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daverich4
2015-11-19, 13:14
I'm not sure quite where to post this as I'm not a new user but these seem like newbie questions. I control my Touch, Transporter, Duet and Squeezbox using IPeng 8. Recently while poking around the IPeng interface I came across the More Info menu choice which gives detailed information on each song. I've discovered that I get different bitrates and sometimes a volume adjustment thrown in as well. I'll list a small sample selection

24/96 Flac Bitrate: 2760 kbps VBR
24/96 Flac Bitrate: 2781 kbps VBR
24/96 Aiff Bitrate: 4608 kbps VBR
24/44.1 Aiff Bitrate: 2116 kbps CBR
16/44 Apple Lossless Bitrate: 927 kbps VBR Volume adjustment -7.34 db different songs from the same album have different bitrates & volume adjustments
16/44 Aiff Bitrate: 1411 kbps CBR Volume adjustment -3.91
And from time to time I also find songs that say something like 16/44 Apple Lossless 876 kbps VBR (Converted to 705 kbps Flac)

As far as I can tell I don't have auto volume equalizing turned on anywhere so I'm not sure what the different Volume adjustment notations mean or why they don't apply to every song. Also, why would I get different bitrates from different songs ripped from the same CD? Or even ripped from different CD's using the same file format? And some albums appear to be downsampled/converted when played? And finally, can someone tell me what VBR & CBR signifies? Thanks for your help.

pippin
2015-11-19, 13:22
All bitrate values are estimates by the server

Julf
2015-11-19, 13:36
VBR is variable bit rate, CBR is constant bit rate.

DJanGo
2015-11-19, 13:46
Also, why would I get different bitrates from different songs ripped from the same CD?

VBR mean Variable BitRate

d6jg
2015-11-20, 03:50
To pad out the answer a bit.

When mp3's first came along everything was CBR - constant bit rate at whatever level you had decided. Some clever folks realised that this wasted space (nano seconds of silence and low level sound) in the file and changed the compression algorithims to become VBR. You tell your ripper you want 320kbps VBR and your software will compress the files at whatever is the most sensible bit rate up to a max of 320kbps. The same now applies to FLAC and other lossless formats.

Your final example is where LMS is transcoding your file to FLAC on the fly.

Does that help?

daverich4
2015-11-20, 04:07
To pad out the answer a bit.

When mp3's first came along everything was CBR - constant bit rate at whatever level you had decided. Some clever folks realised that this wasted space (nano seconds of silence and low level sound) in the file and changed the compression algorithims to become VBR. You tell your ripper you want 320kbps VBR and your software will compress the files at whatever is the most sensible bit rate up to a max of 320kbps. The same now applies to FLAC and other lossless formats.

Your final example is where LMS is transcoding your file to FLAC on the fly.

Does that help?

Thanks for the reply. I think one thing I still don't understand is why different things are being done to the same types of files. In other words, why are some Apple Lossless files being transcoded to Flac and others are not? And some Aiff files are CBR and others are VBR. Is that because they were ripped at different times? I've always used iTunes to rip my files but have done so for more than 10 years so perhaps iTunes has changed the method used to rip over that time? Thanks again.

d6jg
2015-11-20, 04:13
Thanks for the reply. I think one thing I still don't understand is why different things are being done to the same types of files. In other words, why are some Apple Lossless files being transcoded to Flac and others are not? And some Aiff files are CBR and others are VBR. Is that because they were ripped at different times? I've always used iTunes to rip my files but have done so for more than 10 years so perhaps iTunes has changed the method used to rip over that time? Thanks again.

CBR/VBR - yes thats probably because at some point you changed the settings in iTunes. There are much better rippers availoable - Exact Audio Copy & DbPoweramp to name the best two.

Your LMS transcodes files when your player won't natively play the flle type. So it could be the player in question that doesn't support the type of Apple Lossless file you want to play. The very early SBs didn't support all the file formats that the later ones do.

See - https://en.wikipedia.org/wiki/Squeezebox_%28network_music_player%29

Mnyb
2015-11-20, 04:28
Also when transcoding the server does not actually know the final result of the algorithm . So you see the placeholder value of 750k regardless . Imho lms should only display "transcoded" on those instances..