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Sample formats: fltp (lossy) to s16p or s32p (ALAC)

Hello,

because of compatibility problems I need to convert some DTS, DTS-HD HR, AC-3 and E-AC-3 audio streams to ALAC.
The lossy formats are stored as fltp (depth: 32 bit).

So my question is:

To preserve all information, should I convert them to s16p-ALAC or better s32p-ALAC (although mediainfo sometimes tells me bit depth of lossy stream is 16 bit).

Best regards,
Felix

Re: Sample formats: fltp (lossy) to s16p or s32p (ALAC)

Reply #1
I didn't think ALAC supported s32 samples? Assuming it does, that would be lossless, whereas 16 bit would lose some tiny bit of information.

Re: Sample formats: fltp (lossy) to s16p or s32p (ALAC)

Reply #2
I've never used ALAC so I don't know what the options are...

But, just some reference points -

"CD quality" (16/44.1) is "better than human hearing".

The "pro studio standard" seems to be 24/96 (with the software using floating-point "internally"...  There a couple of good reasons for using floating-point for audio editing/processing/DSP).

I think one company makes a 32-bit DAC chip.  I'm not aware of any floating-point audio DACs.    And, from what I've read most 24-bit DACs (and ADCs) are only accurate to around 20-bits.   So, you can't directly-play a 32-bit or floating-point file.

Quote
although mediainfo sometimes tells me bit depth of lossy stream is 16 bit
Most lossy formats don't store integer samples so there is no bit depth.

Re: Sample formats: fltp (lossy) to s16p or s32p (ALAC)

Reply #3
24 bit depth is more than enough.

 

Re: Sample formats: fltp (lossy) to s16p or s32p (ALAC)

Reply #4
I think s32p for ALAC is 24 bit.
ffmpeg output:  Stream #0:0: Audio: alac (alac / 0x63616C61), 48000 Hz, 7.1(wide), s32p (24 bit), 128 kb/s

So again for stupid me.
fltp --> s16p: losing tiny bit of information; but I lose information.
fltp --> s32p: no lose of information.

Re: Sample formats: fltp (lossy) to s16p or s32p (ALAC)

Reply #5
I only want to preserve the possibility to get back to the beginnig condition.
And I‘m not sure about the in-depth technics and algorithm the encoders use.

But when ffmpeg shows me a depth of 32 bit for the floating point algorithm and for the s32p algorithm also 32 bit. I see with my limited knowledge to stick with the s32p algorithm should be the best.
Am I right?

Re: Sample formats: fltp (lossy) to s16p or s32p (ALAC)

Reply #6
ALAC should support 24 bit
"I hear it when I see it."

 
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