advantage over cdparanoia?

Crontab 4y ago
Back when I was ripping my collection to FLAC, I used EAC because of AccurateRip, which is something that cdparanoia did not offer - at least at that time.
thrtythreeforty 4y ago
Ha, I like the irony of being picky about the bits that came off the CD then immediately mashing it into a medium-bitrate MP3. I'm not judging; I spent more time curating a WMA collection than I care to admit.
- brewdad 4y ago
  I keep 3 copies of every CD I own (4 if you count the CD itself). A FLAC copy ripped using EAC that lives on my NAS and gets streamed in my home. An MP3 copy at a 192 bitrate for use in our cars. And a 128 bit OPUS file that lives on my phone. It's a pretty easy workflow. EAC to rip. FlacSquisher to convert to MP3 and OPUS. Then copy the files where they need to go and delete them from my laptop. CD then goes into a bin in the garage until I need it again or want to admire the artwork.
leokennis 4y ago
My audio quality journey went from: - 192 kbps CBR mp3 - this was supposed to be good enough (it is) and I had an iPod with only 20 GB so I went with it - V0 VBR mp3 - I told myself I could hear the difference on my now slightly fancier headphones, and this would not kill my OiNK and later What.cd ratio as fast as lossless - FLAC, if possible 192 KHz and 24 bit - now I got into really expensive headphones and I only downloaded the most verified of torrents (if possible vinyl rips) or I ripped using all the EAC/Paranoia guides out there. Played music via Foobar2000 with some plugins to minimize “interference” in the audio path. Had a full DAC + Amp setup - Got a job and kids - 256 kbps VBR AAC, via Bluetooth to my AirPods Pro - I don’t have time anymore to fret about audio quality, streaming is so super convenient and let’s be honest, above a certain baseline no one hears the difference anyway…
- puzzlingcaptcha 4y ago
  Hearing begins to deteriorate in the late 20s / early 30s, so for better of worse audiophilia is a young people's game.
  - kirenida 4y ago
    That's the funny thing - young people can hear better, but most don't have enough money to buy the really fancy stuff until they get older and their hearing deteriorates.
snarfy 4y ago
Exact Audio Copy is a marvel of ripping technology. I would 100% use it if I cared about ripping CDs accurately. Ages ago I made custom cdrom drivers that would purposefully randomize data returned from reads (cd copy protection). EAC would rip right through it without skipping a beat and reconstruct the correct audio. The only way to defeat it was to never return all of data, randomized or not.

ploek 4y ago

Not sure what the confidence intervals of these numbers are. For example, the BH14NS40 drive is listed with an accuracy of 99.4937, whereas the WH14NS40 is listed with 98.0869. These are the same model of drive with the black and the white front respectively.

sandreas 4y ago
Sometimes it's different firmware revisions, sometimes it's just statistical noise... I wrote this article mainly for myself... I just converted the dbPowerAmp stats into a somewhat searchable JavaScript table and added some useful notes I found out over the last days. I did not expect HN Top 10 for a whole day with this... :-)

javajosh 4y ago

I wish I could use my physical CD collection as a "pass" to download high quality rips so I can skip the part where I have to do the labor of ripping them myself.

solardev 4y ago
That would be awesome. I know some indie bands do that (buy our CD, get free downloads) but it would be better to see an industry effort, the same way we have MoviesAnywhere for films on disc
gaudat 4y ago
>high quality rips I cannot unhear the Flintstones now...
pvg 4y ago
It's popped up before in various forms, an early one was https://en.wikipedia.org/wiki/MP3.com#My.MP3.com https://en.wikipedia.org/wiki/MP3.com#My.MP3.com https://www.youtube.com/watch?v=DNb4VKln1uw https://www.youtube.com/watch?v=DNb4VKln1uw
- waffle_ss 4y ago
  Another one was Murfie (now defunct): https://en.wikipedia.org/wiki/Murfie https://en.wikipedia.org/wiki/Murfie
- QuackyTheDuck 4y ago
  I think iTunes Match still offers this, too.
  - steve1977 4y ago
    They problem is that you might get remastered editions of tracks. So don’t actually get what you have on CD.
- deleted 4y ago
  [deleted]

randombits0 4y ago

If you get even an error-corrected rip, why would that not be perfect? I guess I’m failing to understand how any of this could improve accuracy in any way.

