FLAC uncompressed Q

[Gussy]

I´ve noticed when converting a 16bit/44,1 (wav or flac) file to FLAC uncompressed you do indeed get an uncompressed file as a result - no problems!

But when I try to convert higher bit rate files (wav or flac) you do not get an uncompressed output but something like 17% or 34% compressed even though I´ve definately used the "lossless uncompressed" setting. Am I doing something wrong...?

Many thanks for any help!

Gussy

[Spoon]

24 bit? if they contain large amount of true silence then the silence is skipped even in uncompressed mode.

[Gussy]

Hi Spoon,

Many thanks for your reply!

Yes, I´m referring to 20bit (HDCD) or 24bit files.

For example, I´ve just ripped Roxy Music/ Avalon (HDCD) and each resultant flac file is either 33% or 34% compressed but there is no silence at all during the 10 tracks - the only silence occurs between tracks - is that what you mean by "true silence"...?

Thanks once again,

Gussy

[Spoon]

To be honest I have not tried 24 bit uncompressed flac, it is possible that the 24 bit encoding inside of FLAC disables the uncompression options.

[Gussy]

Spoon - I owe you an apology!

I´ve just been browsing my collection and have found some 24bit flac files that have indeed converted to 0% compression successfully....

Ummm... it seems that sometimes it works and sometimes it doesn´t...I´ll keep thinking.

Sorry to waste your time!

Gussy

[Gussy]

On closer inspection it seems to be the 20bit flac files which are causing the problem.

None of my HDCDs have converted to 0% and I´ve identified a 20bit/44.1 download from Hyperion - this also gave a value of 17% compression...

[Porcus]

FLAC has a per-file wordlength and a per-frame wordlength, see the "<3>" entry from http://xiph.org/flac/format.html*frame_header . If I have understood it right - all reservations made! - it means that if a 24-bit file contains a frame where there is no 1 in the last four bits, the frame will specify 20 (knowing that the last four are zeroes), encode 20 (no information lost!) and only on decoding pad up with the last four zeroes.
That would be consistent with the 24 bit file being one 6th smaller than you expect - basically it is because it says that the last four bits of each sample are zeroes. One 3rd smaller, that would be if the signal is 16 bits and encoded in a 24 bit file.

Still I do not understand why anyone wants to use the uncompressed for other things than verifying that you cannot tell the difference. Or toying around with for fun.

[CTR1]

I just purchased an Antipodes server and the manufacturer tells his customers to use flac uncompressed.

[drjenkins]

Actually, this is what Antipodes says about FLAC files:

Flac files are lossless but are typically compressed. The compression process breaks the music file down into frames and potentially applies different levels of compression to each frame. The reason why many audiophiles say WAV or AIFF files sound better than flac files is that they have compared them to compressed flac files. Compressed flac files add jitter to playback because the bit rate of compressed flac files varies significantly throughout the file. But uncompressed flac files sound identical to the original WAV files.
http://www.antipodesaudio.com/load_music.html

This sets off my baloney detector, but I'm no expert. What do the experts say?