Question regarding HDCD and pressing offset

[JustaNewUser]

Hi,
when I use the HDCD DSP on non HDCD discs, the flac files that are output are slightly larger (around 20kb more per avarage 4 min track) compared to a rip without this option. Both rips output the same Checksum.
Now I thought it is safe to leave the HDCD option on even with normal discs (some discs don't even mention that they are HDCDs). But now I am worried if this small change is causes any distortion or change to the music. Do I need to re-rip?
Could it be due to the +6 dB amplification or is this only used when the disc actually is an HDCD?

Also I am curious if I have to (or can) find out if there is a pressing offset on the discs I rip or if the ripper does this automatically?
When I rip, I very often see my rip result being single digit accurate ie. 4, below that often is another result for other discs with a higher number and below that again are two results with different pressing offsets that most often are much higher (double sometimes triple digit). I seldom (or never) had it be the other way around.
So does this mean I am doing something wrong? Or can I count the pressing offsets towards my lower accuracy (same identical results just that the discs were pressed differently)?

A recommendation to make the program even more user friendly: When a profile is created not just the path and filenaming need to be defined anew (which can at least be seen right below the Profile field and so one is reminded about this) but also ALL the metatag options etc. wich are a bit hidden below the options button and then under settings next to the field. This can be a little agitating especially when you notice that you did not change certain options well after ripping many new cds.

Oh and one more, very small, improvement reccomendation: without the HDCD option the log displayed after a rip has the accuracy and pressing offset accuracies for each track neatly one below the other. WITH HDCD enabled these accuracies get skewed a little, and are not all in a row anymore.
Not a big deal.

Thanks for your answers and making a great program even better!

[Spoon]

Re: Question regarding HDCD and pressing offset

If the checksums are the same, then the audio is 100% identical.

The ripper handles pressing checking automatically, any confidence above 1 is all that is needed, or even 1 if you have never ripped the disc yourself.

[JustaNewUser]

Re: Question regarding HDCD and pressing offset

Thanks for the fast repl.

and the different sized output whith the HDCD option? Just coincidence or does the +6 amplification get added to non HDCDs as well?

[garym]

Re: Question regarding HDCD and pressing offset

Thanks for the fast repl.

and the different sized output whith the HDCD option? Just coincidence or does the +6 amplification get added to non HDCDs as well?

you might want to read this:

http://forum.dbpoweramp.com/showthread.php?27540-Ripping-HDCDs-Best-practices&highlight=hdcd

[Henkjan]

Re: Question regarding HDCD and pressing offset

The ripper handles pressing checking automatically, any confidence above 1 is all that is needed, or even 1 if you have never ripped the disc yourself.

so these messages after a rip are not an indication of a problem?

Information ripping to FLAC, 'Track 1' to 'C:\Documents and Settings\Henkjan\Ludus.flac'
AccurateRip Verified Using Pressing Offset +2080, Confidence 2 [old crc 31050553]

[garym]

Re: Question regarding HDCD and pressing offset

so these messages after a rip are not an indication of a problem?

No, that message confirms that your disk matches two independent other rips (confidence = 2). So this is an excellent result.

[JustaNewUser]

Re: Question regarding HDCD and pressing offset

Thanks a lot for the tip (and now I am a bit more confused). I posted my thoughs on that post.

I still am a bit frustrated to still see with almost any rip I do that the result of my rips have a accuracy that has never been the highest (even on high accuracies like 49 or more I still see accuracies "using pressing offset +xxx" that are way higher oftentimes being many times higher like 100-200. It is not because of the Drive I use right?

One last question regaring the version of poweramp and especially the codecs, is it safe/worth it to go from 14.2 to 14.3 (DSP version 7 to 8)? I have (painfully) seen that often a version change can bring its share of troubles, and the program seems to be working well now.
Are the newer flac (right now 1.2.1) and mp3 (lame right now 3.98.4) versions better/recommended/safe or even needed or are the changes tiny.
I hate to find out in a few months after updating that all files now suffer from some sound bug...
Thanks again.

[garym]

Re: Question regarding HDCD and pressing offset

Thanks a lot for the tip (and now I am a bit more confused). I posted my thoughs on that post.

I still am a bit frustrated to still see with almost any rip I do that the result of my rips have a accuracy that has never been the highest (even on high accuracies like 49 or more I still see accuracies "using pressing offset +xxx" that are way higher oftentimes being many times higher like 100-200. It is not because of the Drive I use right?

