heres the jist of what im attempting to do:
bluray #1: 16-bit DTS-MA audio
bluray #2: 24-bit DTS-MA audio, with 20 bits of actual data (several applications identify the bit-depth as "20/24")
...
id like to save the 20-bit audio as 24-bit with the last 4 bits zero'd out, which is the exact same way the source audio stream is stored). eac3to retains this even when transcoding to flac, which means that "fake" 24-bit flac files are clearly possible. however, the best ive been able to do is an "actual" 20-bit 5.1ch wav that next to nothing (including the flac encoder) can process, and a 24-bit 5.1ch wav that contains 24 bits of actual data (which bloats the file size to 3.68gb vs 2.52 for the source).
Help?
Hmm, I'm still not sure exactly what you are trying to do, but WavPack will probably have no problems creating a lossless copy of a 20-bit, 5.1 WAV file.
i have a 24-bit (with 20 bits of actual data) audio file from one bluray. ive managed to sync it to the higher-quality video of another bluray of the same movie. i can save it as 24-bit (bloats file size) or 20-bit (nothing will read it), but im trying to find out how to save a 20-in-24bit audio file.
i actually found a post you made (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=3404&view=findpost&p=33299t) several years ago where you describe doing exactly what im attempting:
I also created a 24-bit file that has 20-bit data in it and got these results:
BPS20-24 WAV 3,856,856 (100%)
BPS20-24 APE 2,815,552 (73.00%, ~7 seconds)
BPS20-24 WV 2,303,130 (59.72%, ~3 seconds)
BPS20-24 FLAC 2,301,059 (59.66%, ~18 seconds)
BPS20-24 RKA 2,231,401 (57.86%, ~69 seconds)
BPS20-24 PAC 2,228,449 (57.78%, ~13 seconds)
... 20-24 FLAC. how did you do this?
So basically your source is saved as 24 bit with garbage in the last 4 bits, so you want a way to zero the last 4 bits so it compresses more efficiently? This is pretty easy to do if you write code, but I can't think of a ready made program to do it.
That said, if you want to make a file smaller by throwing out useless bits, you might be interested in lossywav.
A lot of programs have trouble with WAV files that identify themselves as “20-bit” in the header, which was the point of that post. However, whether WAV files identify themselves as 20-bit or 24-bit, they both have exactly the same data (i.e., each sample is stored in 3 bytes with 4 of the bits zeroed).
Using CoolEdit (or probably Adobe Audition) it is easy to zero the lower 4 bits of a 24-bit WAV file. You just have to save it as a 20-bit WAV (the kind that programs have trouble with) and then load it back and save it again as a 24-bit WAV (making sure you don’t have dithering enabled!). How you might do that with a 5.1 file (which CoolEdit won’t handle) I’m not sure.
Just curious, but what's the size difference between the original DTS-MA file and the 24-bit FLAC file that you could compress?
DTS-MA: 3.14 GB (3,375,416,304 bytes)
FLAC: 2.52 GB (2,713,783,205 bytes)
also i discovered that eac3to has the -down20 switch, which makes a 20-in-24bit audio file. and i was so sure i wasnt asking a stupid question...