Issues with lossless.

[DrBenway]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif If we're talking about a DAP that is not so well designed from an electrical noise perspective - like a sansa e200 - some formats may increase the amount of noise coming from the cpu and storage and memory busses due to the increased amount of processing power required to play it back. But you shouldn't be using lossless on such a crummy DAP anyway. fwiw FLAC is one of the easiest formats to decode, and APE is one of the hardest.

Is that a matter of raw processing power, or the lack of it, or is it a matter of poor design that doesn't effectively exploit processing power? Or are there other issues that contribute to excess noise?

 

[ericj]

Quote:

Originally Posted by DrBenway /img/forum/go_quote.gif Is that a matter of raw processing power, or the lack of it, or is it a matter of poor design that doesn't effectively exploit processing power? Or are there other issues that contribute to excess noise?

The e200 has the same dual 80mhz cores as damn near all portalplayer DAPs (most ipods, etc).

It's a matter of board routing, power supply bypassing, component placement, etc.

They allow switching noise from the circuit that drives the backlight to bleed into the audio power supply, for example.

From a digital perspective there's nothing wrong with the design - but the audio output suffers due to the lack of finesse.

Sandisk repented, hired smarter engineers (or just stopped outsourcing to MSI), and the 2nd generation sansas have no such issues. Also a dramatically faster single-core Austria Microsystems SoC replacing the relatively antiquated PortalPlayer chip.

Edit: If you meant difficulty to decode, then yes - the old portalplayer chips (and most other chips used in older DAPs) just aren't very fast. APE seems to have been designed for archival. It can compress very tight but there is no DAP in existence that can decode it's highest compression levels in real time. FLAC on the other hand seems to have been designed for playback, and is very easy to decode, but doesn't compress as tight as APE.

 

[DrBenway]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif The e200 has the same dual 80mhz cores as damn near all portalplayer DAPs (most ipods, etc). It's a matter of board routing, power supply bypassing, component placement, etc. They allow switching noise from the circuit that drives the backlight to bleed into the audio power supply, for example. From a digital perspective there's nothing wrong with the design - but the audio output suffers due to the lack of finesse. Sandisk repented, hired smarter engineers (or just stopped outsourcing to MSI), and the 2nd generation sansas have no such issues. Also a dramatically faster single-core Austria Microsystems SoC replacing the relatively antiquated PortalPlayer chip. Edit: If you meant difficulty to decode, then yes - the old portalplayer chips (and most other chips used in older DAPs) just aren't very fast. APE seems to have been designed for archival. It can compress very tight but there is no DAP in existence that can decode it's highest compression levels in real time. FLAC on the other hand seems to have been designed for playback, and is very easy to decode, but doesn't compress as tight as APE.

Thanks for the patient explanation! I don't have the electronics background to fully understand your explanation, but I do get most of it. I really wish I could go back to school and study circuit design...

 

[krmathis]

There are several differences.
* WAV is a container format, while Apple Lossless and WMA Lossless are codecs.
* Apple Lossless and WMA Lossless support metadata (tags) and artwork (album art), while WAV does not.
* Apple Lossless and WMA Lossless compress the audio data, while WAV usually contain uncompressed audio data (PCM). Meaning they save space.

Sound wise there should be no difference. As long as they all come from the same source.

 

[prosound]

Quote:

Originally Posted by lilkoolaidman /img/forum/go_quote.gif Yeah, so I guess it's not so much the format that makes a difference it's what you use to rip the CD. And dBpoweramp and EAC are better than WMP at ripping to WMA lossless?

Why and in what ways? The ignorant like me remain to be enlightened.

 

[krmathis]

Quote:

Originally Posted by prosound /img/forum/go_quote.gif Why and in what ways? The ignorant like me remain to be enlightened.

Because dBpoweramp, EAC, Rip and other 'secure' rippers have ways to get the correct bits out. Checking for C2 error, checksum compare with Accurate Rip database, rip sector multiple times and compare, and more.
While applications like WMP probably just rip the data once without any checking or comparing.

 

[Punnisher]

Ripping programs rip to wav first then uses an external program to convert to FLAC and apply tags.

 

[bba1973]

Quote:

Originally Posted by prosound /img/forum/go_quote.gif Why and in what ways? The ignorant like me remain to be enlightened.

The ignorant like you seem to skip post 15

.

 

[prosound]

Quote:

Originally Posted by krmathis /img/forum/go_quote.gif Because dBpoweramp, EAC, Rip and other 'secure' rippers have ways to get the correct bits out. Checking for C2 error, checksum compare with Accurate Rip database, rip sector multiple times and compare, and more. While applications like WMP probably just rip the data once without any checking or comparing.

Thanks. That helps. So it's similar to, or cleverer than the "use error correction" option of iTunes?

 

[krmathis]

^ I do not know for sure what kind of tests iTunes "use error correction" runs.
But I doubt it match the tests performed by the applications mentioned above. Especially the part about comparing checksums with the Accurate Rip database.

iTunes may indeed be all you need for ripping CDs in great condition. But for badly scratched CDs it may run into problem, giving you pops and noise. Where the others may get the correct bits off.