arbitrage 4y ago
Error-correction in audio CDs can correct errors up to a specific threshold of corruption. Additionally, there is no way to know that you've passed that threshold -- the drive will just return bits, with no way to guarantee that they're correct. A better description for this is "passive" error-correction. To try to get a 100% bit-perfect rip, it's preferable to start off with a drive that you know minimizes errors in the initial read process.
- randombits0 4y ago
  Ah, so audio CDs were engineered to provide best effort data correction instead of dead-sure data correction to serve the audio market instead of the data market. That just goes to show the lack of design foresight. They were still thinking in terms of grooves carved in plastic or a waveform on tape.
  - at_a_remove 4y ago
    What do you suppose dead-sure data correction would look like? My guess is that you couldn't fit a lot of information on it, what with the redundancy to make it perfect.
    - Tempest1981 4y ago
      3 copies of each CD, stored in different locations, inserted into different players, interconnected via ...
    - gnramires 4y ago
      With coding dead-sure correct isn't usually much different in capacity -- you usually don't need to sacrifice bandwidth completely to get reliability. In fact, a simple checksum with a good number of bits (e.g. CRC32) will pretty much give dead-sure accuracy (non-adversarial, you can hash e.g. SHA256 to get cryptographic certainty). If errors were evenly distributed (independent and identically distributed bit flips), it's generally very easy and well known how to obtain dead sure error correction, and the bandwidth you get is known as the channel capacity (C) of the medium (usually in bits/bit or bits/symbol) -- a "good code" operating at a rate R < C (under or equal to capacity) will give you this property; good codes, depending on the error rates, require moderately large block sizes (usually from 8b to 1-2kb in practice). Real media like CDs usually have 'burst errors' like scratches that give a whole bunch of successive bit errors; however, there's an interleaving process to "spread" the errors across blocks, i.e. spread the information so it will resist a scratch. In an absolute way, indeed it's impossible to guarantee almost no errors (although you can guarantee almost no undetected errors) -- simply because your CD might be ruined in a way (which I guess isn't all too unlikely). By setting your rate R to a reasonable level above your drive error rates, you can get almost no errors (as few as you like) within those bounds (and fail above). Here's a typical error rate curve for a moderately large (255b) code: https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction#/media/File:RS_BER.png https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_cor...

nickelpro 4y ago

I mean this is mostly nonsense right? The data is digitally encoded 16-bit PCM, and already has builtin CIRC error correction, there is no "quality" or "accuracy". Your software/hardware either correctly ripped the data or it didn't and this can be trivially verified with crc32 against CUETools or AccurateRip or whatever.

gruez 4y ago
Evidently not, as seen by the linked post: https://forum.dbpoweramp.com/showthread.php?48320-CD-Drive-Accuracy-2022 https://forum.dbpoweramp.com/showthread.php?48320-CD-Drive-A... The data seems to be based on telemetry collected for a CD ripping software, which I'm slightly more inclined to believe is real than some mumbo jumbo about vinyl warmth or whatever.
- nickelpro 4y ago
  So look at how the data is broken down: > Drive: HL-DT-ST - BD-RE BH14NS48 (116 users): Submissions: 10260 accurate, 23 inaccurate, 99.7763 % accuracy 23 of these submissions come from a broken drive, or the disc is damaged to the point a correct read cannot be made. It's not that the drive is producing 99.7% accurate data, there are 10260 100% accurate submissions and there are 23 wrong submissions. It's a binary state, either the drive is functional and the CD in decent condition, or the drive is broken/CD is damaged. Some drives may have a higher failure rate than other drives, but every drive is either 100% accurate or busted, there is no 95% accurate drive. That's just a broken drive.
  - mvhvv 4y ago
    It's definitely unclear what "inaccurate" means in this sense? Is an entire track inaccurate if a single sample is inaccurate? In that case then yeah, rather than measuring some level of audio purity, this is measuring your likelihood of getting a perfect rip before taking CD condition into account.
  - mlyle 4y ago
    > It's a binary state, either the drive is functional and the CD in decent condition No. How good the drive is at reading marginal discs varies a lot between drives. The problem is, these populations are not identical disks, and the error rates are low enough that we're not really sure we're seeing a good metric of this.

