[Shoreman]

Hello everyone,

I understand that lossless is lossless, but I am curious as to why, everything being equal, my FLAC rips (EAC) are consistently at a lower bitrate than previous ALAC rips using iTunes (you know, before I got religion

). The differences are relatively small, but it's 100% (as in no exceptions) across the board, as I gradually replace hundreds of previous ALAC rips with new FLAC rips, and I would love to know the technical reason for the difference. If anyone knows, or can explain, great. Thanks.

PS. I've also had different kbps readings for different FLAC rips of the same track, which I occasionally do when converting from alternate formats

.

 

[teenage kicks]

Regarding the different readings -- FLAC is variable bitrate. Say there's a section of complete silence, it'll encode that at a really low bitrate like 40kbps, and when the instruments kick in it'll shoot up to 1000kbps. That's why whenever your media players looks at a piece of the song, it's a different bitrate.

 

[Zathan]

Quote:

Originally Posted by teenage kicks /img/forum/go_quote.gif Regarding the different readings -- FLAC is variable bitrate. Say there's a section of complete silence, it'll encode that at a really low bitrate like 40kbps, and when the instruments kick in it'll shoot up to 1000kbps. That's why whenever your media players looks at a piece of the song, it's a different bitrate.

didn't know. Very informative.
Wouldn't it be better if it were 'stable'?

 

[jamess71]

Even though they are both lossless formats they are still compressed formats. They use entirely different Codecs. They are both lossless so once decoded they should both be the same as the original. FLAC rules.

James

 

[jilgiljongiljing]

Quote:

FLAC rules

Indeed!

 

[krmathis]

Quite simple.
ALAC (Apple Lossless) and FLAC use different compression algorithms. Hence they don't compress equally, and one of them may but out larger/smaller files.

 

[teenage kicks]

Quote:

Originally Posted by Zathan /img/forum/go_quote.gif didn't know. Very informative. Wouldn't it be better if it were 'stable'?

No, it would be larger in size and the exact same quality. It's because some things are really simple and easy to compress, so FLAC can squish them down really small without losing quality, but some sounds are complicated and can't be compressed.

 

[Shoreman]

Thanks for the comments so far, folks. I think, stated simply, this is what I'm trying to reconcile: Up to 320 kbps, we have always associated higher bitrates with higher quality. We also know that 1411 kbps represents pure, unadulterated, uncompressed wave audio output. The source recording. I'm trying to understand why, for example, the ALAC rip of Springsteen's Thunder Road at 892 kbps shouldn't theoretically sound audibly superior to the FLAC rip of the same track at 841 kbps. I already know that it doesn't. We all acknowledge that lossless is lossless. But why then is more audio data flowing through per second on the ALAC than on the FLAC rip? And why doesn't that make a difference? I hope I'm making sense, but I'm not so sure

.

 

[trains are bad]

The ALAC is bigger because it sucks at compressing data compared to FLAC. There you have it. There isn't 'more audible data per second.

 

[krmathis]

Quote:

Originally Posted by Shoreman /img/forum/go_quote.gif Thanks for the comments so far, folks. I think, stated simply, this is what I'm trying to reconcile: Up to 320 kbps, we have always associated higher bitrates with higher

For lossy codecs that is correct.
Since a higher bitrate means that less audio data are thrown away during encoding.

For lossless it does not matter, as its lossless whatever bitrate its put out to. Its bitrate can vary from 1kbps to 1411kbps (for audio CD that is), and still reproduce the exact same sound as the source file.

Quote:

We also know that 1411 kbps represents pure, unadulterated, uncompressed wave audio output. The source recording. I'm trying to understand why, for example, the ALAC rip of Springsteen's Thunder Road at 892 kbps shouldn't theoretically sound audibly superior to the FLAC rip of the same track at 841 kbps. I already know that it doesn't.

Because for that specific type of audio data the FLAC encoder are more efficient than the ALAC one. While for other recordings it might be the other way around.

Hence its able to compress to a smaller file size (which corresponds to the bitrate).

Quote:

We all acknowledge that lossless is lossless. But why then is more audio data flowing through per second on the ALAC than on the FLAC rip?

See my previous answer.

Quote:

And why doesn't that make a difference?

Because its lossless.
Meaning that the decoded audio data are an exact copy (100% identical) to the source file. Regardless which encoder are used (FLAC, ALAC; WavPack, ...) and bitrate (1kbps or 1411kbps).

 

[Shoreman]

Thanks, guys (and especially you, krmathis, for your detailed responses). I think I get it now...

 

[krmathis]

You're welcome!

..and let us know if its still not all clear to you.