One last question regaring the version of poweramp and especially the codecs, is it safe/worth it to go from 14.2 to 14.3 (DSP version 7 to 8)? I have (painfully) seen that often a version change can bring its share of troubles, and the program seems to be working well now.
Are the newer flac (right now 1.2.1) and mp3 (lame right now 3.98.4) versions better/recommended/safe or even needed or are the changes tiny.
I hate to find out in a few months after updating that all files now suffer from some sound bug...
Thanks again.

You are misunderstanding the meaning of the accuraterip report. I'm travelling so ill write more later on this if someone else doesn't chime in. And new versions of dbpa software have all worked perfectly for me.

[garym]

Re: Question regarding HDCD and pressing offset

You are misunderstanding the meaning of the accuraterip report. I'm travelling so ill write more later on this if someone else doesn't chime in. And new versions of dbpa software have all worked perfectly for me.

For example an accuraterip of 50 is not 10 times better than 5. In fact even a single match is great. What are the odds that two people's rips on different computers of different copies of the cd are bit perfect matches if there is an error? These are not the same as the quality measure reported by EAC.

[JustaNewUser]

Re: Question regarding HDCD and pressing offset

Thanks for your quick answer and time and for the clarification. It is suprising to see results of 200, even more so if your own results are consistently less. But nonetheless reassuring that everything is ok with the rips.
And regarding the new versions in particular of lame, flac I definetely don't have worry about later re rips because some programmers messed up some sound relevant codes? Do you wait for longer periods before installing new versions?

[Porcus]

Re: Question regarding HDCD and pressing offset

The "200" in AccurateRip means that 200 persons have submitted the same track with the same checksum.

The +2080 offset from your log, means that there are two different pressings, where in one of them the entire audio stream is 2080 samples to the left of the other. The reason for that is that CD players and writers do not agree on precisely where to start the CD, and if you send off a file to two CD pressing plants, they will do things like this.

The HDCD thing, as mentioned in the other thread, is something you should not use. However, the AccurateRip checksum is performed before the HDCD processing (or any other processing).

As for versions of LAME: LAME is fairly well tried and tested.
As for versions of FLAC: That is absolutely not a problem - enable the verify option, and dBpoweramp will write the FLAC, decode the FLAC and compare to the raw audio. It is a good idea to enable it, not because FLAC calculates wrong, but in order to make sure nothing else screws up the writing to disc.

[JustaNewUser]

Re: Question regarding HDCD and pressing offset

Thanks for your help.
So could you actually think of the results with a different pressing offset as identical to your copy? Meaning that you could safely assume the accuracy is even higher than with the just the pressing version you have? (Say yours is 2 (of which you don't remember if you ripped it a couple times already with EAC reporting to the database) and the pressing offset version is 56, does this really mean 58 because it differs just by the offset?)

[Porcus]

Re: Question regarding HDCD and pressing offset

Yes, more recent dBpoweramp versions do that. If you read the logs, you will see figures with more offsets (if those exist). You can turn the feature off, but there is no reason to.
The principle behind AccurateRip is that if your rip is identical to someone else's, then that is not a coincidence, and most likely[note] they are both correct.
Now if your rip is identical to someone else's after having been shifted some samples to the left or right, then that is still not a coincidence.


[note] If you rip and submit multiple times, you have to subtract to get the true number - you should compare to someone else. Also, there are sources of error that dBpoweramp cannot reliably deal with, for example if both you and the other person has ticked the reverse channels box in EAC, or if a drive's firmware actually makes the mistake of swapping left and right. (Spoon can purge those submissions from the database if he gets the knowledge that a certain drive does that, but there is no autumatic way.)

[JustaNewUser]

Re: Question regarding HDCD and pressing offset

You got me a little worried about the swapping of the left and right... I have an about 5 year old Samsung external drive (DVD rewriter) doing most of my rips. Is there a way to tell? I mean on some CDs I get Accuracies of 40-50 sometimes even over 100 but the majority are from 3-9... While different pressings are consistently higher (except maybe in one or two cases out of 250 cds), could this be an indication that something is wrong. I have ripped the collection before so I hate to do it all again....again. Way too many hours.

[Porcus]

Re: Question regarding HDCD and pressing offset

You got me a little worried about the swapping of the left and right...
[...]
Is there a way to tell?

Yes.

1) Listening! If you got a CD with test signals, then channel is usually one of them. Many live recordings are mixed so that you hear crowd noise from the side the artist is addressing, and quite a few recordings list who is playing the left guitar and right guitar, if you got that kind of music.

2) EAC can swap channels. Rip with, rip without, compare AR matches. http://wiki.hydrogenaudio.org/index....*Drive_Options

3) Rip, use a utility that swaps, burn, rip, compare AR matches.