shmerl 4y ago

I don't get it. It's not analog data. So how can quality of digital data differ unless you have deteriorated disk and simply data loss? Is this about what hardware recovers data from defective disks better?

userbinator 4y ago
The data is digital but the reading is actually somewhat error-prone; even when the disc and drive are perfect, occasional correctable errors will appear. Also, in audio mode, the error correction is weaker than in data mode.
- shmerl 4y ago
  So it means some percentage of data can end up being incorrect depending on the quality of the drive?
  - giantrobot 4y ago
    Sort of. If you take the same disc between different drives it's possible to get different readings on each of the drives. Red Book audio data is at a fairly high frequency with multiple channels. A few corrupted samples are likely not noticeable. So its error correction is best effort and interpolates between previous and later samples. Two different drives with different read mechanisms and implementation of the Red Book standard might produce different samples when reading an error and depending on the nature of the error.
  - mlyle 4y ago
    If your disc is marginal, some data can end up being incorrect. Depending upon the quality of the drive mechanism itself, and how it reports errors to the ripping software, you can end up with incorrect data more or less often.
adql 4y ago
There is no "digital data" in physical reality. There is "analog data that is within a threshold of the bit that we decided". Hard drive or CD doesn't read "1" or "0", it reads say (after normalization) 0.823V. Or 0.654V. Or 0.983V. The way circuit is designed decides that above some value its "1", below that is "0", but physical deterioration and material variance will change that value and it will differ bit by bit too. It's all good when signal is strong and say all the 1's are > 0.8, all the 0's are < 0.2 but when it starts to blur (again, bad media, degradation etc.) you get bits that can be 1 one read, 0 another. And having "tri state" input that can say "ok, it's between 0.4-0.6, we can't tell whetehr that's 0 or 1" is generally rare.

Nav_Panel 4y ago

Sadly this omits the metric I'm most interested in, which is speed. I've noticed that, with the same rip settings, different drives -- some are a lot faster, but both produce bit-perfect rips. Biggest difference was between a slim, new consumer drive, and an old, late 90s IDE drive. The latter was significantly faster, and had far better error correction too! In general, error correction adds a lot of time. My sense is it will re-read the damaged sectors several times and take the "most common" reading. Then, it compares that with the external full-track hashes to establish correctness. So, it has to do a lot of seeking to read and re-read a damaged portion, which can take minutes for "secure" rips in EAC.

chasil 4y ago
I usually rely on cdparanoia, which claims accuracy, but not speed. https://xiph.org/paranoia/ https://xiph.org/paranoia/
steve1977 4y ago
Some drives (for example those using Pioneer PureRead) will actually vary parameters like laser power and angle between re-reads, so it‘s possible that a damaged sector can get read probably after some retries.

indigodaddy 4y ago

Can anyone comment on why the author suggests to “DISABLE C2 error correction” beyond his assertion that most drives just don’t do it well? Does it impede the process and/or actually produce inferior rips? Or is it just that in the vast majority of ripping outcomes, C2 error correction makes little to no difference ? (and might perhaps even cause issues?)

aidenn0 4y ago
According to wikipedia, C2 error correction is lossy on VCD and CDDA, but not on data CDs.
- account42 4y ago
  > but not on data CDs Except when intentional errors are used for copy protection.
- TheRealDunkirk 4y ago
  Why bother? If you make a CD drive to go into a computer (and not a stereo cabinet), why bother to have a lossy error correction method, when you must have a lossless one sitting right beside it?
- kroeckx 4y ago
  C2 is error detection, not correction. C1 is the error correction. I think what wikipedia is trying to say is that the C2 error detection just points out something is wrong, even after the C1 error correction, and so you can't fix it. But a data CD has additional error correction, so it can correct more errors.
orev 4y ago
When ripping with EAC, you want EAC to be doing the error detection/correction, not C2. EAC tries to read the data multiple times and takes the best results. C2 will hide issues in the raw data.
- indigodaddy 4y ago

