Q&A - Ripping & Compression
Impress your friendsMartin has written this brief explanation of compression
Hi Looked everywhere but cant find the answer to a very simple question (this should be in your spec I think)
Mp3 ripping is at what bitrate?
320 / 256 / 192 / 128 ?
Be grateful to know - the not knowing is driving me nuts :)
Overall love the product and your upgrades are fantastic - especially the recent one on playlists.
Hi Marcus - its 128k - it was hard to find even for me - I had to look at the code. I can't remember the reasoning for a lowish bitrate - I think its because of the shift to lossless - if you need MP3 the assumption is you want a lot of compression - if you see what I mean. Martin
Load CD that is already compressed.
I have 1000s of tracks in a separate 2TB hard drive which is linked to and works with iTunes.
For the vast majority of these tracks I have the original CDs. The iTunes versions are mp3, but would want to take advantage of the uncompressed FLAC system.
What would be the best way to achieve this?
If I copied the compressed mp3 files into the B2 from the 2TB hard drive, what would happen if I loaded a CD - would the compressed mp3 files be over-written or would I end up with 2 copies, one mp3 and one FLAC, with the former needing a manual deletion?
Good question - in general when you rip a CD it replaces any existing tracks with the same name - whether they are compressed or not. I did that so you can do exactly what you want - replace a compressed track with uncompressed from the CD.
However if the name on the iTunes disk is not not exactly the same as the CDDB entry - then B2 will create a new copy of the music with the different name- so you will have to manually delete the old compressed music.
The newly ripped music is initially stored as WAV for speed and gets compressed to FLAC while B2 is in standby.
Ripping and Compression Speed
Why does the ripping speed vary from CD to CD?
Why do some CDs take longer to compress than others?
Hi John. I've noticed that. Some CDs will start ripping at about 12x and get faster and faster up to about 24x (actually thats because the disk is spinning at the same number of revolutions per second but as the laser works its way out from the middle the circumference increases so the data rate increases). Other CDs start at 4x. The speed is down to the CD mechanism and we have seen this behaviour in both JB7 and B2 using CD mechanisms from a variety of manufacturers. My hunch is that CD mech measures the quality of the signal coming back from the CD and slows down if its not a good signal. Sometimes a CD will slow down mid rip - but then get faster again. But I tend to find that if it starts slow - it stays slow. I have found in the past that cleaning a CD has helped.
Compression should simply be down to the length of the music. FLAC is quicker than MP3.
Q: If my cd isn't a official cd, can I then program the track/artist info myself?
Yes you can rename the artist, album and tracks any time. An unrecognised CD will be filed under artist "Uknown" initially.
Ripping Single Tracks
Q: My good old JB7 allowed the loading of individual tracks from a CD, but the B2 seems to only rip the whole disc. Is there any way round this?
Sorry you have to load the entire CD and delete what you don't want.
Q: I have a JB7 500GB - with this I can load/rip cds with no compression ie perfect copy of the cd - on looking through your literature for B2 it states cds loaded with no compression are then converted to FLAC - is there any way I can have my cds loaded and playable with no compression on the B2 like the JB7 - many thanks
Hi at the moment B2 compresses either to FLAC or MP3. You can reconstitute the orginal WAV file from the FLAC because it is lossless. There is no way to turn it off. However if you have no space worries then I can see it might be useful to disable compression - I've added it to the wish list - won't be hard to add - as it involves doing nothing.
Update 8th September - can now turn off compression.
Q: Can you confirm that an up to date database will be included? If not please include a database CD with my order.
Yes your B2 will have the latest album database installed. You won't need it if you connect the B2 to the internet.
The B2 does not update its "offline" database with a CD like the JB7. You need to download this file. Copy it to a USB memory stick and plug it into B2 USB C. Then Select USB Functions -> Load Database.
Q: A small fraction of my CDs give the message "rip incomplete". What does this mean and is there any way I can rectify it?"
This usually means there is a video track on the CD - sometimes not mentioned on the CD cover. In this case it is the last track that fails to load. Can also happen if the CD is damaged. Try washing gently with Fairy liquid, rinse and dab dry. Then retry. Sometimes you will find that a larger desktop CD mechanism will read a difficult CD - so try ripping on a PC as a last resort. Then transfer the music using a USB memory stick.
Q: Even though all the tracks I've just loaded are already compressed, I notice that the unit is showing "compressing xxx" before it goes into standby. There is not indication of what sort of compression is involved, and I'm not keen on having tracks that have already been compressed compressed all over again
B2 only compresses wav files - the original uncompressed files created when you ripped your CDs. It displays compressing xyz just before it goes into standby as it checks the disk to see if there is anything to do. B2 will not compress mp3s again.
Why is the b2 so slow compressing to mp3? Took 21 hours to compress 450 tracks.
Also my music is not in the order as per my jb7 backup ie multiple disc sets are no longer alpha numerical. I downloaded the latest software before entering everything.
Other than that, love it.
Hi Leon - Glad you are enjoying it. Mp3 encoding is slower than JB7 for instance because JB7 used my own handwritten assembly language MP3 encoder. B2 uses the Raspberry Pi running Linux so I use an MP3 library which is not tuned in the same way. MP3 encoders on PCs have the triple advantage that they have hand coded software on a faster processor with dedicated (accelerated) instructions for this sort of job.
As you have observed - it encodes in about real time - which is a nuisance but you only do it once and its typically done overnight.
The reordering of albums is a Linux thing. I know this is incovenient to some owners and I'm thinking of adding album numbers and displaying alphabetically as a way to remedy this - Martin
Multi CD Set
Q: I have a multi CD recording of Aida but when I rip the second CD it seems to overwrite the first CD so I end up with tracks from both the first and second Acts mixed up. What is happening? Ian
Hi Ian, You need to be careful with multi CD sets. What happened here is that the album names in the database is the same for the first two CDs - although the tracks are different. I bought this multi CD set and found that the album name for the first two CDs is simply "Aida" and for the third CD it is "Aida - CD3" - a bit more helpful.
The way to deal with multi CD sets is to load the first CD then rename the album so it is likely to be unique "Aida - CD1" would be a good choice. Then load the second and repeat the process.
The web interface makes finding and renaming clearer - but you can always find the last album loaded on the front panel by using Browse Albums and turning the knob anticlockwise - it wraps from the first to the last if you see what I mean.
If you do get a mixed up album like that you can just delete it and start again. - Martin
Nimbus Records have issued some large CD sets in MP3 (320kbps) format, which allows them to cram more onto each CD, arguing (as you have) that it's difficult to hear any quality difference. Their set of Scarlatti keyboard sonatas, for instance, is 38 normal CDs but just 9 MP3 CDs.
Presented with one of these CDs the B2 either spits it out if asked to rip it or has a bit of a fit if asked to play it. But the files it contains are loaded, and play, quite happily if imported by USB.
Is there / can there be a way of loading these MP3 CDs onto the B2?
Hello Peter - The short answer is no. You need to use a PC or Mac to transfer the music from CD to USB and then import - as you have found. I wasn't aware of any significant body of work in this format so thanks for bringing it to my attention. In theory a Linux computer can read these so its possible in principal but it would not be a high priority unless I hear from more owners. Martin
Offline DatabaseIf your B2 is connected to the internet you don't need this.
The B2 does not update its "offline" or internal album database with a CD like the JB7.
You need to download this file. Copy it to a USB memory stick and plug it into B2 USB C. Then Select
USB Functions -> Load Database.