flobosg 4y ago

This reminds me of “Why I Ripped The Same CD 300 Times” – https://john-millikin.com/%F0%9F%A4%94/why-i-ripped-the-same-cd-300-times https://john-millikin.com/%F0%9F%A4%94/why-i-ripped-the-same... (HN discussion: https://news.ycombinator.com/item?id=17649374 https://news.ycombinator.com/item?id=17649374)

sandreas 4y ago
Thank you, this is a great ressource for understanding how cd ripping works! I added this to the article along with some other things, I took from this discussion. Thank you HN for providing more details!
xtracto 4y ago
This is a great great read thanks, and the follow up HN comment regarding "weak sectors" is amazing.

rodric 4y ago

X Lossless Decoder is a good alternative for the Mac – and perhaps the only app that runs natively on PowerPC, Intel and ARM! https://tmkk.undo.jp/xld/index_e.html https://tmkk.undo.jp/xld/index_e.html

ace2358 4y ago
So many reasons to love this app :)

kobaroko 4y ago

I don't get it. CD is digital isn't zero always zero and one is always one? Are there no checksum or some other methods that ensure that the data is read in correct manner?

ColonelBlimp 4y ago
I suggest you read adql's response below. Also copied here just in case: "There is no "digital data" in physical reality. There is "analog data that is within a threshold of the bit that we decided". Hard drive or CD doesn't read "1" or "0", it reads say (after normalization) 0.823V. Or 0.654V. Or 0.983V. The way circuit is designed decides that above some value its "1", below that is "0", but physical deterioration and material variance will change that value and it will differ bit by bit too. It's all good when signal is strong and say all the 1's are > 0.8, all the 0's are < 0.2 but when it starts to blur (again, bad media, degradation etc.) you get bits that can be 1 one read, 0 another. And having "tri state" input that can say "ok, it's between 0.4-0.6, we can't tell whetehr that's 0 or 1" is generally rare."

liotier 4y ago

The much vaunted Plextor aren't as good as I thought they were...

sandreas 4y ago
That's something that surprised me, too.
kevin_thibedeau 4y ago
They're only listing new drives. Plextor hasn't made their own transports for a long time.
- liotier 4y ago
  The source doesn't mention anything about that - it merely reflects popular submissions by a self-selected pool.
rasz 4y ago
Its amazing how bad interpretation of statistical data can make you think.

speedgoose 4y ago

Is bit perfect reading necessary? It’s so many samples per second, 44100 to be precise, than one bit error once in a while cannot be noticed. And it’s not like audio is actually high fidelity. Any DAC will introduce a lot of errors. And the original recordings are not perfect either. Microphones, loud speakers, amplifiers, that’s a lot more errors than one wrong bit too.

MaPi_ 4y ago
I imagine that a bit flip in the most significant bit could cause an unpleasant pop.
- speedgoose 4y ago
  I'm not sure a loud speaker can produce a pop so quickly.
  - martyvis 4y ago
    A bit flip at the most significant bit is a one cycle 22.05kHz pulse - so yes you almost certainly wouldn't hear it even if the speaker could reproduce it.
    - jefftk 4y ago
      You would totally hear it, as a small click. I had a bug in some audio software I was working with that did almost exactly this, and it sounded terrible.
  - danadam 4y ago
    Here are some examples to listen to: https://audiophilestyle.com/forums/topic/61633-intel-cpus-don%E2%80%99t-support-ecc-memory-how-bad-for-av-quality/#comment-1102705 https://audiophilestyle.com/forums/topic/61633-intel-cpus-do...
    - speedgoose 4y ago

rootw0rm 4y ago

shout out to OiNK, where i first learned about proper rips

letters90 4y ago

No mentioning of abcde ? Would like to know how it's seen in the ripping community https://wiki.ubuntuusers.de/abcde/ https://wiki.ubuntuusers.de/abcde/

sandreas 4y ago
thanks, I'll add that later.

kroeckx 4y ago

If you care about accurate rips on Linux, the best tool to use is whipper: https://github.com/whipper-team/whipper https://github.com/whipper-team/whipper. It makes use of the AccurateRip database, which is used to calculate the statistics. I don't know about any other native Linux application that makes use of it. Other tools like cdparanoia, and all the other wrappers around it, just attempt to read it multiple times and still get the wrong result, as the post shows.

sandreas 4y ago
Great addition, thank you... I'll add this to the article soon
SSLy 4y ago
Or just run EAC in wine.
AdmiralAsshat 4y ago
The frustrating thing about AccurateRip is that several open source apps can pull down from it to compare your local rip, but IIRC the only app that is allowed to push rips back up to the AccurateRip DB (and hence make it more "accurate") is the proprietary, Windows-only EAC.
- 88 4y ago
  That’s a feature. The value of AccurateRip comes from the accuracy of data submitted to it. Tightly controlling how data can be submitted allows that accuracy to be maintained.
ubercow13 4y ago
Isn't "just" attempting to read multiple times basically how AccurateRip is itself populated, as that is how EAC works?
UltraViolence 4y ago
Looking at the source code Whipper seems to be a Python wrapper around common command line tools in Linux.

Cockbrand 4y ago

Thank you for posting this! I still have hundreds of CDs that I'd like to rip, but I don't have any device to connect my ancient Plextor SCSI CD drive to. I didn't want to buy just any CD drive because I want to rip these CDs as accurately as possible. One of the top contestants (HP GUE1N) is available for cheap on eBay, so I went and bought one. So I guess I'll do a lot of disc changing during the long winter evenings to come, but then I'll finally be able to throw out all these CDs.

kevin_thibedeau 4y ago
I set up a system with two SCSI drives and one USB to mass rip a few hundred discs. Modern Linux can't handle media changes over SCSI without interfering with an existing transfer so I had to synchronize disc swaps on those two drives. I wouldn't attempt it with only one drive.
TacticalCoder 4y ago
> I didn't want to buy just any CD drive because I want to rip these CDs as accurately as possible. Ripping software like EAC or whipper do verify, using an online DB of rips, that your rip is 100% bitperfect. So ripping "as accurately as possible" ain't a concern: your rip is either 100% correct, bit for bit, or it's not and you should start over. If you're on Windows use EAC while if you're on Linux, use whipper. I use whipper and it's nowadays stock on many Linux distros (Fedora, Debian, etc.). > but then I'll finally be able to throw out all these CDs. Well I think that legally you need to keep the CDs if you want to keep your rips (it may depend on the country but in Europe you're allowed to rip CDs you physically own).

extropy 4y ago

The accuracy figures in TA are kinda low - 99.7 for the top one, averaging out at 98.5%. Anyone has some idea what is this measuring? Bit accuracy (way too low)? A full disk read 100% error free? The actual accuracy really depends on the quality of the disc, is this measured with a reference disc?

rasz 4y ago
Its a shit way of expressing data they collect. It means every single drive model had at least one owner try to rip badly scratched disk.
gcbirzan 4y ago
How many of the discs ripped were 100% error free, from what I understand it compares against a database of checksums, the one that has the most 'votes' is considered to be correct.
kroeckx 4y ago
This is based on submission to AccurateRip. As I understand it, it's how many tracks submitted by users owning that drive match the what AccurateRip considers the correct rip.
- TacticalCoder 4y ago
  > As I understand it, it's how many tracks submitted by users owning that drive match the what AccurateRip considers the correct rip. Wait: I'm pretty sure that's not how it works at all. No matter the drive, there's only one correct rip. And two people won't, by coincidence, happen to read the same disc with the exact same error(s). So when you rip and compare to the AccurateRip DB, you know you have the correct rip if it matches the one already in the DB. I don't think AccurateRip "considers" rips correct not: to me it knows with 100% guarantee. Which is the entire selling point of the AccurateRip DB. And which is why it's called that way.

daneel_w 4y ago

Could someone give a brief explanation of why this (bitwise accuracy) is such a problem when reading CDDA discs while it's not a problem at all for regular data discs?

TazeTSchnitzel 4y ago
The problem is that there's several layers of encoding and encapsulation, each with their own type of error correction and bits of extra information, and the system was designed to hide all the layers from the end user; in its normal mode of operation, the final output of the CD drive is audio (digital or analogue), not the contents of an “audio file” or anything like that. There's also the fact that audio CD drives aren't designed for truly random access (jumping to different tracks is approximate IIRC). So it's a problem to dump because there's many options for which layer to dump, and it depends on the drive which layer you can get to, and whether you can get it without error correction already applied. For data discs (or more accurately, the data portion of a disc, because some discs have other types of content on them too), the drive essentially functions as a standard random-access block device, just like a hard drive or floppy disk. The error correction etc is still hidden from you, but as long as your entire disc is just data, there's an easy, obvious thing to dump: the bytes of that block device.
tremon 4y ago
In addition to what the sibling says, CDDA discs have less error correction than CDROM discs. Each audio sector (frame) carries 2352 bytes of audio data, while a data sector carries just 2048 bytes of data; a different coding is used to reduce bit errors, at the expense of storage capacity. On top of that, the audio extraction mode (in the drive) is usually optimized for constant-time delivery rather than accuracy; if an audio sector is damaged, most players will opt to deliver inaccurate data rather than stop the audio stream altogether.
- kroeckx 4y ago
  An audio CD has 2352 audio bytes per sector. The sector also contains C1 error correction and C2 error detection. On a data CD, those 2352 bytes are split in 2048 data bytes, plus an additional 4 error detection, 276 error correction, plus some other bytes including an address. So there is an extra layer of error correction.

PaulHoule 4y ago

It is possible to make a CD that has a DTS data stream on it instead of a PCM stream and most home theatre receivers will process it as a 5.1 multichannel signal if you connect the SPIDF output of a CD player to the receiver. https://en.wikipedia.org/wiki/5.1_Music_Disc https://en.wikipedia.org/wiki/5.1_Music_Disc I have a 300 disc Sony changer that I am filling up with DTS discs. The normal interpolation algorithm in CD players is not going to work right for a DTA stream so the quality of the stream is excellent. This guy dumped the digital output of two identical CDs into a digital recorder and found the output was bit-by-bit identical https://www.youtube.com/watch?v=f-QxLAxwxkM https://www.youtube.com/watch?v=f-QxLAxwxkM For the life of me I can’t figure out why Techmoan hasn’t demoed a DTS cd on his show.

sandreas 4y ago
Cool.

_def 4y ago

> NEVER normalize (!!) Why not? Shouldn't it be non-destructive?

UltraViolence 4y ago
No, it recomputes the samples and there's always some loss during this process.
- brewdad 4y ago
  I realized that I had normalization set to 98%. I think that's the only setting I changed after going through all of the menus. I'm not re-ripping hundreds of CDs at this point, so I guess I'll have to live with almost accurate. :)
nayuki 4y ago
Suppose you have an unsigned 16-bit integer signal of [0, 1, 3, 2000]. You want to multiply every value by some scaling constant so that the maximum value is 65535. So the multiplier is 65535/2000, and the intermediate result is [0, 32.7675, 98.3025, 65535]. But because the output must be integers, so decimals will get rounded off. It is possible to restore the original numbers exactly if you know the scaling factor, but it's an extra complication that is not worth the hassle. It's better not to burn the normalization into the CD rip; it's better to do normalization on the fly at playback time.

UltraViolence 4y ago

I just want to add that you don't need special ripping software. Just clean your CD's carefully and meticulously before ripping. If possible also clean the CD-ROM player lens using a cotton swab wrapped in non-abrasive lens tissue (available at photographic stores) and dipped in lens cleaning fluid. Check that your ripping software doesn't do any other processing. For example the 'freac' ripping software has an "Enable Signal Processing" menu item which should be turned off.

amelius 4y ago

The problem: some music isn't even released on CD anymore.

deleted 4y ago
[deleted]

indigodaddy 4y ago

I’ve been using CyanRip and it’s been working nicely. Has excellent defaults Eg just run cyanrip from cli with a CD in and it rips to flac in the current dir with the most sensible/reasonable defaults (at least it’s opinions have worked for me). https://github.com/cyanreg/cyanrip https://github.com/cyanreg/cyanrip

sandreas 4y ago
thanks, will add this later